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