mono/metadata/sgen-gc.c

   1 /*
   2  * sgen-gc.c: Simple generational GC.
   3  *
   4  * Author:
   5  *      Paolo Molaro (lupus@ximian.com)
   6  *  Rodrigo Kumpera (kumpera@gmail.com)
   7  *
   8  * Copyright 2005-2011 Novell, Inc (http://www.novell.com)
   9  * Copyright 2011 Xamarin Inc (http://www.xamarin.com)
  10  *
  11  * Thread start/stop adapted from Boehm's GC:
  12  * Copyright (c) 1994 by Xerox Corporation.  All rights reserved.
  13  * Copyright (c) 1996 by Silicon Graphics.  All rights reserved.
  14  * Copyright (c) 1998 by Fergus Henderson.  All rights reserved.
  15  * Copyright (c) 2000-2004 by Hewlett-Packard Company.  All rights reserved.
  16  * Copyright 2001-2003 Ximian, Inc
  17  * Copyright 2003-2010 Novell, Inc.
  18  * Copyright 2011 Xamarin, Inc.
  19  * Copyright (C) 2012 Xamarin Inc
  20  *
  21  * This library is free software; you can redistribute it and/or
  22  * modify it under the terms of the GNU Library General Public
  23  * License 2.0 as published by the Free Software Foundation;
  24  *
  25  * This library is distributed in the hope that it will be useful,
  26  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  27  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  28  * Library General Public License for more details.
  29  *
  30  * You should have received a copy of the GNU Library General Public
  31  * License 2.0 along with this library; if not, write to the Free
  32  * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  33  *
  34  * Important: allocation provides always zeroed memory, having to do
  35  * a memset after allocation is deadly for performance.
  36  * Memory usage at startup is currently as follows:
  37  * 64 KB pinned space
  38  * 64 KB internal space
  39  * size of nursery
  40  * We should provide a small memory config with half the sizes
  41  *
  42  * We currently try to make as few mono assumptions as possible:
  43  * 1) 2-word header with no GC pointers in it (first vtable, second to store the
  44  *    forwarding ptr)
  45  * 2) gc descriptor is the second word in the vtable (first word in the class)
  46  * 3) 8 byte alignment is the minimum and enough (not true for special structures (SIMD), FIXME)
  47  * 4) there is a function to get an object's size and the number of
  48  *    elements in an array.
  49  * 5) we know the special way bounds are allocated for complex arrays
  50  * 6) we know about proxies and how to treat them when domains are unloaded
  51  *
  52  * Always try to keep stack usage to a minimum: no recursive behaviour
  53  * and no large stack allocs.
  54  *
  55  * General description.
  56  * Objects are initially allocated in a nursery using a fast bump-pointer technique.
  57  * When the nursery is full we start a nursery collection: this is performed with a
  58  * copying GC.
  59  * When the old generation is full we start a copying GC of the old generation as well:
  60  * this will be changed to mark&sweep with copying when fragmentation becomes to severe
  61  * in the future.  Maybe we'll even do both during the same collection like IMMIX.
  62  *
  63  * The things that complicate this description are:
  64  * *) pinned objects: we can't move them so we need to keep track of them
  65  * *) no precise info of the thread stacks and registers: we need to be able to
  66  *    quickly find the objects that may be referenced conservatively and pin them
  67  *    (this makes the first issues more important)
  68  * *) large objects are too expensive to be dealt with using copying GC: we handle them
  69  *    with mark/sweep during major collections
  70  * *) some objects need to not move even if they are small (interned strings, Type handles):
  71  *    we use mark/sweep for them, too: they are not allocated in the nursery, but inside
  72  *    PinnedChunks regions
  73  */
  74
  75 /*
  76  * TODO:
  77
  78  *) we could have a function pointer in MonoClass to implement
  79   customized write barriers for value types
  80
  81  *) investigate the stuff needed to advance a thread to a GC-safe
  82   point (single-stepping, read from unmapped memory etc) and implement it.
  83   This would enable us to inline allocations and write barriers, for example,
  84   or at least parts of them, like the write barrier checks.
  85   We may need this also for handling precise info on stacks, even simple things
  86   as having uninitialized data on the stack and having to wait for the prolog
  87   to zero it. Not an issue for the last frame that we scan conservatively.
  88   We could always not trust the value in the slots anyway.
  89
  90  *) modify the jit to save info about references in stack locations:
  91   this can be done just for locals as a start, so that at least
  92   part of the stack is handled precisely.
  93
  94  *) test/fix endianess issues
  95
  96  *) Implement a card table as the write barrier instead of remembered
  97     sets?  Card tables are not easy to implement with our current
  98     memory layout.  We have several different kinds of major heap
  99     objects: Small objects in regular blocks, small objects in pinned
 100     chunks and LOS objects.  If we just have a pointer we have no way
 101     to tell which kind of object it points into, therefore we cannot
 102     know where its card table is.  The least we have to do to make
 103     this happen is to get rid of write barriers for indirect stores.
 104     (See next item)
 105
 106  *) Get rid of write barriers for indirect stores.  We can do this by
 107     telling the GC to wbarrier-register an object once we do an ldloca
 108     or ldelema on it, and to unregister it once it's not used anymore
 109     (it can only travel downwards on the stack).  The problem with
 110     unregistering is that it needs to happen eventually no matter
 111     what, even if exceptions are thrown, the thread aborts, etc.
 112     Rodrigo suggested that we could do only the registering part and
 113     let the collector find out (pessimistically) when it's safe to
 114     unregister, namely when the stack pointer of the thread that
 115     registered the object is higher than it was when the registering
 116     happened.  This might make for a good first implementation to get
 117     some data on performance.
 118
 119  *) Some sort of blacklist support?  Blacklists is a concept from the
 120     Boehm GC: if during a conservative scan we find pointers to an
 121     area which we might use as heap, we mark that area as unusable, so
 122     pointer retention by random pinning pointers is reduced.
 123
 124  *) experiment with max small object size (very small right now - 2kb,
 125     because it's tied to the max freelist size)
 126
 127   *) add an option to mmap the whole heap in one chunk: it makes for many
 128      simplifications in the checks (put the nursery at the top and just use a single
 129      check for inclusion/exclusion): the issue this has is that on 32 bit systems it's
 130      not flexible (too much of the address space may be used by default or we can't
 131      increase the heap as needed) and we'd need a race-free mechanism to return memory
 132      back to the system (mprotect(PROT_NONE) will still keep the memory allocated if it
 133      was written to, munmap is needed, but the following mmap may not find the same segment
 134      free...)
 135
 136  *) memzero the major fragments after restarting the world and optionally a smaller
 137     chunk at a time
 138
 139  *) investigate having fragment zeroing threads
 140
 141  *) separate locks for finalization and other minor stuff to reduce
 142     lock contention
 143
 144  *) try a different copying order to improve memory locality
 145
 146  *) a thread abort after a store but before the write barrier will
 147     prevent the write barrier from executing
 148
 149  *) specialized dynamically generated markers/copiers
 150
 151  *) Dynamically adjust TLAB size to the number of threads.  If we have
 152     too many threads that do allocation, we might need smaller TLABs,
 153     and we might get better performance with larger TLABs if we only
 154     have a handful of threads.  We could sum up the space left in all
 155     assigned TLABs and if that's more than some percentage of the
 156     nursery size, reduce the TLAB size.
 157
 158  *) Explore placing unreachable objects on unused nursery memory.
 159         Instead of memset'ng a region to zero, place an int[] covering it.
 160         A good place to start is add_nursery_frag. The tricky thing here is
 161         placing those objects atomically outside of a collection.
 162
 163  *) Allocation should use asymmetric Dekker synchronization:
 164         http://blogs.oracle.com/dave/resource/Asymmetric-Dekker-Synchronization.txt
 165         This should help weak consistency archs.
 166  */
 167 #include "config.h"
 168 #ifdef HAVE_SGEN_GC
 169
 170 #ifdef __MACH__
 171 #undef _XOPEN_SOURCE
 172 #define _XOPEN_SOURCE
 173 #define _DARWIN_C_SOURCE
 174 #endif
 175
 176 #ifdef HAVE_UNISTD_H
 177 #include <unistd.h>
 178 #endif
 179 #ifdef HAVE_PTHREAD_H
 180 #include <pthread.h>
 181 #endif
 182 #ifdef HAVE_PTHREAD_NP_H
 183 #include <pthread_np.h>
 184 #endif
 185 #ifdef HAVE_SEMAPHORE_H
 186 #include <semaphore.h>
 187 #endif
 188 #include <stdio.h>
 189 #include <string.h>
 190 #include <signal.h>
 191 #include <errno.h>
 192 #include <assert.h>
 193
 194 #include "metadata/sgen-gc.h"
 195 #include "metadata/metadata-internals.h"
 196 #include "metadata/class-internals.h"
 197 #include "metadata/gc-internal.h"
 198 #include "metadata/object-internals.h"
 199 #include "metadata/threads.h"
 200 #include "metadata/sgen-cardtable.h"
 201 #include "metadata/sgen-ssb.h"
 202 #include "metadata/sgen-protocol.h"
 203 #include "metadata/sgen-archdep.h"
 204 #include "metadata/sgen-bridge.h"
 205 #include "metadata/sgen-memory-governor.h"
 206 #include "metadata/sgen-hash-table.h"
 207 #include "metadata/mono-gc.h"
 208 #include "metadata/method-builder.h"
 209 #include "metadata/profiler-private.h"
 210 #include "metadata/monitor.h"
 211 #include "metadata/threadpool-internals.h"
 212 #include "metadata/mempool-internals.h"
 213 #include "metadata/marshal.h"
 214 #include "metadata/runtime.h"
 215 #include "metadata/sgen-cardtable.h"
 216 #include "metadata/sgen-pinning.h"
 217 #include "metadata/sgen-workers.h"
 218 #include "utils/mono-mmap.h"
 219 #include "utils/mono-time.h"
 220 #include "utils/mono-semaphore.h"
 221 #include "utils/mono-counters.h"
 222 #include "utils/mono-proclib.h"
 223 #include "utils/mono-memory-model.h"
 224 #include "utils/mono-logger-internal.h"
 225 #include "utils/dtrace.h"
 226
 227 #include <mono/utils/mono-logger-internal.h>
 228 #include <mono/utils/memcheck.h>
 229
 230 #if defined(__MACH__)
 231 #include "utils/mach-support.h"
 232 #endif
 233
 234 #define OPDEF(a,b,c,d,e,f,g,h,i,j) \
 235         a = i,
 236
 237 enum {
 238 #include "mono/cil/opcode.def"
 239         CEE_LAST
 240 };
 241
 242 #undef OPDEF
 243
 244 #undef pthread_create
 245 #undef pthread_join
 246 #undef pthread_detach
 247
 248 /*
 249  * ######################################################################
 250  * ########  Types and constants used by the GC.
 251  * ######################################################################
 252  */
 253
 254 /* 0 means not initialized, 1 is initialized, -1 means in progress */
 255 static int gc_initialized = 0;
 256 /* If set, check if we need to do something every X allocations */
 257 gboolean has_per_allocation_action;
 258 /* If set, do a heap check every X allocation */
 259 guint32 verify_before_allocs = 0;
 260 /* If set, do a minor collection before every X allocation */
 261 guint32 collect_before_allocs = 0;
 262 /* If set, do a whole heap check before each collection */
 263 static gboolean whole_heap_check_before_collection = FALSE;
 264 /* If set, do a heap consistency check before each minor collection */
 265 static gboolean consistency_check_at_minor_collection = FALSE;
 266 /* If set, check whether mark bits are consistent after major collections */
 267 static gboolean check_mark_bits_after_major_collection = FALSE;
 268 /* If set, check that all nursery objects are pinned/not pinned, depending on context */
 269 static gboolean check_nursery_objects_pinned = FALSE;
 270 /* If set, do a few checks when the concurrent collector is used */
 271 static gboolean do_concurrent_checks = FALSE;
 272 /* If set, check that there are no references to the domain left at domain unload */
 273 static gboolean xdomain_checks = FALSE;
 274 /* If not null, dump the heap after each collection into this file */
 275 static FILE *heap_dump_file = NULL;
 276 /* If set, mark stacks conservatively, even if precise marking is possible */
 277 static gboolean conservative_stack_mark = FALSE;
 278 /* If set, do a plausibility check on the scan_starts before and after
 279    each collection */
 280 static gboolean do_scan_starts_check = FALSE;
 281 static gboolean nursery_collection_is_parallel = FALSE;
 282 static gboolean disable_minor_collections = FALSE;
 283 static gboolean disable_major_collections = FALSE;
 284 gboolean do_pin_stats = FALSE;
 285 static gboolean do_verify_nursery = FALSE;
 286 static gboolean do_dump_nursery_content = FALSE;
 287
 288 #ifdef HEAVY_STATISTICS
 289 long long stat_objects_alloced_degraded = 0;
 290 long long stat_bytes_alloced_degraded = 0;
 291
 292 long long stat_copy_object_called_nursery = 0;
 293 long long stat_objects_copied_nursery = 0;
 294 long long stat_copy_object_called_major = 0;
 295 long long stat_objects_copied_major = 0;
 296
 297 long long stat_scan_object_called_nursery = 0;
 298 long long stat_scan_object_called_major = 0;
 299
 300 long long stat_slots_allocated_in_vain;
 301
 302 long long stat_nursery_copy_object_failed_from_space = 0;
 303 long long stat_nursery_copy_object_failed_forwarded = 0;
 304 long long stat_nursery_copy_object_failed_pinned = 0;
 305 long long stat_nursery_copy_object_failed_to_space = 0;
 306
 307 static int stat_wbarrier_set_field = 0;
 308 static int stat_wbarrier_set_arrayref = 0;
 309 static int stat_wbarrier_arrayref_copy = 0;
 310 static int stat_wbarrier_generic_store = 0;
 311 static int stat_wbarrier_set_root = 0;
 312 static int stat_wbarrier_value_copy = 0;
 313 static int stat_wbarrier_object_copy = 0;
 314 #endif
 315
 316 int stat_minor_gcs = 0;
 317 int stat_major_gcs = 0;
 318
 319 static long long stat_pinned_objects = 0;
 320
 321 static long long time_minor_pre_collection_fragment_clear = 0;
 322 static long long time_minor_pinning = 0;
 323 static long long time_minor_scan_remsets = 0;
 324 static long long time_minor_scan_pinned = 0;
 325 static long long time_minor_scan_registered_roots = 0;
 326 static long long time_minor_scan_thread_data = 0;
 327 static long long time_minor_finish_gray_stack = 0;
 328 static long long time_minor_fragment_creation = 0;
 329
 330 static long long time_major_pre_collection_fragment_clear = 0;
 331 static long long time_major_pinning = 0;
 332 static long long time_major_scan_pinned = 0;
 333 static long long time_major_scan_registered_roots = 0;
 334 static long long time_major_scan_thread_data = 0;
 335 static long long time_major_scan_alloc_pinned = 0;
 336 static long long time_major_scan_finalized = 0;
 337 static long long time_major_scan_big_objects = 0;
 338 static long long time_major_finish_gray_stack = 0;
 339 static long long time_major_free_bigobjs = 0;
 340 static long long time_major_los_sweep = 0;
 341 static long long time_major_sweep = 0;
 342 static long long time_major_fragment_creation = 0;
 343
 344 int gc_debug_level = 0;
 345 FILE* gc_debug_file;
 346
 347 /*
 348 void
 349 mono_gc_flush_info (void)
 350 {
 351         fflush (gc_debug_file);
 352 }
 353 */
 354
 355 #define TV_DECLARE SGEN_TV_DECLARE
 356 #define TV_GETTIME SGEN_TV_GETTIME
 357 #define TV_ELAPSED SGEN_TV_ELAPSED
 358 #define TV_ELAPSED_MS SGEN_TV_ELAPSED_MS
 359
 360 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
 361
 362 NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
 363
 364 #define object_is_forwarded     SGEN_OBJECT_IS_FORWARDED
 365 #define object_is_pinned        SGEN_OBJECT_IS_PINNED
 366 #define pin_object              SGEN_PIN_OBJECT
 367 #define unpin_object            SGEN_UNPIN_OBJECT
 368
 369 #define ptr_in_nursery sgen_ptr_in_nursery
 370
 371 #define LOAD_VTABLE     SGEN_LOAD_VTABLE
 372
 373 static const char*
 374 safe_name (void* obj)
 375 {
 376         MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
 377         return vt->klass->name;
 378 }
 379
 380 #define safe_object_get_size    sgen_safe_object_get_size
 381
 382 const char*
 383 sgen_safe_name (void* obj)
 384 {
 385         return safe_name (obj);
 386 }
 387
 388 /*
 389  * ######################################################################
 390  * ########  Global data.
 391  * ######################################################################
 392  */
 393 LOCK_DECLARE (gc_mutex);
 394 static int gc_disabled = 0;
 395
 396 static gboolean use_cardtable;
 397
 398 #define SCAN_START_SIZE SGEN_SCAN_START_SIZE
 399
 400 static mword pagesize = 4096;
 401 int degraded_mode = 0;
 402
 403 static mword bytes_pinned_from_failed_allocation = 0;
 404
 405 GCMemSection *nursery_section = NULL;
 406 static mword lowest_heap_address = ~(mword)0;
 407 static mword highest_heap_address = 0;
 408
 409 LOCK_DECLARE (sgen_interruption_mutex);
 410 static LOCK_DECLARE (pin_queue_mutex);
 411
 412 #define LOCK_PIN_QUEUE mono_mutex_lock (&pin_queue_mutex)
 413 #define UNLOCK_PIN_QUEUE mono_mutex_unlock (&pin_queue_mutex)
 414
 415 typedef struct _FinalizeReadyEntry FinalizeReadyEntry;
 416 struct _FinalizeReadyEntry {
 417         FinalizeReadyEntry *next;
 418         void *object;
 419 };
 420
 421 typedef struct _EphemeronLinkNode EphemeronLinkNode;
 422
 423 struct _EphemeronLinkNode {
 424         EphemeronLinkNode *next;
 425         char *array;
 426 };
 427
 428 typedef struct {
 429        void *key;
 430        void *value;
 431 } Ephemeron;
 432
 433 int current_collection_generation = -1;
 434 volatile gboolean concurrent_collection_in_progress = FALSE;
 435
 436 /* objects that are ready to be finalized */
 437 static FinalizeReadyEntry *fin_ready_list = NULL;
 438 static FinalizeReadyEntry *critical_fin_list = NULL;
 439
 440 static EphemeronLinkNode *ephemeron_list;
 441
 442 /* registered roots: the key to the hash is the root start address */
 443 /*
 444  * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
 445  */
 446 SgenHashTable roots_hash [ROOT_TYPE_NUM] = {
 447         SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
 448         SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
 449         SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL)
 450 };
 451 static mword roots_size = 0; /* amount of memory in the root set */
 452
 453 #define GC_ROOT_NUM 32
 454 typedef struct {
 455         int count;              /* must be the first field */
 456         void *objects [GC_ROOT_NUM];
 457         int root_types [GC_ROOT_NUM];
 458         uintptr_t extra_info [GC_ROOT_NUM];
 459 } GCRootReport;
 460
 461 static void
 462 notify_gc_roots (GCRootReport *report)
 463 {
 464         if (!report->count)
 465                 return;
 466         mono_profiler_gc_roots (report->count, report->objects, report->root_types, report->extra_info);
 467         report->count = 0;
 468 }
 469
 470 static void
 471 add_profile_gc_root (GCRootReport *report, void *object, int rtype, uintptr_t extra_info)
 472 {
 473         if (report->count == GC_ROOT_NUM)
 474                 notify_gc_roots (report);
 475         report->objects [report->count] = object;
 476         report->root_types [report->count] = rtype;
 477         report->extra_info [report->count++] = (uintptr_t)((MonoVTable*)LOAD_VTABLE (object))->klass;
 478 }
 479
 480 MonoNativeTlsKey thread_info_key;
 481
 482 #ifdef HAVE_KW_THREAD
 483 __thread SgenThreadInfo *sgen_thread_info;
 484 __thread gpointer *store_remset_buffer;
 485 __thread long store_remset_buffer_index;
 486 __thread char *stack_end;
 487 __thread long *store_remset_buffer_index_addr;
 488 #endif
 489
 490 /* The size of a TLAB */
 491 /* The bigger the value, the less often we have to go to the slow path to allocate a new
 492  * one, but the more space is wasted by threads not allocating much memory.
 493  * FIXME: Tune this.
 494  * FIXME: Make this self-tuning for each thread.
 495  */
 496 guint32 tlab_size = (1024 * 4);
 497
 498 #define MAX_SMALL_OBJ_SIZE      SGEN_MAX_SMALL_OBJ_SIZE
 499
 500 /* Functions supplied by the runtime to be called by the GC */
 501 static MonoGCCallbacks gc_callbacks;
 502
 503 #define ALLOC_ALIGN             SGEN_ALLOC_ALIGN
 504 #define ALLOC_ALIGN_BITS        SGEN_ALLOC_ALIGN_BITS
 505
 506 #define ALIGN_UP                SGEN_ALIGN_UP
 507
 508 #define MOVED_OBJECTS_NUM 64
 509 static void *moved_objects [MOVED_OBJECTS_NUM];
 510 static int moved_objects_idx = 0;
 511
 512 /* Vtable of the objects used to fill out nursery fragments before a collection */
 513 static MonoVTable *array_fill_vtable;
 514
 515 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
 516 MonoNativeThreadId main_gc_thread = NULL;
 517 #endif
 518
 519 /*Object was pinned during the current collection*/
 520 static mword objects_pinned;
 521
 522 /*
 523  * ######################################################################
 524  * ########  Macros and function declarations.
 525  * ######################################################################
 526  */
 527
 528 inline static void*
 529 align_pointer (void *ptr)
 530 {
 531         mword p = (mword)ptr;
 532         p += sizeof (gpointer) - 1;
 533         p &= ~ (sizeof (gpointer) - 1);
 534         return (void*)p;
 535 }
 536
 537 typedef SgenGrayQueue GrayQueue;
 538
 539 /* forward declarations */
 540 static void scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue);
 541 static void scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx);
 542 static void scan_finalizer_entries (FinalizeReadyEntry *list, ScanCopyContext ctx);
 543 static void report_finalizer_roots (void);
 544 static void report_registered_roots (void);
 545
 546 static void pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue);
 547 static int pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, ScanCopyContext ctx);
 548 static void finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue);
 549
 550 void mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise);
 551
 552
 553 static void init_stats (void);
 554
 555 static int mark_ephemerons_in_range (ScanCopyContext ctx);
 556 static void clear_unreachable_ephemerons (gboolean concurrent_cementing, ScanCopyContext ctx);
 557 static void null_ephemerons_for_domain (MonoDomain *domain);
 558
 559 static gboolean major_update_or_finish_concurrent_collection (gboolean force_finish);
 560
 561 SgenObjectOperations current_object_ops;
 562 SgenMajorCollector major_collector;
 563 SgenMinorCollector sgen_minor_collector;
 564 static GrayQueue gray_queue;
 565 static GrayQueue remember_major_objects_gray_queue;
 566
 567 static SgenRemeberedSet remset;
 568
 569 /* The gray queue to use from the main collection thread. */
 570 #define WORKERS_DISTRIBUTE_GRAY_QUEUE   (&gray_queue)
 571
 572 /*
 573  * The gray queue a worker job must use.  If we're not parallel or
 574  * concurrent, we use the main gray queue.
 575  */
 576 static SgenGrayQueue*
 577 sgen_workers_get_job_gray_queue (WorkerData *worker_data)
 578 {
 579         return worker_data ? &worker_data->private_gray_queue : WORKERS_DISTRIBUTE_GRAY_QUEUE;
 580 }
 581
 582 static gboolean have_non_collection_major_object_remembers = FALSE;
 583
 584 gboolean
 585 sgen_remember_major_object_for_concurrent_mark (char *obj)
 586 {
 587         if (!major_collector.is_concurrent)
 588                 return FALSE;
 589
 590         g_assert (current_collection_generation == GENERATION_NURSERY || current_collection_generation == -1);
 591
 592         if (!concurrent_collection_in_progress)
 593                 return FALSE;
 594
 595         GRAY_OBJECT_ENQUEUE (&remember_major_objects_gray_queue, obj);
 596
 597         if (current_collection_generation != GENERATION_NURSERY) {
 598                 /*
 599                  * This happens when the mutator allocates large or
 600                  * pinned objects or when allocating in degraded
 601                  * mode.
 602                  */
 603                 have_non_collection_major_object_remembers = TRUE;
 604         }
 605
 606         return TRUE;
 607 }
 608
 609 static void
 610 gray_queue_redirect (SgenGrayQueue *queue)
 611 {
 612         gboolean wake = FALSE;
 613
 614
 615         for (;;) {
 616                 GrayQueueSection *section = sgen_gray_object_dequeue_section (queue);
 617                 if (!section)
 618                         break;
 619                 sgen_section_gray_queue_enqueue (queue->alloc_prepare_data, section);
 620                 wake = TRUE;
 621         }
 622
 623         if (wake) {
 624                 g_assert (concurrent_collection_in_progress ||
 625                                 (current_collection_generation == GENERATION_OLD && major_collector.is_parallel));
 626                 if (sgen_workers_have_started ()) {
 627                         sgen_workers_wake_up_all ();
 628                 } else {
 629                         if (concurrent_collection_in_progress)
 630                                 g_assert (current_collection_generation == -1);
 631                 }
 632         }
 633 }
 634
 635 static void
 636 redirect_major_object_remembers (void)
 637 {
 638         gray_queue_redirect (&remember_major_objects_gray_queue);
 639         have_non_collection_major_object_remembers = FALSE;
 640 }
 641
 642 static gboolean
 643 is_xdomain_ref_allowed (gpointer *ptr, char *obj, MonoDomain *domain)
 644 {
 645         MonoObject *o = (MonoObject*)(obj);
 646         MonoObject *ref = (MonoObject*)*(ptr);
 647         int offset = (char*)(ptr) - (char*)o;
 648
 649         if (o->vtable->klass == mono_defaults.thread_class && offset == G_STRUCT_OFFSET (MonoThread, internal_thread))
 650                 return TRUE;
 651         if (o->vtable->klass == mono_defaults.internal_thread_class && offset == G_STRUCT_OFFSET (MonoInternalThread, current_appcontext))
 652                 return TRUE;
 653         if (mono_class_has_parent_fast (o->vtable->klass, mono_defaults.real_proxy_class) &&
 654                         offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
 655                 return TRUE;
 656         /* Thread.cached_culture_info */
 657         if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
 658                         !strcmp (ref->vtable->klass->name, "CultureInfo") &&
 659                         !strcmp(o->vtable->klass->name_space, "System") &&
 660                         !strcmp(o->vtable->klass->name, "Object[]"))
 661                 return TRUE;
 662         /*
 663          *  at System.IO.MemoryStream.InternalConstructor (byte[],int,int,bool,bool) [0x0004d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:121
 664          * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81
 665          * at (wrapper remoting-invoke-with-check) System.IO.MemoryStream..ctor (byte[]) <IL 0x00020, 0xffffffff>
 666          * at System.Runtime.Remoting.Messaging.CADMethodCallMessage.GetArguments () [0x0000d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/CADMessages.cs:327
 667          * at System.Runtime.Remoting.Messaging.MethodCall..ctor (System.Runtime.Remoting.Messaging.CADMethodCallMessage) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/MethodCall.cs:87
 668          * at System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) [0x00018] in /home/schani/Work/novell/trunk/mcs/class/corlib/System/AppDomain.cs:1213
 669          * at (wrapper remoting-invoke-with-check) System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) <IL 0x0003d, 0xffffffff>
 670          * at System.Runtime.Remoting.Channels.CrossAppDomainSink.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage) [0x00008] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Channels/CrossAppDomainChannel.cs:198
 671          * at (wrapper runtime-invoke) object.runtime_invoke_CrossAppDomainSink/ProcessMessageRes_object_object (object,intptr,intptr,intptr) <IL 0x0004c, 0xffffffff>
 672          */
 673         if (!strcmp (ref->vtable->klass->name_space, "System") &&
 674                         !strcmp (ref->vtable->klass->name, "Byte[]") &&
 675                         !strcmp (o->vtable->klass->name_space, "System.IO") &&
 676                         !strcmp (o->vtable->klass->name, "MemoryStream"))
 677                 return TRUE;
 678         /* append_job() in threadpool.c */
 679         if (!strcmp (ref->vtable->klass->name_space, "System.Runtime.Remoting.Messaging") &&
 680                         !strcmp (ref->vtable->klass->name, "AsyncResult") &&
 681                         !strcmp (o->vtable->klass->name_space, "System") &&
 682                         !strcmp (o->vtable->klass->name, "Object[]") &&
 683                         mono_thread_pool_is_queue_array ((MonoArray*) o))
 684                 return TRUE;
 685         return FALSE;
 686 }
 687
 688 static void
 689 check_reference_for_xdomain (gpointer *ptr, char *obj, MonoDomain *domain)
 690 {
 691         MonoObject *o = (MonoObject*)(obj);
 692         MonoObject *ref = (MonoObject*)*(ptr);
 693         int offset = (char*)(ptr) - (char*)o;
 694         MonoClass *class;
 695         MonoClassField *field;
 696         char *str;
 697
 698         if (!ref || ref->vtable->domain == domain)
 699                 return;
 700         if (is_xdomain_ref_allowed (ptr, obj, domain))
 701                 return;
 702
 703         field = NULL;
 704         for (class = o->vtable->klass; class; class = class->parent) {
 705                 int i;
 706
 707                 for (i = 0; i < class->field.count; ++i) {
 708                         if (class->fields[i].offset == offset) {
 709                                 field = &class->fields[i];
 710                                 break;
 711                         }
 712                 }
 713                 if (field)
 714                         break;
 715         }
 716
 717         if (ref->vtable->klass == mono_defaults.string_class)
 718                 str = mono_string_to_utf8 ((MonoString*)ref);
 719         else
 720                 str = NULL;
 721         g_print ("xdomain reference in %p (%s.%s) at offset %d (%s) to %p (%s.%s) (%s)  -  pointed to by:\n",
 722                         o, o->vtable->klass->name_space, o->vtable->klass->name,
 723                         offset, field ? field->name : "",
 724                         ref, ref->vtable->klass->name_space, ref->vtable->klass->name, str ? str : "");
 725         mono_gc_scan_for_specific_ref (o, TRUE);
 726         if (str)
 727                 g_free (str);
 728 }
 729
 730 #undef HANDLE_PTR
 731 #define HANDLE_PTR(ptr,obj)     check_reference_for_xdomain ((ptr), (obj), domain)
 732
 733 static void
 734 scan_object_for_xdomain_refs (char *start, mword size, void *data)
 735 {
 736         MonoDomain *domain = ((MonoObject*)start)->vtable->domain;
 737
 738         #include "sgen-scan-object.h"
 739 }
 740
 741 static gboolean scan_object_for_specific_ref_precise = TRUE;
 742
 743 #undef HANDLE_PTR
 744 #define HANDLE_PTR(ptr,obj) do {                \
 745         if ((MonoObject*)*(ptr) == key) {       \
 746         g_print ("found ref to %p in object %p (%s) at offset %td\n",   \
 747                         key, (obj), safe_name ((obj)), ((char*)(ptr) - (char*)(obj))); \
 748         }                                                               \
 749         } while (0)
 750
 751 static void
 752 scan_object_for_specific_ref (char *start, MonoObject *key)
 753 {
 754         char *forwarded;
 755
 756         if ((forwarded = SGEN_OBJECT_IS_FORWARDED (start)))
 757                 start = forwarded;
 758
 759         if (scan_object_for_specific_ref_precise) {
 760                 #include "sgen-scan-object.h"
 761         } else {
 762                 mword *words = (mword*)start;
 763                 size_t size = safe_object_get_size ((MonoObject*)start);
 764                 int i;
 765                 for (i = 0; i < size / sizeof (mword); ++i) {
 766                         if (words [i] == (mword)key) {
 767                                 g_print ("found possible ref to %p in object %p (%s) at offset %td\n",
 768                                                 key, start, safe_name (start), i * sizeof (mword));
 769                         }
 770                 }
 771         }
 772 }
 773
 774 void
 775 sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags)
 776 {
 777         while (start < end) {
 778                 size_t size;
 779                 char *obj;
 780
 781                 if (!*(void**)start) {
 782                         start += sizeof (void*); /* should be ALLOC_ALIGN, really */
 783                         continue;
 784                 }
 785
 786                 if (allow_flags) {
 787                         if (!(obj = SGEN_OBJECT_IS_FORWARDED (start)))
 788                                 obj = start;
 789                 } else {
 790                         obj = start;
 791                 }
 792
 793                 size = ALIGN_UP (safe_object_get_size ((MonoObject*)obj));
 794
 795                 if ((MonoVTable*)SGEN_LOAD_VTABLE (obj) != array_fill_vtable)
 796                         callback (obj, size, data);
 797
 798                 start += size;
 799         }
 800 }
 801
 802 static void
 803 scan_object_for_specific_ref_callback (char *obj, size_t size, MonoObject *key)
 804 {
 805         scan_object_for_specific_ref (obj, key);
 806 }
 807
 808 static void
 809 check_root_obj_specific_ref (RootRecord *root, MonoObject *key, MonoObject *obj)
 810 {
 811         if (key != obj)
 812                 return;
 813         g_print ("found ref to %p in root record %p\n", key, root);
 814 }
 815
 816 static MonoObject *check_key = NULL;
 817 static RootRecord *check_root = NULL;
 818
 819 static void
 820 check_root_obj_specific_ref_from_marker (void **obj)
 821 {
 822         check_root_obj_specific_ref (check_root, check_key, *obj);
 823 }
 824
 825 static void
 826 scan_roots_for_specific_ref (MonoObject *key, int root_type)
 827 {
 828         void **start_root;
 829         RootRecord *root;
 830         check_key = key;
 831
 832         SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
 833                 mword desc = root->root_desc;
 834
 835                 check_root = root;
 836
 837                 switch (desc & ROOT_DESC_TYPE_MASK) {
 838                 case ROOT_DESC_BITMAP:
 839                         desc >>= ROOT_DESC_TYPE_SHIFT;
 840                         while (desc) {
 841                                 if (desc & 1)
 842                                         check_root_obj_specific_ref (root, key, *start_root);
 843                                 desc >>= 1;
 844                                 start_root++;
 845                         }
 846                         return;
 847                 case ROOT_DESC_COMPLEX: {
 848                         gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
 849                         int bwords = (*bitmap_data) - 1;
 850                         void **start_run = start_root;
 851                         bitmap_data++;
 852                         while (bwords-- > 0) {
 853                                 gsize bmap = *bitmap_data++;
 854                                 void **objptr = start_run;
 855                                 while (bmap) {
 856                                         if (bmap & 1)
 857                                                 check_root_obj_specific_ref (root, key, *objptr);
 858                                         bmap >>= 1;
 859                                         ++objptr;
 860                                 }
 861                                 start_run += GC_BITS_PER_WORD;
 862                         }
 863                         break;
 864                 }
 865                 case ROOT_DESC_USER: {
 866                         MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
 867                         marker (start_root, check_root_obj_specific_ref_from_marker);
 868                         break;
 869                 }
 870                 case ROOT_DESC_RUN_LEN:
 871                         g_assert_not_reached ();
 872                 default:
 873                         g_assert_not_reached ();
 874                 }
 875         } SGEN_HASH_TABLE_FOREACH_END;
 876
 877         check_key = NULL;
 878         check_root = NULL;
 879 }
 880
 881 void
 882 mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise)
 883 {
 884         void **ptr;
 885         RootRecord *root;
 886
 887         scan_object_for_specific_ref_precise = precise;
 888
 889         sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
 890                         (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key, TRUE);
 891
 892         major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
 893
 894         sgen_los_iterate_objects ((IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
 895
 896         scan_roots_for_specific_ref (key, ROOT_TYPE_NORMAL);
 897         scan_roots_for_specific_ref (key, ROOT_TYPE_WBARRIER);
 898
 899         SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], ptr, root) {
 900                 while (ptr < (void**)root->end_root) {
 901                         check_root_obj_specific_ref (root, *ptr, key);
 902                         ++ptr;
 903                 }
 904         } SGEN_HASH_TABLE_FOREACH_END;
 905 }
 906
 907 static gboolean
 908 need_remove_object_for_domain (char *start, MonoDomain *domain)
 909 {
 910         if (mono_object_domain (start) == domain) {
 911                 SGEN_LOG (4, "Need to cleanup object %p", start);
 912                 binary_protocol_cleanup (start, (gpointer)LOAD_VTABLE (start), safe_object_get_size ((MonoObject*)start));
 913                 return TRUE;
 914         }
 915         return FALSE;
 916 }
 917
 918 static void
 919 process_object_for_domain_clearing (char *start, MonoDomain *domain)
 920 {
 921         GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
 922         if (vt->klass == mono_defaults.internal_thread_class)
 923                 g_assert (mono_object_domain (start) == mono_get_root_domain ());
 924         /* The object could be a proxy for an object in the domain
 925            we're deleting. */
 926         if (mono_class_has_parent_fast (vt->klass, mono_defaults.real_proxy_class)) {
 927                 MonoObject *server = ((MonoRealProxy*)start)->unwrapped_server;
 928
 929                 /* The server could already have been zeroed out, so
 930                    we need to check for that, too. */
 931                 if (server && (!LOAD_VTABLE (server) || mono_object_domain (server) == domain)) {
 932                         SGEN_LOG (4, "Cleaning up remote pointer in %p to object %p", start, server);
 933                         ((MonoRealProxy*)start)->unwrapped_server = NULL;
 934                 }
 935         }
 936 }
 937
 938 static MonoDomain *check_domain = NULL;
 939
 940 static void
 941 check_obj_not_in_domain (void **o)
 942 {
 943         g_assert (((MonoObject*)(*o))->vtable->domain != check_domain);
 944 }
 945
 946 static void
 947 scan_for_registered_roots_in_domain (MonoDomain *domain, int root_type)
 948 {
 949         void **start_root;
 950         RootRecord *root;
 951         check_domain = domain;
 952         SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
 953                 mword desc = root->root_desc;
 954
 955                 /* The MonoDomain struct is allowed to hold
 956                    references to objects in its own domain. */
 957                 if (start_root == (void**)domain)
 958                         continue;
 959
 960                 switch (desc & ROOT_DESC_TYPE_MASK) {
 961                 case ROOT_DESC_BITMAP:
 962                         desc >>= ROOT_DESC_TYPE_SHIFT;
 963                         while (desc) {
 964                                 if ((desc & 1) && *start_root)
 965                                         check_obj_not_in_domain (*start_root);
 966                                 desc >>= 1;
 967                                 start_root++;
 968                         }
 969                         break;
 970                 case ROOT_DESC_COMPLEX: {
 971                         gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
 972                         int bwords = (*bitmap_data) - 1;
 973                         void **start_run = start_root;
 974                         bitmap_data++;
 975                         while (bwords-- > 0) {
 976                                 gsize bmap = *bitmap_data++;
 977                                 void **objptr = start_run;
 978                                 while (bmap) {
 979                                         if ((bmap & 1) && *objptr)
 980                                                 check_obj_not_in_domain (*objptr);
 981                                         bmap >>= 1;
 982                                         ++objptr;
 983                                 }
 984                                 start_run += GC_BITS_PER_WORD;
 985                         }
 986                         break;
 987                 }
 988                 case ROOT_DESC_USER: {
 989                         MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
 990                         marker (start_root, check_obj_not_in_domain);
 991                         break;
 992                 }
 993                 case ROOT_DESC_RUN_LEN:
 994                         g_assert_not_reached ();
 995                 default:
 996                         g_assert_not_reached ();
 997                 }
 998         } SGEN_HASH_TABLE_FOREACH_END;
 999
1000         check_domain = NULL;
1001 }
1002
1003 static void
1004 check_for_xdomain_refs (void)
1005 {
1006         LOSObject *bigobj;
1007
1008         sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1009                         (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL, FALSE);
1010
1011         major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL);
1012
1013         for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1014                 scan_object_for_xdomain_refs (bigobj->data, sgen_los_object_size (bigobj), NULL);
1015 }
1016
1017 static gboolean
1018 clear_domain_process_object (char *obj, MonoDomain *domain)
1019 {
1020         gboolean remove;
1021
1022         process_object_for_domain_clearing (obj, domain);
1023         remove = need_remove_object_for_domain (obj, domain);
1024
1025         if (remove && ((MonoObject*)obj)->synchronisation) {
1026                 void **dislink = mono_monitor_get_object_monitor_weak_link ((MonoObject*)obj);
1027                 if (dislink)
1028                         sgen_register_disappearing_link (NULL, dislink, FALSE, TRUE);
1029         }
1030
1031         return remove;
1032 }
1033
1034 static void
1035 clear_domain_process_minor_object_callback (char *obj, size_t size, MonoDomain *domain)
1036 {
1037         if (clear_domain_process_object (obj, domain))
1038                 memset (obj, 0, size);
1039 }
1040
1041 static void
1042 clear_domain_process_major_object_callback (char *obj, size_t size, MonoDomain *domain)
1043 {
1044         clear_domain_process_object (obj, domain);
1045 }
1046
1047 static void
1048 clear_domain_free_major_non_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1049 {
1050         if (need_remove_object_for_domain (obj, domain))
1051                 major_collector.free_non_pinned_object (obj, size);
1052 }
1053
1054 static void
1055 clear_domain_free_major_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1056 {
1057         if (need_remove_object_for_domain (obj, domain))
1058                 major_collector.free_pinned_object (obj, size);
1059 }
1060
1061 /*
1062  * When appdomains are unloaded we can easily remove objects that have finalizers,
1063  * but all the others could still be present in random places on the heap.
1064  * We need a sweep to get rid of them even though it's going to be costly
1065  * with big heaps.
1066  * The reason we need to remove them is because we access the vtable and class
1067  * structures to know the object size and the reference bitmap: once the domain is
1068  * unloaded the point to random memory.
1069  */
1070 void
1071 mono_gc_clear_domain (MonoDomain * domain)
1072 {
1073         LOSObject *bigobj, *prev;
1074         int i;
1075
1076         LOCK_GC;
1077
1078         if (concurrent_collection_in_progress)
1079                 sgen_perform_collection (0, GENERATION_OLD, "clear domain", TRUE);
1080         g_assert (!concurrent_collection_in_progress);
1081
1082         sgen_process_fin_stage_entries ();
1083         sgen_process_dislink_stage_entries ();
1084
1085         sgen_clear_nursery_fragments ();
1086
1087         if (xdomain_checks && domain != mono_get_root_domain ()) {
1088                 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_NORMAL);
1089                 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_WBARRIER);
1090                 check_for_xdomain_refs ();
1091         }
1092
1093         /*Ephemerons and dislinks must be processed before LOS since they might end up pointing
1094         to memory returned to the OS.*/
1095         null_ephemerons_for_domain (domain);
1096
1097         for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1098                 sgen_null_links_for_domain (domain, i);
1099
1100         for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1101                 sgen_remove_finalizers_for_domain (domain, i);
1102
1103         sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1104                         (IterateObjectCallbackFunc)clear_domain_process_minor_object_callback, domain, FALSE);
1105
1106         /* We need two passes over major and large objects because
1107            freeing such objects might give their memory back to the OS
1108            (in the case of large objects) or obliterate its vtable
1109            (pinned objects with major-copying or pinned and non-pinned
1110            objects with major-mark&sweep), but we might need to
1111            dereference a pointer from an object to another object if
1112            the first object is a proxy. */
1113         major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)clear_domain_process_major_object_callback, domain);
1114         for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1115                 clear_domain_process_object (bigobj->data, domain);
1116
1117         prev = NULL;
1118         for (bigobj = los_object_list; bigobj;) {
1119                 if (need_remove_object_for_domain (bigobj->data, domain)) {
1120                         LOSObject *to_free = bigobj;
1121                         if (prev)
1122                                 prev->next = bigobj->next;
1123                         else
1124                                 los_object_list = bigobj->next;
1125                         bigobj = bigobj->next;
1126                         SGEN_LOG (4, "Freeing large object %p", bigobj->data);
1127                         sgen_los_free_object (to_free);
1128                         continue;
1129                 }
1130                 prev = bigobj;
1131                 bigobj = bigobj->next;
1132         }
1133         major_collector.iterate_objects (TRUE, FALSE, (IterateObjectCallbackFunc)clear_domain_free_major_non_pinned_object_callback, domain);
1134         major_collector.iterate_objects (FALSE, TRUE, (IterateObjectCallbackFunc)clear_domain_free_major_pinned_object_callback, domain);
1135
1136         if (G_UNLIKELY (do_pin_stats)) {
1137                 if (domain == mono_get_root_domain ())
1138                         sgen_pin_stats_print_class_stats ();
1139         }
1140
1141         UNLOCK_GC;
1142 }
1143
1144 /*
1145  * sgen_add_to_global_remset:
1146  *
1147  *   The global remset contains locations which point into newspace after
1148  * a minor collection. This can happen if the objects they point to are pinned.
1149  *
1150  * LOCKING: If called from a parallel collector, the global remset
1151  * lock must be held.  For serial collectors that is not necessary.
1152  */
1153 void
1154 sgen_add_to_global_remset (gpointer ptr, gpointer obj, gboolean concurrent_cementing)
1155 {
1156         SGEN_ASSERT (5, sgen_ptr_in_nursery (obj), "Target pointer of global remset must be in the nursery");
1157
1158         if (!major_collector.is_concurrent) {
1159                 SGEN_ASSERT (5, !concurrent_cementing, "Concurrent cementing must only happen with the concurrent collector");
1160                 SGEN_ASSERT (5, current_collection_generation != -1, "Global remsets can only be added during collections");
1161         } else {
1162                 if (current_collection_generation == -1)
1163                         SGEN_ASSERT (5, concurrent_cementing, "Global remsets outside of collection pauses can only be added by the concurrent collector");
1164                 if (concurrent_cementing)
1165                         SGEN_ASSERT (5, concurrent_collection_in_progress, "Concurrent collection must be in process in order to add global remsets");
1166         }
1167
1168         if (!object_is_pinned (obj))
1169                 SGEN_ASSERT (5, concurrent_cementing || sgen_minor_collector.is_split, "Non-pinned objects can only remain in nursery if it is a split nursery");
1170         else if (sgen_cement_lookup_or_register (obj, concurrent_cementing))
1171                 return;
1172
1173         remset.record_pointer (ptr);
1174
1175 #ifdef ENABLE_DTRACE
1176         if (G_UNLIKELY (do_pin_stats))
1177                 sgen_pin_stats_register_global_remset (obj);
1178
1179         SGEN_LOG (8, "Adding global remset for %p", ptr);
1180         binary_protocol_global_remset (ptr, obj, (gpointer)SGEN_LOAD_VTABLE (obj));
1181
1182         HEAVY_STAT (++stat_global_remsets_added);
1183
1184         if (G_UNLIKELY (MONO_GC_GLOBAL_REMSET_ADD_ENABLED ())) {
1185                 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
1186                 MONO_GC_GLOBAL_REMSET_ADD ((mword)ptr, (mword)obj, sgen_safe_object_get_size (obj),
1187                                 vt->klass->name_space, vt->klass->name);
1188         }
1189 #endif
1190 }
1191
1192 /*
1193  * sgen_drain_gray_stack:
1194  *
1195  *   Scan objects in the gray stack until the stack is empty. This should be called
1196  * frequently after each object is copied, to achieve better locality and cache
1197  * usage.
1198  */
1199 gboolean
1200 sgen_drain_gray_stack (int max_objs, ScanCopyContext ctx)
1201 {
1202         char *obj;
1203         ScanObjectFunc scan_func = ctx.scan_func;
1204         GrayQueue *queue = ctx.queue;
1205
1206         if (max_objs == -1) {
1207                 for (;;) {
1208                         GRAY_OBJECT_DEQUEUE (queue, obj);
1209                         if (!obj)
1210                                 return TRUE;
1211                         SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1212                         scan_func (obj, queue);
1213                 }
1214         } else {
1215                 int i;
1216
1217                 do {
1218                         for (i = 0; i != max_objs; ++i) {
1219                                 GRAY_OBJECT_DEQUEUE (queue, obj);
1220                                 if (!obj)
1221                                         return TRUE;
1222                                 SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1223                                 scan_func (obj, queue);
1224                         }
1225                 } while (max_objs < 0);
1226                 return FALSE;
1227         }
1228 }
1229
1230 /*
1231  * Addresses from start to end are already sorted. This function finds
1232  * the object header for each address and pins the object. The
1233  * addresses must be inside the passed section.  The (start of the)
1234  * address array is overwritten with the addresses of the actually
1235  * pinned objects.  Return the number of pinned objects.
1236  */
1237 static int
1238 pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, ScanCopyContext ctx)
1239 {
1240         void *last = NULL;
1241         int count = 0;
1242         void *search_start;
1243         void *last_obj = NULL;
1244         size_t last_obj_size = 0;
1245         void *addr;
1246         int idx;
1247         void **definitely_pinned = start;
1248         ScanObjectFunc scan_func = ctx.scan_func;
1249         SgenGrayQueue *queue = ctx.queue;
1250
1251         sgen_nursery_allocator_prepare_for_pinning ();
1252
1253         while (start < end) {
1254                 addr = *start;
1255                 /* the range check should be reduntant */
1256                 if (addr != last && addr >= start_nursery && addr < end_nursery) {
1257                         SGEN_LOG (5, "Considering pinning addr %p", addr);
1258                         /* multiple pointers to the same object */
1259                         if (addr >= last_obj && (char*)addr < (char*)last_obj + last_obj_size) {
1260                                 start++;
1261                                 continue;
1262                         }
1263                         idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
1264                         g_assert (idx < section->num_scan_start);
1265                         search_start = (void*)section->scan_starts [idx];
1266                         if (!search_start || search_start > addr) {
1267                                 while (idx) {
1268                                         --idx;
1269                                         search_start = section->scan_starts [idx];
1270                                         if (search_start && search_start <= addr)
1271                                                 break;
1272                                 }
1273                                 if (!search_start || search_start > addr)
1274                                         search_start = start_nursery;
1275                         }
1276                         if (search_start < last_obj)
1277                                 search_start = (char*)last_obj + last_obj_size;
1278                         /* now addr should be in an object a short distance from search_start
1279                          * Note that search_start must point to zeroed mem or point to an object.
1280                          */
1281
1282                         do {
1283                                 if (!*(void**)search_start) {
1284                                         /* Consistency check */
1285                                         /*
1286                                         for (frag = nursery_fragments; frag; frag = frag->next) {
1287                                                 if (search_start >= frag->fragment_start && search_start < frag->fragment_end)
1288                                                         g_assert_not_reached ();
1289                                         }
1290                                         */
1291
1292                                         search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
1293                                         continue;
1294                                 }
1295                                 last_obj = search_start;
1296                                 last_obj_size = ALIGN_UP (safe_object_get_size ((MonoObject*)search_start));
1297
1298                                 if (((MonoObject*)last_obj)->synchronisation == GINT_TO_POINTER (-1)) {
1299                                         /* Marks the beginning of a nursery fragment, skip */
1300                                 } else {
1301                                         SGEN_LOG (8, "Pinned try match %p (%s), size %zd", last_obj, safe_name (last_obj), last_obj_size);
1302                                         if (addr >= search_start && (char*)addr < (char*)last_obj + last_obj_size) {
1303                                                 if (scan_func) {
1304                                                         scan_func (search_start, queue);
1305                                                 } else {
1306                                                         SGEN_LOG (4, "Pinned object %p, vtable %p (%s), count %d\n",
1307                                                                         search_start, *(void**)search_start, safe_name (search_start), count);
1308                                                         binary_protocol_pin (search_start,
1309                                                                         (gpointer)LOAD_VTABLE (search_start),
1310                                                                         safe_object_get_size (search_start));
1311
1312 #ifdef ENABLE_DTRACE
1313                                                         if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1314                                                                 int gen = sgen_ptr_in_nursery (search_start) ? GENERATION_NURSERY : GENERATION_OLD;
1315                                                                 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (search_start);
1316                                                                 MONO_GC_OBJ_PINNED ((mword)search_start,
1317                                                                                 sgen_safe_object_get_size (search_start),
1318                                                                                 vt->klass->name_space, vt->klass->name, gen);
1319                                                         }
1320 #endif
1321
1322                                                         pin_object (search_start);
1323                                                         GRAY_OBJECT_ENQUEUE (queue, search_start);
1324                                                         if (G_UNLIKELY (do_pin_stats))
1325                                                                 sgen_pin_stats_register_object (search_start, last_obj_size);
1326                                                         definitely_pinned [count] = search_start;
1327                                                         count++;
1328                                                 }
1329                                                 break;
1330                                         }
1331                                 }
1332                                 /* skip to the next object */
1333                                 search_start = (void*)((char*)search_start + last_obj_size);
1334                         } while (search_start <= addr);
1335                         /* we either pinned the correct object or we ignored the addr because
1336                          * it points to unused zeroed memory.
1337                          */
1338                         last = addr;
1339                 }
1340                 start++;
1341         }
1342         //printf ("effective pinned: %d (at the end: %d)\n", count, (char*)end_nursery - (char*)last);
1343         if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS) {
1344                 GCRootReport report;
1345                 report.count = 0;
1346                 for (idx = 0; idx < count; ++idx)
1347                         add_profile_gc_root (&report, definitely_pinned [idx], MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
1348                 notify_gc_roots (&report);
1349         }
1350         stat_pinned_objects += count;
1351         return count;
1352 }
1353
1354 void
1355 sgen_pin_objects_in_section (GCMemSection *section, ScanCopyContext ctx)
1356 {
1357         int num_entries = section->pin_queue_num_entries;
1358         if (num_entries) {
1359                 void **start = section->pin_queue_start;
1360                 int reduced_to;
1361                 reduced_to = pin_objects_from_addresses (section, start, start + num_entries,
1362                                 section->data, section->next_data, ctx);
1363                 section->pin_queue_num_entries = reduced_to;
1364                 if (!reduced_to)
1365                         section->pin_queue_start = NULL;
1366         }
1367 }
1368
1369
1370 void
1371 sgen_pin_object (void *object, GrayQueue *queue)
1372 {
1373         g_assert (!concurrent_collection_in_progress);
1374
1375         if (sgen_collection_is_parallel ()) {
1376                 LOCK_PIN_QUEUE;
1377                 /*object arrives pinned*/
1378                 sgen_pin_stage_ptr (object);
1379                 ++objects_pinned ;
1380                 UNLOCK_PIN_QUEUE;
1381         } else {
1382                 SGEN_PIN_OBJECT (object);
1383                 sgen_pin_stage_ptr (object);
1384                 ++objects_pinned;
1385                 if (G_UNLIKELY (do_pin_stats))
1386                         sgen_pin_stats_register_object (object, safe_object_get_size (object));
1387         }
1388         GRAY_OBJECT_ENQUEUE (queue, object);
1389         binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
1390
1391 #ifdef ENABLE_DTRACE
1392         if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1393                 int gen = sgen_ptr_in_nursery (object) ? GENERATION_NURSERY : GENERATION_OLD;
1394                 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (object);
1395                 MONO_GC_OBJ_PINNED ((mword)object, sgen_safe_object_get_size (object), vt->klass->name_space, vt->klass->name, gen);
1396         }
1397 #endif
1398 }
1399
1400 void
1401 sgen_parallel_pin_or_update (void **ptr, void *obj, MonoVTable *vt, SgenGrayQueue *queue)
1402 {
1403         for (;;) {
1404                 mword vtable_word;
1405                 gboolean major_pinned = FALSE;
1406
1407                 if (sgen_ptr_in_nursery (obj)) {
1408                         if (SGEN_CAS_PTR (obj, (void*)((mword)vt | SGEN_PINNED_BIT), vt) == vt) {
1409                                 sgen_pin_object (obj, queue);
1410                                 break;
1411                         }
1412                 } else {
1413                         major_collector.pin_major_object (obj, queue);
1414                         major_pinned = TRUE;
1415                 }
1416
1417                 vtable_word = *(mword*)obj;
1418                 /*someone else forwarded it, update the pointer and bail out*/
1419                 if (vtable_word & SGEN_FORWARDED_BIT) {
1420                         *ptr = (void*)(vtable_word & ~SGEN_VTABLE_BITS_MASK);
1421                         break;
1422                 }
1423
1424                 /*someone pinned it, nothing to do.*/
1425                 if (vtable_word & SGEN_PINNED_BIT || major_pinned)
1426                         break;
1427         }
1428 }
1429
1430 /* Sort the addresses in array in increasing order.
1431  * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
1432  */
1433 void
1434 sgen_sort_addresses (void **array, int size)
1435 {
1436         int i;
1437         void *tmp;
1438
1439         for (i = 1; i < size; ++i) {
1440                 int child = i;
1441                 while (child > 0) {
1442                         int parent = (child - 1) / 2;
1443
1444                         if (array [parent] >= array [child])
1445                                 break;
1446
1447                         tmp = array [parent];
1448                         array [parent] = array [child];
1449                         array [child] = tmp;
1450
1451                         child = parent;
1452                 }
1453         }
1454
1455         for (i = size - 1; i > 0; --i) {
1456                 int end, root;
1457                 tmp = array [i];
1458                 array [i] = array [0];
1459                 array [0] = tmp;
1460
1461                 end = i - 1;
1462                 root = 0;
1463
1464                 while (root * 2 + 1 <= end) {
1465                         int child = root * 2 + 1;
1466
1467                         if (child < end && array [child] < array [child + 1])
1468                                 ++child;
1469                         if (array [root] >= array [child])
1470                                 break;
1471
1472                         tmp = array [root];
1473                         array [root] = array [child];
1474                         array [child] = tmp;
1475
1476                         root = child;
1477                 }
1478         }
1479 }
1480
1481 /*
1482  * Scan the memory between start and end and queue values which could be pointers
1483  * to the area between start_nursery and end_nursery for later consideration.
1484  * Typically used for thread stacks.
1485  */
1486 static void
1487 conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
1488 {
1489         int count = 0;
1490
1491 #ifdef VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE
1492         VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE (start, (char*)end - (char*)start);
1493 #endif
1494
1495         while (start < end) {
1496                 if (*start >= start_nursery && *start < end_nursery) {
1497                         /*
1498                          * *start can point to the middle of an object
1499                          * note: should we handle pointing at the end of an object?
1500                          * pinning in C# code disallows pointing at the end of an object
1501                          * but there is some small chance that an optimizing C compiler
1502                          * may keep the only reference to an object by pointing
1503                          * at the end of it. We ignore this small chance for now.
1504                          * Pointers to the end of an object are indistinguishable
1505                          * from pointers to the start of the next object in memory
1506                          * so if we allow that we'd need to pin two objects...
1507                          * We queue the pointer in an array, the
1508                          * array will then be sorted and uniqued. This way
1509                          * we can coalesce several pinning pointers and it should
1510                          * be faster since we'd do a memory scan with increasing
1511                          * addresses. Note: we can align the address to the allocation
1512                          * alignment, so the unique process is more effective.
1513                          */
1514                         mword addr = (mword)*start;
1515                         addr &= ~(ALLOC_ALIGN - 1);
1516                         if (addr >= (mword)start_nursery && addr < (mword)end_nursery) {
1517                                 SGEN_LOG (6, "Pinning address %p from %p", (void*)addr, start);
1518                                 sgen_pin_stage_ptr ((void*)addr);
1519                                 count++;
1520                         }
1521                         if (G_UNLIKELY (do_pin_stats)) {
1522                                 if (ptr_in_nursery ((void*)addr))
1523                                         sgen_pin_stats_register_address ((char*)addr, pin_type);
1524                         }
1525                 }
1526                 start++;
1527         }
1528         if (count)
1529                 SGEN_LOG (7, "found %d potential pinned heap pointers", count);
1530 }
1531
1532 /*
1533  * The first thing we do in a collection is to identify pinned objects.
1534  * This function considers all the areas of memory that need to be
1535  * conservatively scanned.
1536  */
1537 static void
1538 pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue)
1539 {
1540         void **start_root;
1541         RootRecord *root;
1542         SGEN_LOG (2, "Scanning pinned roots (%d bytes, %d/%d entries)", (int)roots_size, roots_hash [ROOT_TYPE_NORMAL].num_entries, roots_hash [ROOT_TYPE_PINNED].num_entries);
1543         /* objects pinned from the API are inside these roots */
1544         SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], start_root, root) {
1545                 SGEN_LOG (6, "Pinned roots %p-%p", start_root, root->end_root);
1546                 conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
1547         } SGEN_HASH_TABLE_FOREACH_END;
1548         /* now deal with the thread stacks
1549          * in the future we should be able to conservatively scan only:
1550          * *) the cpu registers
1551          * *) the unmanaged stack frames
1552          * *) the _last_ managed stack frame
1553          * *) pointers slots in managed frames
1554          */
1555         scan_thread_data (start_nursery, end_nursery, FALSE, queue);
1556 }
1557
1558 static void
1559 unpin_objects_from_queue (SgenGrayQueue *queue)
1560 {
1561         for (;;) {
1562                 char *addr;
1563                 GRAY_OBJECT_DEQUEUE (queue, addr);
1564                 if (!addr)
1565                         break;
1566                 g_assert (SGEN_OBJECT_IS_PINNED (addr));
1567                 SGEN_UNPIN_OBJECT (addr);
1568         }
1569 }
1570
1571 typedef struct {
1572         CopyOrMarkObjectFunc func;
1573         GrayQueue *queue;
1574 } UserCopyOrMarkData;
1575
1576 static MonoNativeTlsKey user_copy_or_mark_key;
1577
1578 static void
1579 init_user_copy_or_mark_key (void)
1580 {
1581         mono_native_tls_alloc (&user_copy_or_mark_key, NULL);
1582 }
1583
1584 static void
1585 set_user_copy_or_mark_data (UserCopyOrMarkData *data)
1586 {
1587         mono_native_tls_set_value (user_copy_or_mark_key, data);
1588 }
1589
1590 static void
1591 single_arg_user_copy_or_mark (void **obj)
1592 {
1593         UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
1594
1595         data->func (obj, data->queue);
1596 }
1597
1598 /*
1599  * The memory area from start_root to end_root contains pointers to objects.
1600  * Their position is precisely described by @desc (this means that the pointer
1601  * can be either NULL or the pointer to the start of an object).
1602  * This functions copies them to to_space updates them.
1603  *
1604  * This function is not thread-safe!
1605  */
1606 static void
1607 precisely_scan_objects_from (void** start_root, void** end_root, char* n_start, char *n_end, mword desc, ScanCopyContext ctx)
1608 {
1609         CopyOrMarkObjectFunc copy_func = ctx.copy_func;
1610         SgenGrayQueue *queue = ctx.queue;
1611
1612         switch (desc & ROOT_DESC_TYPE_MASK) {
1613         case ROOT_DESC_BITMAP:
1614                 desc >>= ROOT_DESC_TYPE_SHIFT;
1615                 while (desc) {
1616                         if ((desc & 1) && *start_root) {
1617                                 copy_func (start_root, queue);
1618                                 SGEN_LOG (9, "Overwrote root at %p with %p", start_root, *start_root);
1619                                 sgen_drain_gray_stack (-1, ctx);
1620                         }
1621                         desc >>= 1;
1622                         start_root++;
1623                 }
1624                 return;
1625         case ROOT_DESC_COMPLEX: {
1626                 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1627                 int bwords = (*bitmap_data) - 1;
1628                 void **start_run = start_root;
1629                 bitmap_data++;
1630                 while (bwords-- > 0) {
1631                         gsize bmap = *bitmap_data++;
1632                         void **objptr = start_run;
1633                         while (bmap) {
1634                                 if ((bmap & 1) && *objptr) {
1635                                         copy_func (objptr, queue);
1636                                         SGEN_LOG (9, "Overwrote root at %p with %p", objptr, *objptr);
1637                                         sgen_drain_gray_stack (-1, ctx);
1638                                 }
1639                                 bmap >>= 1;
1640                                 ++objptr;
1641                         }
1642                         start_run += GC_BITS_PER_WORD;
1643                 }
1644                 break;
1645         }
1646         case ROOT_DESC_USER: {
1647                 UserCopyOrMarkData data = { copy_func, queue };
1648                 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1649                 set_user_copy_or_mark_data (&data);
1650                 marker (start_root, single_arg_user_copy_or_mark);
1651                 set_user_copy_or_mark_data (NULL);
1652                 break;
1653         }
1654         case ROOT_DESC_RUN_LEN:
1655                 g_assert_not_reached ();
1656         default:
1657                 g_assert_not_reached ();
1658         }
1659 }
1660
1661 static void
1662 reset_heap_boundaries (void)
1663 {
1664         lowest_heap_address = ~(mword)0;
1665         highest_heap_address = 0;
1666 }
1667
1668 void
1669 sgen_update_heap_boundaries (mword low, mword high)
1670 {
1671         mword old;
1672
1673         do {
1674                 old = lowest_heap_address;
1675                 if (low >= old)
1676                         break;
1677         } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
1678
1679         do {
1680                 old = highest_heap_address;
1681                 if (high <= old)
1682                         break;
1683         } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
1684 }
1685
1686 /*
1687  * Allocate and setup the data structures needed to be able to allocate objects
1688  * in the nursery. The nursery is stored in nursery_section.
1689  */
1690 static void
1691 alloc_nursery (void)
1692 {
1693         GCMemSection *section;
1694         char *data;
1695         int scan_starts;
1696         int alloc_size;
1697
1698         if (nursery_section)
1699                 return;
1700         SGEN_LOG (2, "Allocating nursery size: %lu", (unsigned long)sgen_nursery_size);
1701         /* later we will alloc a larger area for the nursery but only activate
1702          * what we need. The rest will be used as expansion if we have too many pinned
1703          * objects in the existing nursery.
1704          */
1705         /* FIXME: handle OOM */
1706         section = sgen_alloc_internal (INTERNAL_MEM_SECTION);
1707
1708         alloc_size = sgen_nursery_size;
1709
1710         /* If there isn't enough space even for the nursery we should simply abort. */
1711         g_assert (sgen_memgov_try_alloc_space (alloc_size, SPACE_NURSERY));
1712
1713 #ifdef SGEN_ALIGN_NURSERY
1714         data = major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
1715 #else
1716         data = major_collector.alloc_heap (alloc_size, 0, DEFAULT_NURSERY_BITS);
1717 #endif
1718         sgen_update_heap_boundaries ((mword)data, (mword)(data + sgen_nursery_size));
1719         SGEN_LOG (4, "Expanding nursery size (%p-%p): %lu, total: %lu", data, data + alloc_size, (unsigned long)sgen_nursery_size, (unsigned long)mono_gc_get_heap_size ());
1720         section->data = section->next_data = data;
1721         section->size = alloc_size;
1722         section->end_data = data + sgen_nursery_size;
1723         scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
1724         section->scan_starts = sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS, TRUE);
1725         section->num_scan_start = scan_starts;
1726
1727         nursery_section = section;
1728
1729         sgen_nursery_allocator_set_nursery_bounds (data, data + sgen_nursery_size);
1730 }
1731
1732 void*
1733 mono_gc_get_nursery (int *shift_bits, size_t *size)
1734 {
1735         *size = sgen_nursery_size;
1736 #ifdef SGEN_ALIGN_NURSERY
1737         *shift_bits = DEFAULT_NURSERY_BITS;
1738 #else
1739         *shift_bits = -1;
1740 #endif
1741         return sgen_get_nursery_start ();
1742 }
1743
1744 void
1745 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1746 {
1747         SgenThreadInfo *info = mono_thread_info_current ();
1748
1749         /* Could be called from sgen_thread_unregister () with a NULL info */
1750         if (domain) {
1751                 g_assert (info);
1752                 info->stopped_domain = domain;
1753         }
1754 }
1755
1756 gboolean
1757 mono_gc_precise_stack_mark_enabled (void)
1758 {
1759         return !conservative_stack_mark;
1760 }
1761
1762 FILE *
1763 mono_gc_get_logfile (void)
1764 {
1765         return gc_debug_file;
1766 }
1767
1768 static void
1769 report_finalizer_roots_list (FinalizeReadyEntry *list)
1770 {
1771         GCRootReport report;
1772         FinalizeReadyEntry *fin;
1773
1774         report.count = 0;
1775         for (fin = list; fin; fin = fin->next) {
1776                 if (!fin->object)
1777                         continue;
1778                 add_profile_gc_root (&report, fin->object, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1779         }
1780         notify_gc_roots (&report);
1781 }
1782
1783 static void
1784 report_finalizer_roots (void)
1785 {
1786         report_finalizer_roots_list (fin_ready_list);
1787         report_finalizer_roots_list (critical_fin_list);
1788 }
1789
1790 static GCRootReport *root_report;
1791
1792 static void
1793 single_arg_report_root (void **obj)
1794 {
1795         if (*obj)
1796                 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1797 }
1798
1799 static void
1800 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1801 {
1802         switch (desc & ROOT_DESC_TYPE_MASK) {
1803         case ROOT_DESC_BITMAP:
1804                 desc >>= ROOT_DESC_TYPE_SHIFT;
1805                 while (desc) {
1806                         if ((desc & 1) && *start_root) {
1807                                 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1808                         }
1809                         desc >>= 1;
1810                         start_root++;
1811                 }
1812                 return;
1813         case ROOT_DESC_COMPLEX: {
1814                 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1815                 int bwords = (*bitmap_data) - 1;
1816                 void **start_run = start_root;
1817                 bitmap_data++;
1818                 while (bwords-- > 0) {
1819                         gsize bmap = *bitmap_data++;
1820                         void **objptr = start_run;
1821                         while (bmap) {
1822                                 if ((bmap & 1) && *objptr) {
1823                                         add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1824                                 }
1825                                 bmap >>= 1;
1826                                 ++objptr;
1827                         }
1828                         start_run += GC_BITS_PER_WORD;
1829                 }
1830                 break;
1831         }
1832         case ROOT_DESC_USER: {
1833                 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1834                 root_report = report;
1835                 marker (start_root, single_arg_report_root);
1836                 break;
1837         }
1838         case ROOT_DESC_RUN_LEN:
1839                 g_assert_not_reached ();
1840         default:
1841                 g_assert_not_reached ();
1842         }
1843 }
1844
1845 static void
1846 report_registered_roots_by_type (int root_type)
1847 {
1848         GCRootReport report;
1849         void **start_root;
1850         RootRecord *root;
1851         report.count = 0;
1852         SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1853                 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
1854                 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
1855         } SGEN_HASH_TABLE_FOREACH_END;
1856         notify_gc_roots (&report);
1857 }
1858
1859 static void
1860 report_registered_roots (void)
1861 {
1862         report_registered_roots_by_type (ROOT_TYPE_NORMAL);
1863         report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
1864 }
1865
1866 static void
1867 scan_finalizer_entries (FinalizeReadyEntry *list, ScanCopyContext ctx)
1868 {
1869         CopyOrMarkObjectFunc copy_func = ctx.copy_func;
1870         SgenGrayQueue *queue = ctx.queue;
1871         FinalizeReadyEntry *fin;
1872
1873         for (fin = list; fin; fin = fin->next) {
1874                 if (!fin->object)
1875                         continue;
1876                 SGEN_LOG (5, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object));
1877                 copy_func (&fin->object, queue);
1878         }
1879 }
1880
1881 static const char*
1882 generation_name (int generation)
1883 {
1884         switch (generation) {
1885         case GENERATION_NURSERY: return "nursery";
1886         case GENERATION_OLD: return "old";
1887         default: g_assert_not_reached ();
1888         }
1889 }
1890
1891 const char*
1892 sgen_generation_name (int generation)
1893 {
1894         return generation_name (generation);
1895 }
1896
1897 SgenObjectOperations *
1898 sgen_get_current_object_ops (void){
1899         return &current_object_ops;
1900 }
1901
1902
1903 static void
1904 finish_gray_stack (char *start_addr, char *end_addr, int generation, GrayQueue *queue)
1905 {
1906         TV_DECLARE (atv);
1907         TV_DECLARE (btv);
1908         int done_with_ephemerons, ephemeron_rounds = 0;
1909         CopyOrMarkObjectFunc copy_func = current_object_ops.copy_or_mark_object;
1910         ScanObjectFunc scan_func = current_object_ops.scan_object;
1911         ScanCopyContext ctx = { scan_func, copy_func, queue };
1912
1913         /*
1914          * We copied all the reachable objects. Now it's the time to copy
1915          * the objects that were not referenced by the roots, but by the copied objects.
1916          * we built a stack of objects pointed to by gray_start: they are
1917          * additional roots and we may add more items as we go.
1918          * We loop until gray_start == gray_objects which means no more objects have
1919          * been added. Note this is iterative: no recursion is involved.
1920          * We need to walk the LO list as well in search of marked big objects
1921          * (use a flag since this is needed only on major collections). We need to loop
1922          * here as well, so keep a counter of marked LO (increasing it in copy_object).
1923          *   To achieve better cache locality and cache usage, we drain the gray stack
1924          * frequently, after each object is copied, and just finish the work here.
1925          */
1926         sgen_drain_gray_stack (-1, ctx);
1927         TV_GETTIME (atv);
1928         SGEN_LOG (2, "%s generation done", generation_name (generation));
1929
1930         /*
1931         Reset bridge data, we might have lingering data from a previous collection if this is a major
1932         collection trigged by minor overflow.
1933
1934         We must reset the gathered bridges since their original block might be evacuated due to major
1935         fragmentation in the meanwhile and the bridge code should not have to deal with that.
1936         */
1937         sgen_bridge_reset_data ();
1938
1939         /*
1940          * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
1941          * before processing finalizable objects and non-tracking weak links to avoid finalizing/clearing
1942          * objects that are in fact reachable.
1943          */
1944         done_with_ephemerons = 0;
1945         do {
1946                 done_with_ephemerons = mark_ephemerons_in_range (ctx);
1947                 sgen_drain_gray_stack (-1, ctx);
1948                 ++ephemeron_rounds;
1949         } while (!done_with_ephemerons);
1950
1951         sgen_scan_togglerefs (start_addr, end_addr, ctx);
1952         if (generation == GENERATION_OLD)
1953                 sgen_scan_togglerefs (sgen_get_nursery_start (), sgen_get_nursery_end (), ctx);
1954
1955         if (sgen_need_bridge_processing ()) {
1956                 sgen_collect_bridge_objects (generation, ctx);
1957                 if (generation == GENERATION_OLD)
1958                         sgen_collect_bridge_objects (GENERATION_NURSERY, ctx);
1959         }
1960
1961         /*
1962         Make sure we drain the gray stack before processing disappearing links and finalizers.
1963         If we don't make sure it is empty we might wrongly see a live object as dead.
1964         */
1965         sgen_drain_gray_stack (-1, ctx);
1966
1967         /*
1968         We must clear weak links that don't track resurrection before processing object ready for
1969         finalization so they can be cleared before that.
1970         */
1971         sgen_null_link_in_range (generation, TRUE, ctx);
1972         if (generation == GENERATION_OLD)
1973                 sgen_null_link_in_range (GENERATION_NURSERY, TRUE, ctx);
1974
1975
1976         /* walk the finalization queue and move also the objects that need to be
1977          * finalized: use the finalized objects as new roots so the objects they depend
1978          * on are also not reclaimed. As with the roots above, only objects in the nursery
1979          * are marked/copied.
1980          */
1981         sgen_finalize_in_range (generation, ctx);
1982         if (generation == GENERATION_OLD)
1983                 sgen_finalize_in_range (GENERATION_NURSERY, ctx);
1984         /* drain the new stack that might have been created */
1985         SGEN_LOG (6, "Precise scan of gray area post fin");
1986         sgen_drain_gray_stack (-1, ctx);
1987
1988         /*
1989          * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
1990          */
1991         done_with_ephemerons = 0;
1992         do {
1993                 done_with_ephemerons = mark_ephemerons_in_range (ctx);
1994                 sgen_drain_gray_stack (-1, ctx);
1995                 ++ephemeron_rounds;
1996         } while (!done_with_ephemerons);
1997
1998         /*
1999          * Clear ephemeron pairs with unreachable keys.
2000          * We pass the copy func so we can figure out if an array was promoted or not.
2001          */
2002         clear_unreachable_ephemerons (generation == GENERATION_OLD && major_collector.is_concurrent, ctx);
2003
2004         TV_GETTIME (btv);
2005         SGEN_LOG (2, "Finalize queue handling scan for %s generation: %d usecs %d ephemeron rounds", generation_name (generation), TV_ELAPSED (atv, btv), ephemeron_rounds);
2006
2007         /*
2008          * handle disappearing links
2009          * Note we do this after checking the finalization queue because if an object
2010          * survives (at least long enough to be finalized) we don't clear the link.
2011          * This also deals with a possible issue with the monitor reclamation: with the Boehm
2012          * GC a finalized object my lose the monitor because it is cleared before the finalizer is
2013          * called.
2014          */
2015         g_assert (sgen_gray_object_queue_is_empty (queue));
2016         for (;;) {
2017                 sgen_null_link_in_range (generation, FALSE, ctx);
2018                 if (generation == GENERATION_OLD)
2019                         sgen_null_link_in_range (GENERATION_NURSERY, FALSE, ctx);
2020                 if (sgen_gray_object_queue_is_empty (queue))
2021                         break;
2022                 sgen_drain_gray_stack (-1, ctx);
2023         }
2024
2025         g_assert (sgen_gray_object_queue_is_empty (queue));
2026 }
2027
2028 void
2029 sgen_check_section_scan_starts (GCMemSection *section)
2030 {
2031         int i;
2032         for (i = 0; i < section->num_scan_start; ++i) {
2033                 if (section->scan_starts [i]) {
2034                         guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
2035                         g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
2036                 }
2037         }
2038 }
2039
2040 static void
2041 check_scan_starts (void)
2042 {
2043         if (!do_scan_starts_check)
2044                 return;
2045         sgen_check_section_scan_starts (nursery_section);
2046         major_collector.check_scan_starts ();
2047 }
2048
2049 static void
2050 scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx)
2051 {
2052         void **start_root;
2053         RootRecord *root;
2054         SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
2055                 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
2056                 precisely_scan_objects_from (start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, ctx);
2057         } SGEN_HASH_TABLE_FOREACH_END;
2058 }
2059
2060 void
2061 sgen_dump_occupied (char *start, char *end, char *section_start)
2062 {
2063         fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
2064 }
2065
2066 void
2067 sgen_dump_section (GCMemSection *section, const char *type)
2068 {
2069         char *start = section->data;
2070         char *end = section->data + section->size;
2071         char *occ_start = NULL;
2072         GCVTable *vt;
2073         char *old_start = NULL; /* just for debugging */
2074
2075         fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
2076
2077         while (start < end) {
2078                 guint size;
2079                 MonoClass *class;
2080
2081                 if (!*(void**)start) {
2082                         if (occ_start) {
2083                                 sgen_dump_occupied (occ_start, start, section->data);
2084                                 occ_start = NULL;
2085                         }
2086                         start += sizeof (void*); /* should be ALLOC_ALIGN, really */
2087                         continue;
2088                 }
2089                 g_assert (start < section->next_data);
2090
2091                 if (!occ_start)
2092                         occ_start = start;
2093
2094                 vt = (GCVTable*)LOAD_VTABLE (start);
2095                 class = vt->klass;
2096
2097                 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
2098
2099                 /*
2100                 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
2101                                 start - section->data,
2102                                 vt->klass->name_space, vt->klass->name,
2103                                 size);
2104                 */
2105
2106                 old_start = start;
2107                 start += size;
2108         }
2109         if (occ_start)
2110                 sgen_dump_occupied (occ_start, start, section->data);
2111
2112         fprintf (heap_dump_file, "</section>\n");
2113 }
2114
2115 static void
2116 dump_object (MonoObject *obj, gboolean dump_location)
2117 {
2118         static char class_name [1024];
2119
2120         MonoClass *class = mono_object_class (obj);
2121         int i, j;
2122
2123         /*
2124          * Python's XML parser is too stupid to parse angle brackets
2125          * in strings, so we just ignore them;
2126          */
2127         i = j = 0;
2128         while (class->name [i] && j < sizeof (class_name) - 1) {
2129                 if (!strchr ("<>\"", class->name [i]))
2130                         class_name [j++] = class->name [i];
2131                 ++i;
2132         }
2133         g_assert (j < sizeof (class_name));
2134         class_name [j] = 0;
2135
2136         fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2137                         class->name_space, class_name,
2138                         safe_object_get_size (obj));
2139         if (dump_location) {
2140                 const char *location;
2141                 if (ptr_in_nursery (obj))
2142                         location = "nursery";
2143                 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2144                         location = "major";
2145                 else
2146                         location = "LOS";
2147                 fprintf (heap_dump_file, " location=\"%s\"", location);
2148         }
2149         fprintf (heap_dump_file, "/>\n");
2150 }
2151
2152 static void
2153 dump_heap (const char *type, int num, const char *reason)
2154 {
2155         ObjectList *list;
2156         LOSObject *bigobj;
2157
2158         fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2159         if (reason)
2160                 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2161         fprintf (heap_dump_file, ">\n");
2162         fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2163         sgen_dump_internal_mem_usage (heap_dump_file);
2164         fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2165         /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2166         fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2167
2168         fprintf (heap_dump_file, "<pinned-objects>\n");
2169         for (list = sgen_pin_stats_get_object_list (); list; list = list->next)
2170                 dump_object (list->obj, TRUE);
2171         fprintf (heap_dump_file, "</pinned-objects>\n");
2172
2173         sgen_dump_section (nursery_section, "nursery");
2174
2175         major_collector.dump_heap (heap_dump_file);
2176
2177         fprintf (heap_dump_file, "<los>\n");
2178         for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2179                 dump_object ((MonoObject*)bigobj->data, FALSE);
2180         fprintf (heap_dump_file, "</los>\n");
2181
2182         fprintf (heap_dump_file, "</collection>\n");
2183 }
2184
2185 void
2186 sgen_register_moved_object (void *obj, void *destination)
2187 {
2188         g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2189
2190         /* FIXME: handle this for parallel collector */
2191         g_assert (!sgen_collection_is_parallel ());
2192
2193         if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2194                 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2195                 moved_objects_idx = 0;
2196         }
2197         moved_objects [moved_objects_idx++] = obj;
2198         moved_objects [moved_objects_idx++] = destination;
2199 }
2200
2201 static void
2202 init_stats (void)
2203 {
2204         static gboolean inited = FALSE;
2205
2206         if (inited)
2207                 return;
2208
2209         mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pre_collection_fragment_clear);
2210         mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pinning);
2211         mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_remsets);
2212         mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_pinned);
2213         mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_registered_roots);
2214         mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_thread_data);
2215         mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_finish_gray_stack);
2216         mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_fragment_creation);
2217
2218         mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pre_collection_fragment_clear);
2219         mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pinning);
2220         mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_pinned);
2221         mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_registered_roots);
2222         mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_thread_data);
2223         mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_alloc_pinned);
2224         mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_finalized);
2225         mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_big_objects);
2226         mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_finish_gray_stack);
2227         mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_free_bigobjs);
2228         mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_los_sweep);
2229         mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_sweep);
2230         mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_fragment_creation);
2231
2232         mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2233
2234 #ifdef HEAVY_STATISTICS
2235         mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2236         mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2237         mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2238         mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2239         mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2240         mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2241         mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2242
2243         mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2244         mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2245
2246         mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2247         mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2248         mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2249         mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2250
2251         mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2252         mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2253
2254         mono_counters_register ("Slots allocated in vain", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_slots_allocated_in_vain);
2255
2256         mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2257         mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2258         mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2259         mono_counters_register ("# nursery copy_object() failed to space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_to_space);
2260
2261         sgen_nursery_allocator_init_heavy_stats ();
2262         sgen_alloc_init_heavy_stats ();
2263 #endif
2264
2265         inited = TRUE;
2266 }
2267
2268
2269 static void
2270 reset_pinned_from_failed_allocation (void)
2271 {
2272         bytes_pinned_from_failed_allocation = 0;
2273 }
2274
2275 void
2276 sgen_set_pinned_from_failed_allocation (mword objsize)
2277 {
2278         bytes_pinned_from_failed_allocation += objsize;
2279 }
2280
2281 gboolean
2282 sgen_collection_is_parallel (void)
2283 {
2284         switch (current_collection_generation) {
2285         case GENERATION_NURSERY:
2286                 return nursery_collection_is_parallel;
2287         case GENERATION_OLD:
2288                 return major_collector.is_parallel;
2289         default:
2290                 g_error ("Invalid current generation %d", current_collection_generation);
2291         }
2292 }
2293
2294 gboolean
2295 sgen_collection_is_concurrent (void)
2296 {
2297         switch (current_collection_generation) {
2298         case GENERATION_NURSERY:
2299                 return FALSE;
2300         case GENERATION_OLD:
2301                 return major_collector.is_concurrent;
2302         default:
2303                 g_error ("Invalid current generation %d", current_collection_generation);
2304         }
2305 }
2306
2307 gboolean
2308 sgen_concurrent_collection_in_progress (void)
2309 {
2310         return concurrent_collection_in_progress;
2311 }
2312
2313 typedef struct
2314 {
2315         char *heap_start;
2316         char *heap_end;
2317 } FinishRememberedSetScanJobData;
2318
2319 static void
2320 job_finish_remembered_set_scan (WorkerData *worker_data, void *job_data_untyped)
2321 {
2322         FinishRememberedSetScanJobData *job_data = job_data_untyped;
2323
2324         remset.finish_scan_remsets (job_data->heap_start, job_data->heap_end, sgen_workers_get_job_gray_queue (worker_data));
2325         sgen_free_internal_dynamic (job_data, sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2326 }
2327
2328 typedef struct
2329 {
2330         CopyOrMarkObjectFunc copy_or_mark_func;
2331         ScanObjectFunc scan_func;
2332         char *heap_start;
2333         char *heap_end;
2334         int root_type;
2335 } ScanFromRegisteredRootsJobData;
2336
2337 static void
2338 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2339 {
2340         ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2341         ScanCopyContext ctx = { job_data->scan_func, job_data->copy_or_mark_func,
2342                 sgen_workers_get_job_gray_queue (worker_data) };
2343
2344         scan_from_registered_roots (job_data->heap_start, job_data->heap_end, job_data->root_type, ctx);
2345         sgen_free_internal_dynamic (job_data, sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2346 }
2347
2348 typedef struct
2349 {
2350         char *heap_start;
2351         char *heap_end;
2352 } ScanThreadDataJobData;
2353
2354 static void
2355 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2356 {
2357         ScanThreadDataJobData *job_data = job_data_untyped;
2358
2359         scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2360                         sgen_workers_get_job_gray_queue (worker_data));
2361         sgen_free_internal_dynamic (job_data, sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2362 }
2363
2364 typedef struct
2365 {
2366         FinalizeReadyEntry *list;
2367 } ScanFinalizerEntriesJobData;
2368
2369 static void
2370 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2371 {
2372         ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2373         ScanCopyContext ctx = { NULL, current_object_ops.copy_or_mark_object, sgen_workers_get_job_gray_queue (worker_data) };
2374
2375         scan_finalizer_entries (job_data->list, ctx);
2376         sgen_free_internal_dynamic (job_data, sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2377 }
2378
2379 static void
2380 job_scan_major_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2381 {
2382         g_assert (concurrent_collection_in_progress);
2383         major_collector.scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2384 }
2385
2386 static void
2387 job_scan_los_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2388 {
2389         g_assert (concurrent_collection_in_progress);
2390         sgen_los_scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2391 }
2392
2393 static void
2394 verify_scan_starts (char *start, char *end)
2395 {
2396         int i;
2397
2398         for (i = 0; i < nursery_section->num_scan_start; ++i) {
2399                 char *addr = nursery_section->scan_starts [i];
2400                 if (addr > start && addr < end)
2401                         SGEN_LOG (1, "NFC-BAD SCAN START [%d] %p for obj [%p %p]", i, addr, start, end);
2402         }
2403 }
2404
2405 static void
2406 verify_nursery (void)
2407 {
2408         char *start, *end, *cur, *hole_start;
2409
2410         if (!do_verify_nursery)
2411                 return;
2412
2413         /*This cleans up unused fragments */
2414         sgen_nursery_allocator_prepare_for_pinning ();
2415
2416         hole_start = start = cur = sgen_get_nursery_start ();
2417         end = sgen_get_nursery_end ();
2418
2419         while (cur < end) {
2420                 size_t ss, size;
2421
2422                 if (!*(void**)cur) {
2423                         cur += sizeof (void*);
2424                         continue;
2425                 }
2426
2427                 if (object_is_forwarded (cur))
2428                         SGEN_LOG (1, "FORWARDED OBJ %p", cur);
2429                 else if (object_is_pinned (cur))
2430                         SGEN_LOG (1, "PINNED OBJ %p", cur);
2431
2432                 ss = safe_object_get_size ((MonoObject*)cur);
2433                 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2434                 verify_scan_starts (cur, cur + size);
2435                 if (do_dump_nursery_content) {
2436                         if (cur > hole_start)
2437                                 SGEN_LOG (1, "HOLE [%p %p %d]", hole_start, cur, (int)(cur - hole_start));
2438                         SGEN_LOG (1, "OBJ  [%p %p %d %d %s %d]", cur, cur + size, (int)size, (int)ss, sgen_safe_name ((MonoObject*)cur), (gpointer)LOAD_VTABLE (cur) == sgen_get_array_fill_vtable ());
2439                 }
2440                 cur += size;
2441                 hole_start = cur;
2442         }
2443 }
2444
2445 /*
2446  * Checks that no objects in the nursery are fowarded or pinned.  This
2447  * is a precondition to restarting the mutator while doing a
2448  * concurrent collection.  Note that we don't clear fragments because
2449  * we depend on that having happened earlier.
2450  */
2451 static void
2452 check_nursery_is_clean (void)
2453 {
2454         char *start, *end, *cur;
2455
2456         start = cur = sgen_get_nursery_start ();
2457         end = sgen_get_nursery_end ();
2458
2459         while (cur < end) {
2460                 size_t ss, size;
2461
2462                 if (!*(void**)cur) {
2463                         cur += sizeof (void*);
2464                         continue;
2465                 }
2466
2467                 g_assert (!object_is_forwarded (cur));
2468                 g_assert (!object_is_pinned (cur));
2469
2470                 ss = safe_object_get_size ((MonoObject*)cur);
2471                 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2472                 verify_scan_starts (cur, cur + size);
2473
2474                 cur += size;
2475         }
2476 }
2477
2478 static void
2479 init_gray_queue (void)
2480 {
2481         if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ()) {
2482                 sgen_workers_init_distribute_gray_queue ();
2483                 sgen_gray_object_queue_init_with_alloc_prepare (&gray_queue, NULL,
2484                                 gray_queue_redirect, sgen_workers_get_distribute_section_gray_queue ());
2485         } else {
2486                 sgen_gray_object_queue_init (&gray_queue, NULL);
2487         }
2488
2489         if (major_collector.is_concurrent) {
2490                 sgen_gray_object_queue_init_with_alloc_prepare (&remember_major_objects_gray_queue, NULL,
2491                                 gray_queue_redirect, sgen_workers_get_distribute_section_gray_queue ());
2492         } else {
2493                 sgen_gray_object_queue_init_invalid (&remember_major_objects_gray_queue);
2494         }
2495 }
2496
2497 static void
2498 pin_stage_object_callback (char *obj, size_t size, void *data)
2499 {
2500         sgen_pin_stage_ptr (obj);
2501         /* FIXME: do pin stats if enabled */
2502 }
2503
2504 /*
2505  * Collect objects in the nursery.  Returns whether to trigger a major
2506  * collection.
2507  */
2508 static gboolean
2509 collect_nursery (SgenGrayQueue *unpin_queue, gboolean finish_up_concurrent_mark)
2510 {
2511         gboolean needs_major;
2512         size_t max_garbage_amount;
2513         char *nursery_next;
2514         FinishRememberedSetScanJobData *frssjd;
2515         ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2516         ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2517         ScanThreadDataJobData *stdjd;
2518         mword fragment_total;
2519         ScanCopyContext ctx;
2520         TV_DECLARE (all_atv);
2521         TV_DECLARE (all_btv);
2522         TV_DECLARE (atv);
2523         TV_DECLARE (btv);
2524
2525         if (disable_minor_collections)
2526                 return TRUE;
2527
2528         MONO_GC_BEGIN (GENERATION_NURSERY);
2529         binary_protocol_collection_begin (stat_minor_gcs, GENERATION_NURSERY);
2530
2531         verify_nursery ();
2532
2533 #ifndef DISABLE_PERFCOUNTERS
2534         mono_perfcounters->gc_collections0++;
2535 #endif
2536
2537         current_collection_generation = GENERATION_NURSERY;
2538         if (sgen_collection_is_parallel ())
2539                 current_object_ops = sgen_minor_collector.parallel_ops;
2540         else
2541                 current_object_ops = sgen_minor_collector.serial_ops;
2542
2543         reset_pinned_from_failed_allocation ();
2544
2545         check_scan_starts ();
2546
2547         sgen_nursery_alloc_prepare_for_minor ();
2548
2549         degraded_mode = 0;
2550         objects_pinned = 0;
2551         nursery_next = sgen_nursery_alloc_get_upper_alloc_bound ();
2552         /* FIXME: optimize later to use the higher address where an object can be present */
2553         nursery_next = MAX (nursery_next, sgen_get_nursery_end ());
2554
2555         SGEN_LOG (1, "Start nursery collection %d %p-%p, size: %d", stat_minor_gcs, sgen_get_nursery_start (), nursery_next, (int)(nursery_next - sgen_get_nursery_start ()));
2556         max_garbage_amount = nursery_next - sgen_get_nursery_start ();
2557         g_assert (nursery_section->size >= max_garbage_amount);
2558
2559         /* world must be stopped already */
2560         TV_GETTIME (all_atv);
2561         atv = all_atv;
2562
2563         TV_GETTIME (btv);
2564         time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2565
2566         if (xdomain_checks) {
2567                 sgen_clear_nursery_fragments ();
2568                 check_for_xdomain_refs ();
2569         }
2570
2571         nursery_section->next_data = nursery_next;
2572
2573         major_collector.start_nursery_collection ();
2574
2575         sgen_memgov_minor_collection_start ();
2576
2577         init_gray_queue ();
2578
2579         stat_minor_gcs++;
2580         gc_stats.minor_gc_count ++;
2581
2582         if (remset.prepare_for_minor_collection)
2583                 remset.prepare_for_minor_collection ();
2584
2585         MONO_GC_CHECKPOINT_1 (GENERATION_NURSERY);
2586
2587         sgen_process_fin_stage_entries ();
2588         sgen_process_dislink_stage_entries ();
2589
2590         MONO_GC_CHECKPOINT_2 (GENERATION_NURSERY);
2591
2592         /* pin from pinned handles */
2593         sgen_init_pinning ();
2594         mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2595         pin_from_roots (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2596         /* pin cemented objects */
2597         sgen_cement_iterate (pin_stage_object_callback, NULL);
2598         /* identify pinned objects */
2599         sgen_optimize_pin_queue (0);
2600         sgen_pinning_setup_section (nursery_section);
2601         ctx.scan_func = NULL;
2602         ctx.copy_func = NULL;
2603         ctx.queue = WORKERS_DISTRIBUTE_GRAY_QUEUE;
2604         sgen_pin_objects_in_section (nursery_section, ctx);
2605         sgen_pinning_trim_queue_to_section (nursery_section);
2606
2607         TV_GETTIME (atv);
2608         time_minor_pinning += TV_ELAPSED (btv, atv);
2609         SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (btv, atv));
2610         SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2611
2612         MONO_GC_CHECKPOINT_3 (GENERATION_NURSERY);
2613
2614         if (whole_heap_check_before_collection) {
2615                 sgen_clear_nursery_fragments ();
2616                 sgen_check_whole_heap (finish_up_concurrent_mark);
2617         }
2618         if (consistency_check_at_minor_collection)
2619                 sgen_check_consistency ();
2620
2621         sgen_workers_start_all_workers ();
2622
2623         /*
2624          * Perform the sequential part of remembered set scanning.
2625          * This usually involves scanning global information that might later be produced by evacuation.
2626          */
2627         if (remset.begin_scan_remsets)
2628                 remset.begin_scan_remsets (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2629
2630         sgen_workers_start_marking ();
2631
2632         frssjd = sgen_alloc_internal_dynamic (sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2633         frssjd->heap_start = sgen_get_nursery_start ();
2634         frssjd->heap_end = nursery_next;
2635         sgen_workers_enqueue_job (job_finish_remembered_set_scan, frssjd);
2636
2637         /* we don't have complete write barrier yet, so we scan all the old generation sections */
2638         TV_GETTIME (btv);
2639         time_minor_scan_remsets += TV_ELAPSED (atv, btv);
2640         SGEN_LOG (2, "Old generation scan: %d usecs", TV_ELAPSED (atv, btv));
2641
2642         MONO_GC_CHECKPOINT_4 (GENERATION_NURSERY);
2643
2644         if (!sgen_collection_is_parallel ()) {
2645                 ctx.scan_func = current_object_ops.scan_object;
2646                 ctx.copy_func = NULL;
2647                 ctx.queue = &gray_queue;
2648                 sgen_drain_gray_stack (-1, ctx);
2649         }
2650
2651         if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2652                 report_registered_roots ();
2653         if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2654                 report_finalizer_roots ();
2655         TV_GETTIME (atv);
2656         time_minor_scan_pinned += TV_ELAPSED (btv, atv);
2657
2658         MONO_GC_CHECKPOINT_5 (GENERATION_NURSERY);
2659
2660         /* registered roots, this includes static fields */
2661         scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2662         scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2663         scrrjd_normal->scan_func = current_object_ops.scan_object;
2664         scrrjd_normal->heap_start = sgen_get_nursery_start ();
2665         scrrjd_normal->heap_end = nursery_next;
2666         scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
2667         sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
2668
2669         scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2670         scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2671         scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
2672         scrrjd_wbarrier->heap_start = sgen_get_nursery_start ();
2673         scrrjd_wbarrier->heap_end = nursery_next;
2674         scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
2675         sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
2676
2677         TV_GETTIME (btv);
2678         time_minor_scan_registered_roots += TV_ELAPSED (atv, btv);
2679
2680         MONO_GC_CHECKPOINT_6 (GENERATION_NURSERY);
2681
2682         /* thread data */
2683         stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2684         stdjd->heap_start = sgen_get_nursery_start ();
2685         stdjd->heap_end = nursery_next;
2686         sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
2687
2688         TV_GETTIME (atv);
2689         time_minor_scan_thread_data += TV_ELAPSED (btv, atv);
2690         btv = atv;
2691
2692         MONO_GC_CHECKPOINT_7 (GENERATION_NURSERY);
2693
2694         g_assert (!sgen_collection_is_parallel () && !sgen_collection_is_concurrent ());
2695
2696         if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ())
2697                 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2698
2699         /* Scan the list of objects ready for finalization. If */
2700         sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2701         sfejd_fin_ready->list = fin_ready_list;
2702         sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
2703
2704         sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2705         sfejd_critical_fin->list = critical_fin_list;
2706         sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
2707
2708         MONO_GC_CHECKPOINT_8 (GENERATION_NURSERY);
2709
2710         finish_gray_stack (sgen_get_nursery_start (), nursery_next, GENERATION_NURSERY, &gray_queue);
2711         TV_GETTIME (atv);
2712         time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
2713         mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2714
2715         MONO_GC_CHECKPOINT_9 (GENERATION_NURSERY);
2716
2717         /*
2718          * The (single-threaded) finalization code might have done
2719          * some copying/marking so we can only reset the GC thread's
2720          * worker data here instead of earlier when we joined the
2721          * workers.
2722          */
2723         sgen_workers_reset_data ();
2724
2725         if (objects_pinned) {
2726                 sgen_optimize_pin_queue (0);
2727                 sgen_pinning_setup_section (nursery_section);
2728         }
2729
2730         /* walk the pin_queue, build up the fragment list of free memory, unmark
2731          * pinned objects as we go, memzero() the empty fragments so they are ready for the
2732          * next allocations.
2733          */
2734         mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2735         fragment_total = sgen_build_nursery_fragments (nursery_section,
2736                         nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries,
2737                         unpin_queue);
2738         if (!fragment_total)
2739                 degraded_mode = 1;
2740
2741         /* Clear TLABs for all threads */
2742         sgen_clear_tlabs ();
2743
2744         mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2745         TV_GETTIME (btv);
2746         time_minor_fragment_creation += TV_ELAPSED (atv, btv);
2747         SGEN_LOG (2, "Fragment creation: %d usecs, %lu bytes available", TV_ELAPSED (atv, btv), (unsigned long)fragment_total);
2748
2749         if (consistency_check_at_minor_collection)
2750                 sgen_check_major_refs ();
2751
2752         major_collector.finish_nursery_collection ();
2753
2754         TV_GETTIME (all_btv);
2755         gc_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2756
2757         if (heap_dump_file)
2758                 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2759
2760         /* prepare the pin queue for the next collection */
2761         sgen_finish_pinning ();
2762         if (fin_ready_list || critical_fin_list) {
2763                 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
2764                 mono_gc_finalize_notify ();
2765         }
2766         sgen_pin_stats_reset ();
2767         /* clear cemented hash */
2768         sgen_cement_clear_below_threshold ();
2769
2770         g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2771
2772         if (remset.finish_minor_collection)
2773                 remset.finish_minor_collection ();
2774
2775         check_scan_starts ();
2776
2777         binary_protocol_flush_buffers (FALSE);
2778
2779         sgen_memgov_minor_collection_end ();
2780
2781         /*objects are late pinned because of lack of memory, so a major is a good call*/
2782         needs_major = objects_pinned > 0;
2783         current_collection_generation = -1;
2784         objects_pinned = 0;
2785
2786         MONO_GC_END (GENERATION_NURSERY);
2787         binary_protocol_collection_end (stat_minor_gcs - 1, GENERATION_NURSERY);
2788
2789         if (check_nursery_objects_pinned && !sgen_minor_collector.is_split)
2790                 sgen_check_nursery_objects_pinned (unpin_queue != NULL);
2791
2792         return needs_major;
2793 }
2794
2795 static void
2796 scan_nursery_objects_callback (char *obj, size_t size, ScanCopyContext *ctx)
2797 {
2798         ctx->scan_func (obj, ctx->queue);
2799 }
2800
2801 static void
2802 scan_nursery_objects (ScanCopyContext ctx)
2803 {
2804         sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
2805                         (IterateObjectCallbackFunc)scan_nursery_objects_callback, (void*)&ctx, FALSE);
2806 }
2807
2808 static void
2809 major_copy_or_mark_from_roots (int *old_next_pin_slot, gboolean finish_up_concurrent_mark, gboolean scan_mod_union)
2810 {
2811         LOSObject *bigobj;
2812         TV_DECLARE (atv);
2813         TV_DECLARE (btv);
2814         /* FIXME: only use these values for the precise scan
2815          * note that to_space pointers should be excluded anyway...
2816          */
2817         char *heap_start = NULL;
2818         char *heap_end = (char*)-1;
2819         gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2820         GCRootReport root_report = { 0 };
2821         ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2822         ScanThreadDataJobData *stdjd;
2823         ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2824         ScanCopyContext ctx;
2825
2826         if (major_collector.is_concurrent) {
2827                 /*This cleans up unused fragments */
2828                 sgen_nursery_allocator_prepare_for_pinning ();
2829
2830                 if (do_concurrent_checks)
2831                         check_nursery_is_clean ();
2832         } else {
2833                 /* The concurrent collector doesn't touch the nursery. */
2834                 sgen_nursery_alloc_prepare_for_major ();
2835         }
2836
2837         init_gray_queue ();
2838
2839         TV_GETTIME (atv);
2840
2841         /* Pinning depends on this */
2842         sgen_clear_nursery_fragments ();
2843
2844         if (whole_heap_check_before_collection)
2845                 sgen_check_whole_heap (finish_up_concurrent_mark);
2846
2847         if (!major_collector.is_concurrent)
2848                 sgen_cement_reset ();
2849
2850         TV_GETTIME (btv);
2851         time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2852
2853         if (!sgen_collection_is_concurrent ())
2854                 nursery_section->next_data = sgen_get_nursery_end ();
2855         /* we should also coalesce scanning from sections close to each other
2856          * and deal with pointers outside of the sections later.
2857          */
2858
2859         objects_pinned = 0;
2860         *major_collector.have_swept = FALSE;
2861
2862         if (xdomain_checks) {
2863                 sgen_clear_nursery_fragments ();
2864                 check_for_xdomain_refs ();
2865         }
2866
2867         if (!major_collector.is_concurrent) {
2868                 /* Remsets are not useful for a major collection */
2869                 remset.prepare_for_major_collection ();
2870         }
2871
2872         sgen_process_fin_stage_entries ();
2873         sgen_process_dislink_stage_entries ();
2874
2875         TV_GETTIME (atv);
2876         sgen_init_pinning ();
2877         SGEN_LOG (6, "Collecting pinned addresses");
2878         pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2879         sgen_optimize_pin_queue (0);
2880
2881         /*
2882          * The concurrent collector doesn't move objects, neither on
2883          * the major heap nor in the nursery, so we can mark even
2884          * before pinning has finished.  For the non-concurrent
2885          * collector we start the workers after pinning.
2886          */
2887         if (major_collector.is_concurrent) {
2888                 sgen_workers_start_all_workers ();
2889                 sgen_workers_start_marking ();
2890         }
2891
2892         /*
2893          * pin_queue now contains all candidate pointers, sorted and
2894          * uniqued.  We must do two passes now to figure out which
2895          * objects are pinned.
2896          *
2897          * The first is to find within the pin_queue the area for each
2898          * section.  This requires that the pin_queue be sorted.  We
2899          * also process the LOS objects and pinned chunks here.
2900          *
2901          * The second, destructive, pass is to reduce the section
2902          * areas to pointers to the actually pinned objects.
2903          */
2904         SGEN_LOG (6, "Pinning from sections");
2905         /* first pass for the sections */
2906         sgen_find_section_pin_queue_start_end (nursery_section);
2907         major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2908         /* identify possible pointers to the insize of large objects */
2909         SGEN_LOG (6, "Pinning from large objects");
2910         for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
2911                 int dummy;
2912                 if (sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + sgen_los_object_size (bigobj), &dummy)) {
2913                         binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (((MonoObject*)(bigobj->data))));
2914
2915 #ifdef ENABLE_DTRACE
2916                         if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
2917                                 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (bigobj->data);
2918                                 MONO_GC_OBJ_PINNED ((mword)bigobj->data, sgen_safe_object_get_size ((MonoObject*)bigobj->data), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
2919                         }
2920 #endif
2921
2922                         if (sgen_los_object_is_pinned (bigobj->data)) {
2923                                 g_assert (finish_up_concurrent_mark);
2924                                 continue;
2925                         }
2926                         sgen_los_pin_object (bigobj->data);
2927                         /* FIXME: only enqueue if object has references */
2928                         GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
2929                         if (G_UNLIKELY (do_pin_stats))
2930                                 sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
2931                         SGEN_LOG (6, "Marked large object %p (%s) size: %lu from roots", bigobj->data, safe_name (bigobj->data), (unsigned long)sgen_los_object_size (bigobj));
2932
2933                         if (profile_roots)
2934                                 add_profile_gc_root (&root_report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2935                 }
2936         }
2937         if (profile_roots)
2938                 notify_gc_roots (&root_report);
2939         /* second pass for the sections */
2940         ctx.scan_func = concurrent_collection_in_progress ? current_object_ops.scan_object : NULL;
2941         ctx.copy_func = NULL;
2942         ctx.queue = WORKERS_DISTRIBUTE_GRAY_QUEUE;
2943
2944         /*
2945          * Concurrent mark never follows references into the nursery.
2946          * In the start and finish pauses we must scan live nursery
2947          * objects, though.  We could simply scan all nursery objects,
2948          * but that would be conservative.  The easiest way is to do a
2949          * nursery collection, which copies all live nursery objects
2950          * (except pinned ones, with the simple nursery) to the major
2951          * heap.  Scanning the mod union table later will then scan
2952          * those promoted objects, provided they're reachable.  Pinned
2953          * objects in the nursery - which we can trivially find in the
2954          * pinning queue - are treated as roots in the mark pauses.
2955          *
2956          * The split nursery complicates the latter part because
2957          * non-pinned objects can survive in the nursery.  That's why
2958          * we need to do a full front-to-back scan of the nursery,
2959          * marking all objects.
2960          *
2961          * Non-concurrent mark evacuates from the nursery, so it's
2962          * sufficient to just scan pinned nursery objects.
2963          */
2964         if (major_collector.is_concurrent && sgen_minor_collector.is_split) {
2965                 scan_nursery_objects (ctx);
2966         } else {
2967                 sgen_pin_objects_in_section (nursery_section, ctx);
2968                 if (check_nursery_objects_pinned && !sgen_minor_collector.is_split)
2969                         sgen_check_nursery_objects_pinned (!concurrent_collection_in_progress || finish_up_concurrent_mark);
2970         }
2971
2972         major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2973         if (old_next_pin_slot)
2974                 *old_next_pin_slot = sgen_get_pinned_count ();
2975
2976         TV_GETTIME (btv);
2977         time_major_pinning += TV_ELAPSED (atv, btv);
2978         SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (atv, btv));
2979         SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2980
2981         major_collector.init_to_space ();
2982
2983 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2984         main_gc_thread = mono_native_thread_self ();
2985 #endif
2986
2987         if (!major_collector.is_concurrent) {
2988                 sgen_workers_start_all_workers ();
2989                 sgen_workers_start_marking ();
2990         }
2991
2992         if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2993                 report_registered_roots ();
2994         TV_GETTIME (atv);
2995         time_major_scan_pinned += TV_ELAPSED (btv, atv);
2996
2997         /* registered roots, this includes static fields */
2998         scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2999         scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
3000         scrrjd_normal->scan_func = current_object_ops.scan_object;
3001         scrrjd_normal->heap_start = heap_start;
3002         scrrjd_normal->heap_end = heap_end;
3003         scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
3004         sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
3005
3006         scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3007         scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
3008         scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
3009         scrrjd_wbarrier->heap_start = heap_start;
3010         scrrjd_wbarrier->heap_end = heap_end;
3011         scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
3012         sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
3013
3014         TV_GETTIME (btv);
3015         time_major_scan_registered_roots += TV_ELAPSED (atv, btv);
3016
3017         /* Threads */
3018         stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3019         stdjd->heap_start = heap_start;
3020         stdjd->heap_end = heap_end;
3021         sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
3022
3023         TV_GETTIME (atv);
3024         time_major_scan_thread_data += TV_ELAPSED (btv, atv);
3025
3026         TV_GETTIME (btv);
3027         time_major_scan_alloc_pinned += TV_ELAPSED (atv, btv);
3028
3029         if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
3030                 report_finalizer_roots ();
3031
3032         /* scan the list of objects ready for finalization */
3033         sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3034         sfejd_fin_ready->list = fin_ready_list;
3035         sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
3036
3037         sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3038         sfejd_critical_fin->list = critical_fin_list;
3039         sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
3040
3041         if (scan_mod_union) {
3042                 g_assert (finish_up_concurrent_mark);
3043
3044                 /* Mod union card table */
3045                 sgen_workers_enqueue_job (job_scan_major_mod_union_cardtable, NULL);
3046                 sgen_workers_enqueue_job (job_scan_los_mod_union_cardtable, NULL);
3047         }
3048
3049         TV_GETTIME (atv);
3050         time_major_scan_finalized += TV_ELAPSED (btv, atv);
3051         SGEN_LOG (2, "Root scan: %d usecs", TV_ELAPSED (btv, atv));
3052
3053         TV_GETTIME (btv);
3054         time_major_scan_big_objects += TV_ELAPSED (atv, btv);
3055
3056         if (major_collector.is_concurrent) {
3057                 /* prepare the pin queue for the next collection */
3058                 sgen_finish_pinning ();
3059
3060                 sgen_pin_stats_reset ();
3061
3062                 if (do_concurrent_checks)
3063                         check_nursery_is_clean ();
3064         }
3065 }
3066
3067 static void
3068 major_start_collection (int *old_next_pin_slot)
3069 {
3070         MONO_GC_BEGIN (GENERATION_OLD);
3071         binary_protocol_collection_begin (stat_major_gcs, GENERATION_OLD);
3072
3073         current_collection_generation = GENERATION_OLD;
3074 #ifndef DISABLE_PERFCOUNTERS
3075         mono_perfcounters->gc_collections1++;
3076 #endif
3077
3078         g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3079
3080         if (major_collector.is_concurrent) {
3081                 concurrent_collection_in_progress = TRUE;
3082
3083                 sgen_cement_concurrent_start ();
3084         }
3085
3086         current_object_ops = major_collector.major_ops;
3087
3088         reset_pinned_from_failed_allocation ();
3089
3090         sgen_memgov_major_collection_start ();
3091
3092         //count_ref_nonref_objs ();
3093         //consistency_check ();
3094
3095         check_scan_starts ();
3096
3097         degraded_mode = 0;
3098         SGEN_LOG (1, "Start major collection %d", stat_major_gcs);
3099         stat_major_gcs++;
3100         gc_stats.major_gc_count ++;
3101
3102         if (major_collector.start_major_collection)
3103                 major_collector.start_major_collection ();
3104
3105         major_copy_or_mark_from_roots (old_next_pin_slot, FALSE, FALSE);
3106 }
3107
3108 static void
3109 wait_for_workers_to_finish (void)
3110 {
3111         g_assert (sgen_gray_object_queue_is_empty (&remember_major_objects_gray_queue));
3112
3113         if (major_collector.is_parallel || major_collector.is_concurrent) {
3114                 gray_queue_redirect (&gray_queue);
3115                 sgen_workers_join ();
3116         }
3117
3118         g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3119
3120 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
3121         main_gc_thread = NULL;
3122 #endif
3123 }
3124
3125 static void
3126 major_finish_collection (const char *reason, int old_next_pin_slot, gboolean scan_mod_union)
3127 {
3128         LOSObject *bigobj, *prevbo;
3129         TV_DECLARE (atv);
3130         TV_DECLARE (btv);
3131         char *heap_start = NULL;
3132         char *heap_end = (char*)-1;
3133
3134         TV_GETTIME (btv);
3135
3136         if (major_collector.is_concurrent || major_collector.is_parallel)
3137                 wait_for_workers_to_finish ();
3138
3139         current_object_ops = major_collector.major_ops;
3140
3141         if (major_collector.is_concurrent) {
3142                 major_copy_or_mark_from_roots (NULL, TRUE, scan_mod_union);
3143                 wait_for_workers_to_finish ();
3144
3145                 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3146
3147                 if (do_concurrent_checks)
3148                         check_nursery_is_clean ();
3149         }
3150
3151         /*
3152          * The workers have stopped so we need to finish gray queue
3153          * work that might result from finalization in the main GC
3154          * thread.  Redirection must therefore be turned off.
3155          */
3156         sgen_gray_object_queue_disable_alloc_prepare (&gray_queue);
3157         g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3158
3159         /* all the objects in the heap */
3160         finish_gray_stack (heap_start, heap_end, GENERATION_OLD, &gray_queue);
3161         TV_GETTIME (atv);
3162         time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
3163
3164         /*
3165          * The (single-threaded) finalization code might have done
3166          * some copying/marking so we can only reset the GC thread's
3167          * worker data here instead of earlier when we joined the
3168          * workers.
3169          */
3170         sgen_workers_reset_data ();
3171
3172         if (objects_pinned) {
3173                 g_assert (!major_collector.is_concurrent);
3174
3175                 /*This is slow, but we just OOM'd*/
3176                 sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
3177                 sgen_optimize_pin_queue (0);
3178                 sgen_find_section_pin_queue_start_end (nursery_section);
3179                 objects_pinned = 0;
3180         }
3181
3182         reset_heap_boundaries ();
3183         sgen_update_heap_boundaries ((mword)sgen_get_nursery_start (), (mword)sgen_get_nursery_end ());
3184
3185         if (check_mark_bits_after_major_collection)
3186                 sgen_check_major_heap_marked ();
3187
3188         MONO_GC_SWEEP_BEGIN (GENERATION_OLD, !major_collector.sweeps_lazily);
3189
3190         /* sweep the big objects list */
3191         prevbo = NULL;
3192         for (bigobj = los_object_list; bigobj;) {
3193                 g_assert (!object_is_pinned (bigobj->data));
3194                 if (sgen_los_object_is_pinned (bigobj->data)) {
3195                         sgen_los_unpin_object (bigobj->data);
3196                         sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + sgen_los_object_size (bigobj));
3197                 } else {
3198                         LOSObject *to_free;
3199                         /* not referenced anywhere, so we can free it */
3200                         if (prevbo)
3201                                 prevbo->next = bigobj->next;
3202                         else
3203                                 los_object_list = bigobj->next;
3204                         to_free = bigobj;
3205                         bigobj = bigobj->next;
3206                         sgen_los_free_object (to_free);
3207                         continue;
3208                 }
3209                 prevbo = bigobj;
3210                 bigobj = bigobj->next;
3211         }
3212
3213         TV_GETTIME (btv);
3214         time_major_free_bigobjs += TV_ELAPSED (atv, btv);
3215
3216         sgen_los_sweep ();
3217
3218         TV_GETTIME (atv);
3219         time_major_los_sweep += TV_ELAPSED (btv, atv);
3220
3221         major_collector.sweep ();
3222
3223         MONO_GC_SWEEP_END (GENERATION_OLD, !major_collector.sweeps_lazily);
3224
3225         TV_GETTIME (btv);
3226         time_major_sweep += TV_ELAPSED (atv, btv);
3227
3228         if (!major_collector.is_concurrent) {
3229                 /* walk the pin_queue, build up the fragment list of free memory, unmark
3230                  * pinned objects as we go, memzero() the empty fragments so they are ready for the
3231                  * next allocations.
3232                  */
3233                 if (!sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries, NULL))
3234                         degraded_mode = 1;
3235
3236                 /* prepare the pin queue for the next collection */
3237                 sgen_finish_pinning ();
3238
3239                 /* Clear TLABs for all threads */
3240                 sgen_clear_tlabs ();
3241
3242                 sgen_pin_stats_reset ();
3243         }
3244
3245         if (major_collector.is_concurrent)
3246                 sgen_cement_concurrent_finish ();
3247         sgen_cement_clear_below_threshold ();
3248
3249         TV_GETTIME (atv);
3250         time_major_fragment_creation += TV_ELAPSED (btv, atv);
3251
3252         if (heap_dump_file)
3253                 dump_heap ("major", stat_major_gcs - 1, reason);
3254
3255         if (fin_ready_list || critical_fin_list) {
3256                 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
3257                 mono_gc_finalize_notify ();
3258         }
3259
3260         g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3261
3262         sgen_memgov_major_collection_end ();
3263         current_collection_generation = -1;
3264
3265         major_collector.finish_major_collection ();
3266
3267         g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3268
3269         if (major_collector.is_concurrent)
3270                 concurrent_collection_in_progress = FALSE;
3271
3272         check_scan_starts ();
3273
3274         binary_protocol_flush_buffers (FALSE);
3275
3276         //consistency_check ();
3277
3278         MONO_GC_END (GENERATION_OLD);
3279         binary_protocol_collection_end (stat_major_gcs - 1, GENERATION_OLD);
3280 }
3281
3282 static gboolean
3283 major_do_collection (const char *reason)
3284 {
3285         TV_DECLARE (all_atv);
3286         TV_DECLARE (all_btv);
3287         int old_next_pin_slot;
3288
3289         if (major_collector.get_and_reset_num_major_objects_marked) {
3290                 long long num_marked = major_collector.get_and_reset_num_major_objects_marked ();
3291                 g_assert (!num_marked);
3292         }
3293
3294         /* world must be stopped already */
3295         TV_GETTIME (all_atv);
3296
3297         major_start_collection (&old_next_pin_slot);
3298         major_finish_collection (reason, old_next_pin_slot, FALSE);
3299
3300         TV_GETTIME (all_btv);
3301         gc_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
3302
3303         /* FIXME: also report this to the user, preferably in gc-end. */
3304         if (major_collector.get_and_reset_num_major_objects_marked)
3305                 major_collector.get_and_reset_num_major_objects_marked ();
3306
3307         return bytes_pinned_from_failed_allocation > 0;
3308 }
3309
3310 static gboolean major_do_collection (const char *reason);
3311
3312 static void
3313 major_start_concurrent_collection (const char *reason)
3314 {
3315         long long num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
3316
3317         g_assert (num_objects_marked == 0);
3318
3319         MONO_GC_CONCURRENT_START_BEGIN (GENERATION_OLD);
3320
3321         // FIXME: store reason and pass it when finishing
3322         major_start_collection (NULL);
3323
3324         gray_queue_redirect (&gray_queue);
3325         sgen_workers_wait_for_jobs ();
3326
3327         num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
3328         MONO_GC_CONCURRENT_START_END (GENERATION_OLD, num_objects_marked);
3329
3330         current_collection_generation = -1;
3331 }
3332
3333 static gboolean
3334 major_update_or_finish_concurrent_collection (gboolean force_finish)
3335 {
3336         SgenGrayQueue unpin_queue;
3337         memset (&unpin_queue, 0, sizeof (unpin_queue));
3338
3339         MONO_GC_CONCURRENT_UPDATE_FINISH_BEGIN (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3340
3341         g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3342         if (!have_non_collection_major_object_remembers)
3343                 g_assert (sgen_gray_object_queue_is_empty (&remember_major_objects_gray_queue));
3344
3345         major_collector.update_cardtable_mod_union ();
3346         sgen_los_update_cardtable_mod_union ();
3347
3348         if (!force_finish && !sgen_workers_all_done ()) {
3349                 MONO_GC_CONCURRENT_UPDATE_END (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3350                 return FALSE;
3351         }
3352
3353         collect_nursery (&unpin_queue, TRUE);
3354         redirect_major_object_remembers ();
3355
3356         current_collection_generation = GENERATION_OLD;
3357         major_finish_collection ("finishing", -1, TRUE);
3358
3359         if (whole_heap_check_before_collection)
3360                 sgen_check_whole_heap (FALSE);
3361
3362         unpin_objects_from_queue (&unpin_queue);
3363         sgen_gray_object_queue_deinit (&unpin_queue);
3364
3365         MONO_GC_CONCURRENT_FINISH_END (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3366
3367         current_collection_generation = -1;
3368
3369         return TRUE;
3370 }
3371
3372 /*
3373  * Ensure an allocation request for @size will succeed by freeing enough memory.
3374  *
3375  * LOCKING: The GC lock MUST be held.
3376  */
3377 void
3378 sgen_ensure_free_space (size_t size)
3379 {
3380         int generation_to_collect = -1;
3381         const char *reason = NULL;
3382
3383
3384         if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
3385                 if (sgen_need_major_collection (size)) {
3386                         reason = "LOS overflow";
3387                         generation_to_collect = GENERATION_OLD;
3388                 }
3389         } else {
3390                 if (degraded_mode) {
3391                         if (sgen_need_major_collection (size)) {
3392                                 reason = "Degraded mode overflow";
3393                                 generation_to_collect = GENERATION_OLD;
3394                         }
3395                 } else if (sgen_need_major_collection (size)) {
3396                         reason = "Minor allowance";
3397                         generation_to_collect = GENERATION_OLD;
3398                 } else {
3399                         generation_to_collect = GENERATION_NURSERY;
3400                         reason = "Nursery full";
3401                 }
3402         }
3403
3404         if (generation_to_collect == -1) {
3405                 if (concurrent_collection_in_progress && sgen_workers_all_done ()) {
3406                         generation_to_collect = GENERATION_OLD;
3407                         reason = "Finish concurrent collection";
3408                 }
3409         }
3410
3411         if (generation_to_collect == -1)
3412                 return;
3413         sgen_perform_collection (size, generation_to_collect, reason, FALSE);
3414 }
3415
3416 void
3417 sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish)
3418 {
3419         TV_DECLARE (gc_end);
3420         GGTimingInfo infos [2];
3421         int overflow_generation_to_collect = -1;
3422         int oldest_generation_collected = generation_to_collect;
3423         const char *overflow_reason = NULL;
3424
3425         MONO_GC_REQUESTED (generation_to_collect, requested_size, wait_to_finish ? 1 : 0);
3426
3427         g_assert (generation_to_collect == GENERATION_NURSERY || generation_to_collect == GENERATION_OLD);
3428
3429         if (have_non_collection_major_object_remembers) {
3430                 g_assert (concurrent_collection_in_progress);
3431                 redirect_major_object_remembers ();
3432         }
3433
3434         memset (infos, 0, sizeof (infos));
3435         mono_profiler_gc_event (MONO_GC_EVENT_START, generation_to_collect);
3436
3437         infos [0].generation = generation_to_collect;
3438         infos [0].reason = reason;
3439         infos [0].is_overflow = FALSE;
3440         TV_GETTIME (infos [0].total_time);
3441         infos [1].generation = -1;
3442
3443         sgen_stop_world (generation_to_collect);
3444
3445         if (concurrent_collection_in_progress) {
3446                 if (major_update_or_finish_concurrent_collection (wait_to_finish && generation_to_collect == GENERATION_OLD)) {
3447                         oldest_generation_collected = GENERATION_OLD;
3448                         goto done;
3449                 }
3450                 if (generation_to_collect == GENERATION_OLD)
3451                         goto done;
3452         }
3453
3454         //FIXME extract overflow reason
3455         if (generation_to_collect == GENERATION_NURSERY) {
3456                 if (collect_nursery (NULL, FALSE)) {
3457                         overflow_generation_to_collect = GENERATION_OLD;
3458                         overflow_reason = "Minor overflow";
3459                 }
3460                 if (concurrent_collection_in_progress) {
3461                         redirect_major_object_remembers ();
3462                         sgen_workers_wake_up_all ();
3463                 }
3464         } else {
3465                 SgenGrayQueue unpin_queue;
3466                 SgenGrayQueue *unpin_queue_ptr;
3467                 memset (&unpin_queue, 0, sizeof (unpin_queue));
3468
3469                 if (major_collector.is_concurrent && wait_to_finish)
3470                         unpin_queue_ptr = &unpin_queue;
3471                 else
3472                         unpin_queue_ptr = NULL;
3473
3474                 if (major_collector.is_concurrent) {
3475                         g_assert (!concurrent_collection_in_progress);
3476                         collect_nursery (unpin_queue_ptr, FALSE);
3477                 }
3478
3479                 if (major_collector.is_concurrent && !wait_to_finish) {
3480                         major_start_concurrent_collection (reason);
3481                         // FIXME: set infos[0] properly
3482                         goto done;
3483                 } else {
3484                         if (major_do_collection (reason)) {
3485                                 overflow_generation_to_collect = GENERATION_NURSERY;
3486                                 overflow_reason = "Excessive pinning";
3487                         }
3488                 }
3489
3490                 if (unpin_queue_ptr) {
3491                         unpin_objects_from_queue (unpin_queue_ptr);
3492                         sgen_gray_object_queue_deinit (unpin_queue_ptr);
3493                 }
3494         }
3495
3496         TV_GETTIME (gc_end);
3497         infos [0].total_time = SGEN_TV_ELAPSED (infos [0].total_time, gc_end);
3498
3499
3500         if (!major_collector.is_concurrent && overflow_generation_to_collect != -1) {
3501                 mono_profiler_gc_event (MONO_GC_EVENT_START, overflow_generation_to_collect);
3502                 infos [1].generation = overflow_generation_to_collect;
3503                 infos [1].reason = overflow_reason;
3504                 infos [1].is_overflow = TRUE;
3505                 infos [1].total_time = gc_end;
3506
3507                 if (overflow_generation_to_collect == GENERATION_NURSERY)
3508                         collect_nursery (NULL, FALSE);
3509                 else
3510                         major_do_collection (overflow_reason);
3511
3512                 TV_GETTIME (gc_end);
3513                 infos [1].total_time = SGEN_TV_ELAPSED (infos [1].total_time, gc_end);
3514
3515                 /* keep events symmetric */
3516                 mono_profiler_gc_event (MONO_GC_EVENT_END, overflow_generation_to_collect);
3517
3518                 oldest_generation_collected = MAX (oldest_generation_collected, overflow_generation_to_collect);
3519         }
3520
3521         SGEN_LOG (2, "Heap size: %lu, LOS size: %lu", (unsigned long)mono_gc_get_heap_size (), (unsigned long)los_memory_usage);
3522
3523         /* this also sets the proper pointers for the next allocation */
3524         if (generation_to_collect == GENERATION_NURSERY && !sgen_can_alloc_size (requested_size)) {
3525                 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3526                 SGEN_LOG (1, "nursery collection didn't find enough room for %zd alloc (%d pinned)", requested_size, sgen_get_pinned_count ());
3527                 sgen_dump_pin_queue ();
3528                 degraded_mode = 1;
3529         }
3530
3531  done:
3532         g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3533         g_assert (sgen_gray_object_queue_is_empty (&remember_major_objects_gray_queue));
3534
3535         sgen_restart_world (oldest_generation_collected, infos);
3536
3537         mono_profiler_gc_event (MONO_GC_EVENT_END, generation_to_collect);
3538 }
3539
3540 /*
3541  * ######################################################################
3542  * ########  Memory allocation from the OS
3543  * ######################################################################
3544  * This section of code deals with getting memory from the OS and
3545  * allocating memory for GC-internal data structures.
3546  * Internal memory can be handled with a freelist for small objects.
3547  */
3548
3549 /*
3550  * Debug reporting.
3551  */
3552 G_GNUC_UNUSED static void
3553 report_internal_mem_usage (void)
3554 {
3555         printf ("Internal memory usage:\n");
3556         sgen_report_internal_mem_usage ();
3557         printf ("Pinned memory usage:\n");
3558         major_collector.report_pinned_memory_usage ();
3559 }
3560
3561 /*
3562  * ######################################################################
3563  * ########  Finalization support
3564  * ######################################################################
3565  */
3566
3567 static inline gboolean
3568 sgen_major_is_object_alive (void *object)
3569 {
3570         mword objsize;
3571
3572         /* Oldgen objects can be pinned and forwarded too */
3573         if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
3574                 return TRUE;
3575
3576         /*
3577          * FIXME: major_collector.is_object_live() also calculates the
3578          * size.  Avoid the double calculation.
3579          */
3580         objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)object));
3581         if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
3582                 return sgen_los_object_is_pinned (object);
3583
3584         return major_collector.is_object_live (object);
3585 }
3586
3587 /*
3588  * If the object has been forwarded it means it's still referenced from a root.
3589  * If it is pinned it's still alive as well.
3590  * A LOS object is only alive if we have pinned it.
3591  * Return TRUE if @obj is ready to be finalized.
3592  */
3593 static inline gboolean
3594 sgen_is_object_alive (void *object)
3595 {
3596         if (ptr_in_nursery (object))
3597                 return sgen_nursery_is_object_alive (object);
3598
3599         return sgen_major_is_object_alive (object);
3600 }
3601
3602 /*
3603  * This function returns true if @object is either alive or it belongs to the old gen
3604  * and we're currently doing a minor collection.
3605  */
3606 static inline int
3607 sgen_is_object_alive_for_current_gen (char *object)
3608 {
3609         if (ptr_in_nursery (object))
3610                 return sgen_nursery_is_object_alive (object);
3611
3612         if (current_collection_generation == GENERATION_NURSERY)
3613                 return TRUE;
3614
3615         return sgen_major_is_object_alive (object);
3616 }
3617
3618 /*
3619  * This function returns true if @object is either alive and belongs to the
3620  * current collection - major collections are full heap, so old gen objects
3621  * are never alive during a minor collection.
3622  */
3623 static inline int
3624 sgen_is_object_alive_and_on_current_collection (char *object)
3625 {
3626         if (ptr_in_nursery (object))
3627                 return sgen_nursery_is_object_alive (object);
3628
3629         if (current_collection_generation == GENERATION_NURSERY)
3630                 return FALSE;
3631
3632         return sgen_major_is_object_alive (object);
3633 }
3634
3635
3636 gboolean
3637 sgen_gc_is_object_ready_for_finalization (void *object)
3638 {
3639         return !sgen_is_object_alive (object);
3640 }
3641
3642 static gboolean
3643 has_critical_finalizer (MonoObject *obj)
3644 {
3645         MonoClass *class;
3646
3647         if (!mono_defaults.critical_finalizer_object)
3648                 return FALSE;
3649
3650         class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3651
3652         return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3653 }
3654
3655 void
3656 sgen_queue_finalization_entry (MonoObject *obj)
3657 {
3658         FinalizeReadyEntry *entry = sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3659         gboolean critical = has_critical_finalizer (obj);
3660         entry->object = obj;
3661         if (critical) {
3662                 entry->next = critical_fin_list;
3663                 critical_fin_list = entry;
3664         } else {
3665                 entry->next = fin_ready_list;
3666                 fin_ready_list = entry;
3667         }
3668
3669 #ifdef ENABLE_DTRACE
3670         if (G_UNLIKELY (MONO_GC_FINALIZE_ENQUEUE_ENABLED ())) {
3671                 int gen = sgen_ptr_in_nursery (obj) ? GENERATION_NURSERY : GENERATION_OLD;
3672                 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
3673                 MONO_GC_FINALIZE_ENQUEUE ((mword)obj, sgen_safe_object_get_size (obj),
3674                                 vt->klass->name_space, vt->klass->name, gen, critical);
3675         }
3676 #endif
3677 }
3678
3679 gboolean
3680 sgen_object_is_live (void *obj)
3681 {
3682         return sgen_is_object_alive_and_on_current_collection (obj);
3683 }
3684
3685 /* LOCKING: requires that the GC lock is held */
3686 static void
3687 null_ephemerons_for_domain (MonoDomain *domain)
3688 {
3689         EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3690
3691         while (current) {
3692                 MonoObject *object = (MonoObject*)current->array;
3693
3694                 if (object && !object->vtable) {
3695                         EphemeronLinkNode *tmp = current;
3696
3697                         if (prev)
3698                                 prev->next = current->next;
3699                         else
3700                                 ephemeron_list = current->next;
3701
3702                         current = current->next;
3703                         sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3704                 } else {
3705                         prev = current;
3706                         current = current->next;
3707                 }
3708         }
3709 }
3710
3711 /* LOCKING: requires that the GC lock is held */
3712 static void
3713 clear_unreachable_ephemerons (gboolean concurrent_cementing, ScanCopyContext ctx)
3714 {
3715         CopyOrMarkObjectFunc copy_func = ctx.copy_func;
3716         GrayQueue *queue = ctx.queue;
3717         EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3718         MonoArray *array;
3719         Ephemeron *cur, *array_end;
3720         char *tombstone;
3721
3722         while (current) {
3723                 char *object = current->array;
3724
3725                 if (!sgen_is_object_alive_for_current_gen (object)) {
3726                         EphemeronLinkNode *tmp = current;
3727
3728                         SGEN_LOG (5, "Dead Ephemeron array at %p", object);
3729
3730                         if (prev)
3731                                 prev->next = current->next;
3732                         else
3733                                 ephemeron_list = current->next;
3734
3735                         current = current->next;
3736                         sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3737
3738                         continue;
3739                 }
3740
3741                 copy_func ((void**)&object, queue);
3742                 current->array = object;
3743
3744                 SGEN_LOG (5, "Clearing unreachable entries for ephemeron array at %p", object);
3745
3746                 array = (MonoArray*)object;
3747                 cur = mono_array_addr (array, Ephemeron, 0);
3748                 array_end = cur + mono_array_length_fast (array);
3749                 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3750
3751                 for (; cur < array_end; ++cur) {
3752                         char *key = (char*)cur->key;
3753
3754                         if (!key || key == tombstone)
3755                                 continue;
3756
3757                         SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3758                                 key, sgen_is_object_alive_for_current_gen (key) ? "reachable" : "unreachable",
3759                                 cur->value, cur->value && sgen_is_object_alive_for_current_gen (cur->value) ? "reachable" : "unreachable");
3760
3761                         if (!sgen_is_object_alive_for_current_gen (key)) {
3762                                 cur->key = tombstone;
3763                                 cur->value = NULL;
3764                                 continue;
3765                         }
3766                 }
3767                 prev = current;
3768                 current = current->next;
3769         }
3770 }
3771
3772 /*
3773 LOCKING: requires that the GC lock is held
3774
3775 Limitations: We scan all ephemerons on every collection since the current design doesn't allow for a simple nursery/mature split.
3776 */
3777 static int
3778 mark_ephemerons_in_range (ScanCopyContext ctx)
3779 {
3780         CopyOrMarkObjectFunc copy_func = ctx.copy_func;
3781         GrayQueue *queue = ctx.queue;
3782         int nothing_marked = 1;
3783         EphemeronLinkNode *current = ephemeron_list;
3784         MonoArray *array;
3785         Ephemeron *cur, *array_end;
3786         char *tombstone;
3787
3788         for (current = ephemeron_list; current; current = current->next) {
3789                 char *object = current->array;
3790                 SGEN_LOG (5, "Ephemeron array at %p", object);
3791
3792                 /*It has to be alive*/
3793                 if (!sgen_is_object_alive_for_current_gen (object)) {
3794                         SGEN_LOG (5, "\tnot reachable");
3795                         continue;
3796                 }
3797
3798                 copy_func ((void**)&object, queue);
3799
3800                 array = (MonoArray*)object;
3801                 cur = mono_array_addr (array, Ephemeron, 0);
3802                 array_end = cur + mono_array_length_fast (array);
3803                 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3804
3805                 for (; cur < array_end; ++cur) {
3806                         char *key = cur->key;
3807
3808                         if (!key || key == tombstone)
3809                                 continue;
3810
3811                         SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3812                                 key, sgen_is_object_alive_for_current_gen (key) ? "reachable" : "unreachable",
3813                                 cur->value, cur->value && sgen_is_object_alive_for_current_gen (cur->value) ? "reachable" : "unreachable");
3814
3815                         if (sgen_is_object_alive_for_current_gen (key)) {
3816                                 char *value = cur->value;
3817
3818                                 copy_func ((void**)&cur->key, queue);
3819                                 if (value) {
3820                                         if (!sgen_is_object_alive_for_current_gen (value))
3821                                                 nothing_marked = 0;
3822                                         copy_func ((void**)&cur->value, queue);
3823                                 }
3824                         }
3825                 }
3826         }
3827
3828         SGEN_LOG (5, "Ephemeron run finished. Is it done %d", nothing_marked);
3829         return nothing_marked;
3830 }
3831
3832 int
3833 mono_gc_invoke_finalizers (void)
3834 {
3835         FinalizeReadyEntry *entry = NULL;
3836         gboolean entry_is_critical = FALSE;
3837         int count = 0;
3838         void *obj;
3839         /* FIXME: batch to reduce lock contention */
3840         while (fin_ready_list || critical_fin_list) {
3841                 LOCK_GC;
3842
3843                 if (entry) {
3844                         FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3845
3846                         /* We have finalized entry in the last
3847                            interation, now we need to remove it from
3848                            the list. */
3849                         if (*list == entry)
3850                                 *list = entry->next;
3851                         else {
3852                                 FinalizeReadyEntry *e = *list;
3853                                 while (e->next != entry)
3854                                         e = e->next;
3855                                 e->next = entry->next;
3856                         }
3857                         sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3858                         entry = NULL;
3859                 }
3860
3861                 /* Now look for the first non-null entry. */
3862                 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3863                         ;
3864                 if (entry) {
3865                         entry_is_critical = FALSE;
3866                 } else {
3867                         entry_is_critical = TRUE;
3868                         for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3869                                 ;
3870                 }
3871
3872                 if (entry) {
3873                         g_assert (entry->object);
3874                         num_ready_finalizers--;
3875                         obj = entry->object;
3876                         entry->object = NULL;
3877                         SGEN_LOG (7, "Finalizing object %p (%s)", obj, safe_name (obj));
3878                 }
3879
3880                 UNLOCK_GC;
3881
3882                 if (!entry)
3883                         break;
3884
3885                 g_assert (entry->object == NULL);
3886                 count++;
3887                 /* the object is on the stack so it is pinned */
3888                 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3889                 mono_gc_run_finalize (obj, NULL);
3890         }
3891         g_assert (!entry);
3892         return count;
3893 }
3894
3895 gboolean
3896 mono_gc_pending_finalizers (void)
3897 {
3898         return fin_ready_list || critical_fin_list;
3899 }
3900
3901 /*
3902  * ######################################################################
3903  * ########  registered roots support
3904  * ######################################################################
3905  */
3906
3907 /*
3908  * We do not coalesce roots.
3909  */
3910 static int
3911 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3912 {
3913         RootRecord new_root;
3914         int i;
3915         LOCK_GC;
3916         for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3917                 RootRecord *root = sgen_hash_table_lookup (&roots_hash [i], start);
3918                 /* we allow changing the size and the descriptor (for thread statics etc) */
3919                 if (root) {
3920                         size_t old_size = root->end_root - start;
3921                         root->end_root = start + size;
3922                         g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3923                                           ((root->root_desc == 0) && (descr == NULL)));
3924                         root->root_desc = (mword)descr;
3925                         roots_size += size;
3926                         roots_size -= old_size;
3927                         UNLOCK_GC;
3928                         return TRUE;
3929                 }
3930         }
3931
3932         new_root.end_root = start + size;
3933         new_root.root_desc = (mword)descr;
3934
3935         sgen_hash_table_replace (&roots_hash [root_type], start, &new_root, NULL);
3936         roots_size += size;
3937
3938         SGEN_LOG (3, "Added root for range: %p-%p, descr: %p  (%d/%d bytes)", start, new_root.end_root, descr, (int)size, (int)roots_size);
3939
3940         UNLOCK_GC;
3941         return TRUE;
3942 }
3943
3944 int
3945 mono_gc_register_root (char *start, size_t size, void *descr)
3946 {
3947         return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3948 }
3949
3950 int
3951 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3952 {
3953         return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3954 }
3955
3956 void
3957 mono_gc_deregister_root (char* addr)
3958 {
3959         int root_type;
3960         RootRecord root;
3961
3962         LOCK_GC;
3963         for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3964                 if (sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3965                         roots_size -= (root.end_root - addr);
3966         }
3967         UNLOCK_GC;
3968 }
3969
3970 /*
3971  * ######################################################################
3972  * ########  Thread handling (stop/start code)
3973  * ######################################################################
3974  */
3975
3976 unsigned int sgen_global_stop_count = 0;
3977
3978 void
3979 sgen_fill_thread_info_for_suspend (SgenThreadInfo *info)
3980 {
3981         if (remset.fill_thread_info_for_suspend)
3982                 remset.fill_thread_info_for_suspend (info);
3983 }
3984
3985 int
3986 sgen_get_current_collection_generation (void)
3987 {
3988         return current_collection_generation;
3989 }
3990
3991 void
3992 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
3993 {
3994         gc_callbacks = *callbacks;
3995 }
3996
3997 MonoGCCallbacks *
3998 mono_gc_get_gc_callbacks ()
3999 {
4000         return &gc_callbacks;
4001 }
4002
4003 /* Variables holding start/end nursery so it won't have to be passed at every call */
4004 static void *scan_area_arg_start, *scan_area_arg_end;
4005
4006 void
4007 mono_gc_conservatively_scan_area (void *start, void *end)
4008 {
4009         conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
4010 }
4011
4012 void*
4013 mono_gc_scan_object (void *obj)
4014 {
4015         UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
4016         current_object_ops.copy_or_mark_object (&obj, data->queue);
4017         return obj;
4018 }
4019
4020 /*
4021  * Mark from thread stacks and registers.
4022  */
4023 static void
4024 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
4025 {
4026         SgenThreadInfo *info;
4027
4028         scan_area_arg_start = start_nursery;
4029         scan_area_arg_end = end_nursery;
4030
4031         FOREACH_THREAD (info) {
4032                 if (info->skip) {
4033                         SGEN_LOG (3, "Skipping dead thread %p, range: %p-%p, size: %td", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start);
4034                         continue;
4035                 }
4036                 if (info->gc_disabled) {
4037                         SGEN_LOG (3, "GC disabled for thread %p, range: %p-%p, size: %td", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start);
4038                         continue;
4039                 }
4040
4041                 if (!info->joined_stw) {
4042                         SGEN_LOG (3, "Skipping thread not seen in STW %p, range: %p-%p, size: %td", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start);
4043                         continue;
4044                 }
4045
4046                 SGEN_LOG (3, "Scanning thread %p, range: %p-%p, size: %td, pinned=%d", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start, sgen_get_pinned_count ());
4047                 if (!info->thread_is_dying) {
4048                         if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
4049                                 UserCopyOrMarkData data = { NULL, queue };
4050                                 set_user_copy_or_mark_data (&data);
4051                                 gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
4052                                 set_user_copy_or_mark_data (NULL);
4053                         } else if (!precise) {
4054                                 if (!conservative_stack_mark) {
4055                                         fprintf (stderr, "Precise stack mark not supported - disabling.\n");
4056                                         conservative_stack_mark = TRUE;
4057                                 }
4058                                 conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
4059                         }
4060                 }
4061
4062                 if (!info->thread_is_dying && !precise) {
4063 #ifdef USE_MONO_CTX
4064                         conservatively_pin_objects_from ((void**)&info->ctx, (void**)&info->ctx + ARCH_NUM_REGS,
4065                                 start_nursery, end_nursery, PIN_TYPE_STACK);
4066 #else
4067                         conservatively_pin_objects_from (&info->regs, &info->regs + ARCH_NUM_REGS,
4068                                         start_nursery, end_nursery, PIN_TYPE_STACK);
4069 #endif
4070                 }
4071         } END_FOREACH_THREAD
4072 }
4073
4074 static gboolean
4075 ptr_on_stack (void *ptr)
4076 {
4077         gpointer stack_start = &stack_start;
4078         SgenThreadInfo *info = mono_thread_info_current ();
4079
4080         if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
4081                 return TRUE;
4082         return FALSE;
4083 }
4084
4085 static void*
4086 sgen_thread_register (SgenThreadInfo* info, void *addr)
4087 {
4088 #ifndef HAVE_KW_THREAD
4089         SgenThreadInfo *__thread_info__ = info;
4090 #endif
4091
4092         LOCK_GC;
4093 #ifndef HAVE_KW_THREAD
4094         info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
4095
4096         g_assert (!mono_native_tls_get_value (thread_info_key));
4097         mono_native_tls_set_value (thread_info_key, info);
4098 #else
4099         sgen_thread_info = info;
4100 #endif
4101
4102 #if !defined(__MACH__)
4103         info->stop_count = -1;
4104         info->signal = 0;
4105 #endif
4106         info->skip = 0;
4107         info->joined_stw = FALSE;
4108         info->doing_handshake = FALSE;
4109         info->thread_is_dying = FALSE;
4110         info->stack_start = NULL;
4111         info->store_remset_buffer_addr = &STORE_REMSET_BUFFER;
4112         info->store_remset_buffer_index_addr = &STORE_REMSET_BUFFER_INDEX;
4113         info->stopped_ip = NULL;
4114         info->stopped_domain = NULL;
4115 #ifdef USE_MONO_CTX
4116         memset (&info->ctx, 0, sizeof (MonoContext));
4117 #else
4118         memset (&info->regs, 0, sizeof (info->regs));
4119 #endif
4120
4121         sgen_init_tlab_info (info);
4122
4123         binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
4124
4125 #ifdef HAVE_KW_THREAD
4126         store_remset_buffer_index_addr = &store_remset_buffer_index;
4127 #endif
4128
4129         /* try to get it with attributes first */
4130 #if (defined(HAVE_PTHREAD_GETATTR_NP) || defined(HAVE_PTHREAD_ATTR_GET_NP)) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
4131   {
4132      size_t size;
4133      void *sstart;
4134      pthread_attr_t attr;
4135
4136 #if defined(HAVE_PTHREAD_GETATTR_NP)
4137     /* Linux */
4138     pthread_getattr_np (pthread_self (), &attr);
4139 #elif defined(HAVE_PTHREAD_ATTR_GET_NP)
4140     /* BSD */
4141     pthread_attr_init (&attr);
4142     pthread_attr_get_np (pthread_self (), &attr);
4143 #else
4144 #error Cannot determine which API is needed to retrieve pthread attributes.
4145 #endif
4146
4147      pthread_attr_getstack (&attr, &sstart, &size);
4148      info->stack_start_limit = sstart;
4149      info->stack_end = (char*)sstart + size;
4150      pthread_attr_destroy (&attr);
4151   }
4152 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
4153                  info->stack_end = (char*)pthread_get_stackaddr_np (pthread_self ());
4154                  info->stack_start_limit = (char*)info->stack_end - pthread_get_stacksize_np (pthread_self ());
4155 #else
4156         {
4157                 /* FIXME: we assume the stack grows down */
4158                 gsize stack_bottom = (gsize)addr;
4159                 stack_bottom += 4095;
4160                 stack_bottom &= ~4095;
4161                 info->stack_end = (char*)stack_bottom;
4162         }
4163 #endif
4164
4165 #ifdef HAVE_KW_THREAD
4166         stack_end = info->stack_end;
4167 #endif
4168
4169         if (remset.register_thread)
4170                 remset.register_thread (info);
4171
4172         SGEN_LOG (3, "registered thread %p (%p) stack end %p", info, (gpointer)mono_thread_info_get_tid (info), info->stack_end);
4173
4174         if (gc_callbacks.thread_attach_func)
4175                 info->runtime_data = gc_callbacks.thread_attach_func ();
4176
4177         UNLOCK_GC;
4178         return info;
4179 }
4180
4181 static void
4182 sgen_wbarrier_cleanup_thread (SgenThreadInfo *p)
4183 {
4184         if (remset.cleanup_thread)
4185                 remset.cleanup_thread (p);
4186 }
4187
4188 static void
4189 sgen_thread_unregister (SgenThreadInfo *p)
4190 {
4191         /* If a delegate is passed to native code and invoked on a thread we dont
4192          * know about, the jit will register it with mono_jit_thread_attach, but
4193          * we have no way of knowing when that thread goes away.  SGen has a TSD
4194          * so we assume that if the domain is still registered, we can detach
4195          * the thread
4196          */
4197         if (mono_domain_get ())
4198                 mono_thread_detach (mono_thread_current ());
4199
4200         p->thread_is_dying = TRUE;
4201
4202         /*
4203         There is a race condition between a thread finishing executing and been removed
4204         from the GC thread set.
4205         This happens on posix systems when TLS data is been cleaned-up, libpthread will
4206         set the thread_info slot to NULL before calling the cleanup function. This
4207         opens a window in which the thread is registered but has a NULL TLS.
4208
4209         The suspend signal handler needs TLS data to know where to store thread state
4210         data or otherwise it will simply ignore the thread.
4211
4212         This solution works because the thread doing STW will wait until all threads been
4213         suspended handshake back, so there is no race between the doing_hankshake test
4214         and the suspend_thread call.
4215
4216         This is not required on systems that do synchronous STW as those can deal with
4217         the above race at suspend time.
4218
4219         FIXME: I believe we could avoid this by using mono_thread_info_lookup when
4220         mono_thread_info_current returns NULL. Or fix mono_thread_info_lookup to do so.
4221         */
4222 #if (defined(__MACH__) && MONO_MACH_ARCH_SUPPORTED) || !defined(HAVE_PTHREAD_KILL)
4223         LOCK_GC;
4224 #else
4225         while (!TRYLOCK_GC) {
4226                 if (!sgen_park_current_thread_if_doing_handshake (p))
4227                         g_usleep (50);
4228         }
4229         MONO_GC_LOCKED ();
4230 #endif
4231
4232         binary_protocol_thread_unregister ((gpointer)mono_thread_info_get_tid (p));
4233         SGEN_LOG (3, "unregister thread %p (%p)", p, (gpointer)mono_thread_info_get_tid (p));
4234
4235         if (gc_callbacks.thread_detach_func) {
4236                 gc_callbacks.thread_detach_func (p->runtime_data);
4237                 p->runtime_data = NULL;
4238         }
4239         sgen_wbarrier_cleanup_thread (p);
4240
4241         mono_threads_unregister_current_thread (p);
4242         UNLOCK_GC;
4243 }
4244
4245
4246 static void
4247 sgen_thread_attach (SgenThreadInfo *info)
4248 {
4249         LOCK_GC;
4250         /*this is odd, can we get attached before the gc is inited?*/
4251         init_stats ();
4252         UNLOCK_GC;
4253
4254         if (gc_callbacks.thread_attach_func && !info->runtime_data)
4255                 info->runtime_data = gc_callbacks.thread_attach_func ();
4256 }
4257 gboolean
4258 mono_gc_register_thread (void *baseptr)
4259 {
4260         return mono_thread_info_attach (baseptr) != NULL;
4261 }
4262
4263 /*
4264  * mono_gc_set_stack_end:
4265  *
4266  *   Set the end of the current threads stack to STACK_END. The stack space between
4267  * STACK_END and the real end of the threads stack will not be scanned during collections.
4268  */
4269 void
4270 mono_gc_set_stack_end (void *stack_end)
4271 {
4272         SgenThreadInfo *info;
4273
4274         LOCK_GC;
4275         info = mono_thread_info_current ();
4276         if (info) {
4277                 g_assert (stack_end < info->stack_end);
4278                 info->stack_end = stack_end;
4279         }
4280         UNLOCK_GC;
4281 }
4282
4283 #if USE_PTHREAD_INTERCEPT
4284
4285
4286 int
4287 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
4288 {
4289         return pthread_create (new_thread, attr, start_routine, arg);
4290 }
4291
4292 int
4293 mono_gc_pthread_join (pthread_t thread, void **retval)
4294 {
4295         return pthread_join (thread, retval);
4296 }
4297
4298 int
4299 mono_gc_pthread_detach (pthread_t thread)
4300 {
4301         return pthread_detach (thread);
4302 }
4303
4304 void
4305 mono_gc_pthread_exit (void *retval)
4306 {
4307         pthread_exit (retval);
4308 }
4309
4310 #endif /* USE_PTHREAD_INTERCEPT */
4311
4312 /*
4313  * ######################################################################
4314  * ########  Write barriers
4315  * ######################################################################
4316  */
4317
4318 /*
4319  * Note: the write barriers first do the needed GC work and then do the actual store:
4320  * this way the value is visible to the conservative GC scan after the write barrier
4321  * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
4322  * the conservative scan, otherwise by the remembered set scan.
4323  */
4324 void
4325 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
4326 {
4327         HEAVY_STAT (++stat_wbarrier_set_field);
4328         if (ptr_in_nursery (field_ptr)) {
4329                 *(void**)field_ptr = value;
4330                 return;
4331         }
4332         SGEN_LOG (8, "Adding remset at %p", field_ptr);
4333         if (value)
4334                 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4335
4336         remset.wbarrier_set_field (obj, field_ptr, value);
4337 }
4338
4339 void
4340 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4341 {
4342         HEAVY_STAT (++stat_wbarrier_set_arrayref);
4343         if (ptr_in_nursery (slot_ptr)) {
4344                 *(void**)slot_ptr = value;
4345                 return;
4346         }
4347         SGEN_LOG (8, "Adding remset at %p", slot_ptr);
4348         if (value)
4349                 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4350
4351         remset.wbarrier_set_arrayref (arr, slot_ptr, value);
4352 }
4353
4354 void
4355 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4356 {
4357         HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4358         /*This check can be done without taking a lock since dest_ptr array is pinned*/
4359         if (ptr_in_nursery (dest_ptr) || count <= 0) {
4360                 mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
4361                 return;
4362         }
4363
4364 #ifdef SGEN_BINARY_PROTOCOL
4365         {
4366                 int i;
4367                 for (i = 0; i < count; ++i) {
4368                         gpointer dest = (gpointer*)dest_ptr + i;
4369                         gpointer obj = *((gpointer*)src_ptr + i);
4370                         if (obj)
4371                                 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4372                 }
4373         }
4374 #endif
4375
4376         remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4377 }
4378
4379 static char *found_obj;
4380
4381 static void
4382 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4383 {
4384         char *ptr = user_data;
4385
4386         if (ptr >= obj && ptr < obj + size) {
4387                 g_assert (!found_obj);
4388                 found_obj = obj;
4389         }
4390 }
4391
4392 /* for use in the debugger */
4393 char* find_object_for_ptr (char *ptr);
4394 char*
4395 find_object_for_ptr (char *ptr)
4396 {
4397         if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4398                 found_obj = NULL;
4399                 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4400                                 find_object_for_ptr_callback, ptr, TRUE);
4401                 if (found_obj)
4402                         return found_obj;
4403         }
4404
4405         found_obj = NULL;
4406         sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4407         if (found_obj)
4408                 return found_obj;
4409
4410         /*
4411          * Very inefficient, but this is debugging code, supposed to
4412          * be called from gdb, so we don't care.
4413          */
4414         found_obj = NULL;
4415         major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4416         return found_obj;
4417 }
4418
4419 void
4420 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4421 {
4422         gpointer obj;
4423
4424         HEAVY_STAT (++stat_wbarrier_generic_store);
4425
4426 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4427         /* FIXME: ptr_in_heap must be called with the GC lock held */
4428         if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4429                 char *start = find_object_for_ptr (ptr);
4430                 MonoObject *value = *(MonoObject**)ptr;
4431                 LOCK_GC;
4432                 g_assert (start);
4433                 if (start) {
4434                         MonoObject *obj = (MonoObject*)start;
4435                         if (obj->vtable->domain != value->vtable->domain)
4436                                 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4437                 }
4438                 UNLOCK_GC;
4439         }
4440 #endif
4441
4442         obj = *(gpointer*)ptr;
4443         if (obj)
4444                 binary_protocol_wbarrier (ptr, obj, (gpointer)LOAD_VTABLE (obj));
4445
4446         if (ptr_in_nursery (ptr) || ptr_on_stack (ptr)) {
4447                 SGEN_LOG (8, "Skipping remset at %p", ptr);
4448                 return;
4449         }
4450
4451         /*
4452          * We need to record old->old pointer locations for the
4453          * concurrent collector.
4454          */
4455         if (!ptr_in_nursery (obj) && !concurrent_collection_in_progress) {
4456                 SGEN_LOG (8, "Skipping remset at %p", ptr);
4457                 return;
4458         }
4459
4460         SGEN_LOG (8, "Adding remset at %p", ptr);
4461
4462         remset.wbarrier_generic_nostore (ptr);
4463 }
4464
4465 void
4466 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4467 {
4468         SGEN_LOG (8, "Wbarrier store at %p to %p (%s)", ptr, value, value ? safe_name (value) : "null");
4469         *(void**)ptr = value;
4470         if (ptr_in_nursery (value))
4471                 mono_gc_wbarrier_generic_nostore (ptr);
4472         sgen_dummy_use (value);
4473 }
4474
4475 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4476 {
4477         mword *dest = _dest;
4478         mword *src = _src;
4479
4480         while (size) {
4481                 if (bitmap & 0x1)
4482                         mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4483                 else
4484                         *dest = *src;
4485                 ++src;
4486                 ++dest;
4487                 size -= SIZEOF_VOID_P;
4488                 bitmap >>= 1;
4489         }
4490 }
4491
4492 #ifdef SGEN_BINARY_PROTOCOL
4493 #undef HANDLE_PTR
4494 #define HANDLE_PTR(ptr,obj) do {                                        \
4495                 gpointer o = *(gpointer*)(ptr);                         \
4496                 if ((o)) {                                              \
4497                         gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4498                         binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4499                 }                                                       \
4500         } while (0)
4501
4502 static void
4503 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4504 {
4505 #define SCAN_OBJECT_NOVTABLE
4506 #include "sgen-scan-object.h"
4507 }
4508 #endif
4509
4510 void
4511 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4512 {
4513         HEAVY_STAT (++stat_wbarrier_value_copy);
4514         g_assert (klass->valuetype);
4515
4516         SGEN_LOG (8, "Adding value remset at %p, count %d, descr %p for class %s (%p)", dest, count, klass->gc_descr, klass->name, klass);
4517
4518         if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4519                 size_t element_size = mono_class_value_size (klass, NULL);
4520                 size_t size = count * element_size;
4521                 mono_gc_memmove (dest, src, size);
4522                 return;
4523         }
4524
4525 #ifdef SGEN_BINARY_PROTOCOL
4526         {
4527                 size_t element_size = mono_class_value_size (klass, NULL);
4528                 int i;
4529                 for (i = 0; i < count; ++i) {
4530                         scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4531                                         (char*)src + i * element_size - sizeof (MonoObject),
4532                                         (mword) klass->gc_descr);
4533                 }
4534         }
4535 #endif
4536
4537         remset.wbarrier_value_copy (dest, src, count, klass);
4538 }
4539
4540 /**
4541  * mono_gc_wbarrier_object_copy:
4542  *
4543  * Write barrier to call when obj is the result of a clone or copy of an object.
4544  */
4545 void
4546 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4547 {
4548         int size;
4549
4550         HEAVY_STAT (++stat_wbarrier_object_copy);
4551
4552         if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4553                 size = mono_object_class (obj)->instance_size;
4554                 mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4555                                 size - sizeof (MonoObject));
4556                 return;
4557         }
4558
4559 #ifdef SGEN_BINARY_PROTOCOL
4560         scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4561 #endif
4562
4563         remset.wbarrier_object_copy (obj, src);
4564 }
4565
4566
4567 /*
4568  * ######################################################################
4569  * ########  Other mono public interface functions.
4570  * ######################################################################
4571  */
4572
4573 #define REFS_SIZE 128
4574 typedef struct {
4575         void *data;
4576         MonoGCReferences callback;
4577         int flags;
4578         int count;
4579         int called;
4580         MonoObject *refs [REFS_SIZE];
4581         uintptr_t offsets [REFS_SIZE];
4582 } HeapWalkInfo;
4583
4584 #undef HANDLE_PTR
4585 #define HANDLE_PTR(ptr,obj)     do {    \
4586                 if (*(ptr)) {   \
4587                         if (hwi->count == REFS_SIZE) {  \
4588                                 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);    \
4589                                 hwi->count = 0; \
4590                                 hwi->called = 1;        \
4591                         }       \
4592                         hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start;  \
4593                         hwi->refs [hwi->count++] = *(ptr);      \
4594                 }       \
4595         } while (0)
4596
4597 static void
4598 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4599 {
4600 #include "sgen-scan-object.h"
4601 }
4602
4603 static void
4604 walk_references (char *start, size_t size, void *data)
4605 {
4606         HeapWalkInfo *hwi = data;
4607         hwi->called = 0;
4608         hwi->count = 0;
4609         collect_references (hwi, start, size);
4610         if (hwi->count || !hwi->called)
4611                 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4612 }
4613
4614 /**
4615  * mono_gc_walk_heap:
4616  * @flags: flags for future use
4617  * @callback: a function pointer called for each object in the heap
4618  * @data: a user data pointer that is passed to callback
4619  *
4620  * This function can be used to iterate over all the live objects in the heap:
4621  * for each object, @callback is invoked, providing info about the object's
4622  * location in memory, its class, its size and the objects it references.
4623  * For each referenced object it's offset from the object address is
4624  * reported in the offsets array.
4625  * The object references may be buffered, so the callback may be invoked
4626  * multiple times for the same object: in all but the first call, the size
4627  * argument will be zero.
4628  * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4629  * profiler event handler.
4630  *
4631  * Returns: a non-zero value if the GC doesn't support heap walking
4632  */
4633 int
4634 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4635 {
4636         HeapWalkInfo hwi;
4637
4638         hwi.flags = flags;
4639         hwi.callback = callback;
4640         hwi.data = data;
4641
4642         sgen_clear_nursery_fragments ();
4643         sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4644
4645         major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4646         sgen_los_iterate_objects (walk_references, &hwi);
4647
4648         return 0;
4649 }
4650
4651 void
4652 mono_gc_collect (int generation)
4653 {
4654         LOCK_GC;
4655         if (generation > 1)
4656                 generation = 1;
4657         sgen_perform_collection (0, generation, "user request", TRUE);
4658         UNLOCK_GC;
4659 }
4660
4661 int
4662 mono_gc_max_generation (void)
4663 {
4664         return 1;
4665 }
4666
4667 int
4668 mono_gc_collection_count (int generation)
4669 {
4670         if (generation == 0)
4671                 return stat_minor_gcs;
4672         return stat_major_gcs;
4673 }
4674
4675 int64_t
4676 mono_gc_get_used_size (void)
4677 {
4678         gint64 tot = 0;
4679         LOCK_GC;
4680         tot = los_memory_usage;
4681         tot += nursery_section->next_data - nursery_section->data;
4682         tot += major_collector.get_used_size ();
4683         /* FIXME: account for pinned objects */
4684         UNLOCK_GC;
4685         return tot;
4686 }
4687
4688 void
4689 mono_gc_disable (void)
4690 {
4691         LOCK_GC;
4692         gc_disabled++;
4693         UNLOCK_GC;
4694 }
4695
4696 void
4697 mono_gc_enable (void)
4698 {
4699         LOCK_GC;
4700         gc_disabled--;
4701         UNLOCK_GC;
4702 }
4703
4704 int
4705 mono_gc_get_los_limit (void)
4706 {
4707         return MAX_SMALL_OBJ_SIZE;
4708 }
4709
4710 gboolean
4711 mono_gc_user_markers_supported (void)
4712 {
4713         return TRUE;
4714 }
4715
4716 gboolean
4717 mono_object_is_alive (MonoObject* o)
4718 {
4719         return TRUE;
4720 }
4721
4722 int
4723 mono_gc_get_generation (MonoObject *obj)
4724 {
4725         if (ptr_in_nursery (obj))
4726                 return 0;
4727         return 1;
4728 }
4729
4730 void
4731 mono_gc_enable_events (void)
4732 {
4733 }
4734
4735 void
4736 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4737 {
4738         sgen_register_disappearing_link (obj, link_addr, track, FALSE);
4739 }
4740
4741 void
4742 mono_gc_weak_link_remove (void **link_addr, gboolean track)
4743 {
4744         sgen_register_disappearing_link (NULL, link_addr, track, FALSE);
4745 }
4746
4747 MonoObject*
4748 mono_gc_weak_link_get (void **link_addr)
4749 {
4750         /*
4751          * We must only load *link_addr once because it might change
4752          * under our feet, and REVEAL_POINTER (NULL) results in an
4753          * invalid reference.
4754          */
4755         void *ptr = *link_addr;
4756         if (!ptr)
4757                 return NULL;
4758
4759         /*
4760          * During the second bridge processing step the world is
4761          * running again.  That step processes all weak links once
4762          * more to null those that refer to dead objects.  Before that
4763          * is completed, those links must not be followed, so we
4764          * conservatively wait for bridge processing when any weak
4765          * link is dereferenced.
4766          */
4767         if (G_UNLIKELY (bridge_processing_in_progress))
4768                 mono_gc_wait_for_bridge_processing ();
4769
4770         return (MonoObject*) REVEAL_POINTER (ptr);
4771 }
4772
4773 gboolean
4774 mono_gc_ephemeron_array_add (MonoObject *obj)
4775 {
4776         EphemeronLinkNode *node;
4777
4778         LOCK_GC;
4779
4780         node = sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4781         if (!node) {
4782                 UNLOCK_GC;
4783                 return FALSE;
4784         }
4785         node->array = (char*)obj;
4786         node->next = ephemeron_list;
4787         ephemeron_list = node;
4788
4789         SGEN_LOG (5, "Registered ephemeron array %p", obj);
4790
4791         UNLOCK_GC;
4792         return TRUE;
4793 }
4794
4795 void*
4796 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4797 {
4798         void *result;
4799         LOCK_INTERRUPTION;
4800         result = func (data);
4801         UNLOCK_INTERRUPTION;
4802         return result;
4803 }
4804
4805 gboolean
4806 mono_gc_is_gc_thread (void)
4807 {
4808         gboolean result;
4809         LOCK_GC;
4810         result = mono_thread_info_current () != NULL;
4811         UNLOCK_GC;
4812         return result;
4813 }
4814
4815 static gboolean
4816 is_critical_method (MonoMethod *method)
4817 {
4818         return mono_runtime_is_critical_method (method) || sgen_is_critical_method (method);
4819 }
4820
4821 void
4822 mono_gc_base_init (void)
4823 {
4824         MonoThreadInfoCallbacks cb;
4825         char *env;
4826         char **opts, **ptr;
4827         char *major_collector_opt = NULL;
4828         char *minor_collector_opt = NULL;
4829         glong max_heap = 0;
4830         glong soft_limit = 0;
4831         int num_workers;
4832         int result;
4833         int dummy;
4834         gboolean debug_print_allowance = FALSE;
4835         double allowance_ratio = 0, save_target = 0;
4836         gboolean have_split_nursery = FALSE;
4837         gboolean cement_enabled = TRUE;
4838
4839         do {
4840                 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4841                 switch (result) {
4842                 case 1:
4843                         /* already inited */
4844                         return;
4845                 case -1:
4846                         /* being inited by another thread */
4847                         g_usleep (1000);
4848                         break;
4849                 case 0:
4850                         /* we will init it */
4851                         break;
4852                 default:
4853                         g_assert_not_reached ();
4854                 }
4855         } while (result != 0);
4856
4857         LOCK_INIT (gc_mutex);
4858
4859         pagesize = mono_pagesize ();
4860         gc_debug_file = stderr;
4861
4862         cb.thread_register = sgen_thread_register;
4863         cb.thread_unregister = sgen_thread_unregister;
4864         cb.thread_attach = sgen_thread_attach;
4865         cb.mono_method_is_critical = (gpointer)is_critical_method;
4866 #ifndef HOST_WIN32
4867         cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4868 #endif
4869
4870         mono_threads_init (&cb, sizeof (SgenThreadInfo));
4871
4872         LOCK_INIT (sgen_interruption_mutex);
4873         LOCK_INIT (pin_queue_mutex);
4874
4875         init_user_copy_or_mark_key ();
4876
4877         if ((env = getenv ("MONO_GC_PARAMS"))) {
4878                 opts = g_strsplit (env, ",", -1);
4879                 for (ptr = opts; *ptr; ++ptr) {
4880                         char *opt = *ptr;
4881                         if (g_str_has_prefix (opt, "major=")) {
4882                                 opt = strchr (opt, '=') + 1;
4883                                 major_collector_opt = g_strdup (opt);
4884                         } else if (g_str_has_prefix (opt, "minor=")) {
4885                                 opt = strchr (opt, '=') + 1;
4886                                 minor_collector_opt = g_strdup (opt);
4887                         }
4888                 }
4889         } else {
4890                 opts = NULL;
4891         }
4892
4893         init_stats ();
4894         sgen_init_internal_allocator ();
4895         sgen_init_nursery_allocator ();
4896
4897         sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4898         sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4899         sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4900         g_assert (sizeof (GenericStoreRememberedSet) == sizeof (gpointer) * STORE_REMSET_BUFFER_SIZE);
4901         sgen_register_fixed_internal_mem_type (INTERNAL_MEM_STORE_REMSET, sizeof (GenericStoreRememberedSet));
4902         sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4903
4904 #ifndef HAVE_KW_THREAD
4905         mono_native_tls_alloc (&thread_info_key, NULL);
4906 #endif
4907
4908         /*
4909          * This needs to happen before any internal allocations because
4910          * it inits the small id which is required for hazard pointer
4911          * operations.
4912          */
4913         sgen_os_init ();
4914
4915         mono_thread_info_attach (&dummy);
4916
4917         if (!minor_collector_opt) {
4918                 sgen_simple_nursery_init (&sgen_minor_collector);
4919         } else {
4920                 if (!strcmp (minor_collector_opt, "simple")) {
4921                         sgen_simple_nursery_init (&sgen_minor_collector);
4922                 } else if (!strcmp (minor_collector_opt, "split")) {
4923                         sgen_split_nursery_init (&sgen_minor_collector);
4924                         have_split_nursery = TRUE;
4925                 } else {
4926                         fprintf (stderr, "Unknown minor collector `%s'.\n", minor_collector_opt);
4927                         exit (1);
4928                 }
4929         }
4930
4931         if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4932                 sgen_marksweep_init (&major_collector);
4933         } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4934                 sgen_marksweep_fixed_init (&major_collector);
4935         } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4936                 sgen_marksweep_par_init (&major_collector);
4937         } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4938                 sgen_marksweep_fixed_par_init (&major_collector);
4939         } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-conc")) {
4940                 sgen_marksweep_conc_init (&major_collector);
4941         } else {
4942                 fprintf (stderr, "Unknown major collector `%s'.\n", major_collector_opt);
4943                 exit (1);
4944         }
4945
4946 #ifdef SGEN_HAVE_CARDTABLE
4947         use_cardtable = major_collector.supports_cardtable;
4948 #else
4949         use_cardtable = FALSE;
4950 #endif
4951
4952         num_workers = mono_cpu_count ();
4953         g_assert (num_workers > 0);
4954         if (num_workers > 16)
4955                 num_workers = 16;
4956
4957         ///* Keep this the default for now */
4958         /* Precise marking is broken on all supported targets. Disable until fixed. */
4959         conservative_stack_mark = TRUE;
4960
4961         sgen_nursery_size = DEFAULT_NURSERY_SIZE;
4962
4963         if (opts) {
4964                 for (ptr = opts; *ptr; ++ptr) {
4965                         char *opt = *ptr;
4966                         if (g_str_has_prefix (opt, "major="))
4967                                 continue;
4968                         if (g_str_has_prefix (opt, "minor="))
4969                                 continue;
4970                         if (g_str_has_prefix (opt, "wbarrier=")) {
4971                                 opt = strchr (opt, '=') + 1;
4972                                 if (strcmp (opt, "remset") == 0) {
4973                                         if (major_collector.is_concurrent) {
4974                                                 fprintf (stderr, "The concurrent collector does not support the SSB write barrier.\n");
4975                                                 exit (1);
4976                                         }
4977                                         use_cardtable = FALSE;
4978                                 } else if (strcmp (opt, "cardtable") == 0) {
4979                                         if (!use_cardtable) {
4980                                                 if (major_collector.supports_cardtable)
4981                                                         fprintf (stderr, "The cardtable write barrier is not supported on this platform.\n");
4982                                                 else
4983                                                         fprintf (stderr, "The major collector does not support the cardtable write barrier.\n");
4984                                                 exit (1);
4985                                         }
4986                                 } else {
4987                                         fprintf (stderr, "wbarrier must either be `remset' or `cardtable'.");
4988                                         exit (1);
4989                                 }
4990                                 continue;
4991                         }
4992                         if (g_str_has_prefix (opt, "max-heap-size=")) {
4993                                 opt = strchr (opt, '=') + 1;
4994                                 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
4995                                         if ((max_heap & (mono_pagesize () - 1))) {
4996                                                 fprintf (stderr, "max-heap-size size must be a multiple of %d.\n", mono_pagesize ());
4997                                                 exit (1);
4998                                         }
4999                                 } else {
5000                                         fprintf (stderr, "max-heap-size must be an integer.\n");
5001                                         exit (1);
5002                                 }
5003                                 continue;
5004                         }
5005                         if (g_str_has_prefix (opt, "soft-heap-limit=")) {
5006                                 opt = strchr (opt, '=') + 1;
5007                                 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
5008                                         if (soft_limit <= 0) {
5009                                                 fprintf (stderr, "soft-heap-limit must be positive.\n");
5010                                                 exit (1);
5011                                         }
5012                                 } else {
5013                                         fprintf (stderr, "soft-heap-limit must be an integer.\n");
5014                                         exit (1);
5015                                 }
5016                                 continue;
5017                         }
5018                         if (g_str_has_prefix (opt, "workers=")) {
5019                                 long val;
5020                                 char *endptr;
5021                                 if (!major_collector.is_parallel) {
5022                                         fprintf (stderr, "The workers= option can only be used for parallel collectors.");
5023                                         exit (1);
5024                                 }
5025                                 opt = strchr (opt, '=') + 1;
5026                                 val = strtol (opt, &endptr, 10);
5027                                 if (!*opt || *endptr) {
5028                                         fprintf (stderr, "Cannot parse the workers= option value.");
5029                                         exit (1);
5030                                 }
5031                                 if (val <= 0 || val > 16) {
5032                                         fprintf (stderr, "The number of workers must be in the range 1 to 16.");
5033                                         exit (1);
5034                                 }
5035                                 num_workers = (int)val;
5036                                 continue;
5037                         }
5038                         if (g_str_has_prefix (opt, "stack-mark=")) {
5039                                 opt = strchr (opt, '=') + 1;
5040                                 if (!strcmp (opt, "precise")) {
5041                                         conservative_stack_mark = FALSE;
5042                                 } else if (!strcmp (opt, "conservative")) {
5043                                         conservative_stack_mark = TRUE;
5044                                 } else {
5045                                         fprintf (stderr, "Invalid value '%s' for stack-mark= option, possible values are: 'precise', 'conservative'.\n", opt);
5046                                         exit (1);
5047                                 }
5048                                 continue;
5049                         }
5050                         if (g_str_has_prefix (opt, "bridge=")) {
5051                                 opt = strchr (opt, '=') + 1;
5052                                 sgen_register_test_bridge_callbacks (g_strdup (opt));
5053                                 continue;
5054                         }
5055 #ifdef USER_CONFIG
5056                         if (g_str_has_prefix (opt, "nursery-size=")) {
5057                                 long val;
5058                                 opt = strchr (opt, '=') + 1;
5059                                 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
5060                                         sgen_nursery_size = val;
5061 #ifdef SGEN_ALIGN_NURSERY
5062                                         if ((val & (val - 1))) {
5063                                                 fprintf (stderr, "The nursery size must be a power of two.\n");
5064                                                 exit (1);
5065                                         }
5066
5067                                         if (val < SGEN_MAX_NURSERY_WASTE) {
5068                                                 fprintf (stderr, "The nursery size must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
5069                                                 exit (1);
5070                                         }
5071
5072                                         sgen_nursery_bits = 0;
5073                                         while (1 << (++ sgen_nursery_bits) != sgen_nursery_size)
5074                                                 ;
5075 #endif
5076                                 } else {
5077                                         fprintf (stderr, "nursery-size must be an integer.\n");
5078                                         exit (1);
5079                                 }
5080                                 continue;
5081                         }
5082 #endif
5083                         if (g_str_has_prefix (opt, "save-target-ratio=")) {
5084                                 char *endptr;
5085                                 opt = strchr (opt, '=') + 1;
5086                                 save_target = strtod (opt, &endptr);
5087                                 if (endptr == opt) {
5088                                         fprintf (stderr, "save-target-ratio must be a number.");
5089                                         exit (1);
5090                                 }
5091                                 if (save_target < SGEN_MIN_SAVE_TARGET_RATIO || save_target > SGEN_MAX_SAVE_TARGET_RATIO) {
5092                                         fprintf (stderr, "save-target-ratio must be between %.2f - %.2f.", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
5093                                         exit (1);
5094                                 }
5095                                 continue;
5096                         }
5097                         if (g_str_has_prefix (opt, "default-allowance-ratio=")) {
5098                                 char *endptr;
5099                                 opt = strchr (opt, '=') + 1;
5100
5101                                 allowance_ratio = strtod (opt, &endptr);
5102                                 if (endptr == opt) {
5103                                         fprintf (stderr, "save-target-ratio must be a number.");
5104                                         exit (1);
5105                                 }
5106                                 if (allowance_ratio < SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO || allowance_ratio > SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO) {
5107                                         fprintf (stderr, "default-allowance-ratio must be between %.2f - %.2f.", SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO);
5108                                         exit (1);
5109                                 }
5110                                 continue;
5111                         }
5112
5113                         if (!strcmp (opt, "cementing")) {
5114                                 cement_enabled = TRUE;
5115                                 continue;
5116                         }
5117                         if (!strcmp (opt, "no-cementing")) {
5118                                 cement_enabled = FALSE;
5119                                 continue;
5120                         }
5121
5122                         if (major_collector.handle_gc_param && major_collector.handle_gc_param (opt))
5123                                 continue;
5124
5125                         if (sgen_minor_collector.handle_gc_param && sgen_minor_collector.handle_gc_param (opt))
5126                                 continue;
5127
5128                         fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
5129                         fprintf (stderr, "  max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
5130                         fprintf (stderr, "  soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
5131                         fprintf (stderr, "  nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
5132                         fprintf (stderr, "  major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-par', 'marksweep-fixed' or 'marksweep-fixed-par')\n");
5133                         fprintf (stderr, "  minor=COLLECTOR (where COLLECTOR is `simple' or `split')\n");
5134                         fprintf (stderr, "  wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
5135                         fprintf (stderr, "  stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
5136                         fprintf (stderr, "  [no-]cementing\n");
5137                         if (major_collector.print_gc_param_usage)
5138                                 major_collector.print_gc_param_usage ();
5139                         if (sgen_minor_collector.print_gc_param_usage)
5140                                 sgen_minor_collector.print_gc_param_usage ();
5141                         fprintf (stderr, " Experimental options:\n");
5142                         fprintf (stderr, "  save-target-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
5143                         fprintf (stderr, "  default-allowance-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MAX_ALLOWANCE_NURSERY_SIZE_RATIO);
5144                         exit (1);
5145                 }
5146                 g_strfreev (opts);
5147         }
5148
5149         if (major_collector.is_parallel)
5150                 sgen_workers_init (num_workers);
5151         else if (major_collector.is_concurrent)
5152                 sgen_workers_init (1);
5153
5154         if (major_collector_opt)
5155                 g_free (major_collector_opt);
5156
5157         if (minor_collector_opt)
5158                 g_free (minor_collector_opt);
5159
5160         alloc_nursery ();
5161
5162         sgen_cement_init (cement_enabled);
5163
5164         if ((env = getenv ("MONO_GC_DEBUG"))) {
5165                 opts = g_strsplit (env, ",", -1);
5166                 for (ptr = opts; ptr && *ptr; ptr ++) {
5167                         char *opt = *ptr;
5168                         if (opt [0] >= '0' && opt [0] <= '9') {
5169                                 gc_debug_level = atoi (opt);
5170                                 opt++;
5171                                 if (opt [0] == ':')
5172                                         opt++;
5173                                 if (opt [0]) {
5174 #ifdef HOST_WIN32
5175                                         char *rf = g_strdup_printf ("%s.%d", opt, GetCurrentProcessId ());
5176 #else
5177                                         char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
5178 #endif
5179                                         gc_debug_file = fopen (rf, "wb");
5180                                         if (!gc_debug_file)
5181                                                 gc_debug_file = stderr;
5182                                         g_free (rf);
5183                                 }
5184                         } else if (!strcmp (opt, "print-allowance")) {
5185                                 debug_print_allowance = TRUE;
5186                         } else if (!strcmp (opt, "print-pinning")) {
5187                                 do_pin_stats = TRUE;
5188                         } else if (!strcmp (opt, "verify-before-allocs")) {
5189                                 verify_before_allocs = 1;
5190                                 has_per_allocation_action = TRUE;
5191                         } else if (g_str_has_prefix (opt, "verify-before-allocs=")) {
5192                                 char *arg = strchr (opt, '=') + 1;
5193                                 verify_before_allocs = atoi (arg);
5194                                 has_per_allocation_action = TRUE;
5195                         } else if (!strcmp (opt, "collect-before-allocs")) {
5196                                 collect_before_allocs = 1;
5197                                 has_per_allocation_action = TRUE;
5198                         } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
5199                                 char *arg = strchr (opt, '=') + 1;
5200                                 has_per_allocation_action = TRUE;
5201                                 collect_before_allocs = atoi (arg);
5202                         } else if (!strcmp (opt, "verify-before-collections")) {
5203                                 whole_heap_check_before_collection = TRUE;
5204                         } else if (!strcmp (opt, "check-at-minor-collections")) {
5205                                 consistency_check_at_minor_collection = TRUE;
5206                                 nursery_clear_policy = CLEAR_AT_GC;
5207                         } else if (!strcmp (opt, "check-mark-bits")) {
5208                                 check_mark_bits_after_major_collection = TRUE;
5209                         } else if (!strcmp (opt, "check-nursery-pinned")) {
5210                                 check_nursery_objects_pinned = TRUE;
5211                         } else if (!strcmp (opt, "xdomain-checks")) {
5212                                 xdomain_checks = TRUE;
5213                         } else if (!strcmp (opt, "clear-at-gc")) {
5214                                 nursery_clear_policy = CLEAR_AT_GC;
5215                         } else if (!strcmp (opt, "clear-nursery-at-gc")) {
5216                                 nursery_clear_policy = CLEAR_AT_GC;
5217                         } else if (!strcmp (opt, "check-scan-starts")) {
5218                                 do_scan_starts_check = TRUE;
5219                         } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
5220                                 do_verify_nursery = TRUE;
5221                         } else if (!strcmp (opt, "check-concurrent")) {
5222                                 if (!major_collector.is_concurrent) {
5223                                         fprintf (stderr, "Error: check-concurrent only world with concurrent major collectors.\n");
5224                                         exit (1);
5225                                 }
5226                                 do_concurrent_checks = TRUE;
5227                         } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
5228                                 do_dump_nursery_content = TRUE;
5229                         } else if (!strcmp (opt, "no-managed-allocator")) {
5230                                 sgen_set_use_managed_allocator (FALSE);
5231                         } else if (!strcmp (opt, "disable-minor")) {
5232                                 disable_minor_collections = TRUE;
5233                         } else if (!strcmp (opt, "disable-major")) {
5234                                 disable_major_collections = TRUE;
5235                         } else if (g_str_has_prefix (opt, "heap-dump=")) {
5236                                 char *filename = strchr (opt, '=') + 1;
5237                                 nursery_clear_policy = CLEAR_AT_GC;
5238                                 heap_dump_file = fopen (filename, "w");
5239                                 if (heap_dump_file) {
5240                                         fprintf (heap_dump_file, "<sgen-dump>\n");
5241                                         do_pin_stats = TRUE;
5242                                 }
5243 #ifdef SGEN_BINARY_PROTOCOL
5244                         } else if (g_str_has_prefix (opt, "binary-protocol=")) {
5245                                 char *filename = strchr (opt, '=') + 1;
5246                                 binary_protocol_init (filename);
5247                                 if (use_cardtable)
5248                                         fprintf (stderr, "Warning: Cardtable write barriers will not be binary-protocolled.\n");
5249 #endif
5250                         } else {
5251                                 fprintf (stderr, "Invalid format for the MONO_GC_DEBUG env variable: '%s'\n", env);
5252                                 fprintf (stderr, "The format is: MONO_GC_DEBUG=[l[:filename]|<option>]+ where l is a debug level 0-9.\n");
5253                                 fprintf (stderr, "Valid options are:\n");
5254                                 fprintf (stderr, "  collect-before-allocs[=<n>]\n");
5255                                 fprintf (stderr, "  verify-before-allocs[=<n>]\n");
5256                                 fprintf (stderr, "  check-at-minor-collections\n");
5257                                 fprintf (stderr, "  check-mark-bits\n");
5258                                 fprintf (stderr, "  check-nursery-pinned\n");
5259                                 fprintf (stderr, "  verify-before-collections\n");
5260                                 fprintf (stderr, "  verify-nursery-at-minor-gc\n");
5261                                 fprintf (stderr, "  dump-nursery-at-minor-gc\n");
5262                                 fprintf (stderr, "  disable-minor\n");
5263                                 fprintf (stderr, "  disable-major\n");
5264                                 fprintf (stderr, "  xdomain-checks\n");
5265                                 fprintf (stderr, "  check-concurrent\n");
5266                                 fprintf (stderr, "  clear-at-gc\n");
5267                                 fprintf (stderr, "  clear-nursery-at-gc\n");
5268                                 fprintf (stderr, "  check-scan-starts\n");
5269                                 fprintf (stderr, "  no-managed-allocator\n");
5270                                 fprintf (stderr, "  print-allowance\n");
5271                                 fprintf (stderr, "  print-pinning\n");
5272                                 fprintf (stderr, "  heap-dump=<filename>\n");
5273 #ifdef SGEN_BINARY_PROTOCOL
5274                                 fprintf (stderr, "  binary-protocol=<filename>\n");
5275 #endif
5276                                 exit (1);
5277                         }
5278                 }
5279                 g_strfreev (opts);
5280         }
5281
5282         if (major_collector.is_parallel) {
5283                 if (heap_dump_file) {
5284                         fprintf (stderr, "Error: Cannot do heap dump with the parallel collector.\n");
5285                         exit (1);
5286                 }
5287                 if (do_pin_stats) {
5288                         fprintf (stderr, "Error: Cannot gather pinning statistics with the parallel collector.\n");
5289                         exit (1);
5290                 }
5291         }
5292
5293         if (major_collector.post_param_init)
5294                 major_collector.post_param_init (&major_collector);
5295
5296         sgen_memgov_init (max_heap, soft_limit, debug_print_allowance, allowance_ratio, save_target);
5297
5298         memset (&remset, 0, sizeof (remset));
5299
5300 #ifdef SGEN_HAVE_CARDTABLE
5301         if (use_cardtable)
5302                 sgen_card_table_init (&remset);
5303         else
5304 #endif
5305                 sgen_ssb_init (&remset);
5306
5307         if (remset.register_thread)
5308                 remset.register_thread (mono_thread_info_current ());
5309
5310         gc_initialized = 1;
5311 }
5312
5313 const char *
5314 mono_gc_get_gc_name (void)
5315 {
5316         return "sgen";
5317 }
5318
5319 static MonoMethod *write_barrier_method;
5320
5321 gboolean
5322 sgen_is_critical_method (MonoMethod *method)
5323 {
5324         return (method == write_barrier_method || sgen_is_managed_allocator (method));
5325 }
5326
5327 gboolean
5328 sgen_has_critical_method (void)
5329 {
5330         return write_barrier_method || sgen_has_managed_allocator ();
5331 }
5332
5333 static void
5334 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
5335 {
5336         memset (nursery_check_return_labels, 0, sizeof (int) * 3);
5337 #ifdef SGEN_ALIGN_NURSERY
5338         // if (ptr_in_nursery (ptr)) return;
5339         /*
5340          * Masking out the bits might be faster, but we would have to use 64 bit
5341          * immediates, which might be slower.
5342          */
5343         mono_mb_emit_ldarg (mb, 0);
5344         mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5345         mono_mb_emit_byte (mb, CEE_SHR_UN);
5346         mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5347         nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
5348
5349         if (!major_collector.is_concurrent) {
5350                 // if (!ptr_in_nursery (*ptr)) return;
5351                 mono_mb_emit_ldarg (mb, 0);
5352                 mono_mb_emit_byte (mb, CEE_LDIND_I);
5353                 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5354                 mono_mb_emit_byte (mb, CEE_SHR_UN);
5355                 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5356                 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
5357         }
5358 #else
5359         int label_continue1, label_continue2;
5360         int dereferenced_var;
5361
5362         // if (ptr < (sgen_get_nursery_start ())) goto continue;
5363         mono_mb_emit_ldarg (mb, 0);
5364         mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5365         label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
5366
5367         // if (ptr >= sgen_get_nursery_end ())) goto continue;
5368         mono_mb_emit_ldarg (mb, 0);
5369         mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5370         label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
5371
5372         // Otherwise return
5373         nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
5374
5375         // continue:
5376         mono_mb_patch_branch (mb, label_continue_1);
5377         mono_mb_patch_branch (mb, label_continue_2);
5378
5379         // Dereference and store in local var
5380         dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5381         mono_mb_emit_ldarg (mb, 0);
5382         mono_mb_emit_byte (mb, CEE_LDIND_I);
5383         mono_mb_emit_stloc (mb, dereferenced_var);
5384
5385         if (!major_collector.is_concurrent) {
5386                 // if (*ptr < sgen_get_nursery_start ()) return;
5387                 mono_mb_emit_ldloc (mb, dereferenced_var);
5388                 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5389                 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5390
5391                 // if (*ptr >= sgen_get_nursery_end ()) return;
5392                 mono_mb_emit_ldloc (mb, dereferenced_var);
5393                 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5394                 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5395         }
5396 #endif
5397 }
5398
5399 MonoMethod*
5400 mono_gc_get_write_barrier (void)
5401 {
5402         MonoMethod *res;
5403         MonoMethodBuilder *mb;
5404         MonoMethodSignature *sig;
5405 #ifdef MANAGED_WBARRIER
5406         int i, nursery_check_labels [3];
5407         int label_no_wb_3, label_no_wb_4, label_need_wb, label_slow_path;
5408         int buffer_var, buffer_index_var, dummy_var;
5409
5410 #ifdef HAVE_KW_THREAD
5411         int stack_end_offset = -1, store_remset_buffer_offset = -1;
5412         int store_remset_buffer_index_offset = -1, store_remset_buffer_index_addr_offset = -1;
5413
5414         MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5415         g_assert (stack_end_offset != -1);
5416         MONO_THREAD_VAR_OFFSET (store_remset_buffer, store_remset_buffer_offset);
5417         g_assert (store_remset_buffer_offset != -1);
5418         MONO_THREAD_VAR_OFFSET (store_remset_buffer_index, store_remset_buffer_index_offset);
5419         g_assert (store_remset_buffer_index_offset != -1);
5420         MONO_THREAD_VAR_OFFSET (store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5421         g_assert (store_remset_buffer_index_addr_offset != -1);
5422 #endif
5423 #endif
5424
5425         // FIXME: Maybe create a separate version for ctors (the branch would be
5426         // correctly predicted more times)
5427         if (write_barrier_method)
5428                 return write_barrier_method;
5429
5430         /* Create the IL version of mono_gc_barrier_generic_store () */
5431         sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5432         sig->ret = &mono_defaults.void_class->byval_arg;
5433         sig->params [0] = &mono_defaults.int_class->byval_arg;
5434
5435         mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5436
5437 #ifdef MANAGED_WBARRIER
5438         if (use_cardtable) {
5439                 emit_nursery_check (mb, nursery_check_labels);
5440                 /*
5441                 addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5442                 *addr = 1;
5443
5444                 sgen_cardtable:
5445                         LDC_PTR sgen_cardtable
5446
5447                 address >> CARD_BITS
5448                         LDARG_0
5449                         LDC_I4 CARD_BITS
5450                         SHR_UN
5451                 if (SGEN_HAVE_OVERLAPPING_CARDS) {
5452                         LDC_PTR card_table_mask
5453                         AND
5454                 }
5455                 AND
5456                 ldc_i4_1
5457                 stind_i1
5458                 */
5459                 mono_mb_emit_ptr (mb, sgen_cardtable);
5460                 mono_mb_emit_ldarg (mb, 0);
5461                 mono_mb_emit_icon (mb, CARD_BITS);
5462                 mono_mb_emit_byte (mb, CEE_SHR_UN);
5463 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5464                 mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5465                 mono_mb_emit_byte (mb, CEE_AND);
5466 #endif
5467                 mono_mb_emit_byte (mb, CEE_ADD);
5468                 mono_mb_emit_icon (mb, 1);
5469                 mono_mb_emit_byte (mb, CEE_STIND_I1);
5470
5471                 // return;
5472                 for (i = 0; i < 3; ++i) {
5473                         if (nursery_check_labels [i])
5474                                 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5475                 }
5476                 mono_mb_emit_byte (mb, CEE_RET);
5477         } else if (mono_runtime_has_tls_get ()) {
5478                 emit_nursery_check (mb, nursery_check_labels);
5479
5480                 // if (ptr >= stack_end) goto need_wb;
5481                 mono_mb_emit_ldarg (mb, 0);
5482                 EMIT_TLS_ACCESS (mb, stack_end, stack_end_offset);
5483                 label_need_wb = mono_mb_emit_branch (mb, CEE_BGE_UN);
5484
5485                 // if (ptr >= stack_start) return;
5486                 dummy_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5487                 mono_mb_emit_ldarg (mb, 0);
5488                 mono_mb_emit_ldloc_addr (mb, dummy_var);
5489                 label_no_wb_3 = mono_mb_emit_branch (mb, CEE_BGE_UN);
5490
5491                 // need_wb:
5492                 mono_mb_patch_branch (mb, label_need_wb);
5493
5494                 // buffer = STORE_REMSET_BUFFER;
5495                 buffer_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5496                 EMIT_TLS_ACCESS (mb, store_remset_buffer, store_remset_buffer_offset);
5497                 mono_mb_emit_stloc (mb, buffer_var);
5498
5499                 // buffer_index = STORE_REMSET_BUFFER_INDEX;
5500                 buffer_index_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5501                 EMIT_TLS_ACCESS (mb, store_remset_buffer_index, store_remset_buffer_index_offset);
5502                 mono_mb_emit_stloc (mb, buffer_index_var);
5503
5504                 // if (buffer [buffer_index] == ptr) return;
5505                 mono_mb_emit_ldloc (mb, buffer_var);
5506                 mono_mb_emit_ldloc (mb, buffer_index_var);
5507                 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5508                 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5509                 mono_mb_emit_byte (mb, CEE_SHL);
5510                 mono_mb_emit_byte (mb, CEE_ADD);
5511                 mono_mb_emit_byte (mb, CEE_LDIND_I);
5512                 mono_mb_emit_ldarg (mb, 0);
5513                 label_no_wb_4 = mono_mb_emit_branch (mb, CEE_BEQ);
5514
5515                 // ++buffer_index;
5516                 mono_mb_emit_ldloc (mb, buffer_index_var);
5517                 mono_mb_emit_icon (mb, 1);
5518                 mono_mb_emit_byte (mb, CEE_ADD);
5519                 mono_mb_emit_stloc (mb, buffer_index_var);
5520
5521                 // if (buffer_index >= STORE_REMSET_BUFFER_SIZE) goto slow_path;
5522                 mono_mb_emit_ldloc (mb, buffer_index_var);
5523                 mono_mb_emit_icon (mb, STORE_REMSET_BUFFER_SIZE);
5524                 label_slow_path = mono_mb_emit_branch (mb, CEE_BGE);
5525
5526                 // buffer [buffer_index] = ptr;
5527                 mono_mb_emit_ldloc (mb, buffer_var);
5528                 mono_mb_emit_ldloc (mb, buffer_index_var);
5529                 g_assert (sizeof (gpointer) == 4 || sizeof (gpointer) == 8);
5530                 mono_mb_emit_icon (mb, sizeof (gpointer) == 4 ? 2 : 3);
5531                 mono_mb_emit_byte (mb, CEE_SHL);
5532                 mono_mb_emit_byte (mb, CEE_ADD);
5533                 mono_mb_emit_ldarg (mb, 0);
5534                 mono_mb_emit_byte (mb, CEE_STIND_I);
5535
5536                 // STORE_REMSET_BUFFER_INDEX = buffer_index;
5537                 EMIT_TLS_ACCESS (mb, store_remset_buffer_index_addr, store_remset_buffer_index_addr_offset);
5538                 mono_mb_emit_ldloc (mb, buffer_index_var);
5539                 mono_mb_emit_byte (mb, CEE_STIND_I);
5540
5541                 // return;
5542                 for (i = 0; i < 3; ++i) {
5543                         if (nursery_check_labels [i])
5544                                 mono_mb_patch_branch (mb, nursery_check_labels [i]);
5545                 }
5546                 mono_mb_patch_branch (mb, label_no_wb_3);
5547                 mono_mb_patch_branch (mb, label_no_wb_4);
5548                 mono_mb_emit_byte (mb, CEE_RET);
5549
5550                 // slow path
5551                 mono_mb_patch_branch (mb, label_slow_path);
5552
5553                 mono_mb_emit_ldarg (mb, 0);
5554                 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5555                 mono_mb_emit_byte (mb, CEE_RET);
5556         } else
5557 #endif
5558         {
5559                 mono_mb_emit_ldarg (mb, 0);
5560                 mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5561                 mono_mb_emit_byte (mb, CEE_RET);
5562         }
5563
5564         res = mono_mb_create_method (mb, sig, 16);
5565         mono_mb_free (mb);
5566
5567         mono_loader_lock ();
5568         if (write_barrier_method) {
5569                 /* Already created */
5570                 mono_free_method (res);
5571         } else {
5572                 /* double-checked locking */
5573                 mono_memory_barrier ();
5574                 write_barrier_method = res;
5575         }
5576         mono_loader_unlock ();
5577
5578         return write_barrier_method;
5579 }
5580
5581 char*
5582 mono_gc_get_description (void)
5583 {
5584         return g_strdup ("sgen");
5585 }
5586
5587 void
5588 mono_gc_set_desktop_mode (void)
5589 {
5590 }
5591
5592 gboolean
5593 mono_gc_is_moving (void)
5594 {
5595         return TRUE;
5596 }
5597
5598 gboolean
5599 mono_gc_is_disabled (void)
5600 {
5601         return FALSE;
5602 }
5603
5604 #ifdef HOST_WIN32
5605 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5606 {
5607         return TRUE;
5608 }
5609 #endif
5610
5611 NurseryClearPolicy
5612 sgen_get_nursery_clear_policy (void)
5613 {
5614         return nursery_clear_policy;
5615 }
5616
5617 MonoVTable*
5618 sgen_get_array_fill_vtable (void)
5619 {
5620         if (!array_fill_vtable) {
5621                 static MonoClass klass;
5622                 static MonoVTable vtable;
5623                 gsize bmap;
5624
5625                 MonoDomain *domain = mono_get_root_domain ();
5626                 g_assert (domain);
5627
5628                 klass.element_class = mono_defaults.byte_class;
5629                 klass.rank = 1;
5630                 klass.instance_size = sizeof (MonoArray);
5631                 klass.sizes.element_size = 1;
5632                 klass.name = "array_filler_type";
5633
5634                 vtable.klass = &klass;
5635                 bmap = 0;
5636                 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5637                 vtable.rank = 1;
5638
5639                 array_fill_vtable = &vtable;
5640         }
5641         return array_fill_vtable;
5642 }
5643
5644 void
5645 sgen_gc_lock (void)
5646 {
5647         LOCK_GC;
5648 }
5649
5650 void
5651 sgen_gc_unlock (void)
5652 {
5653         UNLOCK_GC;
5654 }
5655
5656 void
5657 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5658 {
5659         major_collector.iterate_live_block_ranges (callback);
5660 }
5661
5662 void
5663 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5664 {
5665         major_collector.scan_card_table (FALSE, queue);
5666 }
5667
5668 SgenMajorCollector*
5669 sgen_get_major_collector (void)
5670 {
5671         return &major_collector;
5672 }
5673
5674 void mono_gc_set_skip_thread (gboolean skip)
5675 {
5676         SgenThreadInfo *info = mono_thread_info_current ();
5677
5678         LOCK_GC;
5679         info->gc_disabled = skip;
5680         UNLOCK_GC;
5681 }
5682
5683 SgenRemeberedSet*
5684 sgen_get_remset (void)
5685 {
5686         return &remset;
5687 }
5688
5689 guint
5690 mono_gc_get_vtable_bits (MonoClass *class)
5691 {
5692         if (sgen_need_bridge_processing () && sgen_is_bridge_class (class))
5693                 return SGEN_GC_BIT_BRIDGE_OBJECT;
5694         return 0;
5695 }
5696
5697 void
5698 mono_gc_register_altstack (gpointer stack, gint32 stack_size, gpointer altstack, gint32 altstack_size)
5699 {
5700         // FIXME:
5701 }
5702
5703
5704 void
5705 sgen_check_whole_heap_stw (void)
5706 {
5707         sgen_stop_world (0);
5708         sgen_clear_nursery_fragments ();
5709         sgen_check_whole_heap (FALSE);
5710         sgen_restart_world (0, NULL);
5711 }
5712
5713 void
5714 sgen_gc_event_moves (void)
5715 {
5716         if (moved_objects_idx) {
5717                 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
5718                 moved_objects_idx = 0;
5719         }
5720 }
5721
5722 #endif /* HAVE_SGEN_GC */