mono/metadata/sgen-gc.c

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