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