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