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_generic_store_atomic = 0;
 321 static int stat_wbarrier_set_root = 0;
 322 static int stat_wbarrier_value_copy = 0;
 323 static int stat_wbarrier_object_copy = 0;
 324 #endif
 325
 326 int stat_minor_gcs = 0;
 327 int stat_major_gcs = 0;
 328
 329 static long long stat_pinned_objects = 0;
 330
 331 static long long time_minor_pre_collection_fragment_clear = 0;
 332 static long long time_minor_pinning = 0;
 333 static long long time_minor_scan_remsets = 0;
 334 static long long time_minor_scan_pinned = 0;
 335 static long long time_minor_scan_registered_roots = 0;
 336 static long long time_minor_scan_thread_data = 0;
 337 static long long time_minor_finish_gray_stack = 0;
 338 static long long time_minor_fragment_creation = 0;
 339
 340 static long long time_major_pre_collection_fragment_clear = 0;
 341 static long long time_major_pinning = 0;
 342 static long long time_major_scan_pinned = 0;
 343 static long long time_major_scan_registered_roots = 0;
 344 static long long time_major_scan_thread_data = 0;
 345 static long long time_major_scan_alloc_pinned = 0;
 346 static long long time_major_scan_finalized = 0;
 347 static long long time_major_scan_big_objects = 0;
 348 static long long time_major_finish_gray_stack = 0;
 349 static long long time_major_free_bigobjs = 0;
 350 static long long time_major_los_sweep = 0;
 351 static long long time_major_sweep = 0;
 352 static long long time_major_fragment_creation = 0;
 353
 354 int gc_debug_level = 0;
 355 FILE* gc_debug_file;
 356
 357 /*
 358 void
 359 mono_gc_flush_info (void)
 360 {
 361         fflush (gc_debug_file);
 362 }
 363 */
 364
 365 #define TV_DECLARE SGEN_TV_DECLARE
 366 #define TV_GETTIME SGEN_TV_GETTIME
 367 #define TV_ELAPSED SGEN_TV_ELAPSED
 368 #define TV_ELAPSED_MS SGEN_TV_ELAPSED_MS
 369
 370 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
 371
 372 NurseryClearPolicy nursery_clear_policy = CLEAR_AT_TLAB_CREATION;
 373
 374 #define object_is_forwarded     SGEN_OBJECT_IS_FORWARDED
 375 #define object_is_pinned        SGEN_OBJECT_IS_PINNED
 376 #define pin_object              SGEN_PIN_OBJECT
 377 #define unpin_object            SGEN_UNPIN_OBJECT
 378
 379 #define ptr_in_nursery sgen_ptr_in_nursery
 380
 381 #define LOAD_VTABLE     SGEN_LOAD_VTABLE
 382
 383 static const char*
 384 safe_name (void* obj)
 385 {
 386         MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
 387         return vt->klass->name;
 388 }
 389
 390 #define safe_object_get_size    sgen_safe_object_get_size
 391
 392 const char*
 393 sgen_safe_name (void* obj)
 394 {
 395         return safe_name (obj);
 396 }
 397
 398 /*
 399  * ######################################################################
 400  * ########  Global data.
 401  * ######################################################################
 402  */
 403 LOCK_DECLARE (gc_mutex);
 404 gboolean sgen_try_free_some_memory;
 405
 406 #define SCAN_START_SIZE SGEN_SCAN_START_SIZE
 407
 408 static mword pagesize = 4096;
 409 int degraded_mode = 0;
 410
 411 static mword bytes_pinned_from_failed_allocation = 0;
 412
 413 GCMemSection *nursery_section = NULL;
 414 static mword lowest_heap_address = ~(mword)0;
 415 static mword highest_heap_address = 0;
 416
 417 LOCK_DECLARE (sgen_interruption_mutex);
 418 static LOCK_DECLARE (pin_queue_mutex);
 419
 420 #define LOCK_PIN_QUEUE mono_mutex_lock (&pin_queue_mutex)
 421 #define UNLOCK_PIN_QUEUE mono_mutex_unlock (&pin_queue_mutex)
 422
 423 typedef struct _FinalizeReadyEntry FinalizeReadyEntry;
 424 struct _FinalizeReadyEntry {
 425         FinalizeReadyEntry *next;
 426         void *object;
 427 };
 428
 429 typedef struct _EphemeronLinkNode EphemeronLinkNode;
 430
 431 struct _EphemeronLinkNode {
 432         EphemeronLinkNode *next;
 433         char *array;
 434 };
 435
 436 typedef struct {
 437        void *key;
 438        void *value;
 439 } Ephemeron;
 440
 441 int current_collection_generation = -1;
 442 volatile gboolean concurrent_collection_in_progress = FALSE;
 443
 444 /* objects that are ready to be finalized */
 445 static FinalizeReadyEntry *fin_ready_list = NULL;
 446 static FinalizeReadyEntry *critical_fin_list = NULL;
 447
 448 static EphemeronLinkNode *ephemeron_list;
 449
 450 /* registered roots: the key to the hash is the root start address */
 451 /*
 452  * Different kinds of roots are kept separate to speed up pin_from_roots () for example.
 453  */
 454 SgenHashTable roots_hash [ROOT_TYPE_NUM] = {
 455         SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
 456         SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL),
 457         SGEN_HASH_TABLE_INIT (INTERNAL_MEM_ROOTS_TABLE, INTERNAL_MEM_ROOT_RECORD, sizeof (RootRecord), mono_aligned_addr_hash, NULL)
 458 };
 459 static mword roots_size = 0; /* amount of memory in the root set */
 460
 461 #define GC_ROOT_NUM 32
 462 typedef struct {
 463         int count;              /* must be the first field */
 464         void *objects [GC_ROOT_NUM];
 465         int root_types [GC_ROOT_NUM];
 466         uintptr_t extra_info [GC_ROOT_NUM];
 467 } GCRootReport;
 468
 469 static void
 470 notify_gc_roots (GCRootReport *report)
 471 {
 472         if (!report->count)
 473                 return;
 474         mono_profiler_gc_roots (report->count, report->objects, report->root_types, report->extra_info);
 475         report->count = 0;
 476 }
 477
 478 static void
 479 add_profile_gc_root (GCRootReport *report, void *object, int rtype, uintptr_t extra_info)
 480 {
 481         if (report->count == GC_ROOT_NUM)
 482                 notify_gc_roots (report);
 483         report->objects [report->count] = object;
 484         report->root_types [report->count] = rtype;
 485         report->extra_info [report->count++] = (uintptr_t)((MonoVTable*)LOAD_VTABLE (object))->klass;
 486 }
 487
 488 MonoNativeTlsKey thread_info_key;
 489
 490 #ifdef HAVE_KW_THREAD
 491 __thread SgenThreadInfo *sgen_thread_info;
 492 __thread char *stack_end;
 493 #endif
 494
 495 /* The size of a TLAB */
 496 /* The bigger the value, the less often we have to go to the slow path to allocate a new
 497  * one, but the more space is wasted by threads not allocating much memory.
 498  * FIXME: Tune this.
 499  * FIXME: Make this self-tuning for each thread.
 500  */
 501 guint32 tlab_size = (1024 * 4);
 502
 503 #define MAX_SMALL_OBJ_SIZE      SGEN_MAX_SMALL_OBJ_SIZE
 504
 505 /* Functions supplied by the runtime to be called by the GC */
 506 static MonoGCCallbacks gc_callbacks;
 507
 508 #define ALLOC_ALIGN             SGEN_ALLOC_ALIGN
 509 #define ALLOC_ALIGN_BITS        SGEN_ALLOC_ALIGN_BITS
 510
 511 #define ALIGN_UP                SGEN_ALIGN_UP
 512
 513 #define MOVED_OBJECTS_NUM 64
 514 static void *moved_objects [MOVED_OBJECTS_NUM];
 515 static int moved_objects_idx = 0;
 516
 517 /* Vtable of the objects used to fill out nursery fragments before a collection */
 518 static MonoVTable *array_fill_vtable;
 519
 520 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
 521 MonoNativeThreadId main_gc_thread = NULL;
 522 #endif
 523
 524 /*Object was pinned during the current collection*/
 525 static mword objects_pinned;
 526
 527 /*
 528  * ######################################################################
 529  * ########  Macros and function declarations.
 530  * ######################################################################
 531  */
 532
 533 inline static void*
 534 align_pointer (void *ptr)
 535 {
 536         mword p = (mword)ptr;
 537         p += sizeof (gpointer) - 1;
 538         p &= ~ (sizeof (gpointer) - 1);
 539         return (void*)p;
 540 }
 541
 542 typedef SgenGrayQueue GrayQueue;
 543
 544 /* forward declarations */
 545 static void scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue);
 546 static void scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx);
 547 static void scan_finalizer_entries (FinalizeReadyEntry *list, ScanCopyContext ctx);
 548 static void report_finalizer_roots (void);
 549 static void report_registered_roots (void);
 550
 551 static void pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue);
 552 static int pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, ScanCopyContext ctx);
 553 static void finish_gray_stack (int generation, GrayQueue *queue);
 554
 555 void mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise);
 556
 557
 558 static void init_stats (void);
 559
 560 static int mark_ephemerons_in_range (ScanCopyContext ctx);
 561 static void clear_unreachable_ephemerons (ScanCopyContext ctx);
 562 static void null_ephemerons_for_domain (MonoDomain *domain);
 563
 564 static gboolean major_update_or_finish_concurrent_collection (gboolean force_finish);
 565
 566 SgenObjectOperations current_object_ops;
 567 SgenMajorCollector major_collector;
 568 SgenMinorCollector sgen_minor_collector;
 569 static GrayQueue gray_queue;
 570
 571 static SgenRemeberedSet remset;
 572
 573 /* The gray queue to use from the main collection thread. */
 574 #define WORKERS_DISTRIBUTE_GRAY_QUEUE   (&gray_queue)
 575
 576 /*
 577  * The gray queue a worker job must use.  If we're not parallel or
 578  * concurrent, we use the main gray queue.
 579  */
 580 static SgenGrayQueue*
 581 sgen_workers_get_job_gray_queue (WorkerData *worker_data)
 582 {
 583         return worker_data ? &worker_data->private_gray_queue : WORKERS_DISTRIBUTE_GRAY_QUEUE;
 584 }
 585
 586 static void
 587 gray_queue_redirect (SgenGrayQueue *queue)
 588 {
 589         gboolean wake = FALSE;
 590
 591
 592         for (;;) {
 593                 GrayQueueSection *section = sgen_gray_object_dequeue_section (queue);
 594                 if (!section)
 595                         break;
 596                 sgen_section_gray_queue_enqueue (queue->alloc_prepare_data, section);
 597                 wake = TRUE;
 598         }
 599
 600         if (wake) {
 601                 g_assert (concurrent_collection_in_progress ||
 602                                 (current_collection_generation == GENERATION_OLD && major_collector.is_parallel));
 603                 if (sgen_workers_have_started ()) {
 604                         sgen_workers_wake_up_all ();
 605                 } else {
 606                         if (concurrent_collection_in_progress)
 607                                 g_assert (current_collection_generation == -1);
 608                 }
 609         }
 610 }
 611
 612 static gboolean
 613 is_xdomain_ref_allowed (gpointer *ptr, char *obj, MonoDomain *domain)
 614 {
 615         MonoObject *o = (MonoObject*)(obj);
 616         MonoObject *ref = (MonoObject*)*(ptr);
 617         int offset = (char*)(ptr) - (char*)o;
 618
 619         if (o->vtable->klass == mono_defaults.thread_class && offset == G_STRUCT_OFFSET (MonoThread, internal_thread))
 620                 return TRUE;
 621         if (o->vtable->klass == mono_defaults.internal_thread_class && offset == G_STRUCT_OFFSET (MonoInternalThread, current_appcontext))
 622                 return TRUE;
 623
 624 #ifndef DISABLE_REMOTING
 625         if (mono_class_has_parent_fast (o->vtable->klass, mono_defaults.real_proxy_class) &&
 626                         offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
 627                 return TRUE;
 628 #endif
 629         /* Thread.cached_culture_info */
 630         if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
 631                         !strcmp (ref->vtable->klass->name, "CultureInfo") &&
 632                         !strcmp(o->vtable->klass->name_space, "System") &&
 633                         !strcmp(o->vtable->klass->name, "Object[]"))
 634                 return TRUE;
 635         /*
 636          *  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
 637          * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81
 638          * at (wrapper remoting-invoke-with-check) System.IO.MemoryStream..ctor (byte[]) <IL 0x00020, 0xffffffff>
 639          * at System.Runtime.Remoting.Messaging.CADMethodCallMessage.GetArguments () [0x0000d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/CADMessages.cs:327
 640          * 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
 641          * 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
 642          * at (wrapper remoting-invoke-with-check) System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) <IL 0x0003d, 0xffffffff>
 643          * 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
 644          * at (wrapper runtime-invoke) object.runtime_invoke_CrossAppDomainSink/ProcessMessageRes_object_object (object,intptr,intptr,intptr) <IL 0x0004c, 0xffffffff>
 645          */
 646         if (!strcmp (ref->vtable->klass->name_space, "System") &&
 647                         !strcmp (ref->vtable->klass->name, "Byte[]") &&
 648                         !strcmp (o->vtable->klass->name_space, "System.IO") &&
 649                         !strcmp (o->vtable->klass->name, "MemoryStream"))
 650                 return TRUE;
 651         /* append_job() in threadpool.c */
 652         if (!strcmp (ref->vtable->klass->name_space, "System.Runtime.Remoting.Messaging") &&
 653                         !strcmp (ref->vtable->klass->name, "AsyncResult") &&
 654                         !strcmp (o->vtable->klass->name_space, "System") &&
 655                         !strcmp (o->vtable->klass->name, "Object[]") &&
 656                         mono_thread_pool_is_queue_array ((MonoArray*) o))
 657                 return TRUE;
 658         return FALSE;
 659 }
 660
 661 static void
 662 check_reference_for_xdomain (gpointer *ptr, char *obj, MonoDomain *domain)
 663 {
 664         MonoObject *o = (MonoObject*)(obj);
 665         MonoObject *ref = (MonoObject*)*(ptr);
 666         int offset = (char*)(ptr) - (char*)o;
 667         MonoClass *class;
 668         MonoClassField *field;
 669         char *str;
 670
 671         if (!ref || ref->vtable->domain == domain)
 672                 return;
 673         if (is_xdomain_ref_allowed (ptr, obj, domain))
 674                 return;
 675
 676         field = NULL;
 677         for (class = o->vtable->klass; class; class = class->parent) {
 678                 int i;
 679
 680                 for (i = 0; i < class->field.count; ++i) {
 681                         if (class->fields[i].offset == offset) {
 682                                 field = &class->fields[i];
 683                                 break;
 684                         }
 685                 }
 686                 if (field)
 687                         break;
 688         }
 689
 690         if (ref->vtable->klass == mono_defaults.string_class)
 691                 str = mono_string_to_utf8 ((MonoString*)ref);
 692         else
 693                 str = NULL;
 694         g_print ("xdomain reference in %p (%s.%s) at offset %d (%s) to %p (%s.%s) (%s)  -  pointed to by:\n",
 695                         o, o->vtable->klass->name_space, o->vtable->klass->name,
 696                         offset, field ? field->name : "",
 697                         ref, ref->vtable->klass->name_space, ref->vtable->klass->name, str ? str : "");
 698         mono_gc_scan_for_specific_ref (o, TRUE);
 699         if (str)
 700                 g_free (str);
 701 }
 702
 703 #undef HANDLE_PTR
 704 #define HANDLE_PTR(ptr,obj)     check_reference_for_xdomain ((ptr), (obj), domain)
 705
 706 static void
 707 scan_object_for_xdomain_refs (char *start, mword size, void *data)
 708 {
 709         MonoDomain *domain = ((MonoObject*)start)->vtable->domain;
 710
 711         #include "sgen-scan-object.h"
 712 }
 713
 714 static gboolean scan_object_for_specific_ref_precise = TRUE;
 715
 716 #undef HANDLE_PTR
 717 #define HANDLE_PTR(ptr,obj) do {                \
 718         if ((MonoObject*)*(ptr) == key) {       \
 719         g_print ("found ref to %p in object %p (%s) at offset %td\n",   \
 720                         key, (obj), safe_name ((obj)), ((char*)(ptr) - (char*)(obj))); \
 721         }                                                               \
 722         } while (0)
 723
 724 static void
 725 scan_object_for_specific_ref (char *start, MonoObject *key)
 726 {
 727         char *forwarded;
 728
 729         if ((forwarded = SGEN_OBJECT_IS_FORWARDED (start)))
 730                 start = forwarded;
 731
 732         if (scan_object_for_specific_ref_precise) {
 733                 #include "sgen-scan-object.h"
 734         } else {
 735                 mword *words = (mword*)start;
 736                 size_t size = safe_object_get_size ((MonoObject*)start);
 737                 int i;
 738                 for (i = 0; i < size / sizeof (mword); ++i) {
 739                         if (words [i] == (mword)key) {
 740                                 g_print ("found possible ref to %p in object %p (%s) at offset %td\n",
 741                                                 key, start, safe_name (start), i * sizeof (mword));
 742                         }
 743                 }
 744         }
 745 }
 746
 747 void
 748 sgen_scan_area_with_callback (char *start, char *end, IterateObjectCallbackFunc callback, void *data, gboolean allow_flags)
 749 {
 750         while (start < end) {
 751                 size_t size;
 752                 char *obj;
 753
 754                 if (!*(void**)start) {
 755                         start += sizeof (void*); /* should be ALLOC_ALIGN, really */
 756                         continue;
 757                 }
 758
 759                 if (allow_flags) {
 760                         if (!(obj = SGEN_OBJECT_IS_FORWARDED (start)))
 761                                 obj = start;
 762                 } else {
 763                         obj = start;
 764                 }
 765
 766                 size = ALIGN_UP (safe_object_get_size ((MonoObject*)obj));
 767
 768                 if ((MonoVTable*)SGEN_LOAD_VTABLE (obj) != array_fill_vtable)
 769                         callback (obj, size, data);
 770
 771                 start += size;
 772         }
 773 }
 774
 775 static void
 776 scan_object_for_specific_ref_callback (char *obj, size_t size, MonoObject *key)
 777 {
 778         scan_object_for_specific_ref (obj, key);
 779 }
 780
 781 static void
 782 check_root_obj_specific_ref (RootRecord *root, MonoObject *key, MonoObject *obj)
 783 {
 784         if (key != obj)
 785                 return;
 786         g_print ("found ref to %p in root record %p\n", key, root);
 787 }
 788
 789 static MonoObject *check_key = NULL;
 790 static RootRecord *check_root = NULL;
 791
 792 static void
 793 check_root_obj_specific_ref_from_marker (void **obj)
 794 {
 795         check_root_obj_specific_ref (check_root, check_key, *obj);
 796 }
 797
 798 static void
 799 scan_roots_for_specific_ref (MonoObject *key, int root_type)
 800 {
 801         void **start_root;
 802         RootRecord *root;
 803         check_key = key;
 804
 805         SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
 806                 mword desc = root->root_desc;
 807
 808                 check_root = root;
 809
 810                 switch (desc & ROOT_DESC_TYPE_MASK) {
 811                 case ROOT_DESC_BITMAP:
 812                         desc >>= ROOT_DESC_TYPE_SHIFT;
 813                         while (desc) {
 814                                 if (desc & 1)
 815                                         check_root_obj_specific_ref (root, key, *start_root);
 816                                 desc >>= 1;
 817                                 start_root++;
 818                         }
 819                         return;
 820                 case ROOT_DESC_COMPLEX: {
 821                         gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
 822                         int bwords = (*bitmap_data) - 1;
 823                         void **start_run = start_root;
 824                         bitmap_data++;
 825                         while (bwords-- > 0) {
 826                                 gsize bmap = *bitmap_data++;
 827                                 void **objptr = start_run;
 828                                 while (bmap) {
 829                                         if (bmap & 1)
 830                                                 check_root_obj_specific_ref (root, key, *objptr);
 831                                         bmap >>= 1;
 832                                         ++objptr;
 833                                 }
 834                                 start_run += GC_BITS_PER_WORD;
 835                         }
 836                         break;
 837                 }
 838                 case ROOT_DESC_USER: {
 839                         MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
 840                         marker (start_root, check_root_obj_specific_ref_from_marker);
 841                         break;
 842                 }
 843                 case ROOT_DESC_RUN_LEN:
 844                         g_assert_not_reached ();
 845                 default:
 846                         g_assert_not_reached ();
 847                 }
 848         } SGEN_HASH_TABLE_FOREACH_END;
 849
 850         check_key = NULL;
 851         check_root = NULL;
 852 }
 853
 854 void
 855 mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise)
 856 {
 857         void **ptr;
 858         RootRecord *root;
 859
 860         scan_object_for_specific_ref_precise = precise;
 861
 862         sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
 863                         (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key, TRUE);
 864
 865         major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
 866
 867         sgen_los_iterate_objects ((IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
 868
 869         scan_roots_for_specific_ref (key, ROOT_TYPE_NORMAL);
 870         scan_roots_for_specific_ref (key, ROOT_TYPE_WBARRIER);
 871
 872         SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], ptr, root) {
 873                 while (ptr < (void**)root->end_root) {
 874                         check_root_obj_specific_ref (root, *ptr, key);
 875                         ++ptr;
 876                 }
 877         } SGEN_HASH_TABLE_FOREACH_END;
 878 }
 879
 880 static gboolean
 881 need_remove_object_for_domain (char *start, MonoDomain *domain)
 882 {
 883         if (mono_object_domain (start) == domain) {
 884                 SGEN_LOG (4, "Need to cleanup object %p", start);
 885                 binary_protocol_cleanup (start, (gpointer)LOAD_VTABLE (start), safe_object_get_size ((MonoObject*)start));
 886                 return TRUE;
 887         }
 888         return FALSE;
 889 }
 890
 891 static void
 892 process_object_for_domain_clearing (char *start, MonoDomain *domain)
 893 {
 894         GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
 895         if (vt->klass == mono_defaults.internal_thread_class)
 896                 g_assert (mono_object_domain (start) == mono_get_root_domain ());
 897         /* The object could be a proxy for an object in the domain
 898            we're deleting. */
 899 #ifndef DISABLE_REMOTING
 900         if (mono_class_has_parent_fast (vt->klass, mono_defaults.real_proxy_class)) {
 901                 MonoObject *server = ((MonoRealProxy*)start)->unwrapped_server;
 902
 903                 /* The server could already have been zeroed out, so
 904                    we need to check for that, too. */
 905                 if (server && (!LOAD_VTABLE (server) || mono_object_domain (server) == domain)) {
 906                         SGEN_LOG (4, "Cleaning up remote pointer in %p to object %p", start, server);
 907                         ((MonoRealProxy*)start)->unwrapped_server = NULL;
 908                 }
 909         }
 910 #endif
 911 }
 912
 913 static MonoDomain *check_domain = NULL;
 914
 915 static void
 916 check_obj_not_in_domain (void **o)
 917 {
 918         g_assert (((MonoObject*)(*o))->vtable->domain != check_domain);
 919 }
 920
 921 static void
 922 scan_for_registered_roots_in_domain (MonoDomain *domain, int root_type)
 923 {
 924         void **start_root;
 925         RootRecord *root;
 926         check_domain = domain;
 927         SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
 928                 mword desc = root->root_desc;
 929
 930                 /* The MonoDomain struct is allowed to hold
 931                    references to objects in its own domain. */
 932                 if (start_root == (void**)domain)
 933                         continue;
 934
 935                 switch (desc & ROOT_DESC_TYPE_MASK) {
 936                 case ROOT_DESC_BITMAP:
 937                         desc >>= ROOT_DESC_TYPE_SHIFT;
 938                         while (desc) {
 939                                 if ((desc & 1) && *start_root)
 940                                         check_obj_not_in_domain (*start_root);
 941                                 desc >>= 1;
 942                                 start_root++;
 943                         }
 944                         break;
 945                 case ROOT_DESC_COMPLEX: {
 946                         gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
 947                         int bwords = (*bitmap_data) - 1;
 948                         void **start_run = start_root;
 949                         bitmap_data++;
 950                         while (bwords-- > 0) {
 951                                 gsize bmap = *bitmap_data++;
 952                                 void **objptr = start_run;
 953                                 while (bmap) {
 954                                         if ((bmap & 1) && *objptr)
 955                                                 check_obj_not_in_domain (*objptr);
 956                                         bmap >>= 1;
 957                                         ++objptr;
 958                                 }
 959                                 start_run += GC_BITS_PER_WORD;
 960                         }
 961                         break;
 962                 }
 963                 case ROOT_DESC_USER: {
 964                         MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
 965                         marker (start_root, check_obj_not_in_domain);
 966                         break;
 967                 }
 968                 case ROOT_DESC_RUN_LEN:
 969                         g_assert_not_reached ();
 970                 default:
 971                         g_assert_not_reached ();
 972                 }
 973         } SGEN_HASH_TABLE_FOREACH_END;
 974
 975         check_domain = NULL;
 976 }
 977
 978 static void
 979 check_for_xdomain_refs (void)
 980 {
 981         LOSObject *bigobj;
 982
 983         sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
 984                         (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL, FALSE);
 985
 986         major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL);
 987
 988         for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
 989                 scan_object_for_xdomain_refs (bigobj->data, sgen_los_object_size (bigobj), NULL);
 990 }
 991
 992 static gboolean
 993 clear_domain_process_object (char *obj, MonoDomain *domain)
 994 {
 995         gboolean remove;
 996
 997         process_object_for_domain_clearing (obj, domain);
 998         remove = need_remove_object_for_domain (obj, domain);
 999
1000         if (remove && ((MonoObject*)obj)->synchronisation) {
1001                 void **dislink = mono_monitor_get_object_monitor_weak_link ((MonoObject*)obj);
1002                 if (dislink)
1003                         sgen_register_disappearing_link (NULL, dislink, FALSE, TRUE);
1004         }
1005
1006         return remove;
1007 }
1008
1009 static void
1010 clear_domain_process_minor_object_callback (char *obj, size_t size, MonoDomain *domain)
1011 {
1012         if (clear_domain_process_object (obj, domain))
1013                 memset (obj, 0, size);
1014 }
1015
1016 static void
1017 clear_domain_process_major_object_callback (char *obj, size_t size, MonoDomain *domain)
1018 {
1019         clear_domain_process_object (obj, domain);
1020 }
1021
1022 static void
1023 clear_domain_free_major_non_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1024 {
1025         if (need_remove_object_for_domain (obj, domain))
1026                 major_collector.free_non_pinned_object (obj, size);
1027 }
1028
1029 static void
1030 clear_domain_free_major_pinned_object_callback (char *obj, size_t size, MonoDomain *domain)
1031 {
1032         if (need_remove_object_for_domain (obj, domain))
1033                 major_collector.free_pinned_object (obj, size);
1034 }
1035
1036 /*
1037  * When appdomains are unloaded we can easily remove objects that have finalizers,
1038  * but all the others could still be present in random places on the heap.
1039  * We need a sweep to get rid of them even though it's going to be costly
1040  * with big heaps.
1041  * The reason we need to remove them is because we access the vtable and class
1042  * structures to know the object size and the reference bitmap: once the domain is
1043  * unloaded the point to random memory.
1044  */
1045 void
1046 mono_gc_clear_domain (MonoDomain * domain)
1047 {
1048         LOSObject *bigobj, *prev;
1049         int i;
1050
1051         LOCK_GC;
1052
1053         binary_protocol_domain_unload_begin (domain);
1054
1055         sgen_stop_world (0);
1056
1057         if (concurrent_collection_in_progress)
1058                 sgen_perform_collection (0, GENERATION_OLD, "clear domain", TRUE);
1059         g_assert (!concurrent_collection_in_progress);
1060
1061         sgen_process_fin_stage_entries ();
1062         sgen_process_dislink_stage_entries ();
1063
1064         sgen_clear_nursery_fragments ();
1065
1066         if (xdomain_checks && domain != mono_get_root_domain ()) {
1067                 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_NORMAL);
1068                 scan_for_registered_roots_in_domain (domain, ROOT_TYPE_WBARRIER);
1069                 check_for_xdomain_refs ();
1070         }
1071
1072         /*Ephemerons and dislinks must be processed before LOS since they might end up pointing
1073         to memory returned to the OS.*/
1074         null_ephemerons_for_domain (domain);
1075
1076         for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1077                 sgen_null_links_for_domain (domain, i);
1078
1079         for (i = GENERATION_NURSERY; i < GENERATION_MAX; ++i)
1080                 sgen_remove_finalizers_for_domain (domain, i);
1081
1082         sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
1083                         (IterateObjectCallbackFunc)clear_domain_process_minor_object_callback, domain, FALSE);
1084
1085         /* We need two passes over major and large objects because
1086            freeing such objects might give their memory back to the OS
1087            (in the case of large objects) or obliterate its vtable
1088            (pinned objects with major-copying or pinned and non-pinned
1089            objects with major-mark&sweep), but we might need to
1090            dereference a pointer from an object to another object if
1091            the first object is a proxy. */
1092         major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)clear_domain_process_major_object_callback, domain);
1093         for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
1094                 clear_domain_process_object (bigobj->data, domain);
1095
1096         prev = NULL;
1097         for (bigobj = los_object_list; bigobj;) {
1098                 if (need_remove_object_for_domain (bigobj->data, domain)) {
1099                         LOSObject *to_free = bigobj;
1100                         if (prev)
1101                                 prev->next = bigobj->next;
1102                         else
1103                                 los_object_list = bigobj->next;
1104                         bigobj = bigobj->next;
1105                         SGEN_LOG (4, "Freeing large object %p", bigobj->data);
1106                         sgen_los_free_object (to_free);
1107                         continue;
1108                 }
1109                 prev = bigobj;
1110                 bigobj = bigobj->next;
1111         }
1112         major_collector.iterate_objects (TRUE, FALSE, (IterateObjectCallbackFunc)clear_domain_free_major_non_pinned_object_callback, domain);
1113         major_collector.iterate_objects (FALSE, TRUE, (IterateObjectCallbackFunc)clear_domain_free_major_pinned_object_callback, domain);
1114
1115         if (domain == mono_get_root_domain ()) {
1116                 if (G_UNLIKELY (do_pin_stats))
1117                         sgen_pin_stats_print_class_stats ();
1118                 sgen_object_layout_dump (stdout);
1119         }
1120
1121         sgen_restart_world (0, NULL);
1122
1123         binary_protocol_domain_unload_end (domain);
1124
1125         UNLOCK_GC;
1126 }
1127
1128 /*
1129  * sgen_add_to_global_remset:
1130  *
1131  *   The global remset contains locations which point into newspace after
1132  * a minor collection. This can happen if the objects they point to are pinned.
1133  *
1134  * LOCKING: If called from a parallel collector, the global remset
1135  * lock must be held.  For serial collectors that is not necessary.
1136  */
1137 void
1138 sgen_add_to_global_remset (gpointer ptr, gpointer obj)
1139 {
1140         SGEN_ASSERT (5, sgen_ptr_in_nursery (obj), "Target pointer of global remset must be in the nursery");
1141
1142         HEAVY_STAT (++stat_wbarrier_add_to_global_remset);
1143
1144         if (!major_collector.is_concurrent) {
1145                 SGEN_ASSERT (5, current_collection_generation != -1, "Global remsets can only be added during collections");
1146         } else {
1147                 if (current_collection_generation == -1)
1148                         SGEN_ASSERT (5, sgen_concurrent_collection_in_progress (), "Global remsets outside of collection pauses can only be added by the concurrent collector");
1149         }
1150
1151         if (!object_is_pinned (obj))
1152                 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");
1153         else if (sgen_cement_lookup_or_register (obj))
1154                 return;
1155
1156         remset.record_pointer (ptr);
1157
1158         if (G_UNLIKELY (do_pin_stats))
1159                 sgen_pin_stats_register_global_remset (obj);
1160
1161         SGEN_LOG (8, "Adding global remset for %p", ptr);
1162         binary_protocol_global_remset (ptr, obj, (gpointer)SGEN_LOAD_VTABLE (obj));
1163
1164
1165 #ifdef ENABLE_DTRACE
1166         if (G_UNLIKELY (MONO_GC_GLOBAL_REMSET_ADD_ENABLED ())) {
1167                 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
1168                 MONO_GC_GLOBAL_REMSET_ADD ((mword)ptr, (mword)obj, sgen_safe_object_get_size (obj),
1169                                 vt->klass->name_space, vt->klass->name);
1170         }
1171 #endif
1172 }
1173
1174 /*
1175  * sgen_drain_gray_stack:
1176  *
1177  *   Scan objects in the gray stack until the stack is empty. This should be called
1178  * frequently after each object is copied, to achieve better locality and cache
1179  * usage.
1180  */
1181 gboolean
1182 sgen_drain_gray_stack (int max_objs, ScanCopyContext ctx)
1183 {
1184         char *obj;
1185         ScanObjectFunc scan_func = ctx.scan_func;
1186         GrayQueue *queue = ctx.queue;
1187
1188         if (max_objs == -1) {
1189                 for (;;) {
1190                         GRAY_OBJECT_DEQUEUE (queue, obj);
1191                         if (!obj)
1192                                 return TRUE;
1193                         SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1194                         scan_func (obj, queue);
1195                 }
1196         } else {
1197                 int i;
1198
1199                 do {
1200                         for (i = 0; i != max_objs; ++i) {
1201                                 GRAY_OBJECT_DEQUEUE (queue, obj);
1202                                 if (!obj)
1203                                         return TRUE;
1204                                 SGEN_LOG (9, "Precise gray object scan %p (%s)", obj, safe_name (obj));
1205                                 scan_func (obj, queue);
1206                         }
1207                 } while (max_objs < 0);
1208                 return FALSE;
1209         }
1210 }
1211
1212 /*
1213  * Addresses from start to end are already sorted. This function finds
1214  * the object header for each address and pins the object. The
1215  * addresses must be inside the passed section.  The (start of the)
1216  * address array is overwritten with the addresses of the actually
1217  * pinned objects.  Return the number of pinned objects.
1218  */
1219 static int
1220 pin_objects_from_addresses (GCMemSection *section, void **start, void **end, void *start_nursery, void *end_nursery, ScanCopyContext ctx)
1221 {
1222         void *last = NULL;
1223         int count = 0;
1224         void *search_start;
1225         void *last_obj = NULL;
1226         size_t last_obj_size = 0;
1227         void *addr;
1228         int idx;
1229         void **definitely_pinned = start;
1230         ScanObjectFunc scan_func = ctx.scan_func;
1231         SgenGrayQueue *queue = ctx.queue;
1232
1233         sgen_nursery_allocator_prepare_for_pinning ();
1234
1235         while (start < end) {
1236                 addr = *start;
1237                 /* the range check should be reduntant */
1238                 if (addr != last && addr >= start_nursery && addr < end_nursery) {
1239                         SGEN_LOG (5, "Considering pinning addr %p", addr);
1240                         /* multiple pointers to the same object */
1241                         if (addr >= last_obj && (char*)addr < (char*)last_obj + last_obj_size) {
1242                                 start++;
1243                                 continue;
1244                         }
1245                         idx = ((char*)addr - (char*)section->data) / SCAN_START_SIZE;
1246                         g_assert (idx < section->num_scan_start);
1247                         search_start = (void*)section->scan_starts [idx];
1248                         if (!search_start || search_start > addr) {
1249                                 while (idx) {
1250                                         --idx;
1251                                         search_start = section->scan_starts [idx];
1252                                         if (search_start && search_start <= addr)
1253                                                 break;
1254                                 }
1255                                 if (!search_start || search_start > addr)
1256                                         search_start = start_nursery;
1257                         }
1258                         if (search_start < last_obj)
1259                                 search_start = (char*)last_obj + last_obj_size;
1260                         /* now addr should be in an object a short distance from search_start
1261                          * Note that search_start must point to zeroed mem or point to an object.
1262                          */
1263
1264                         do {
1265                                 if (!*(void**)search_start) {
1266                                         /* Consistency check */
1267                                         /*
1268                                         for (frag = nursery_fragments; frag; frag = frag->next) {
1269                                                 if (search_start >= frag->fragment_start && search_start < frag->fragment_end)
1270                                                         g_assert_not_reached ();
1271                                         }
1272                                         */
1273
1274                                         search_start = (void*)ALIGN_UP ((mword)search_start + sizeof (gpointer));
1275                                         continue;
1276                                 }
1277                                 last_obj = search_start;
1278                                 last_obj_size = ALIGN_UP (safe_object_get_size ((MonoObject*)search_start));
1279
1280                                 if (((MonoObject*)last_obj)->synchronisation == GINT_TO_POINTER (-1)) {
1281                                         /* Marks the beginning of a nursery fragment, skip */
1282                                 } else {
1283                                         SGEN_LOG (8, "Pinned try match %p (%s), size %zd", last_obj, safe_name (last_obj), last_obj_size);
1284                                         if (addr >= search_start && (char*)addr < (char*)last_obj + last_obj_size) {
1285                                                 if (scan_func) {
1286                                                         scan_func (search_start, queue);
1287                                                 } else {
1288                                                         SGEN_LOG (4, "Pinned object %p, vtable %p (%s), count %d\n",
1289                                                                         search_start, *(void**)search_start, safe_name (search_start), count);
1290                                                         binary_protocol_pin (search_start,
1291                                                                         (gpointer)LOAD_VTABLE (search_start),
1292                                                                         safe_object_get_size (search_start));
1293
1294 #ifdef ENABLE_DTRACE
1295                                                         if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1296                                                                 int gen = sgen_ptr_in_nursery (search_start) ? GENERATION_NURSERY : GENERATION_OLD;
1297                                                                 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (search_start);
1298                                                                 MONO_GC_OBJ_PINNED ((mword)search_start,
1299                                                                                 sgen_safe_object_get_size (search_start),
1300                                                                                 vt->klass->name_space, vt->klass->name, gen);
1301                                                         }
1302 #endif
1303
1304                                                         pin_object (search_start);
1305                                                         GRAY_OBJECT_ENQUEUE (queue, search_start);
1306                                                         if (G_UNLIKELY (do_pin_stats))
1307                                                                 sgen_pin_stats_register_object (search_start, last_obj_size);
1308                                                         definitely_pinned [count] = search_start;
1309                                                         count++;
1310                                                 }
1311                                                 break;
1312                                         }
1313                                 }
1314                                 /* skip to the next object */
1315                                 search_start = (void*)((char*)search_start + last_obj_size);
1316                         } while (search_start <= addr);
1317                         /* we either pinned the correct object or we ignored the addr because
1318                          * it points to unused zeroed memory.
1319                          */
1320                         last = addr;
1321                 }
1322                 start++;
1323         }
1324         //printf ("effective pinned: %d (at the end: %d)\n", count, (char*)end_nursery - (char*)last);
1325         if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS) {
1326                 GCRootReport report;
1327                 report.count = 0;
1328                 for (idx = 0; idx < count; ++idx)
1329                         add_profile_gc_root (&report, definitely_pinned [idx], MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
1330                 notify_gc_roots (&report);
1331         }
1332         stat_pinned_objects += count;
1333         return count;
1334 }
1335
1336 void
1337 sgen_pin_objects_in_section (GCMemSection *section, ScanCopyContext ctx)
1338 {
1339         int num_entries = section->pin_queue_num_entries;
1340         if (num_entries) {
1341                 void **start = section->pin_queue_start;
1342                 int reduced_to;
1343                 reduced_to = pin_objects_from_addresses (section, start, start + num_entries,
1344                                 section->data, section->next_data, ctx);
1345                 section->pin_queue_num_entries = reduced_to;
1346                 if (!reduced_to)
1347                         section->pin_queue_start = NULL;
1348         }
1349 }
1350
1351
1352 void
1353 sgen_pin_object (void *object, GrayQueue *queue)
1354 {
1355         g_assert (!concurrent_collection_in_progress);
1356
1357         if (sgen_collection_is_parallel ()) {
1358                 LOCK_PIN_QUEUE;
1359                 /*object arrives pinned*/
1360                 sgen_pin_stage_ptr (object);
1361                 ++objects_pinned ;
1362                 UNLOCK_PIN_QUEUE;
1363         } else {
1364                 SGEN_PIN_OBJECT (object);
1365                 sgen_pin_stage_ptr (object);
1366                 ++objects_pinned;
1367                 if (G_UNLIKELY (do_pin_stats))
1368                         sgen_pin_stats_register_object (object, safe_object_get_size (object));
1369         }
1370         GRAY_OBJECT_ENQUEUE (queue, object);
1371         binary_protocol_pin (object, (gpointer)LOAD_VTABLE (object), safe_object_get_size (object));
1372
1373 #ifdef ENABLE_DTRACE
1374         if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
1375                 int gen = sgen_ptr_in_nursery (object) ? GENERATION_NURSERY : GENERATION_OLD;
1376                 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (object);
1377                 MONO_GC_OBJ_PINNED ((mword)object, sgen_safe_object_get_size (object), vt->klass->name_space, vt->klass->name, gen);
1378         }
1379 #endif
1380 }
1381
1382 void
1383 sgen_parallel_pin_or_update (void **ptr, void *obj, MonoVTable *vt, SgenGrayQueue *queue)
1384 {
1385         for (;;) {
1386                 mword vtable_word;
1387                 gboolean major_pinned = FALSE;
1388
1389                 if (sgen_ptr_in_nursery (obj)) {
1390                         if (SGEN_CAS_PTR (obj, (void*)((mword)vt | SGEN_PINNED_BIT), vt) == vt) {
1391                                 sgen_pin_object (obj, queue);
1392                                 break;
1393                         }
1394                 } else {
1395                         major_collector.pin_major_object (obj, queue);
1396                         major_pinned = TRUE;
1397                 }
1398
1399                 vtable_word = *(mword*)obj;
1400                 /*someone else forwarded it, update the pointer and bail out*/
1401                 if (vtable_word & SGEN_FORWARDED_BIT) {
1402                         *ptr = (void*)(vtable_word & ~SGEN_VTABLE_BITS_MASK);
1403                         break;
1404                 }
1405
1406                 /*someone pinned it, nothing to do.*/
1407                 if (vtable_word & SGEN_PINNED_BIT || major_pinned)
1408                         break;
1409         }
1410 }
1411
1412 /* Sort the addresses in array in increasing order.
1413  * Done using a by-the book heap sort. Which has decent and stable performance, is pretty cache efficient.
1414  */
1415 void
1416 sgen_sort_addresses (void **array, int size)
1417 {
1418         int i;
1419         void *tmp;
1420
1421         for (i = 1; i < size; ++i) {
1422                 int child = i;
1423                 while (child > 0) {
1424                         int parent = (child - 1) / 2;
1425
1426                         if (array [parent] >= array [child])
1427                                 break;
1428
1429                         tmp = array [parent];
1430                         array [parent] = array [child];
1431                         array [child] = tmp;
1432
1433                         child = parent;
1434                 }
1435         }
1436
1437         for (i = size - 1; i > 0; --i) {
1438                 int end, root;
1439                 tmp = array [i];
1440                 array [i] = array [0];
1441                 array [0] = tmp;
1442
1443                 end = i - 1;
1444                 root = 0;
1445
1446                 while (root * 2 + 1 <= end) {
1447                         int child = root * 2 + 1;
1448
1449                         if (child < end && array [child] < array [child + 1])
1450                                 ++child;
1451                         if (array [root] >= array [child])
1452                                 break;
1453
1454                         tmp = array [root];
1455                         array [root] = array [child];
1456                         array [child] = tmp;
1457
1458                         root = child;
1459                 }
1460         }
1461 }
1462
1463 /*
1464  * Scan the memory between start and end and queue values which could be pointers
1465  * to the area between start_nursery and end_nursery for later consideration.
1466  * Typically used for thread stacks.
1467  */
1468 static void
1469 conservatively_pin_objects_from (void **start, void **end, void *start_nursery, void *end_nursery, int pin_type)
1470 {
1471         int count = 0;
1472
1473 #ifdef VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE
1474         VALGRIND_MAKE_MEM_DEFINED_IF_ADDRESSABLE (start, (char*)end - (char*)start);
1475 #endif
1476
1477         while (start < end) {
1478                 if (*start >= start_nursery && *start < end_nursery) {
1479                         /*
1480                          * *start can point to the middle of an object
1481                          * note: should we handle pointing at the end of an object?
1482                          * pinning in C# code disallows pointing at the end of an object
1483                          * but there is some small chance that an optimizing C compiler
1484                          * may keep the only reference to an object by pointing
1485                          * at the end of it. We ignore this small chance for now.
1486                          * Pointers to the end of an object are indistinguishable
1487                          * from pointers to the start of the next object in memory
1488                          * so if we allow that we'd need to pin two objects...
1489                          * We queue the pointer in an array, the
1490                          * array will then be sorted and uniqued. This way
1491                          * we can coalesce several pinning pointers and it should
1492                          * be faster since we'd do a memory scan with increasing
1493                          * addresses. Note: we can align the address to the allocation
1494                          * alignment, so the unique process is more effective.
1495                          */
1496                         mword addr = (mword)*start;
1497                         addr &= ~(ALLOC_ALIGN - 1);
1498                         if (addr >= (mword)start_nursery && addr < (mword)end_nursery) {
1499                                 SGEN_LOG (6, "Pinning address %p from %p", (void*)addr, start);
1500                                 sgen_pin_stage_ptr ((void*)addr);
1501                                 count++;
1502                         }
1503                         if (G_UNLIKELY (do_pin_stats)) {
1504                                 if (ptr_in_nursery ((void*)addr))
1505                                         sgen_pin_stats_register_address ((char*)addr, pin_type);
1506                         }
1507                 }
1508                 start++;
1509         }
1510         if (count)
1511                 SGEN_LOG (7, "found %d potential pinned heap pointers", count);
1512 }
1513
1514 /*
1515  * The first thing we do in a collection is to identify pinned objects.
1516  * This function considers all the areas of memory that need to be
1517  * conservatively scanned.
1518  */
1519 static void
1520 pin_from_roots (void *start_nursery, void *end_nursery, GrayQueue *queue)
1521 {
1522         void **start_root;
1523         RootRecord *root;
1524         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);
1525         /* objects pinned from the API are inside these roots */
1526         SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], start_root, root) {
1527                 SGEN_LOG (6, "Pinned roots %p-%p", start_root, root->end_root);
1528                 conservatively_pin_objects_from (start_root, (void**)root->end_root, start_nursery, end_nursery, PIN_TYPE_OTHER);
1529         } SGEN_HASH_TABLE_FOREACH_END;
1530         /* now deal with the thread stacks
1531          * in the future we should be able to conservatively scan only:
1532          * *) the cpu registers
1533          * *) the unmanaged stack frames
1534          * *) the _last_ managed stack frame
1535          * *) pointers slots in managed frames
1536          */
1537         scan_thread_data (start_nursery, end_nursery, FALSE, queue);
1538 }
1539
1540 static void
1541 unpin_objects_from_queue (SgenGrayQueue *queue)
1542 {
1543         for (;;) {
1544                 char *addr;
1545                 GRAY_OBJECT_DEQUEUE (queue, addr);
1546                 if (!addr)
1547                         break;
1548                 g_assert (SGEN_OBJECT_IS_PINNED (addr));
1549                 SGEN_UNPIN_OBJECT (addr);
1550         }
1551 }
1552
1553 typedef struct {
1554         CopyOrMarkObjectFunc func;
1555         GrayQueue *queue;
1556 } UserCopyOrMarkData;
1557
1558 static MonoNativeTlsKey user_copy_or_mark_key;
1559
1560 static void
1561 init_user_copy_or_mark_key (void)
1562 {
1563         mono_native_tls_alloc (&user_copy_or_mark_key, NULL);
1564 }
1565
1566 static void
1567 set_user_copy_or_mark_data (UserCopyOrMarkData *data)
1568 {
1569         mono_native_tls_set_value (user_copy_or_mark_key, data);
1570 }
1571
1572 static void
1573 single_arg_user_copy_or_mark (void **obj)
1574 {
1575         UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
1576
1577         data->func (obj, data->queue);
1578 }
1579
1580 /*
1581  * The memory area from start_root to end_root contains pointers to objects.
1582  * Their position is precisely described by @desc (this means that the pointer
1583  * can be either NULL or the pointer to the start of an object).
1584  * This functions copies them to to_space updates them.
1585  *
1586  * This function is not thread-safe!
1587  */
1588 static void
1589 precisely_scan_objects_from (void** start_root, void** end_root, char* n_start, char *n_end, mword desc, ScanCopyContext ctx)
1590 {
1591         CopyOrMarkObjectFunc copy_func = ctx.copy_func;
1592         SgenGrayQueue *queue = ctx.queue;
1593
1594         switch (desc & ROOT_DESC_TYPE_MASK) {
1595         case ROOT_DESC_BITMAP:
1596                 desc >>= ROOT_DESC_TYPE_SHIFT;
1597                 while (desc) {
1598                         if ((desc & 1) && *start_root) {
1599                                 copy_func (start_root, queue);
1600                                 SGEN_LOG (9, "Overwrote root at %p with %p", start_root, *start_root);
1601                                 sgen_drain_gray_stack (-1, ctx);
1602                         }
1603                         desc >>= 1;
1604                         start_root++;
1605                 }
1606                 return;
1607         case ROOT_DESC_COMPLEX: {
1608                 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1609                 int bwords = (*bitmap_data) - 1;
1610                 void **start_run = start_root;
1611                 bitmap_data++;
1612                 while (bwords-- > 0) {
1613                         gsize bmap = *bitmap_data++;
1614                         void **objptr = start_run;
1615                         while (bmap) {
1616                                 if ((bmap & 1) && *objptr) {
1617                                         copy_func (objptr, queue);
1618                                         SGEN_LOG (9, "Overwrote root at %p with %p", objptr, *objptr);
1619                                         sgen_drain_gray_stack (-1, ctx);
1620                                 }
1621                                 bmap >>= 1;
1622                                 ++objptr;
1623                         }
1624                         start_run += GC_BITS_PER_WORD;
1625                 }
1626                 break;
1627         }
1628         case ROOT_DESC_USER: {
1629                 UserCopyOrMarkData data = { copy_func, queue };
1630                 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1631                 set_user_copy_or_mark_data (&data);
1632                 marker (start_root, single_arg_user_copy_or_mark);
1633                 set_user_copy_or_mark_data (NULL);
1634                 break;
1635         }
1636         case ROOT_DESC_RUN_LEN:
1637                 g_assert_not_reached ();
1638         default:
1639                 g_assert_not_reached ();
1640         }
1641 }
1642
1643 static void
1644 reset_heap_boundaries (void)
1645 {
1646         lowest_heap_address = ~(mword)0;
1647         highest_heap_address = 0;
1648 }
1649
1650 void
1651 sgen_update_heap_boundaries (mword low, mword high)
1652 {
1653         mword old;
1654
1655         do {
1656                 old = lowest_heap_address;
1657                 if (low >= old)
1658                         break;
1659         } while (SGEN_CAS_PTR ((gpointer*)&lowest_heap_address, (gpointer)low, (gpointer)old) != (gpointer)old);
1660
1661         do {
1662                 old = highest_heap_address;
1663                 if (high <= old)
1664                         break;
1665         } while (SGEN_CAS_PTR ((gpointer*)&highest_heap_address, (gpointer)high, (gpointer)old) != (gpointer)old);
1666 }
1667
1668 /*
1669  * Allocate and setup the data structures needed to be able to allocate objects
1670  * in the nursery. The nursery is stored in nursery_section.
1671  */
1672 static void
1673 alloc_nursery (void)
1674 {
1675         GCMemSection *section;
1676         char *data;
1677         int scan_starts;
1678         int alloc_size;
1679
1680         if (nursery_section)
1681                 return;
1682         SGEN_LOG (2, "Allocating nursery size: %lu", (unsigned long)sgen_nursery_size);
1683         /* later we will alloc a larger area for the nursery but only activate
1684          * what we need. The rest will be used as expansion if we have too many pinned
1685          * objects in the existing nursery.
1686          */
1687         /* FIXME: handle OOM */
1688         section = sgen_alloc_internal (INTERNAL_MEM_SECTION);
1689
1690         alloc_size = sgen_nursery_size;
1691
1692         /* If there isn't enough space even for the nursery we should simply abort. */
1693         g_assert (sgen_memgov_try_alloc_space (alloc_size, SPACE_NURSERY));
1694
1695 #ifdef SGEN_ALIGN_NURSERY
1696         data = major_collector.alloc_heap (alloc_size, alloc_size, DEFAULT_NURSERY_BITS);
1697 #else
1698         data = major_collector.alloc_heap (alloc_size, 0, DEFAULT_NURSERY_BITS);
1699 #endif
1700         sgen_update_heap_boundaries ((mword)data, (mword)(data + sgen_nursery_size));
1701         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 ());
1702         section->data = section->next_data = data;
1703         section->size = alloc_size;
1704         section->end_data = data + sgen_nursery_size;
1705         scan_starts = (alloc_size + SCAN_START_SIZE - 1) / SCAN_START_SIZE;
1706         section->scan_starts = sgen_alloc_internal_dynamic (sizeof (char*) * scan_starts, INTERNAL_MEM_SCAN_STARTS, TRUE);
1707         section->num_scan_start = scan_starts;
1708
1709         nursery_section = section;
1710
1711         sgen_nursery_allocator_set_nursery_bounds (data, data + sgen_nursery_size);
1712 }
1713
1714 void*
1715 mono_gc_get_nursery (int *shift_bits, size_t *size)
1716 {
1717         *size = sgen_nursery_size;
1718 #ifdef SGEN_ALIGN_NURSERY
1719         *shift_bits = DEFAULT_NURSERY_BITS;
1720 #else
1721         *shift_bits = -1;
1722 #endif
1723         return sgen_get_nursery_start ();
1724 }
1725
1726 void
1727 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1728 {
1729         SgenThreadInfo *info = mono_thread_info_current ();
1730
1731         /* Could be called from sgen_thread_unregister () with a NULL info */
1732         if (domain) {
1733                 g_assert (info);
1734                 info->stopped_domain = domain;
1735         }
1736 }
1737
1738 gboolean
1739 mono_gc_precise_stack_mark_enabled (void)
1740 {
1741         return !conservative_stack_mark;
1742 }
1743
1744 FILE *
1745 mono_gc_get_logfile (void)
1746 {
1747         return gc_debug_file;
1748 }
1749
1750 static void
1751 report_finalizer_roots_list (FinalizeReadyEntry *list)
1752 {
1753         GCRootReport report;
1754         FinalizeReadyEntry *fin;
1755
1756         report.count = 0;
1757         for (fin = list; fin; fin = fin->next) {
1758                 if (!fin->object)
1759                         continue;
1760                 add_profile_gc_root (&report, fin->object, MONO_PROFILE_GC_ROOT_FINALIZER, 0);
1761         }
1762         notify_gc_roots (&report);
1763 }
1764
1765 static void
1766 report_finalizer_roots (void)
1767 {
1768         report_finalizer_roots_list (fin_ready_list);
1769         report_finalizer_roots_list (critical_fin_list);
1770 }
1771
1772 static GCRootReport *root_report;
1773
1774 static void
1775 single_arg_report_root (void **obj)
1776 {
1777         if (*obj)
1778                 add_profile_gc_root (root_report, *obj, MONO_PROFILE_GC_ROOT_OTHER, 0);
1779 }
1780
1781 static void
1782 precisely_report_roots_from (GCRootReport *report, void** start_root, void** end_root, mword desc)
1783 {
1784         switch (desc & ROOT_DESC_TYPE_MASK) {
1785         case ROOT_DESC_BITMAP:
1786                 desc >>= ROOT_DESC_TYPE_SHIFT;
1787                 while (desc) {
1788                         if ((desc & 1) && *start_root) {
1789                                 add_profile_gc_root (report, *start_root, MONO_PROFILE_GC_ROOT_OTHER, 0);
1790                         }
1791                         desc >>= 1;
1792                         start_root++;
1793                 }
1794                 return;
1795         case ROOT_DESC_COMPLEX: {
1796                 gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
1797                 int bwords = (*bitmap_data) - 1;
1798                 void **start_run = start_root;
1799                 bitmap_data++;
1800                 while (bwords-- > 0) {
1801                         gsize bmap = *bitmap_data++;
1802                         void **objptr = start_run;
1803                         while (bmap) {
1804                                 if ((bmap & 1) && *objptr) {
1805                                         add_profile_gc_root (report, *objptr, MONO_PROFILE_GC_ROOT_OTHER, 0);
1806                                 }
1807                                 bmap >>= 1;
1808                                 ++objptr;
1809                         }
1810                         start_run += GC_BITS_PER_WORD;
1811                 }
1812                 break;
1813         }
1814         case ROOT_DESC_USER: {
1815                 MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
1816                 root_report = report;
1817                 marker (start_root, single_arg_report_root);
1818                 break;
1819         }
1820         case ROOT_DESC_RUN_LEN:
1821                 g_assert_not_reached ();
1822         default:
1823                 g_assert_not_reached ();
1824         }
1825 }
1826
1827 static void
1828 report_registered_roots_by_type (int root_type)
1829 {
1830         GCRootReport report;
1831         void **start_root;
1832         RootRecord *root;
1833         report.count = 0;
1834         SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
1835                 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
1836                 precisely_report_roots_from (&report, start_root, (void**)root->end_root, root->root_desc);
1837         } SGEN_HASH_TABLE_FOREACH_END;
1838         notify_gc_roots (&report);
1839 }
1840
1841 static void
1842 report_registered_roots (void)
1843 {
1844         report_registered_roots_by_type (ROOT_TYPE_NORMAL);
1845         report_registered_roots_by_type (ROOT_TYPE_WBARRIER);
1846 }
1847
1848 static void
1849 scan_finalizer_entries (FinalizeReadyEntry *list, ScanCopyContext ctx)
1850 {
1851         CopyOrMarkObjectFunc copy_func = ctx.copy_func;
1852         SgenGrayQueue *queue = ctx.queue;
1853         FinalizeReadyEntry *fin;
1854
1855         for (fin = list; fin; fin = fin->next) {
1856                 if (!fin->object)
1857                         continue;
1858                 SGEN_LOG (5, "Scan of fin ready object: %p (%s)\n", fin->object, safe_name (fin->object));
1859                 copy_func (&fin->object, queue);
1860         }
1861 }
1862
1863 static const char*
1864 generation_name (int generation)
1865 {
1866         switch (generation) {
1867         case GENERATION_NURSERY: return "nursery";
1868         case GENERATION_OLD: return "old";
1869         default: g_assert_not_reached ();
1870         }
1871 }
1872
1873 const char*
1874 sgen_generation_name (int generation)
1875 {
1876         return generation_name (generation);
1877 }
1878
1879 SgenObjectOperations *
1880 sgen_get_current_object_ops (void){
1881         return &current_object_ops;
1882 }
1883
1884
1885 static void
1886 finish_gray_stack (int generation, GrayQueue *queue)
1887 {
1888         TV_DECLARE (atv);
1889         TV_DECLARE (btv);
1890         int done_with_ephemerons, ephemeron_rounds = 0;
1891         CopyOrMarkObjectFunc copy_func = current_object_ops.copy_or_mark_object;
1892         ScanObjectFunc scan_func = current_object_ops.scan_object;
1893         ScanCopyContext ctx = { scan_func, copy_func, queue };
1894         char *start_addr = generation == GENERATION_NURSERY ? sgen_get_nursery_start () : NULL;
1895         char *end_addr = generation == GENERATION_NURSERY ? sgen_get_nursery_end () : (char*)-1;
1896
1897         /*
1898          * We copied all the reachable objects. Now it's the time to copy
1899          * the objects that were not referenced by the roots, but by the copied objects.
1900          * we built a stack of objects pointed to by gray_start: they are
1901          * additional roots and we may add more items as we go.
1902          * We loop until gray_start == gray_objects which means no more objects have
1903          * been added. Note this is iterative: no recursion is involved.
1904          * We need to walk the LO list as well in search of marked big objects
1905          * (use a flag since this is needed only on major collections). We need to loop
1906          * here as well, so keep a counter of marked LO (increasing it in copy_object).
1907          *   To achieve better cache locality and cache usage, we drain the gray stack
1908          * frequently, after each object is copied, and just finish the work here.
1909          */
1910         sgen_drain_gray_stack (-1, ctx);
1911         TV_GETTIME (atv);
1912         SGEN_LOG (2, "%s generation done", generation_name (generation));
1913
1914         /*
1915         Reset bridge data, we might have lingering data from a previous collection if this is a major
1916         collection trigged by minor overflow.
1917
1918         We must reset the gathered bridges since their original block might be evacuated due to major
1919         fragmentation in the meanwhile and the bridge code should not have to deal with that.
1920         */
1921         if (sgen_need_bridge_processing ())
1922                 sgen_bridge_reset_data ();
1923
1924         /*
1925          * Walk the ephemeron tables marking all values with reachable keys. This must be completely done
1926          * before processing finalizable objects and non-tracking weak links to avoid finalizing/clearing
1927          * objects that are in fact reachable.
1928          */
1929         done_with_ephemerons = 0;
1930         do {
1931                 done_with_ephemerons = mark_ephemerons_in_range (ctx);
1932                 sgen_drain_gray_stack (-1, ctx);
1933                 ++ephemeron_rounds;
1934         } while (!done_with_ephemerons);
1935
1936         sgen_scan_togglerefs (start_addr, end_addr, ctx);
1937
1938         if (sgen_need_bridge_processing ()) {
1939                 /*Make sure the gray stack is empty before we process bridge objects so we get liveness right*/
1940                 sgen_drain_gray_stack (-1, ctx);
1941                 sgen_collect_bridge_objects (generation, ctx);
1942                 if (generation == GENERATION_OLD)
1943                         sgen_collect_bridge_objects (GENERATION_NURSERY, ctx);
1944
1945                 /*
1946                 Do the first bridge step here, as the collector liveness state will become useless after that.
1947
1948                 An important optimization is to only proccess the possibly dead part of the object graph and skip
1949                 over all live objects as we transitively know everything they point must be alive too.
1950
1951                 The above invariant is completely wrong if we let the gray queue be drained and mark/copy everything.
1952
1953                 This has the unfortunate side effect of making overflow collections perform the first step twice, but
1954                 given we now have heuristics that perform major GC in anticipation of minor overflows this should not
1955                 be a big deal.
1956                 */
1957                 sgen_bridge_processing_stw_step ();
1958         }
1959
1960         /*
1961         Make sure we drain the gray stack before processing disappearing links and finalizers.
1962         If we don't make sure it is empty we might wrongly see a live object as dead.
1963         */
1964         sgen_drain_gray_stack (-1, ctx);
1965
1966         /*
1967         We must clear weak links that don't track resurrection before processing object ready for
1968         finalization so they can be cleared before that.
1969         */
1970         sgen_null_link_in_range (generation, TRUE, ctx);
1971         if (generation == GENERATION_OLD)
1972                 sgen_null_link_in_range (GENERATION_NURSERY, TRUE, ctx);
1973
1974
1975         /* walk the finalization queue and move also the objects that need to be
1976          * finalized: use the finalized objects as new roots so the objects they depend
1977          * on are also not reclaimed. As with the roots above, only objects in the nursery
1978          * are marked/copied.
1979          */
1980         sgen_finalize_in_range (generation, ctx);
1981         if (generation == GENERATION_OLD)
1982                 sgen_finalize_in_range (GENERATION_NURSERY, ctx);
1983         /* drain the new stack that might have been created */
1984         SGEN_LOG (6, "Precise scan of gray area post fin");
1985         sgen_drain_gray_stack (-1, ctx);
1986
1987         /*
1988          * This must be done again after processing finalizable objects since CWL slots are cleared only after the key is finalized.
1989          */
1990         done_with_ephemerons = 0;
1991         do {
1992                 done_with_ephemerons = mark_ephemerons_in_range (ctx);
1993                 sgen_drain_gray_stack (-1, ctx);
1994                 ++ephemeron_rounds;
1995         } while (!done_with_ephemerons);
1996
1997         /*
1998          * Clear ephemeron pairs with unreachable keys.
1999          * We pass the copy func so we can figure out if an array was promoted or not.
2000          */
2001         clear_unreachable_ephemerons (ctx);
2002
2003         TV_GETTIME (btv);
2004         SGEN_LOG (2, "Finalize queue handling scan for %s generation: %d usecs %d ephemeron rounds", generation_name (generation), TV_ELAPSED (atv, btv), ephemeron_rounds);
2005
2006         /*
2007          * handle disappearing links
2008          * Note we do this after checking the finalization queue because if an object
2009          * survives (at least long enough to be finalized) we don't clear the link.
2010          * This also deals with a possible issue with the monitor reclamation: with the Boehm
2011          * GC a finalized object my lose the monitor because it is cleared before the finalizer is
2012          * called.
2013          */
2014         g_assert (sgen_gray_object_queue_is_empty (queue));
2015         for (;;) {
2016                 sgen_null_link_in_range (generation, FALSE, ctx);
2017                 if (generation == GENERATION_OLD)
2018                         sgen_null_link_in_range (GENERATION_NURSERY, FALSE, ctx);
2019                 if (sgen_gray_object_queue_is_empty (queue))
2020                         break;
2021                 sgen_drain_gray_stack (-1, ctx);
2022         }
2023
2024         g_assert (sgen_gray_object_queue_is_empty (queue));
2025 }
2026
2027 void
2028 sgen_check_section_scan_starts (GCMemSection *section)
2029 {
2030         int i;
2031         for (i = 0; i < section->num_scan_start; ++i) {
2032                 if (section->scan_starts [i]) {
2033                         guint size = safe_object_get_size ((MonoObject*) section->scan_starts [i]);
2034                         g_assert (size >= sizeof (MonoObject) && size <= MAX_SMALL_OBJ_SIZE);
2035                 }
2036         }
2037 }
2038
2039 static void
2040 check_scan_starts (void)
2041 {
2042         if (!do_scan_starts_check)
2043                 return;
2044         sgen_check_section_scan_starts (nursery_section);
2045         major_collector.check_scan_starts ();
2046 }
2047
2048 static void
2049 scan_from_registered_roots (char *addr_start, char *addr_end, int root_type, ScanCopyContext ctx)
2050 {
2051         void **start_root;
2052         RootRecord *root;
2053         SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
2054                 SGEN_LOG (6, "Precise root scan %p-%p (desc: %p)", start_root, root->end_root, (void*)root->root_desc);
2055                 precisely_scan_objects_from (start_root, (void**)root->end_root, addr_start, addr_end, root->root_desc, ctx);
2056         } SGEN_HASH_TABLE_FOREACH_END;
2057 }
2058
2059 void
2060 sgen_dump_occupied (char *start, char *end, char *section_start)
2061 {
2062         fprintf (heap_dump_file, "<occupied offset=\"%td\" size=\"%td\"/>\n", start - section_start, end - start);
2063 }
2064
2065 void
2066 sgen_dump_section (GCMemSection *section, const char *type)
2067 {
2068         char *start = section->data;
2069         char *end = section->data + section->size;
2070         char *occ_start = NULL;
2071         GCVTable *vt;
2072         char *old_start = NULL; /* just for debugging */
2073
2074         fprintf (heap_dump_file, "<section type=\"%s\" size=\"%lu\">\n", type, (unsigned long)section->size);
2075
2076         while (start < end) {
2077                 guint size;
2078                 MonoClass *class;
2079
2080                 if (!*(void**)start) {
2081                         if (occ_start) {
2082                                 sgen_dump_occupied (occ_start, start, section->data);
2083                                 occ_start = NULL;
2084                         }
2085                         start += sizeof (void*); /* should be ALLOC_ALIGN, really */
2086                         continue;
2087                 }
2088                 g_assert (start < section->next_data);
2089
2090                 if (!occ_start)
2091                         occ_start = start;
2092
2093                 vt = (GCVTable*)LOAD_VTABLE (start);
2094                 class = vt->klass;
2095
2096                 size = ALIGN_UP (safe_object_get_size ((MonoObject*) start));
2097
2098                 /*
2099                 fprintf (heap_dump_file, "<object offset=\"%d\" class=\"%s.%s\" size=\"%d\"/>\n",
2100                                 start - section->data,
2101                                 vt->klass->name_space, vt->klass->name,
2102                                 size);
2103                 */
2104
2105                 old_start = start;
2106                 start += size;
2107         }
2108         if (occ_start)
2109                 sgen_dump_occupied (occ_start, start, section->data);
2110
2111         fprintf (heap_dump_file, "</section>\n");
2112 }
2113
2114 static void
2115 dump_object (MonoObject *obj, gboolean dump_location)
2116 {
2117         static char class_name [1024];
2118
2119         MonoClass *class = mono_object_class (obj);
2120         int i, j;
2121
2122         /*
2123          * Python's XML parser is too stupid to parse angle brackets
2124          * in strings, so we just ignore them;
2125          */
2126         i = j = 0;
2127         while (class->name [i] && j < sizeof (class_name) - 1) {
2128                 if (!strchr ("<>\"", class->name [i]))
2129                         class_name [j++] = class->name [i];
2130                 ++i;
2131         }
2132         g_assert (j < sizeof (class_name));
2133         class_name [j] = 0;
2134
2135         fprintf (heap_dump_file, "<object class=\"%s.%s\" size=\"%d\"",
2136                         class->name_space, class_name,
2137                         safe_object_get_size (obj));
2138         if (dump_location) {
2139                 const char *location;
2140                 if (ptr_in_nursery (obj))
2141                         location = "nursery";
2142                 else if (safe_object_get_size (obj) <= MAX_SMALL_OBJ_SIZE)
2143                         location = "major";
2144                 else
2145                         location = "LOS";
2146                 fprintf (heap_dump_file, " location=\"%s\"", location);
2147         }
2148         fprintf (heap_dump_file, "/>\n");
2149 }
2150
2151 static void
2152 dump_heap (const char *type, int num, const char *reason)
2153 {
2154         ObjectList *list;
2155         LOSObject *bigobj;
2156
2157         fprintf (heap_dump_file, "<collection type=\"%s\" num=\"%d\"", type, num);
2158         if (reason)
2159                 fprintf (heap_dump_file, " reason=\"%s\"", reason);
2160         fprintf (heap_dump_file, ">\n");
2161         fprintf (heap_dump_file, "<other-mem-usage type=\"mempools\" size=\"%ld\"/>\n", mono_mempool_get_bytes_allocated ());
2162         sgen_dump_internal_mem_usage (heap_dump_file);
2163         fprintf (heap_dump_file, "<pinned type=\"stack\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_STACK));
2164         /* fprintf (heap_dump_file, "<pinned type=\"static-data\" bytes=\"%d\"/>\n", pinned_byte_counts [PIN_TYPE_STATIC_DATA]); */
2165         fprintf (heap_dump_file, "<pinned type=\"other\" bytes=\"%zu\"/>\n", sgen_pin_stats_get_pinned_byte_count (PIN_TYPE_OTHER));
2166
2167         fprintf (heap_dump_file, "<pinned-objects>\n");
2168         for (list = sgen_pin_stats_get_object_list (); list; list = list->next)
2169                 dump_object (list->obj, TRUE);
2170         fprintf (heap_dump_file, "</pinned-objects>\n");
2171
2172         sgen_dump_section (nursery_section, "nursery");
2173
2174         major_collector.dump_heap (heap_dump_file);
2175
2176         fprintf (heap_dump_file, "<los>\n");
2177         for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
2178                 dump_object ((MonoObject*)bigobj->data, FALSE);
2179         fprintf (heap_dump_file, "</los>\n");
2180
2181         fprintf (heap_dump_file, "</collection>\n");
2182 }
2183
2184 void
2185 sgen_register_moved_object (void *obj, void *destination)
2186 {
2187         g_assert (mono_profiler_events & MONO_PROFILE_GC_MOVES);
2188
2189         /* FIXME: handle this for parallel collector */
2190         g_assert (!sgen_collection_is_parallel ());
2191
2192         if (moved_objects_idx == MOVED_OBJECTS_NUM) {
2193                 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
2194                 moved_objects_idx = 0;
2195         }
2196         moved_objects [moved_objects_idx++] = obj;
2197         moved_objects [moved_objects_idx++] = destination;
2198 }
2199
2200 static void
2201 init_stats (void)
2202 {
2203         static gboolean inited = FALSE;
2204
2205         if (inited)
2206                 return;
2207
2208         mono_counters_register ("Minor fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pre_collection_fragment_clear);
2209         mono_counters_register ("Minor pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_pinning);
2210         mono_counters_register ("Minor scan remembered set", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_remsets);
2211         mono_counters_register ("Minor scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_pinned);
2212         mono_counters_register ("Minor scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_registered_roots);
2213         mono_counters_register ("Minor scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_scan_thread_data);
2214         mono_counters_register ("Minor finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_finish_gray_stack);
2215         mono_counters_register ("Minor fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_minor_fragment_creation);
2216
2217         mono_counters_register ("Major fragment clear", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pre_collection_fragment_clear);
2218         mono_counters_register ("Major pinning", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_pinning);
2219         mono_counters_register ("Major scan pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_pinned);
2220         mono_counters_register ("Major scan registered roots", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_registered_roots);
2221         mono_counters_register ("Major scan thread data", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_thread_data);
2222         mono_counters_register ("Major scan alloc_pinned", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_alloc_pinned);
2223         mono_counters_register ("Major scan finalized", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_finalized);
2224         mono_counters_register ("Major scan big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_scan_big_objects);
2225         mono_counters_register ("Major finish gray stack", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_finish_gray_stack);
2226         mono_counters_register ("Major free big objects", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_free_bigobjs);
2227         mono_counters_register ("Major LOS sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_los_sweep);
2228         mono_counters_register ("Major sweep", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_sweep);
2229         mono_counters_register ("Major fragment creation", MONO_COUNTER_GC | MONO_COUNTER_TIME_INTERVAL, &time_major_fragment_creation);
2230
2231         mono_counters_register ("Number of pinned objects", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_pinned_objects);
2232
2233 #ifdef HEAVY_STATISTICS
2234         mono_counters_register ("WBarrier remember pointer", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_add_to_global_remset);
2235         mono_counters_register ("WBarrier set field", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_field);
2236         mono_counters_register ("WBarrier set arrayref", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_arrayref);
2237         mono_counters_register ("WBarrier arrayref copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_arrayref_copy);
2238         mono_counters_register ("WBarrier generic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store);
2239         mono_counters_register ("WBarrier generic atomic store called", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_generic_store_atomic);
2240         mono_counters_register ("WBarrier set root", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_set_root);
2241         mono_counters_register ("WBarrier value copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_value_copy);
2242         mono_counters_register ("WBarrier object copy", MONO_COUNTER_GC | MONO_COUNTER_INT, &stat_wbarrier_object_copy);
2243
2244         mono_counters_register ("# objects allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_alloced_degraded);
2245         mono_counters_register ("bytes allocated degraded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_bytes_alloced_degraded);
2246
2247         mono_counters_register ("# copy_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_nursery);
2248         mono_counters_register ("# objects copied (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_nursery);
2249         mono_counters_register ("# copy_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_copy_object_called_major);
2250         mono_counters_register ("# objects copied (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_objects_copied_major);
2251
2252         mono_counters_register ("# scan_object() called (nursery)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_nursery);
2253         mono_counters_register ("# scan_object() called (major)", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_scan_object_called_major);
2254
2255         mono_counters_register ("Slots allocated in vain", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_slots_allocated_in_vain);
2256
2257         mono_counters_register ("# nursery copy_object() failed from space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_from_space);
2258         mono_counters_register ("# nursery copy_object() failed forwarded", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_forwarded);
2259         mono_counters_register ("# nursery copy_object() failed pinned", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_pinned);
2260         mono_counters_register ("# nursery copy_object() failed to space", MONO_COUNTER_GC | MONO_COUNTER_LONG, &stat_nursery_copy_object_failed_to_space);
2261
2262         sgen_nursery_allocator_init_heavy_stats ();
2263         sgen_alloc_init_heavy_stats ();
2264 #endif
2265
2266         inited = TRUE;
2267 }
2268
2269
2270 static void
2271 reset_pinned_from_failed_allocation (void)
2272 {
2273         bytes_pinned_from_failed_allocation = 0;
2274 }
2275
2276 void
2277 sgen_set_pinned_from_failed_allocation (mword objsize)
2278 {
2279         bytes_pinned_from_failed_allocation += objsize;
2280 }
2281
2282 gboolean
2283 sgen_collection_is_parallel (void)
2284 {
2285         switch (current_collection_generation) {
2286         case GENERATION_NURSERY:
2287                 return nursery_collection_is_parallel;
2288         case GENERATION_OLD:
2289                 return major_collector.is_parallel;
2290         default:
2291                 g_error ("Invalid current generation %d", current_collection_generation);
2292         }
2293 }
2294
2295 gboolean
2296 sgen_collection_is_concurrent (void)
2297 {
2298         switch (current_collection_generation) {
2299         case GENERATION_NURSERY:
2300                 return FALSE;
2301         case GENERATION_OLD:
2302                 return concurrent_collection_in_progress;
2303         default:
2304                 g_error ("Invalid current generation %d", current_collection_generation);
2305         }
2306 }
2307
2308 gboolean
2309 sgen_concurrent_collection_in_progress (void)
2310 {
2311         return concurrent_collection_in_progress;
2312 }
2313
2314 typedef struct
2315 {
2316         char *heap_start;
2317         char *heap_end;
2318 } FinishRememberedSetScanJobData;
2319
2320 static void
2321 job_finish_remembered_set_scan (WorkerData *worker_data, void *job_data_untyped)
2322 {
2323         FinishRememberedSetScanJobData *job_data = job_data_untyped;
2324
2325         remset.finish_scan_remsets (job_data->heap_start, job_data->heap_end, sgen_workers_get_job_gray_queue (worker_data));
2326         sgen_free_internal_dynamic (job_data, sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2327 }
2328
2329 typedef struct
2330 {
2331         CopyOrMarkObjectFunc copy_or_mark_func;
2332         ScanObjectFunc scan_func;
2333         char *heap_start;
2334         char *heap_end;
2335         int root_type;
2336 } ScanFromRegisteredRootsJobData;
2337
2338 static void
2339 job_scan_from_registered_roots (WorkerData *worker_data, void *job_data_untyped)
2340 {
2341         ScanFromRegisteredRootsJobData *job_data = job_data_untyped;
2342         ScanCopyContext ctx = { job_data->scan_func, job_data->copy_or_mark_func,
2343                 sgen_workers_get_job_gray_queue (worker_data) };
2344
2345         scan_from_registered_roots (job_data->heap_start, job_data->heap_end, job_data->root_type, ctx);
2346         sgen_free_internal_dynamic (job_data, sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2347 }
2348
2349 typedef struct
2350 {
2351         char *heap_start;
2352         char *heap_end;
2353 } ScanThreadDataJobData;
2354
2355 static void
2356 job_scan_thread_data (WorkerData *worker_data, void *job_data_untyped)
2357 {
2358         ScanThreadDataJobData *job_data = job_data_untyped;
2359
2360         scan_thread_data (job_data->heap_start, job_data->heap_end, TRUE,
2361                         sgen_workers_get_job_gray_queue (worker_data));
2362         sgen_free_internal_dynamic (job_data, sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2363 }
2364
2365 typedef struct
2366 {
2367         FinalizeReadyEntry *list;
2368 } ScanFinalizerEntriesJobData;
2369
2370 static void
2371 job_scan_finalizer_entries (WorkerData *worker_data, void *job_data_untyped)
2372 {
2373         ScanFinalizerEntriesJobData *job_data = job_data_untyped;
2374         ScanCopyContext ctx = { NULL, current_object_ops.copy_or_mark_object, sgen_workers_get_job_gray_queue (worker_data) };
2375
2376         scan_finalizer_entries (job_data->list, ctx);
2377         sgen_free_internal_dynamic (job_data, sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA);
2378 }
2379
2380 static void
2381 job_scan_major_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2382 {
2383         g_assert (concurrent_collection_in_progress);
2384         major_collector.scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2385 }
2386
2387 static void
2388 job_scan_los_mod_union_cardtable (WorkerData *worker_data, void *job_data_untyped)
2389 {
2390         g_assert (concurrent_collection_in_progress);
2391         sgen_los_scan_card_table (TRUE, sgen_workers_get_job_gray_queue (worker_data));
2392 }
2393
2394 static void
2395 verify_scan_starts (char *start, char *end)
2396 {
2397         int i;
2398
2399         for (i = 0; i < nursery_section->num_scan_start; ++i) {
2400                 char *addr = nursery_section->scan_starts [i];
2401                 if (addr > start && addr < end)
2402                         SGEN_LOG (1, "NFC-BAD SCAN START [%d] %p for obj [%p %p]", i, addr, start, end);
2403         }
2404 }
2405
2406 static void
2407 verify_nursery (void)
2408 {
2409         char *start, *end, *cur, *hole_start;
2410
2411         if (!do_verify_nursery)
2412                 return;
2413
2414         /*This cleans up unused fragments */
2415         sgen_nursery_allocator_prepare_for_pinning ();
2416
2417         hole_start = start = cur = sgen_get_nursery_start ();
2418         end = sgen_get_nursery_end ();
2419
2420         while (cur < end) {
2421                 size_t ss, size;
2422
2423                 if (!*(void**)cur) {
2424                         cur += sizeof (void*);
2425                         continue;
2426                 }
2427
2428                 if (object_is_forwarded (cur))
2429                         SGEN_LOG (1, "FORWARDED OBJ %p", cur);
2430                 else if (object_is_pinned (cur))
2431                         SGEN_LOG (1, "PINNED OBJ %p", cur);
2432
2433                 ss = safe_object_get_size ((MonoObject*)cur);
2434                 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2435                 verify_scan_starts (cur, cur + size);
2436                 if (do_dump_nursery_content) {
2437                         if (cur > hole_start)
2438                                 SGEN_LOG (1, "HOLE [%p %p %d]", hole_start, cur, (int)(cur - hole_start));
2439                         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 ());
2440                 }
2441                 cur += size;
2442                 hole_start = cur;
2443         }
2444 }
2445
2446 /*
2447  * Checks that no objects in the nursery are fowarded or pinned.  This
2448  * is a precondition to restarting the mutator while doing a
2449  * concurrent collection.  Note that we don't clear fragments because
2450  * we depend on that having happened earlier.
2451  */
2452 static void
2453 check_nursery_is_clean (void)
2454 {
2455         char *start, *end, *cur;
2456
2457         start = cur = sgen_get_nursery_start ();
2458         end = sgen_get_nursery_end ();
2459
2460         while (cur < end) {
2461                 size_t ss, size;
2462
2463                 if (!*(void**)cur) {
2464                         cur += sizeof (void*);
2465                         continue;
2466                 }
2467
2468                 g_assert (!object_is_forwarded (cur));
2469                 g_assert (!object_is_pinned (cur));
2470
2471                 ss = safe_object_get_size ((MonoObject*)cur);
2472                 size = ALIGN_UP (safe_object_get_size ((MonoObject*)cur));
2473                 verify_scan_starts (cur, cur + size);
2474
2475                 cur += size;
2476         }
2477 }
2478
2479 static void
2480 init_gray_queue (void)
2481 {
2482         if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ()) {
2483                 sgen_workers_init_distribute_gray_queue ();
2484                 sgen_gray_object_queue_init_with_alloc_prepare (&gray_queue, NULL,
2485                                 gray_queue_redirect, sgen_workers_get_distribute_section_gray_queue ());
2486         } else {
2487                 sgen_gray_object_queue_init (&gray_queue, NULL);
2488         }
2489 }
2490
2491 static void
2492 pin_stage_object_callback (char *obj, size_t size, void *data)
2493 {
2494         sgen_pin_stage_ptr (obj);
2495         /* FIXME: do pin stats if enabled */
2496 }
2497
2498 /*
2499  * Collect objects in the nursery.  Returns whether to trigger a major
2500  * collection.
2501  */
2502 static gboolean
2503 collect_nursery (SgenGrayQueue *unpin_queue, gboolean finish_up_concurrent_mark)
2504 {
2505         gboolean needs_major;
2506         size_t max_garbage_amount;
2507         char *nursery_next;
2508         FinishRememberedSetScanJobData *frssjd;
2509         ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2510         ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2511         ScanThreadDataJobData *stdjd;
2512         mword fragment_total;
2513         ScanCopyContext ctx;
2514         TV_DECLARE (all_atv);
2515         TV_DECLARE (all_btv);
2516         TV_DECLARE (atv);
2517         TV_DECLARE (btv);
2518
2519         if (disable_minor_collections)
2520                 return TRUE;
2521
2522         MONO_GC_BEGIN (GENERATION_NURSERY);
2523         binary_protocol_collection_begin (stat_minor_gcs, GENERATION_NURSERY);
2524
2525         verify_nursery ();
2526
2527 #ifndef DISABLE_PERFCOUNTERS
2528         mono_perfcounters->gc_collections0++;
2529 #endif
2530
2531         current_collection_generation = GENERATION_NURSERY;
2532         if (sgen_collection_is_parallel ())
2533                 current_object_ops = sgen_minor_collector.parallel_ops;
2534         else
2535                 current_object_ops = sgen_minor_collector.serial_ops;
2536
2537         reset_pinned_from_failed_allocation ();
2538
2539         check_scan_starts ();
2540
2541         sgen_nursery_alloc_prepare_for_minor ();
2542
2543         degraded_mode = 0;
2544         objects_pinned = 0;
2545         nursery_next = sgen_nursery_alloc_get_upper_alloc_bound ();
2546         /* FIXME: optimize later to use the higher address where an object can be present */
2547         nursery_next = MAX (nursery_next, sgen_get_nursery_end ());
2548
2549         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 ()));
2550         max_garbage_amount = nursery_next - sgen_get_nursery_start ();
2551         g_assert (nursery_section->size >= max_garbage_amount);
2552
2553         /* world must be stopped already */
2554         TV_GETTIME (all_atv);
2555         atv = all_atv;
2556
2557         TV_GETTIME (btv);
2558         time_minor_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2559
2560         if (xdomain_checks) {
2561                 sgen_clear_nursery_fragments ();
2562                 check_for_xdomain_refs ();
2563         }
2564
2565         nursery_section->next_data = nursery_next;
2566
2567         major_collector.start_nursery_collection ();
2568
2569         sgen_memgov_minor_collection_start ();
2570
2571         init_gray_queue ();
2572
2573         stat_minor_gcs++;
2574         gc_stats.minor_gc_count ++;
2575
2576         MONO_GC_CHECKPOINT_1 (GENERATION_NURSERY);
2577
2578         sgen_process_fin_stage_entries ();
2579         sgen_process_dislink_stage_entries ();
2580
2581         MONO_GC_CHECKPOINT_2 (GENERATION_NURSERY);
2582
2583         /* pin from pinned handles */
2584         sgen_init_pinning ();
2585         mono_profiler_gc_event (MONO_GC_EVENT_MARK_START, 0);
2586         pin_from_roots (sgen_get_nursery_start (), nursery_next, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2587         /* pin cemented objects */
2588         sgen_cement_iterate (pin_stage_object_callback, NULL);
2589         /* identify pinned objects */
2590         sgen_optimize_pin_queue (0);
2591         sgen_pinning_setup_section (nursery_section);
2592         ctx.scan_func = NULL;
2593         ctx.copy_func = NULL;
2594         ctx.queue = WORKERS_DISTRIBUTE_GRAY_QUEUE;
2595         sgen_pin_objects_in_section (nursery_section, ctx);
2596         sgen_pinning_trim_queue_to_section (nursery_section);
2597
2598         TV_GETTIME (atv);
2599         time_minor_pinning += TV_ELAPSED (btv, atv);
2600         SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (btv, atv));
2601         SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2602
2603         MONO_GC_CHECKPOINT_3 (GENERATION_NURSERY);
2604
2605         if (whole_heap_check_before_collection) {
2606                 sgen_clear_nursery_fragments ();
2607                 sgen_check_whole_heap (finish_up_concurrent_mark);
2608         }
2609         if (consistency_check_at_minor_collection)
2610                 sgen_check_consistency ();
2611
2612         sgen_workers_start_all_workers ();
2613         sgen_workers_start_marking ();
2614
2615         frssjd = sgen_alloc_internal_dynamic (sizeof (FinishRememberedSetScanJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2616         frssjd->heap_start = sgen_get_nursery_start ();
2617         frssjd->heap_end = nursery_next;
2618         sgen_workers_enqueue_job (job_finish_remembered_set_scan, frssjd);
2619
2620         /* we don't have complete write barrier yet, so we scan all the old generation sections */
2621         TV_GETTIME (btv);
2622         time_minor_scan_remsets += TV_ELAPSED (atv, btv);
2623         SGEN_LOG (2, "Old generation scan: %d usecs", TV_ELAPSED (atv, btv));
2624
2625         MONO_GC_CHECKPOINT_4 (GENERATION_NURSERY);
2626
2627         if (!sgen_collection_is_parallel ()) {
2628                 ctx.scan_func = current_object_ops.scan_object;
2629                 ctx.copy_func = NULL;
2630                 ctx.queue = &gray_queue;
2631                 sgen_drain_gray_stack (-1, ctx);
2632         }
2633
2634         if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2635                 report_registered_roots ();
2636         if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2637                 report_finalizer_roots ();
2638         TV_GETTIME (atv);
2639         time_minor_scan_pinned += TV_ELAPSED (btv, atv);
2640
2641         MONO_GC_CHECKPOINT_5 (GENERATION_NURSERY);
2642
2643         /* registered roots, this includes static fields */
2644         scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2645         scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2646         scrrjd_normal->scan_func = current_object_ops.scan_object;
2647         scrrjd_normal->heap_start = sgen_get_nursery_start ();
2648         scrrjd_normal->heap_end = nursery_next;
2649         scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
2650         sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
2651
2652         scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2653         scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2654         scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
2655         scrrjd_wbarrier->heap_start = sgen_get_nursery_start ();
2656         scrrjd_wbarrier->heap_end = nursery_next;
2657         scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
2658         sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
2659
2660         TV_GETTIME (btv);
2661         time_minor_scan_registered_roots += TV_ELAPSED (atv, btv);
2662
2663         MONO_GC_CHECKPOINT_6 (GENERATION_NURSERY);
2664
2665         /* thread data */
2666         stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2667         stdjd->heap_start = sgen_get_nursery_start ();
2668         stdjd->heap_end = nursery_next;
2669         sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
2670
2671         TV_GETTIME (atv);
2672         time_minor_scan_thread_data += TV_ELAPSED (btv, atv);
2673         btv = atv;
2674
2675         MONO_GC_CHECKPOINT_7 (GENERATION_NURSERY);
2676
2677         g_assert (!sgen_collection_is_parallel () && !sgen_collection_is_concurrent ());
2678
2679         if (sgen_collection_is_parallel () || sgen_collection_is_concurrent ())
2680                 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2681
2682         /* Scan the list of objects ready for finalization. If */
2683         sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2684         sfejd_fin_ready->list = fin_ready_list;
2685         sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
2686
2687         sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2688         sfejd_critical_fin->list = critical_fin_list;
2689         sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
2690
2691         MONO_GC_CHECKPOINT_8 (GENERATION_NURSERY);
2692
2693         finish_gray_stack (GENERATION_NURSERY, &gray_queue);
2694         TV_GETTIME (atv);
2695         time_minor_finish_gray_stack += TV_ELAPSED (btv, atv);
2696         mono_profiler_gc_event (MONO_GC_EVENT_MARK_END, 0);
2697
2698         MONO_GC_CHECKPOINT_9 (GENERATION_NURSERY);
2699
2700         /*
2701          * The (single-threaded) finalization code might have done
2702          * some copying/marking so we can only reset the GC thread's
2703          * worker data here instead of earlier when we joined the
2704          * workers.
2705          */
2706         sgen_workers_reset_data ();
2707
2708         if (objects_pinned) {
2709                 sgen_optimize_pin_queue (0);
2710                 sgen_pinning_setup_section (nursery_section);
2711         }
2712
2713         /* walk the pin_queue, build up the fragment list of free memory, unmark
2714          * pinned objects as we go, memzero() the empty fragments so they are ready for the
2715          * next allocations.
2716          */
2717         mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_START, 0);
2718         fragment_total = sgen_build_nursery_fragments (nursery_section,
2719                         nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries,
2720                         unpin_queue);
2721         if (!fragment_total)
2722                 degraded_mode = 1;
2723
2724         /* Clear TLABs for all threads */
2725         sgen_clear_tlabs ();
2726
2727         mono_profiler_gc_event (MONO_GC_EVENT_RECLAIM_END, 0);
2728         TV_GETTIME (btv);
2729         time_minor_fragment_creation += TV_ELAPSED (atv, btv);
2730         SGEN_LOG (2, "Fragment creation: %d usecs, %lu bytes available", TV_ELAPSED (atv, btv), (unsigned long)fragment_total);
2731
2732         if (consistency_check_at_minor_collection)
2733                 sgen_check_major_refs ();
2734
2735         major_collector.finish_nursery_collection ();
2736
2737         TV_GETTIME (all_btv);
2738         gc_stats.minor_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
2739
2740         if (heap_dump_file)
2741                 dump_heap ("minor", stat_minor_gcs - 1, NULL);
2742
2743         /* prepare the pin queue for the next collection */
2744         sgen_finish_pinning ();
2745         if (fin_ready_list || critical_fin_list) {
2746                 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
2747                 mono_gc_finalize_notify ();
2748         }
2749         sgen_pin_stats_reset ();
2750         /* clear cemented hash */
2751         sgen_cement_clear_below_threshold ();
2752
2753         g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
2754
2755         remset.finish_minor_collection ();
2756
2757         check_scan_starts ();
2758
2759         binary_protocol_flush_buffers (FALSE);
2760
2761         sgen_memgov_minor_collection_end ();
2762
2763         /*objects are late pinned because of lack of memory, so a major is a good call*/
2764         needs_major = objects_pinned > 0;
2765         current_collection_generation = -1;
2766         objects_pinned = 0;
2767
2768         MONO_GC_END (GENERATION_NURSERY);
2769         binary_protocol_collection_end (stat_minor_gcs - 1, GENERATION_NURSERY);
2770
2771         if (check_nursery_objects_pinned && !sgen_minor_collector.is_split)
2772                 sgen_check_nursery_objects_pinned (unpin_queue != NULL);
2773
2774         return needs_major;
2775 }
2776
2777 static void
2778 scan_nursery_objects_callback (char *obj, size_t size, ScanCopyContext *ctx)
2779 {
2780         ctx->scan_func (obj, ctx->queue);
2781 }
2782
2783 static void
2784 scan_nursery_objects (ScanCopyContext ctx)
2785 {
2786         sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
2787                         (IterateObjectCallbackFunc)scan_nursery_objects_callback, (void*)&ctx, FALSE);
2788 }
2789
2790 static void
2791 major_copy_or_mark_from_roots (int *old_next_pin_slot, gboolean finish_up_concurrent_mark, gboolean scan_mod_union)
2792 {
2793         LOSObject *bigobj;
2794         TV_DECLARE (atv);
2795         TV_DECLARE (btv);
2796         /* FIXME: only use these values for the precise scan
2797          * note that to_space pointers should be excluded anyway...
2798          */
2799         char *heap_start = NULL;
2800         char *heap_end = (char*)-1;
2801         gboolean profile_roots = mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS;
2802         GCRootReport root_report = { 0 };
2803         ScanFromRegisteredRootsJobData *scrrjd_normal, *scrrjd_wbarrier;
2804         ScanThreadDataJobData *stdjd;
2805         ScanFinalizerEntriesJobData *sfejd_fin_ready, *sfejd_critical_fin;
2806         ScanCopyContext ctx;
2807
2808         if (concurrent_collection_in_progress) {
2809                 /*This cleans up unused fragments */
2810                 sgen_nursery_allocator_prepare_for_pinning ();
2811
2812                 if (do_concurrent_checks)
2813                         check_nursery_is_clean ();
2814         } else {
2815                 /* The concurrent collector doesn't touch the nursery. */
2816                 sgen_nursery_alloc_prepare_for_major ();
2817         }
2818
2819         init_gray_queue ();
2820
2821         TV_GETTIME (atv);
2822
2823         /* Pinning depends on this */
2824         sgen_clear_nursery_fragments ();
2825
2826         if (whole_heap_check_before_collection)
2827                 sgen_check_whole_heap (finish_up_concurrent_mark);
2828
2829         TV_GETTIME (btv);
2830         time_major_pre_collection_fragment_clear += TV_ELAPSED (atv, btv);
2831
2832         if (!sgen_collection_is_concurrent ())
2833                 nursery_section->next_data = sgen_get_nursery_end ();
2834         /* we should also coalesce scanning from sections close to each other
2835          * and deal with pointers outside of the sections later.
2836          */
2837
2838         objects_pinned = 0;
2839         *major_collector.have_swept = FALSE;
2840
2841         if (xdomain_checks) {
2842                 sgen_clear_nursery_fragments ();
2843                 check_for_xdomain_refs ();
2844         }
2845
2846         if (!concurrent_collection_in_progress) {
2847                 /* Remsets are not useful for a major collection */
2848                 remset.prepare_for_major_collection ();
2849         }
2850
2851         sgen_process_fin_stage_entries ();
2852         sgen_process_dislink_stage_entries ();
2853
2854         TV_GETTIME (atv);
2855         sgen_init_pinning ();
2856         SGEN_LOG (6, "Collecting pinned addresses");
2857         pin_from_roots ((void*)lowest_heap_address, (void*)highest_heap_address, WORKERS_DISTRIBUTE_GRAY_QUEUE);
2858
2859         if (!concurrent_collection_in_progress || finish_up_concurrent_mark) {
2860                 if (major_collector.is_concurrent) {
2861                         /*
2862                          * The concurrent major collector cannot evict
2863                          * yet, so we need to pin cemented objects to
2864                          * not break some asserts.
2865                          *
2866                          * FIXME: We could evict now!
2867                          */
2868                         sgen_cement_iterate (pin_stage_object_callback, NULL);
2869                 }
2870
2871                 if (!concurrent_collection_in_progress)
2872                         sgen_cement_reset ();
2873         }
2874
2875         sgen_optimize_pin_queue (0);
2876
2877         /*
2878          * The concurrent collector doesn't move objects, neither on
2879          * the major heap nor in the nursery, so we can mark even
2880          * before pinning has finished.  For the non-concurrent
2881          * collector we start the workers after pinning.
2882          */
2883         if (concurrent_collection_in_progress) {
2884                 sgen_workers_start_all_workers ();
2885                 sgen_workers_start_marking ();
2886         }
2887
2888         /*
2889          * pin_queue now contains all candidate pointers, sorted and
2890          * uniqued.  We must do two passes now to figure out which
2891          * objects are pinned.
2892          *
2893          * The first is to find within the pin_queue the area for each
2894          * section.  This requires that the pin_queue be sorted.  We
2895          * also process the LOS objects and pinned chunks here.
2896          *
2897          * The second, destructive, pass is to reduce the section
2898          * areas to pointers to the actually pinned objects.
2899          */
2900         SGEN_LOG (6, "Pinning from sections");
2901         /* first pass for the sections */
2902         sgen_find_section_pin_queue_start_end (nursery_section);
2903         major_collector.find_pin_queue_start_ends (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2904         /* identify possible pointers to the insize of large objects */
2905         SGEN_LOG (6, "Pinning from large objects");
2906         for (bigobj = los_object_list; bigobj; bigobj = bigobj->next) {
2907                 int dummy;
2908                 if (sgen_find_optimized_pin_queue_area (bigobj->data, (char*)bigobj->data + sgen_los_object_size (bigobj), &dummy)) {
2909                         binary_protocol_pin (bigobj->data, (gpointer)LOAD_VTABLE (bigobj->data), safe_object_get_size (((MonoObject*)(bigobj->data))));
2910
2911 #ifdef ENABLE_DTRACE
2912                         if (G_UNLIKELY (MONO_GC_OBJ_PINNED_ENABLED ())) {
2913                                 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (bigobj->data);
2914                                 MONO_GC_OBJ_PINNED ((mword)bigobj->data, sgen_safe_object_get_size ((MonoObject*)bigobj->data), vt->klass->name_space, vt->klass->name, GENERATION_OLD);
2915                         }
2916 #endif
2917
2918                         if (sgen_los_object_is_pinned (bigobj->data)) {
2919                                 g_assert (finish_up_concurrent_mark);
2920                                 continue;
2921                         }
2922                         sgen_los_pin_object (bigobj->data);
2923                         if (SGEN_OBJECT_HAS_REFERENCES (bigobj->data))
2924                                 GRAY_OBJECT_ENQUEUE (WORKERS_DISTRIBUTE_GRAY_QUEUE, bigobj->data);
2925                         if (G_UNLIKELY (do_pin_stats))
2926                                 sgen_pin_stats_register_object ((char*) bigobj->data, safe_object_get_size ((MonoObject*) bigobj->data));
2927                         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));
2928
2929                         if (profile_roots)
2930                                 add_profile_gc_root (&root_report, bigobj->data, MONO_PROFILE_GC_ROOT_PINNING | MONO_PROFILE_GC_ROOT_MISC, 0);
2931                 }
2932         }
2933         if (profile_roots)
2934                 notify_gc_roots (&root_report);
2935         /* second pass for the sections */
2936         ctx.scan_func = concurrent_collection_in_progress ? current_object_ops.scan_object : NULL;
2937         ctx.copy_func = NULL;
2938         ctx.queue = WORKERS_DISTRIBUTE_GRAY_QUEUE;
2939
2940         /*
2941          * Concurrent mark never follows references into the nursery.
2942          * In the start and finish pauses we must scan live nursery
2943          * objects, though.  We could simply scan all nursery objects,
2944          * but that would be conservative.  The easiest way is to do a
2945          * nursery collection, which copies all live nursery objects
2946          * (except pinned ones, with the simple nursery) to the major
2947          * heap.  Scanning the mod union table later will then scan
2948          * those promoted objects, provided they're reachable.  Pinned
2949          * objects in the nursery - which we can trivially find in the
2950          * pinning queue - are treated as roots in the mark pauses.
2951          *
2952          * The split nursery complicates the latter part because
2953          * non-pinned objects can survive in the nursery.  That's why
2954          * we need to do a full front-to-back scan of the nursery,
2955          * marking all objects.
2956          *
2957          * Non-concurrent mark evacuates from the nursery, so it's
2958          * sufficient to just scan pinned nursery objects.
2959          */
2960         if (concurrent_collection_in_progress && sgen_minor_collector.is_split) {
2961                 scan_nursery_objects (ctx);
2962         } else {
2963                 sgen_pin_objects_in_section (nursery_section, ctx);
2964                 if (check_nursery_objects_pinned && !sgen_minor_collector.is_split)
2965                         sgen_check_nursery_objects_pinned (!concurrent_collection_in_progress || finish_up_concurrent_mark);
2966         }
2967
2968         major_collector.pin_objects (WORKERS_DISTRIBUTE_GRAY_QUEUE);
2969         if (old_next_pin_slot)
2970                 *old_next_pin_slot = sgen_get_pinned_count ();
2971
2972         TV_GETTIME (btv);
2973         time_major_pinning += TV_ELAPSED (atv, btv);
2974         SGEN_LOG (2, "Finding pinned pointers: %d in %d usecs", sgen_get_pinned_count (), TV_ELAPSED (atv, btv));
2975         SGEN_LOG (4, "Start scan with %d pinned objects", sgen_get_pinned_count ());
2976
2977         major_collector.init_to_space ();
2978
2979 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
2980         main_gc_thread = mono_native_thread_self ();
2981 #endif
2982
2983         if (!concurrent_collection_in_progress && major_collector.is_parallel) {
2984                 sgen_workers_start_all_workers ();
2985                 sgen_workers_start_marking ();
2986         }
2987
2988         if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
2989                 report_registered_roots ();
2990         TV_GETTIME (atv);
2991         time_major_scan_pinned += TV_ELAPSED (btv, atv);
2992
2993         /* registered roots, this includes static fields */
2994         scrrjd_normal = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
2995         scrrjd_normal->copy_or_mark_func = current_object_ops.copy_or_mark_object;
2996         scrrjd_normal->scan_func = current_object_ops.scan_object;
2997         scrrjd_normal->heap_start = heap_start;
2998         scrrjd_normal->heap_end = heap_end;
2999         scrrjd_normal->root_type = ROOT_TYPE_NORMAL;
3000         sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_normal);
3001
3002         scrrjd_wbarrier = sgen_alloc_internal_dynamic (sizeof (ScanFromRegisteredRootsJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3003         scrrjd_wbarrier->copy_or_mark_func = current_object_ops.copy_or_mark_object;
3004         scrrjd_wbarrier->scan_func = current_object_ops.scan_object;
3005         scrrjd_wbarrier->heap_start = heap_start;
3006         scrrjd_wbarrier->heap_end = heap_end;
3007         scrrjd_wbarrier->root_type = ROOT_TYPE_WBARRIER;
3008         sgen_workers_enqueue_job (job_scan_from_registered_roots, scrrjd_wbarrier);
3009
3010         TV_GETTIME (btv);
3011         time_major_scan_registered_roots += TV_ELAPSED (atv, btv);
3012
3013         /* Threads */
3014         stdjd = sgen_alloc_internal_dynamic (sizeof (ScanThreadDataJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3015         stdjd->heap_start = heap_start;
3016         stdjd->heap_end = heap_end;
3017         sgen_workers_enqueue_job (job_scan_thread_data, stdjd);
3018
3019         TV_GETTIME (atv);
3020         time_major_scan_thread_data += TV_ELAPSED (btv, atv);
3021
3022         TV_GETTIME (btv);
3023         time_major_scan_alloc_pinned += TV_ELAPSED (atv, btv);
3024
3025         if (mono_profiler_get_events () & MONO_PROFILE_GC_ROOTS)
3026                 report_finalizer_roots ();
3027
3028         /* scan the list of objects ready for finalization */
3029         sfejd_fin_ready = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3030         sfejd_fin_ready->list = fin_ready_list;
3031         sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_fin_ready);
3032
3033         sfejd_critical_fin = sgen_alloc_internal_dynamic (sizeof (ScanFinalizerEntriesJobData), INTERNAL_MEM_WORKER_JOB_DATA, TRUE);
3034         sfejd_critical_fin->list = critical_fin_list;
3035         sgen_workers_enqueue_job (job_scan_finalizer_entries, sfejd_critical_fin);
3036
3037         if (scan_mod_union) {
3038                 g_assert (finish_up_concurrent_mark);
3039
3040                 /* Mod union card table */
3041                 sgen_workers_enqueue_job (job_scan_major_mod_union_cardtable, NULL);
3042                 sgen_workers_enqueue_job (job_scan_los_mod_union_cardtable, NULL);
3043         }
3044
3045         TV_GETTIME (atv);
3046         time_major_scan_finalized += TV_ELAPSED (btv, atv);
3047         SGEN_LOG (2, "Root scan: %d usecs", TV_ELAPSED (btv, atv));
3048
3049         TV_GETTIME (btv);
3050         time_major_scan_big_objects += TV_ELAPSED (atv, btv);
3051
3052         if (concurrent_collection_in_progress) {
3053                 /* prepare the pin queue for the next collection */
3054                 sgen_finish_pinning ();
3055
3056                 sgen_pin_stats_reset ();
3057
3058                 if (do_concurrent_checks)
3059                         check_nursery_is_clean ();
3060         }
3061 }
3062
3063 static void
3064 major_start_collection (gboolean concurrent, int *old_next_pin_slot)
3065 {
3066         MONO_GC_BEGIN (GENERATION_OLD);
3067         binary_protocol_collection_begin (stat_major_gcs, GENERATION_OLD);
3068
3069         current_collection_generation = GENERATION_OLD;
3070 #ifndef DISABLE_PERFCOUNTERS
3071         mono_perfcounters->gc_collections1++;
3072 #endif
3073
3074         g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3075
3076         if (concurrent) {
3077                 g_assert (major_collector.is_concurrent);
3078                 concurrent_collection_in_progress = TRUE;
3079
3080                 sgen_cement_concurrent_start ();
3081
3082                 current_object_ops = major_collector.major_concurrent_ops;
3083         } else {
3084                 current_object_ops = major_collector.major_ops;
3085         }
3086
3087         reset_pinned_from_failed_allocation ();
3088
3089         sgen_memgov_major_collection_start ();
3090
3091         //count_ref_nonref_objs ();
3092         //consistency_check ();
3093
3094         check_scan_starts ();
3095
3096         degraded_mode = 0;
3097         SGEN_LOG (1, "Start major collection %d", stat_major_gcs);
3098         stat_major_gcs++;
3099         gc_stats.major_gc_count ++;
3100
3101         if (major_collector.start_major_collection)
3102                 major_collector.start_major_collection ();
3103
3104         major_copy_or_mark_from_roots (old_next_pin_slot, FALSE, FALSE);
3105 }
3106
3107 static void
3108 wait_for_workers_to_finish (void)
3109 {
3110         while (!sgen_workers_all_done ())
3111                 g_usleep (200);
3112 }
3113
3114 static void
3115 join_workers (void)
3116 {
3117         if (concurrent_collection_in_progress || major_collector.is_parallel) {
3118                 gray_queue_redirect (&gray_queue);
3119                 sgen_workers_join ();
3120         }
3121
3122         g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3123
3124 #ifdef SGEN_DEBUG_INTERNAL_ALLOC
3125         main_gc_thread = NULL;
3126 #endif
3127 }
3128
3129 static void
3130 major_finish_collection (const char *reason, int old_next_pin_slot, gboolean scan_mod_union)
3131 {
3132         LOSObject *bigobj, *prevbo;
3133         TV_DECLARE (atv);
3134         TV_DECLARE (btv);
3135
3136         TV_GETTIME (btv);
3137
3138         if (concurrent_collection_in_progress || major_collector.is_parallel)
3139                 join_workers ();
3140
3141         if (concurrent_collection_in_progress) {
3142                 current_object_ops = major_collector.major_concurrent_ops;
3143
3144                 major_copy_or_mark_from_roots (NULL, TRUE, scan_mod_union);
3145                 join_workers ();
3146
3147                 g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3148
3149                 if (do_concurrent_checks)
3150                         check_nursery_is_clean ();
3151         } else {
3152                 current_object_ops = major_collector.major_ops;
3153         }
3154
3155         /*
3156          * The workers have stopped so we need to finish gray queue
3157          * work that might result from finalization in the main GC
3158          * thread.  Redirection must therefore be turned off.
3159          */
3160         sgen_gray_object_queue_disable_alloc_prepare (&gray_queue);
3161         g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3162
3163         /* all the objects in the heap */
3164         finish_gray_stack (GENERATION_OLD, &gray_queue);
3165         TV_GETTIME (atv);
3166         time_major_finish_gray_stack += TV_ELAPSED (btv, atv);
3167
3168         /*
3169          * The (single-threaded) finalization code might have done
3170          * some copying/marking so we can only reset the GC thread's
3171          * worker data here instead of earlier when we joined the
3172          * workers.
3173          */
3174         sgen_workers_reset_data ();
3175
3176         if (objects_pinned) {
3177                 g_assert (!concurrent_collection_in_progress);
3178
3179                 /*This is slow, but we just OOM'd*/
3180                 sgen_pin_queue_clear_discarded_entries (nursery_section, old_next_pin_slot);
3181                 sgen_optimize_pin_queue (0);
3182                 sgen_find_section_pin_queue_start_end (nursery_section);
3183                 objects_pinned = 0;
3184         }
3185
3186         reset_heap_boundaries ();
3187         sgen_update_heap_boundaries ((mword)sgen_get_nursery_start (), (mword)sgen_get_nursery_end ());
3188
3189         if (check_mark_bits_after_major_collection)
3190                 sgen_check_major_heap_marked ();
3191
3192         MONO_GC_SWEEP_BEGIN (GENERATION_OLD, !major_collector.sweeps_lazily);
3193
3194         /* sweep the big objects list */
3195         prevbo = NULL;
3196         for (bigobj = los_object_list; bigobj;) {
3197                 g_assert (!object_is_pinned (bigobj->data));
3198                 if (sgen_los_object_is_pinned (bigobj->data)) {
3199                         sgen_los_unpin_object (bigobj->data);
3200                         sgen_update_heap_boundaries ((mword)bigobj->data, (mword)bigobj->data + sgen_los_object_size (bigobj));
3201                 } else {
3202                         LOSObject *to_free;
3203                         /* not referenced anywhere, so we can free it */
3204                         if (prevbo)
3205                                 prevbo->next = bigobj->next;
3206                         else
3207                                 los_object_list = bigobj->next;
3208                         to_free = bigobj;
3209                         bigobj = bigobj->next;
3210                         sgen_los_free_object (to_free);
3211                         continue;
3212                 }
3213                 prevbo = bigobj;
3214                 bigobj = bigobj->next;
3215         }
3216
3217         TV_GETTIME (btv);
3218         time_major_free_bigobjs += TV_ELAPSED (atv, btv);
3219
3220         sgen_los_sweep ();
3221
3222         TV_GETTIME (atv);
3223         time_major_los_sweep += TV_ELAPSED (btv, atv);
3224
3225         major_collector.sweep ();
3226
3227         MONO_GC_SWEEP_END (GENERATION_OLD, !major_collector.sweeps_lazily);
3228
3229         TV_GETTIME (btv);
3230         time_major_sweep += TV_ELAPSED (atv, btv);
3231
3232         if (!concurrent_collection_in_progress) {
3233                 /* walk the pin_queue, build up the fragment list of free memory, unmark
3234                  * pinned objects as we go, memzero() the empty fragments so they are ready for the
3235                  * next allocations.
3236                  */
3237                 if (!sgen_build_nursery_fragments (nursery_section, nursery_section->pin_queue_start, nursery_section->pin_queue_num_entries, NULL))
3238                         degraded_mode = 1;
3239
3240                 /* prepare the pin queue for the next collection */
3241                 sgen_finish_pinning ();
3242
3243                 /* Clear TLABs for all threads */
3244                 sgen_clear_tlabs ();
3245
3246                 sgen_pin_stats_reset ();
3247         }
3248
3249         if (concurrent_collection_in_progress)
3250                 sgen_cement_concurrent_finish ();
3251         sgen_cement_clear_below_threshold ();
3252
3253         TV_GETTIME (atv);
3254         time_major_fragment_creation += TV_ELAPSED (btv, atv);
3255
3256         if (heap_dump_file)
3257                 dump_heap ("major", stat_major_gcs - 1, reason);
3258
3259         if (fin_ready_list || critical_fin_list) {
3260                 SGEN_LOG (4, "Finalizer-thread wakeup: ready %d", num_ready_finalizers);
3261                 mono_gc_finalize_notify ();
3262         }
3263
3264         g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3265
3266         sgen_memgov_major_collection_end ();
3267         current_collection_generation = -1;
3268
3269         major_collector.finish_major_collection ();
3270
3271         g_assert (sgen_section_gray_queue_is_empty (sgen_workers_get_distribute_section_gray_queue ()));
3272
3273         if (concurrent_collection_in_progress)
3274                 concurrent_collection_in_progress = FALSE;
3275
3276         check_scan_starts ();
3277
3278         binary_protocol_flush_buffers (FALSE);
3279
3280         //consistency_check ();
3281
3282         MONO_GC_END (GENERATION_OLD);
3283         binary_protocol_collection_end (stat_major_gcs - 1, GENERATION_OLD);
3284 }
3285
3286 static gboolean
3287 major_do_collection (const char *reason)
3288 {
3289         TV_DECLARE (all_atv);
3290         TV_DECLARE (all_btv);
3291         int old_next_pin_slot;
3292
3293         if (disable_major_collections)
3294                 return FALSE;
3295
3296         if (major_collector.get_and_reset_num_major_objects_marked) {
3297                 long long num_marked = major_collector.get_and_reset_num_major_objects_marked ();
3298                 g_assert (!num_marked);
3299         }
3300
3301         /* world must be stopped already */
3302         TV_GETTIME (all_atv);
3303
3304         major_start_collection (FALSE, &old_next_pin_slot);
3305         major_finish_collection (reason, old_next_pin_slot, FALSE);
3306
3307         TV_GETTIME (all_btv);
3308         gc_stats.major_gc_time_usecs += TV_ELAPSED (all_atv, all_btv);
3309
3310         /* FIXME: also report this to the user, preferably in gc-end. */
3311         if (major_collector.get_and_reset_num_major_objects_marked)
3312                 major_collector.get_and_reset_num_major_objects_marked ();
3313
3314         return bytes_pinned_from_failed_allocation > 0;
3315 }
3316
3317 static void
3318 major_start_concurrent_collection (const char *reason)
3319 {
3320         long long num_objects_marked;
3321
3322         if (disable_major_collections)
3323                 return;
3324
3325         num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
3326         g_assert (num_objects_marked == 0);
3327
3328         MONO_GC_CONCURRENT_START_BEGIN (GENERATION_OLD);
3329
3330         // FIXME: store reason and pass it when finishing
3331         major_start_collection (TRUE, NULL);
3332
3333         gray_queue_redirect (&gray_queue);
3334         sgen_workers_wait_for_jobs ();
3335
3336         num_objects_marked = major_collector.get_and_reset_num_major_objects_marked ();
3337         MONO_GC_CONCURRENT_START_END (GENERATION_OLD, num_objects_marked);
3338
3339         current_collection_generation = -1;
3340 }
3341
3342 static gboolean
3343 major_update_or_finish_concurrent_collection (gboolean force_finish)
3344 {
3345         SgenGrayQueue unpin_queue;
3346         memset (&unpin_queue, 0, sizeof (unpin_queue));
3347
3348         MONO_GC_CONCURRENT_UPDATE_FINISH_BEGIN (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3349
3350         g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3351
3352         if (!force_finish && !sgen_workers_all_done ()) {
3353                 major_collector.update_cardtable_mod_union ();
3354                 sgen_los_update_cardtable_mod_union ();
3355
3356                 MONO_GC_CONCURRENT_UPDATE_END (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3357                 return FALSE;
3358         }
3359
3360         /*
3361          * The major collector can add global remsets which are processed in the finishing
3362          * nursery collection, below.  That implies that the workers must have finished
3363          * marking before the nursery collection is allowed to run, otherwise we might miss
3364          * some remsets.
3365          */
3366         wait_for_workers_to_finish ();
3367
3368         major_collector.update_cardtable_mod_union ();
3369         sgen_los_update_cardtable_mod_union ();
3370
3371         collect_nursery (&unpin_queue, TRUE);
3372
3373         if (mod_union_consistency_check)
3374                 sgen_check_mod_union_consistency ();
3375
3376         current_collection_generation = GENERATION_OLD;
3377         major_finish_collection ("finishing", -1, TRUE);
3378
3379         if (whole_heap_check_before_collection)
3380                 sgen_check_whole_heap (FALSE);
3381
3382         unpin_objects_from_queue (&unpin_queue);
3383         sgen_gray_object_queue_deinit (&unpin_queue);
3384
3385         MONO_GC_CONCURRENT_FINISH_END (GENERATION_OLD, major_collector.get_and_reset_num_major_objects_marked ());
3386
3387         current_collection_generation = -1;
3388
3389         return TRUE;
3390 }
3391
3392 /*
3393  * Ensure an allocation request for @size will succeed by freeing enough memory.
3394  *
3395  * LOCKING: The GC lock MUST be held.
3396  */
3397 void
3398 sgen_ensure_free_space (size_t size)
3399 {
3400         int generation_to_collect = -1;
3401         const char *reason = NULL;
3402
3403
3404         if (size > SGEN_MAX_SMALL_OBJ_SIZE) {
3405                 if (sgen_need_major_collection (size)) {
3406                         reason = "LOS overflow";
3407                         generation_to_collect = GENERATION_OLD;
3408                 }
3409         } else {
3410                 if (degraded_mode) {
3411                         if (sgen_need_major_collection (size)) {
3412                                 reason = "Degraded mode overflow";
3413                                 generation_to_collect = GENERATION_OLD;
3414                         }
3415                 } else if (sgen_need_major_collection (size)) {
3416                         reason = "Minor allowance";
3417                         generation_to_collect = GENERATION_OLD;
3418                 } else {
3419                         generation_to_collect = GENERATION_NURSERY;
3420                         reason = "Nursery full";
3421                 }
3422         }
3423
3424         if (generation_to_collect == -1) {
3425                 if (concurrent_collection_in_progress && sgen_workers_all_done ()) {
3426                         generation_to_collect = GENERATION_OLD;
3427                         reason = "Finish concurrent collection";
3428                 }
3429         }
3430
3431         if (generation_to_collect == -1)
3432                 return;
3433         sgen_perform_collection (size, generation_to_collect, reason, FALSE);
3434 }
3435
3436 /*
3437  * LOCKING: Assumes the GC lock is held.
3438  */
3439 void
3440 sgen_perform_collection (size_t requested_size, int generation_to_collect, const char *reason, gboolean wait_to_finish)
3441 {
3442         TV_DECLARE (gc_end);
3443         GGTimingInfo infos [2];
3444         int overflow_generation_to_collect = -1;
3445         int oldest_generation_collected = generation_to_collect;
3446         const char *overflow_reason = NULL;
3447
3448         MONO_GC_REQUESTED (generation_to_collect, requested_size, wait_to_finish ? 1 : 0);
3449         if (wait_to_finish)
3450                 binary_protocol_collection_force (generation_to_collect);
3451
3452         g_assert (generation_to_collect == GENERATION_NURSERY || generation_to_collect == GENERATION_OLD);
3453
3454         memset (infos, 0, sizeof (infos));
3455         mono_profiler_gc_event (MONO_GC_EVENT_START, generation_to_collect);
3456
3457         infos [0].generation = generation_to_collect;
3458         infos [0].reason = reason;
3459         infos [0].is_overflow = FALSE;
3460         TV_GETTIME (infos [0].total_time);
3461         infos [1].generation = -1;
3462
3463         sgen_stop_world (generation_to_collect);
3464
3465         if (concurrent_collection_in_progress) {
3466                 if (major_update_or_finish_concurrent_collection (wait_to_finish && generation_to_collect == GENERATION_OLD)) {
3467                         oldest_generation_collected = GENERATION_OLD;
3468                         goto done;
3469                 }
3470                 if (generation_to_collect == GENERATION_OLD)
3471                         goto done;
3472         } else {
3473                 if (generation_to_collect == GENERATION_OLD &&
3474                                 allow_synchronous_major &&
3475                                 major_collector.want_synchronous_collection &&
3476                                 *major_collector.want_synchronous_collection) {
3477                         wait_to_finish = TRUE;
3478                 }
3479         }
3480
3481         //FIXME extract overflow reason
3482         if (generation_to_collect == GENERATION_NURSERY) {
3483                 if (collect_nursery (NULL, FALSE)) {
3484                         overflow_generation_to_collect = GENERATION_OLD;
3485                         overflow_reason = "Minor overflow";
3486                 }
3487         } else {
3488                 if (major_collector.is_concurrent) {
3489                         g_assert (!concurrent_collection_in_progress);
3490                         if (!wait_to_finish)
3491                                 collect_nursery (NULL, FALSE);
3492                 }
3493
3494                 if (major_collector.is_concurrent && !wait_to_finish) {
3495                         major_start_concurrent_collection (reason);
3496                         // FIXME: set infos[0] properly
3497                         goto done;
3498                 } else {
3499                         if (major_do_collection (reason)) {
3500                                 overflow_generation_to_collect = GENERATION_NURSERY;
3501                                 overflow_reason = "Excessive pinning";
3502                         }
3503                 }
3504         }
3505
3506         TV_GETTIME (gc_end);
3507         infos [0].total_time = SGEN_TV_ELAPSED (infos [0].total_time, gc_end);
3508
3509
3510         if (!major_collector.is_concurrent && overflow_generation_to_collect != -1) {
3511                 mono_profiler_gc_event (MONO_GC_EVENT_START, overflow_generation_to_collect);
3512                 infos [1].generation = overflow_generation_to_collect;
3513                 infos [1].reason = overflow_reason;
3514                 infos [1].is_overflow = TRUE;
3515                 infos [1].total_time = gc_end;
3516
3517                 if (overflow_generation_to_collect == GENERATION_NURSERY)
3518                         collect_nursery (NULL, FALSE);
3519                 else
3520                         major_do_collection (overflow_reason);
3521
3522                 TV_GETTIME (gc_end);
3523                 infos [1].total_time = SGEN_TV_ELAPSED (infos [1].total_time, gc_end);
3524
3525                 /* keep events symmetric */
3526                 mono_profiler_gc_event (MONO_GC_EVENT_END, overflow_generation_to_collect);
3527
3528                 oldest_generation_collected = MAX (oldest_generation_collected, overflow_generation_to_collect);
3529         }
3530
3531         SGEN_LOG (2, "Heap size: %lu, LOS size: %lu", (unsigned long)mono_gc_get_heap_size (), (unsigned long)los_memory_usage);
3532
3533         /* this also sets the proper pointers for the next allocation */
3534         if (generation_to_collect == GENERATION_NURSERY && !sgen_can_alloc_size (requested_size)) {
3535                 /* TypeBuilder and MonoMethod are killing mcs with fragmentation */
3536                 SGEN_LOG (1, "nursery collection didn't find enough room for %zd alloc (%d pinned)", requested_size, sgen_get_pinned_count ());
3537                 sgen_dump_pin_queue ();
3538                 degraded_mode = 1;
3539         }
3540
3541  done:
3542         g_assert (sgen_gray_object_queue_is_empty (&gray_queue));
3543
3544         sgen_restart_world (oldest_generation_collected, infos);
3545
3546         mono_profiler_gc_event (MONO_GC_EVENT_END, generation_to_collect);
3547 }
3548
3549 /*
3550  * ######################################################################
3551  * ########  Memory allocation from the OS
3552  * ######################################################################
3553  * This section of code deals with getting memory from the OS and
3554  * allocating memory for GC-internal data structures.
3555  * Internal memory can be handled with a freelist for small objects.
3556  */
3557
3558 /*
3559  * Debug reporting.
3560  */
3561 G_GNUC_UNUSED static void
3562 report_internal_mem_usage (void)
3563 {
3564         printf ("Internal memory usage:\n");
3565         sgen_report_internal_mem_usage ();
3566         printf ("Pinned memory usage:\n");
3567         major_collector.report_pinned_memory_usage ();
3568 }
3569
3570 /*
3571  * ######################################################################
3572  * ########  Finalization support
3573  * ######################################################################
3574  */
3575
3576 static inline gboolean
3577 sgen_major_is_object_alive (void *object)
3578 {
3579         mword objsize;
3580
3581         /* Oldgen objects can be pinned and forwarded too */
3582         if (SGEN_OBJECT_IS_PINNED (object) || SGEN_OBJECT_IS_FORWARDED (object))
3583                 return TRUE;
3584
3585         /*
3586          * FIXME: major_collector.is_object_live() also calculates the
3587          * size.  Avoid the double calculation.
3588          */
3589         objsize = SGEN_ALIGN_UP (sgen_safe_object_get_size ((MonoObject*)object));
3590         if (objsize > SGEN_MAX_SMALL_OBJ_SIZE)
3591                 return sgen_los_object_is_pinned (object);
3592
3593         return major_collector.is_object_live (object);
3594 }
3595
3596 /*
3597  * If the object has been forwarded it means it's still referenced from a root.
3598  * If it is pinned it's still alive as well.
3599  * A LOS object is only alive if we have pinned it.
3600  * Return TRUE if @obj is ready to be finalized.
3601  */
3602 static inline gboolean
3603 sgen_is_object_alive (void *object)
3604 {
3605         if (ptr_in_nursery (object))
3606                 return sgen_nursery_is_object_alive (object);
3607
3608         return sgen_major_is_object_alive (object);
3609 }
3610
3611 /*
3612  * This function returns true if @object is either alive or it belongs to the old gen
3613  * and we're currently doing a minor collection.
3614  */
3615 static inline int
3616 sgen_is_object_alive_for_current_gen (char *object)
3617 {
3618         if (ptr_in_nursery (object))
3619                 return sgen_nursery_is_object_alive (object);
3620
3621         if (current_collection_generation == GENERATION_NURSERY)
3622                 return TRUE;
3623
3624         return sgen_major_is_object_alive (object);
3625 }
3626
3627 /*
3628  * This function returns true if @object is either alive and belongs to the
3629  * current collection - major collections are full heap, so old gen objects
3630  * are never alive during a minor collection.
3631  */
3632 static inline int
3633 sgen_is_object_alive_and_on_current_collection (char *object)
3634 {
3635         if (ptr_in_nursery (object))
3636                 return sgen_nursery_is_object_alive (object);
3637
3638         if (current_collection_generation == GENERATION_NURSERY)
3639                 return FALSE;
3640
3641         return sgen_major_is_object_alive (object);
3642 }
3643
3644
3645 gboolean
3646 sgen_gc_is_object_ready_for_finalization (void *object)
3647 {
3648         return !sgen_is_object_alive (object);
3649 }
3650
3651 static gboolean
3652 has_critical_finalizer (MonoObject *obj)
3653 {
3654         MonoClass *class;
3655
3656         if (!mono_defaults.critical_finalizer_object)
3657                 return FALSE;
3658
3659         class = ((MonoVTable*)LOAD_VTABLE (obj))->klass;
3660
3661         return mono_class_has_parent_fast (class, mono_defaults.critical_finalizer_object);
3662 }
3663
3664 void
3665 sgen_queue_finalization_entry (MonoObject *obj)
3666 {
3667         FinalizeReadyEntry *entry = sgen_alloc_internal (INTERNAL_MEM_FINALIZE_READY_ENTRY);
3668         gboolean critical = has_critical_finalizer (obj);
3669         entry->object = obj;
3670         if (critical) {
3671                 entry->next = critical_fin_list;
3672                 critical_fin_list = entry;
3673         } else {
3674                 entry->next = fin_ready_list;
3675                 fin_ready_list = entry;
3676         }
3677
3678 #ifdef ENABLE_DTRACE
3679         if (G_UNLIKELY (MONO_GC_FINALIZE_ENQUEUE_ENABLED ())) {
3680                 int gen = sgen_ptr_in_nursery (obj) ? GENERATION_NURSERY : GENERATION_OLD;
3681                 MonoVTable *vt = (MonoVTable*)LOAD_VTABLE (obj);
3682                 MONO_GC_FINALIZE_ENQUEUE ((mword)obj, sgen_safe_object_get_size (obj),
3683                                 vt->klass->name_space, vt->klass->name, gen, critical);
3684         }
3685 #endif
3686 }
3687
3688 gboolean
3689 sgen_object_is_live (void *obj)
3690 {
3691         return sgen_is_object_alive_and_on_current_collection (obj);
3692 }
3693
3694 /* LOCKING: requires that the GC lock is held */
3695 static void
3696 null_ephemerons_for_domain (MonoDomain *domain)
3697 {
3698         EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3699
3700         while (current) {
3701                 MonoObject *object = (MonoObject*)current->array;
3702
3703                 if (object && !object->vtable) {
3704                         EphemeronLinkNode *tmp = current;
3705
3706                         if (prev)
3707                                 prev->next = current->next;
3708                         else
3709                                 ephemeron_list = current->next;
3710
3711                         current = current->next;
3712                         sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3713                 } else {
3714                         prev = current;
3715                         current = current->next;
3716                 }
3717         }
3718 }
3719
3720 /* LOCKING: requires that the GC lock is held */
3721 static void
3722 clear_unreachable_ephemerons (ScanCopyContext ctx)
3723 {
3724         CopyOrMarkObjectFunc copy_func = ctx.copy_func;
3725         GrayQueue *queue = ctx.queue;
3726         EphemeronLinkNode *current = ephemeron_list, *prev = NULL;
3727         MonoArray *array;
3728         Ephemeron *cur, *array_end;
3729         char *tombstone;
3730
3731         while (current) {
3732                 char *object = current->array;
3733
3734                 if (!sgen_is_object_alive_for_current_gen (object)) {
3735                         EphemeronLinkNode *tmp = current;
3736
3737                         SGEN_LOG (5, "Dead Ephemeron array at %p", object);
3738
3739                         if (prev)
3740                                 prev->next = current->next;
3741                         else
3742                                 ephemeron_list = current->next;
3743
3744                         current = current->next;
3745                         sgen_free_internal (tmp, INTERNAL_MEM_EPHEMERON_LINK);
3746
3747                         continue;
3748                 }
3749
3750                 copy_func ((void**)&object, queue);
3751                 current->array = object;
3752
3753                 SGEN_LOG (5, "Clearing unreachable entries for ephemeron array at %p", object);
3754
3755                 array = (MonoArray*)object;
3756                 cur = mono_array_addr (array, Ephemeron, 0);
3757                 array_end = cur + mono_array_length_fast (array);
3758                 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3759
3760                 for (; cur < array_end; ++cur) {
3761                         char *key = (char*)cur->key;
3762
3763                         if (!key || key == tombstone)
3764                                 continue;
3765
3766                         SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3767                                 key, sgen_is_object_alive_for_current_gen (key) ? "reachable" : "unreachable",
3768                                 cur->value, cur->value && sgen_is_object_alive_for_current_gen (cur->value) ? "reachable" : "unreachable");
3769
3770                         if (!sgen_is_object_alive_for_current_gen (key)) {
3771                                 cur->key = tombstone;
3772                                 cur->value = NULL;
3773                                 continue;
3774                         }
3775                 }
3776                 prev = current;
3777                 current = current->next;
3778         }
3779 }
3780
3781 /*
3782 LOCKING: requires that the GC lock is held
3783
3784 Limitations: We scan all ephemerons on every collection since the current design doesn't allow for a simple nursery/mature split.
3785 */
3786 static int
3787 mark_ephemerons_in_range (ScanCopyContext ctx)
3788 {
3789         CopyOrMarkObjectFunc copy_func = ctx.copy_func;
3790         GrayQueue *queue = ctx.queue;
3791         int nothing_marked = 1;
3792         EphemeronLinkNode *current = ephemeron_list;
3793         MonoArray *array;
3794         Ephemeron *cur, *array_end;
3795         char *tombstone;
3796
3797         for (current = ephemeron_list; current; current = current->next) {
3798                 char *object = current->array;
3799                 SGEN_LOG (5, "Ephemeron array at %p", object);
3800
3801                 /*It has to be alive*/
3802                 if (!sgen_is_object_alive_for_current_gen (object)) {
3803                         SGEN_LOG (5, "\tnot reachable");
3804                         continue;
3805                 }
3806
3807                 copy_func ((void**)&object, queue);
3808
3809                 array = (MonoArray*)object;
3810                 cur = mono_array_addr (array, Ephemeron, 0);
3811                 array_end = cur + mono_array_length_fast (array);
3812                 tombstone = (char*)((MonoVTable*)LOAD_VTABLE (object))->domain->ephemeron_tombstone;
3813
3814                 for (; cur < array_end; ++cur) {
3815                         char *key = cur->key;
3816
3817                         if (!key || key == tombstone)
3818                                 continue;
3819
3820                         SGEN_LOG (5, "[%td] key %p (%s) value %p (%s)", cur - mono_array_addr (array, Ephemeron, 0),
3821                                 key, sgen_is_object_alive_for_current_gen (key) ? "reachable" : "unreachable",
3822                                 cur->value, cur->value && sgen_is_object_alive_for_current_gen (cur->value) ? "reachable" : "unreachable");
3823
3824                         if (sgen_is_object_alive_for_current_gen (key)) {
3825                                 char *value = cur->value;
3826
3827                                 copy_func ((void**)&cur->key, queue);
3828                                 if (value) {
3829                                         if (!sgen_is_object_alive_for_current_gen (value))
3830                                                 nothing_marked = 0;
3831                                         copy_func ((void**)&cur->value, queue);
3832                                 }
3833                         }
3834                 }
3835         }
3836
3837         SGEN_LOG (5, "Ephemeron run finished. Is it done %d", nothing_marked);
3838         return nothing_marked;
3839 }
3840
3841 int
3842 mono_gc_invoke_finalizers (void)
3843 {
3844         FinalizeReadyEntry *entry = NULL;
3845         gboolean entry_is_critical = FALSE;
3846         int count = 0;
3847         void *obj;
3848         /* FIXME: batch to reduce lock contention */
3849         while (fin_ready_list || critical_fin_list) {
3850                 LOCK_GC;
3851
3852                 if (entry) {
3853                         FinalizeReadyEntry **list = entry_is_critical ? &critical_fin_list : &fin_ready_list;
3854
3855                         /* We have finalized entry in the last
3856                            interation, now we need to remove it from
3857                            the list. */
3858                         if (*list == entry)
3859                                 *list = entry->next;
3860                         else {
3861                                 FinalizeReadyEntry *e = *list;
3862                                 while (e->next != entry)
3863                                         e = e->next;
3864                                 e->next = entry->next;
3865                         }
3866                         sgen_free_internal (entry, INTERNAL_MEM_FINALIZE_READY_ENTRY);
3867                         entry = NULL;
3868                 }
3869
3870                 /* Now look for the first non-null entry. */
3871                 for (entry = fin_ready_list; entry && !entry->object; entry = entry->next)
3872                         ;
3873                 if (entry) {
3874                         entry_is_critical = FALSE;
3875                 } else {
3876                         entry_is_critical = TRUE;
3877                         for (entry = critical_fin_list; entry && !entry->object; entry = entry->next)
3878                                 ;
3879                 }
3880
3881                 if (entry) {
3882                         g_assert (entry->object);
3883                         num_ready_finalizers--;
3884                         obj = entry->object;
3885                         entry->object = NULL;
3886                         SGEN_LOG (7, "Finalizing object %p (%s)", obj, safe_name (obj));
3887                 }
3888
3889                 UNLOCK_GC;
3890
3891                 if (!entry)
3892                         break;
3893
3894                 g_assert (entry->object == NULL);
3895                 count++;
3896                 /* the object is on the stack so it is pinned */
3897                 /*g_print ("Calling finalizer for object: %p (%s)\n", entry->object, safe_name (entry->object));*/
3898                 mono_gc_run_finalize (obj, NULL);
3899         }
3900         g_assert (!entry);
3901         return count;
3902 }
3903
3904 gboolean
3905 mono_gc_pending_finalizers (void)
3906 {
3907         return fin_ready_list || critical_fin_list;
3908 }
3909
3910 /*
3911  * ######################################################################
3912  * ########  registered roots support
3913  * ######################################################################
3914  */
3915
3916 /*
3917  * We do not coalesce roots.
3918  */
3919 static int
3920 mono_gc_register_root_inner (char *start, size_t size, void *descr, int root_type)
3921 {
3922         RootRecord new_root;
3923         int i;
3924         LOCK_GC;
3925         for (i = 0; i < ROOT_TYPE_NUM; ++i) {
3926                 RootRecord *root = sgen_hash_table_lookup (&roots_hash [i], start);
3927                 /* we allow changing the size and the descriptor (for thread statics etc) */
3928                 if (root) {
3929                         size_t old_size = root->end_root - start;
3930                         root->end_root = start + size;
3931                         g_assert (((root->root_desc != 0) && (descr != NULL)) ||
3932                                           ((root->root_desc == 0) && (descr == NULL)));
3933                         root->root_desc = (mword)descr;
3934                         roots_size += size;
3935                         roots_size -= old_size;
3936                         UNLOCK_GC;
3937                         return TRUE;
3938                 }
3939         }
3940
3941         new_root.end_root = start + size;
3942         new_root.root_desc = (mword)descr;
3943
3944         sgen_hash_table_replace (&roots_hash [root_type], start, &new_root, NULL);
3945         roots_size += size;
3946
3947         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);
3948
3949         UNLOCK_GC;
3950         return TRUE;
3951 }
3952
3953 int
3954 mono_gc_register_root (char *start, size_t size, void *descr)
3955 {
3956         return mono_gc_register_root_inner (start, size, descr, descr ? ROOT_TYPE_NORMAL : ROOT_TYPE_PINNED);
3957 }
3958
3959 int
3960 mono_gc_register_root_wbarrier (char *start, size_t size, void *descr)
3961 {
3962         return mono_gc_register_root_inner (start, size, descr, ROOT_TYPE_WBARRIER);
3963 }
3964
3965 void
3966 mono_gc_deregister_root (char* addr)
3967 {
3968         int root_type;
3969         RootRecord root;
3970
3971         LOCK_GC;
3972         for (root_type = 0; root_type < ROOT_TYPE_NUM; ++root_type) {
3973                 if (sgen_hash_table_remove (&roots_hash [root_type], addr, &root))
3974                         roots_size -= (root.end_root - addr);
3975         }
3976         UNLOCK_GC;
3977 }
3978
3979 /*
3980  * ######################################################################
3981  * ########  Thread handling (stop/start code)
3982  * ######################################################################
3983  */
3984
3985 unsigned int sgen_global_stop_count = 0;
3986
3987 int
3988 sgen_get_current_collection_generation (void)
3989 {
3990         return current_collection_generation;
3991 }
3992
3993 void
3994 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
3995 {
3996         gc_callbacks = *callbacks;
3997 }
3998
3999 MonoGCCallbacks *
4000 mono_gc_get_gc_callbacks ()
4001 {
4002         return &gc_callbacks;
4003 }
4004
4005 /* Variables holding start/end nursery so it won't have to be passed at every call */
4006 static void *scan_area_arg_start, *scan_area_arg_end;
4007
4008 void
4009 mono_gc_conservatively_scan_area (void *start, void *end)
4010 {
4011         conservatively_pin_objects_from (start, end, scan_area_arg_start, scan_area_arg_end, PIN_TYPE_STACK);
4012 }
4013
4014 void*
4015 mono_gc_scan_object (void *obj)
4016 {
4017         UserCopyOrMarkData *data = mono_native_tls_get_value (user_copy_or_mark_key);
4018         current_object_ops.copy_or_mark_object (&obj, data->queue);
4019         return obj;
4020 }
4021
4022 /*
4023  * Mark from thread stacks and registers.
4024  */
4025 static void
4026 scan_thread_data (void *start_nursery, void *end_nursery, gboolean precise, GrayQueue *queue)
4027 {
4028         SgenThreadInfo *info;
4029
4030         scan_area_arg_start = start_nursery;
4031         scan_area_arg_end = end_nursery;
4032
4033         FOREACH_THREAD (info) {
4034                 if (info->skip) {
4035                         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);
4036                         continue;
4037                 }
4038                 if (info->gc_disabled) {
4039                         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);
4040                         continue;
4041                 }
4042                 if (mono_thread_info_run_state (info) != STATE_RUNNING) {
4043                         SGEN_LOG (3, "Skipping non-running thread %p, range: %p-%p, size: %td (state %d)", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start, mono_thread_info_run_state (info));
4044                         continue;
4045                 }
4046                 SGEN_LOG (3, "Scanning thread %p, range: %p-%p, size: %td, pinned=%d", info, info->stack_start, info->stack_end, (char*)info->stack_end - (char*)info->stack_start, sgen_get_pinned_count ());
4047                 if (gc_callbacks.thread_mark_func && !conservative_stack_mark) {
4048                         UserCopyOrMarkData data = { NULL, queue };
4049                         set_user_copy_or_mark_data (&data);
4050                         gc_callbacks.thread_mark_func (info->runtime_data, info->stack_start, info->stack_end, precise);
4051                         set_user_copy_or_mark_data (NULL);
4052                 } else if (!precise) {
4053                         if (!conservative_stack_mark) {
4054                                 fprintf (stderr, "Precise stack mark not supported - disabling.\n");
4055                                 conservative_stack_mark = TRUE;
4056                         }
4057                         conservatively_pin_objects_from (info->stack_start, info->stack_end, start_nursery, end_nursery, PIN_TYPE_STACK);
4058                 }
4059
4060                 if (!precise) {
4061 #ifdef USE_MONO_CTX
4062                         conservatively_pin_objects_from ((void**)&info->ctx, (void**)&info->ctx + ARCH_NUM_REGS,
4063                                 start_nursery, end_nursery, PIN_TYPE_STACK);
4064 #else
4065                         conservatively_pin_objects_from ((void**)&info->regs, (void**)&info->regs + ARCH_NUM_REGS,
4066                                         start_nursery, end_nursery, PIN_TYPE_STACK);
4067 #endif
4068                 }
4069         } END_FOREACH_THREAD
4070 }
4071
4072 static gboolean
4073 ptr_on_stack (void *ptr)
4074 {
4075         gpointer stack_start = &stack_start;
4076         SgenThreadInfo *info = mono_thread_info_current ();
4077
4078         if (ptr >= stack_start && ptr < (gpointer)info->stack_end)
4079                 return TRUE;
4080         return FALSE;
4081 }
4082
4083 static void*
4084 sgen_thread_register (SgenThreadInfo* info, void *addr)
4085 {
4086         size_t stsize = 0;
4087         guint8 *staddr = NULL;
4088
4089 #ifndef HAVE_KW_THREAD
4090         info->tlab_start = info->tlab_next = info->tlab_temp_end = info->tlab_real_end = NULL;
4091
4092         g_assert (!mono_native_tls_get_value (thread_info_key));
4093         mono_native_tls_set_value (thread_info_key, info);
4094 #else
4095         sgen_thread_info = info;
4096 #endif
4097
4098 #ifdef SGEN_POSIX_STW
4099         info->stop_count = -1;
4100         info->signal = 0;
4101 #endif
4102         info->skip = 0;
4103         info->stack_start = NULL;
4104         info->stopped_ip = NULL;
4105         info->stopped_domain = NULL;
4106 #ifdef USE_MONO_CTX
4107         memset (&info->ctx, 0, sizeof (MonoContext));
4108 #else
4109         memset (&info->regs, 0, sizeof (info->regs));
4110 #endif
4111
4112         sgen_init_tlab_info (info);
4113
4114         binary_protocol_thread_register ((gpointer)mono_thread_info_get_tid (info));
4115
4116         /* On win32, stack_start_limit should be 0, since the stack can grow dynamically */
4117 #ifndef HOST_WIN32
4118         mono_thread_info_get_stack_bounds (&staddr, &stsize);
4119 #endif
4120         if (staddr) {
4121                 info->stack_start_limit = staddr;
4122                 info->stack_end = staddr + stsize;
4123         } else {
4124                 gsize stack_bottom = (gsize)addr;
4125                 stack_bottom += 4095;
4126                 stack_bottom &= ~4095;
4127                 info->stack_end = (char*)stack_bottom;
4128         }
4129
4130 #ifdef HAVE_KW_THREAD
4131         stack_end = info->stack_end;
4132 #endif
4133
4134         SGEN_LOG (3, "registered thread %p (%p) stack end %p", info, (gpointer)mono_thread_info_get_tid (info), info->stack_end);
4135
4136         if (gc_callbacks.thread_attach_func)
4137                 info->runtime_data = gc_callbacks.thread_attach_func ();
4138         return info;
4139 }
4140
4141 static void
4142 sgen_thread_detach (SgenThreadInfo *p)
4143 {
4144         /* If a delegate is passed to native code and invoked on a thread we dont
4145          * know about, the jit will register it with mono_jit_thread_attach, but
4146          * we have no way of knowing when that thread goes away.  SGen has a TSD
4147          * so we assume that if the domain is still registered, we can detach
4148          * the thread
4149          */
4150         if (mono_domain_get ())
4151                 mono_thread_detach (mono_thread_current ());
4152 }
4153
4154 static void
4155 sgen_thread_unregister (SgenThreadInfo *p)
4156 {
4157         MonoNativeThreadId tid;
4158
4159         tid = mono_thread_info_get_tid (p);
4160         binary_protocol_thread_unregister ((gpointer)tid);
4161         SGEN_LOG (3, "unregister thread %p (%p)", p, (gpointer)tid);
4162
4163         mono_threads_add_joinable_thread ((gpointer)tid);
4164
4165         if (gc_callbacks.thread_detach_func) {
4166                 gc_callbacks.thread_detach_func (p->runtime_data);
4167                 p->runtime_data = NULL;
4168         }
4169 }
4170
4171
4172 static void
4173 sgen_thread_attach (SgenThreadInfo *info)
4174 {
4175         LOCK_GC;
4176         /*this is odd, can we get attached before the gc is inited?*/
4177         init_stats ();
4178         UNLOCK_GC;
4179
4180         if (gc_callbacks.thread_attach_func && !info->runtime_data)
4181                 info->runtime_data = gc_callbacks.thread_attach_func ();
4182 }
4183 gboolean
4184 mono_gc_register_thread (void *baseptr)
4185 {
4186         return mono_thread_info_attach (baseptr) != NULL;
4187 }
4188
4189 /*
4190  * mono_gc_set_stack_end:
4191  *
4192  *   Set the end of the current threads stack to STACK_END. The stack space between
4193  * STACK_END and the real end of the threads stack will not be scanned during collections.
4194  */
4195 void
4196 mono_gc_set_stack_end (void *stack_end)
4197 {
4198         SgenThreadInfo *info;
4199
4200         LOCK_GC;
4201         info = mono_thread_info_current ();
4202         if (info) {
4203                 g_assert (stack_end < info->stack_end);
4204                 info->stack_end = stack_end;
4205         }
4206         UNLOCK_GC;
4207 }
4208
4209 #if USE_PTHREAD_INTERCEPT
4210
4211
4212 int
4213 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
4214 {
4215         return pthread_create (new_thread, attr, start_routine, arg);
4216 }
4217
4218 int
4219 mono_gc_pthread_join (pthread_t thread, void **retval)
4220 {
4221         return pthread_join (thread, retval);
4222 }
4223
4224 int
4225 mono_gc_pthread_detach (pthread_t thread)
4226 {
4227         return pthread_detach (thread);
4228 }
4229
4230 void
4231 mono_gc_pthread_exit (void *retval)
4232 {
4233         mono_thread_info_detach ();
4234         pthread_exit (retval);
4235 }
4236
4237 #endif /* USE_PTHREAD_INTERCEPT */
4238
4239 /*
4240  * ######################################################################
4241  * ########  Write barriers
4242  * ######################################################################
4243  */
4244
4245 /*
4246  * Note: the write barriers first do the needed GC work and then do the actual store:
4247  * this way the value is visible to the conservative GC scan after the write barrier
4248  * itself. If a GC interrupts the barrier in the middle, value will be kept alive by
4249  * the conservative scan, otherwise by the remembered set scan.
4250  */
4251 void
4252 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
4253 {
4254         HEAVY_STAT (++stat_wbarrier_set_field);
4255         if (ptr_in_nursery (field_ptr)) {
4256                 *(void**)field_ptr = value;
4257                 return;
4258         }
4259         SGEN_LOG (8, "Adding remset at %p", field_ptr);
4260         if (value)
4261                 binary_protocol_wbarrier (field_ptr, value, value->vtable);
4262
4263         remset.wbarrier_set_field (obj, field_ptr, value);
4264 }
4265
4266 void
4267 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
4268 {
4269         HEAVY_STAT (++stat_wbarrier_set_arrayref);
4270         if (ptr_in_nursery (slot_ptr)) {
4271                 *(void**)slot_ptr = value;
4272                 return;
4273         }
4274         SGEN_LOG (8, "Adding remset at %p", slot_ptr);
4275         if (value)
4276                 binary_protocol_wbarrier (slot_ptr, value, value->vtable);
4277
4278         remset.wbarrier_set_arrayref (arr, slot_ptr, value);
4279 }
4280
4281 void
4282 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
4283 {
4284         HEAVY_STAT (++stat_wbarrier_arrayref_copy);
4285         /*This check can be done without taking a lock since dest_ptr array is pinned*/
4286         if (ptr_in_nursery (dest_ptr) || count <= 0) {
4287                 mono_gc_memmove_aligned (dest_ptr, src_ptr, count * sizeof (gpointer));
4288                 return;
4289         }
4290
4291 #ifdef SGEN_BINARY_PROTOCOL
4292         {
4293                 int i;
4294                 for (i = 0; i < count; ++i) {
4295                         gpointer dest = (gpointer*)dest_ptr + i;
4296                         gpointer obj = *((gpointer*)src_ptr + i);
4297                         if (obj)
4298                                 binary_protocol_wbarrier (dest, obj, (gpointer)LOAD_VTABLE (obj));
4299                 }
4300         }
4301 #endif
4302
4303         remset.wbarrier_arrayref_copy (dest_ptr, src_ptr, count);
4304 }
4305
4306 static char *found_obj;
4307
4308 static void
4309 find_object_for_ptr_callback (char *obj, size_t size, void *user_data)
4310 {
4311         char *ptr = user_data;
4312
4313         if (ptr >= obj && ptr < obj + size) {
4314                 g_assert (!found_obj);
4315                 found_obj = obj;
4316         }
4317 }
4318
4319 /* for use in the debugger */
4320 char* find_object_for_ptr (char *ptr);
4321 char*
4322 find_object_for_ptr (char *ptr)
4323 {
4324         if (ptr >= nursery_section->data && ptr < nursery_section->end_data) {
4325                 found_obj = NULL;
4326                 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
4327                                 find_object_for_ptr_callback, ptr, TRUE);
4328                 if (found_obj)
4329                         return found_obj;
4330         }
4331
4332         found_obj = NULL;
4333         sgen_los_iterate_objects (find_object_for_ptr_callback, ptr);
4334         if (found_obj)
4335                 return found_obj;
4336
4337         /*
4338          * Very inefficient, but this is debugging code, supposed to
4339          * be called from gdb, so we don't care.
4340          */
4341         found_obj = NULL;
4342         major_collector.iterate_objects (TRUE, TRUE, find_object_for_ptr_callback, ptr);
4343         return found_obj;
4344 }
4345
4346 void
4347 mono_gc_wbarrier_generic_nostore (gpointer ptr)
4348 {
4349         gpointer obj;
4350
4351         HEAVY_STAT (++stat_wbarrier_generic_store);
4352
4353 #ifdef XDOMAIN_CHECKS_IN_WBARRIER
4354         /* FIXME: ptr_in_heap must be called with the GC lock held */
4355         if (xdomain_checks && *(MonoObject**)ptr && ptr_in_heap (ptr)) {
4356                 char *start = find_object_for_ptr (ptr);
4357                 MonoObject *value = *(MonoObject**)ptr;
4358                 LOCK_GC;
4359                 g_assert (start);
4360                 if (start) {
4361                         MonoObject *obj = (MonoObject*)start;
4362                         if (obj->vtable->domain != value->vtable->domain)
4363                                 g_assert (is_xdomain_ref_allowed (ptr, start, obj->vtable->domain));
4364                 }
4365                 UNLOCK_GC;
4366         }
4367 #endif
4368
4369         obj = *(gpointer*)ptr;
4370         if (obj)
4371                 binary_protocol_wbarrier (ptr, obj, (gpointer)LOAD_VTABLE (obj));
4372
4373         if (ptr_in_nursery (ptr) || ptr_on_stack (ptr)) {
4374                 SGEN_LOG (8, "Skipping remset at %p", ptr);
4375                 return;
4376         }
4377
4378         /*
4379          * We need to record old->old pointer locations for the
4380          * concurrent collector.
4381          */
4382         if (!ptr_in_nursery (obj) && !concurrent_collection_in_progress) {
4383                 SGEN_LOG (8, "Skipping remset at %p", ptr);
4384                 return;
4385         }
4386
4387         SGEN_LOG (8, "Adding remset at %p", ptr);
4388
4389         remset.wbarrier_generic_nostore (ptr);
4390 }
4391
4392 void
4393 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
4394 {
4395         SGEN_LOG (8, "Wbarrier store at %p to %p (%s)", ptr, value, value ? safe_name (value) : "null");
4396         *(void**)ptr = value;
4397         if (ptr_in_nursery (value))
4398                 mono_gc_wbarrier_generic_nostore (ptr);
4399         sgen_dummy_use (value);
4400 }
4401
4402 /* Same as mono_gc_wbarrier_generic_store () but performs the store
4403  * as an atomic operation with release semantics.
4404  */
4405 void
4406 mono_gc_wbarrier_generic_store_atomic (gpointer ptr, MonoObject *value)
4407 {
4408         HEAVY_STAT (++stat_wbarrier_generic_store_atomic);
4409
4410         SGEN_LOG (8, "Wbarrier atomic store at %p to %p (%s)", ptr, value, value ? safe_name (value) : "null");
4411
4412         InterlockedWritePointer (ptr, value);
4413
4414         if (ptr_in_nursery (value))
4415                 mono_gc_wbarrier_generic_nostore (ptr);
4416
4417         sgen_dummy_use (value);
4418 }
4419
4420 void mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
4421 {
4422         mword *dest = _dest;
4423         mword *src = _src;
4424
4425         while (size) {
4426                 if (bitmap & 0x1)
4427                         mono_gc_wbarrier_generic_store (dest, (MonoObject*)*src);
4428                 else
4429                         *dest = *src;
4430                 ++src;
4431                 ++dest;
4432                 size -= SIZEOF_VOID_P;
4433                 bitmap >>= 1;
4434         }
4435 }
4436
4437 #ifdef SGEN_BINARY_PROTOCOL
4438 #undef HANDLE_PTR
4439 #define HANDLE_PTR(ptr,obj) do {                                        \
4440                 gpointer o = *(gpointer*)(ptr);                         \
4441                 if ((o)) {                                              \
4442                         gpointer d = ((char*)dest) + ((char*)(ptr) - (char*)(obj)); \
4443                         binary_protocol_wbarrier (d, o, (gpointer) LOAD_VTABLE (o)); \
4444                 }                                                       \
4445         } while (0)
4446
4447 static void
4448 scan_object_for_binary_protocol_copy_wbarrier (gpointer dest, char *start, mword desc)
4449 {
4450 #define SCAN_OBJECT_NOVTABLE
4451 #include "sgen-scan-object.h"
4452 }
4453 #endif
4454
4455 void
4456 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
4457 {
4458         HEAVY_STAT (++stat_wbarrier_value_copy);
4459         g_assert (klass->valuetype);
4460
4461         SGEN_LOG (8, "Adding value remset at %p, count %d, descr %p for class %s (%p)", dest, count, klass->gc_descr, klass->name, klass);
4462
4463         if (ptr_in_nursery (dest) || ptr_on_stack (dest) || !SGEN_CLASS_HAS_REFERENCES (klass)) {
4464                 size_t element_size = mono_class_value_size (klass, NULL);
4465                 size_t size = count * element_size;
4466                 mono_gc_memmove_atomic (dest, src, size);
4467                 return;
4468         }
4469
4470 #ifdef SGEN_BINARY_PROTOCOL
4471         {
4472                 size_t element_size = mono_class_value_size (klass, NULL);
4473                 int i;
4474                 for (i = 0; i < count; ++i) {
4475                         scan_object_for_binary_protocol_copy_wbarrier ((char*)dest + i * element_size,
4476                                         (char*)src + i * element_size - sizeof (MonoObject),
4477                                         (mword) klass->gc_descr);
4478                 }
4479         }
4480 #endif
4481
4482         remset.wbarrier_value_copy (dest, src, count, klass);
4483 }
4484
4485 /**
4486  * mono_gc_wbarrier_object_copy:
4487  *
4488  * Write barrier to call when obj is the result of a clone or copy of an object.
4489  */
4490 void
4491 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
4492 {
4493         int size;
4494
4495         HEAVY_STAT (++stat_wbarrier_object_copy);
4496
4497         if (ptr_in_nursery (obj) || ptr_on_stack (obj)) {
4498                 size = mono_object_class (obj)->instance_size;
4499                 mono_gc_memmove_aligned ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
4500                                 size - sizeof (MonoObject));
4501                 return;
4502         }
4503
4504 #ifdef SGEN_BINARY_PROTOCOL
4505         scan_object_for_binary_protocol_copy_wbarrier (obj, (char*)src, (mword) src->vtable->gc_descr);
4506 #endif
4507
4508         remset.wbarrier_object_copy (obj, src);
4509 }
4510
4511
4512 /*
4513  * ######################################################################
4514  * ########  Other mono public interface functions.
4515  * ######################################################################
4516  */
4517
4518 #define REFS_SIZE 128
4519 typedef struct {
4520         void *data;
4521         MonoGCReferences callback;
4522         int flags;
4523         int count;
4524         int called;
4525         MonoObject *refs [REFS_SIZE];
4526         uintptr_t offsets [REFS_SIZE];
4527 } HeapWalkInfo;
4528
4529 #undef HANDLE_PTR
4530 #define HANDLE_PTR(ptr,obj)     do {    \
4531                 if (*(ptr)) {   \
4532                         if (hwi->count == REFS_SIZE) {  \
4533                                 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);    \
4534                                 hwi->count = 0; \
4535                                 hwi->called = 1;        \
4536                         }       \
4537                         hwi->offsets [hwi->count] = (char*)(ptr)-(char*)start;  \
4538                         hwi->refs [hwi->count++] = *(ptr);      \
4539                 }       \
4540         } while (0)
4541
4542 static void
4543 collect_references (HeapWalkInfo *hwi, char *start, size_t size)
4544 {
4545 #include "sgen-scan-object.h"
4546 }
4547
4548 static void
4549 walk_references (char *start, size_t size, void *data)
4550 {
4551         HeapWalkInfo *hwi = data;
4552         hwi->called = 0;
4553         hwi->count = 0;
4554         collect_references (hwi, start, size);
4555         if (hwi->count || !hwi->called)
4556                 hwi->callback ((MonoObject*)start, mono_object_class (start), hwi->called? 0: size, hwi->count, hwi->refs, hwi->offsets, hwi->data);
4557 }
4558
4559 /**
4560  * mono_gc_walk_heap:
4561  * @flags: flags for future use
4562  * @callback: a function pointer called for each object in the heap
4563  * @data: a user data pointer that is passed to callback
4564  *
4565  * This function can be used to iterate over all the live objects in the heap:
4566  * for each object, @callback is invoked, providing info about the object's
4567  * location in memory, its class, its size and the objects it references.
4568  * For each referenced object it's offset from the object address is
4569  * reported in the offsets array.
4570  * The object references may be buffered, so the callback may be invoked
4571  * multiple times for the same object: in all but the first call, the size
4572  * argument will be zero.
4573  * Note that this function can be only called in the #MONO_GC_EVENT_PRE_START_WORLD
4574  * profiler event handler.
4575  *
4576  * Returns: a non-zero value if the GC doesn't support heap walking
4577  */
4578 int
4579 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
4580 {
4581         HeapWalkInfo hwi;
4582
4583         hwi.flags = flags;
4584         hwi.callback = callback;
4585         hwi.data = data;
4586
4587         sgen_clear_nursery_fragments ();
4588         sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, walk_references, &hwi, FALSE);
4589
4590         major_collector.iterate_objects (TRUE, TRUE, walk_references, &hwi);
4591         sgen_los_iterate_objects (walk_references, &hwi);
4592
4593         return 0;
4594 }
4595
4596 void
4597 mono_gc_collect (int generation)
4598 {
4599         LOCK_GC;
4600         if (generation > 1)
4601                 generation = 1;
4602         sgen_perform_collection (0, generation, "user request", TRUE);
4603         UNLOCK_GC;
4604 }
4605
4606 int
4607 mono_gc_max_generation (void)
4608 {
4609         return 1;
4610 }
4611
4612 int
4613 mono_gc_collection_count (int generation)
4614 {
4615         if (generation == 0)
4616                 return stat_minor_gcs;
4617         return stat_major_gcs;
4618 }
4619
4620 int64_t
4621 mono_gc_get_used_size (void)
4622 {
4623         gint64 tot = 0;
4624         LOCK_GC;
4625         tot = los_memory_usage;
4626         tot += nursery_section->next_data - nursery_section->data;
4627         tot += major_collector.get_used_size ();
4628         /* FIXME: account for pinned objects */
4629         UNLOCK_GC;
4630         return tot;
4631 }
4632
4633 int
4634 mono_gc_get_los_limit (void)
4635 {
4636         return MAX_SMALL_OBJ_SIZE;
4637 }
4638
4639 gboolean
4640 mono_gc_user_markers_supported (void)
4641 {
4642         return TRUE;
4643 }
4644
4645 gboolean
4646 mono_object_is_alive (MonoObject* o)
4647 {
4648         return TRUE;
4649 }
4650
4651 int
4652 mono_gc_get_generation (MonoObject *obj)
4653 {
4654         if (ptr_in_nursery (obj))
4655                 return 0;
4656         return 1;
4657 }
4658
4659 void
4660 mono_gc_enable_events (void)
4661 {
4662 }
4663
4664 void
4665 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
4666 {
4667         sgen_register_disappearing_link (obj, link_addr, track, FALSE);
4668 }
4669
4670 void
4671 mono_gc_weak_link_remove (void **link_addr, gboolean track)
4672 {
4673         sgen_register_disappearing_link (NULL, link_addr, track, FALSE);
4674 }
4675
4676 MonoObject*
4677 mono_gc_weak_link_get (void **link_addr)
4678 {
4679         void * volatile *link_addr_volatile;
4680         void *ptr;
4681         MonoObject *obj;
4682  retry:
4683         link_addr_volatile = link_addr;
4684         ptr = (void*)*link_addr_volatile;
4685         /*
4686          * At this point we have a hidden pointer.  If the GC runs
4687          * here, it will not recognize the hidden pointer as a
4688          * reference, and if the object behind it is not referenced
4689          * elsewhere, it will be freed.  Once the world is restarted
4690          * we reveal the pointer, giving us a pointer to a freed
4691          * object.  To make sure we don't return it, we load the
4692          * hidden pointer again.  If it's still the same, we can be
4693          * sure the object reference is valid.
4694          */
4695         if (ptr)
4696                 obj = (MonoObject*) REVEAL_POINTER (ptr);
4697         else
4698                 return NULL;
4699
4700         mono_memory_barrier ();
4701
4702         /*
4703          * During the second bridge processing step the world is
4704          * running again.  That step processes all weak links once
4705          * more to null those that refer to dead objects.  Before that
4706          * is completed, those links must not be followed, so we
4707          * conservatively wait for bridge processing when any weak
4708          * link is dereferenced.
4709          */
4710         if (G_UNLIKELY (bridge_processing_in_progress))
4711                 mono_gc_wait_for_bridge_processing ();
4712
4713         if ((void*)*link_addr_volatile != ptr)
4714                 goto retry;
4715
4716         return obj;
4717 }
4718
4719 gboolean
4720 mono_gc_ephemeron_array_add (MonoObject *obj)
4721 {
4722         EphemeronLinkNode *node;
4723
4724         LOCK_GC;
4725
4726         node = sgen_alloc_internal (INTERNAL_MEM_EPHEMERON_LINK);
4727         if (!node) {
4728                 UNLOCK_GC;
4729                 return FALSE;
4730         }
4731         node->array = (char*)obj;
4732         node->next = ephemeron_list;
4733         ephemeron_list = node;
4734
4735         SGEN_LOG (5, "Registered ephemeron array %p", obj);
4736
4737         UNLOCK_GC;
4738         return TRUE;
4739 }
4740
4741 gboolean
4742 mono_gc_set_allow_synchronous_major (gboolean flag)
4743 {
4744         if (!major_collector.is_concurrent)
4745                 return flag;
4746
4747         allow_synchronous_major = flag;
4748         return TRUE;
4749 }
4750
4751 void*
4752 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
4753 {
4754         void *result;
4755         LOCK_INTERRUPTION;
4756         result = func (data);
4757         UNLOCK_INTERRUPTION;
4758         return result;
4759 }
4760
4761 gboolean
4762 mono_gc_is_gc_thread (void)
4763 {
4764         gboolean result;
4765         LOCK_GC;
4766         result = mono_thread_info_current () != NULL;
4767         UNLOCK_GC;
4768         return result;
4769 }
4770
4771 static gboolean
4772 is_critical_method (MonoMethod *method)
4773 {
4774         return mono_runtime_is_critical_method (method) || sgen_is_critical_method (method);
4775 }
4776
4777 void
4778 sgen_env_var_error (const char *env_var, const char *fallback, const char *description_format, ...)
4779 {
4780         va_list ap;
4781
4782         va_start (ap, description_format);
4783
4784         fprintf (stderr, "Warning: In environment variable `%s': ", env_var);
4785         vfprintf (stderr, description_format, ap);
4786         if (fallback)
4787                 fprintf (stderr, " - %s", fallback);
4788         fprintf (stderr, "\n");
4789
4790         va_end (ap);
4791 }
4792
4793 static gboolean
4794 parse_double_in_interval (const char *env_var, const char *opt_name, const char *opt, double min, double max, double *result)
4795 {
4796         char *endptr;
4797         double val = strtod (opt, &endptr);
4798         if (endptr == opt) {
4799                 sgen_env_var_error (env_var, "Using default value.", "`%s` must be a number.", opt_name);
4800                 return FALSE;
4801         }
4802         else if (val < min || val > max) {
4803                 sgen_env_var_error (env_var, "Using default value.", "`%s` must be between %.2f - %.2f.", opt_name, min, max);
4804                 return FALSE;
4805         }
4806         *result = val;
4807         return TRUE;
4808 }
4809
4810 void
4811 mono_gc_base_init (void)
4812 {
4813         MonoThreadInfoCallbacks cb;
4814         const char *env;
4815         char **opts, **ptr;
4816         char *major_collector_opt = NULL;
4817         char *minor_collector_opt = NULL;
4818         glong max_heap = 0;
4819         glong soft_limit = 0;
4820         int num_workers;
4821         int result;
4822         int dummy;
4823         gboolean debug_print_allowance = FALSE;
4824         double allowance_ratio = 0, save_target = 0;
4825         gboolean have_split_nursery = FALSE;
4826         gboolean cement_enabled = TRUE;
4827
4828         do {
4829                 result = InterlockedCompareExchange (&gc_initialized, -1, 0);
4830                 switch (result) {
4831                 case 1:
4832                         /* already inited */
4833                         return;
4834                 case -1:
4835                         /* being inited by another thread */
4836                         g_usleep (1000);
4837                         break;
4838                 case 0:
4839                         /* we will init it */
4840                         break;
4841                 default:
4842                         g_assert_not_reached ();
4843                 }
4844         } while (result != 0);
4845
4846         LOCK_INIT (gc_mutex);
4847
4848         pagesize = mono_pagesize ();
4849         gc_debug_file = stderr;
4850
4851         cb.thread_register = sgen_thread_register;
4852         cb.thread_detach = sgen_thread_detach;
4853         cb.thread_unregister = sgen_thread_unregister;
4854         cb.thread_attach = sgen_thread_attach;
4855         cb.mono_method_is_critical = (gpointer)is_critical_method;
4856 #ifndef HOST_WIN32
4857         cb.thread_exit = mono_gc_pthread_exit;
4858         cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
4859 #endif
4860
4861         mono_threads_init (&cb, sizeof (SgenThreadInfo));
4862
4863         LOCK_INIT (sgen_interruption_mutex);
4864         LOCK_INIT (pin_queue_mutex);
4865
4866         init_user_copy_or_mark_key ();
4867
4868         if ((env = g_getenv (MONO_GC_PARAMS_NAME))) {
4869                 opts = g_strsplit (env, ",", -1);
4870                 for (ptr = opts; *ptr; ++ptr) {
4871                         char *opt = *ptr;
4872                         if (g_str_has_prefix (opt, "major=")) {
4873                                 opt = strchr (opt, '=') + 1;
4874                                 major_collector_opt = g_strdup (opt);
4875                         } else if (g_str_has_prefix (opt, "minor=")) {
4876                                 opt = strchr (opt, '=') + 1;
4877                                 minor_collector_opt = g_strdup (opt);
4878                         }
4879                 }
4880         } else {
4881                 opts = NULL;
4882         }
4883
4884         init_stats ();
4885         sgen_init_internal_allocator ();
4886         sgen_init_nursery_allocator ();
4887         sgen_init_fin_weak_hash ();
4888
4889         sgen_register_fixed_internal_mem_type (INTERNAL_MEM_SECTION, SGEN_SIZEOF_GC_MEM_SECTION);
4890         sgen_register_fixed_internal_mem_type (INTERNAL_MEM_FINALIZE_READY_ENTRY, sizeof (FinalizeReadyEntry));
4891         sgen_register_fixed_internal_mem_type (INTERNAL_MEM_GRAY_QUEUE, sizeof (GrayQueueSection));
4892         sgen_register_fixed_internal_mem_type (INTERNAL_MEM_EPHEMERON_LINK, sizeof (EphemeronLinkNode));
4893
4894 #ifndef HAVE_KW_THREAD
4895         mono_native_tls_alloc (&thread_info_key, NULL);
4896 #if defined(__APPLE__) || defined (HOST_WIN32)
4897         /*
4898          * CEE_MONO_TLS requires the tls offset, not the key, so the code below only works on darwin,
4899          * where the two are the same.
4900          */
4901         mono_tls_key_set_offset (TLS_KEY_SGEN_THREAD_INFO, thread_info_key);
4902 #endif
4903 #else
4904         {
4905                 int tls_offset = -1;
4906                 MONO_THREAD_VAR_OFFSET (sgen_thread_info, tls_offset);
4907                 mono_tls_key_set_offset (TLS_KEY_SGEN_THREAD_INFO, tls_offset);
4908         }
4909 #endif
4910
4911         /*
4912          * This needs to happen before any internal allocations because
4913          * it inits the small id which is required for hazard pointer
4914          * operations.
4915          */
4916         sgen_os_init ();
4917
4918         mono_thread_info_attach (&dummy);
4919
4920         if (!minor_collector_opt) {
4921                 sgen_simple_nursery_init (&sgen_minor_collector);
4922         } else {
4923                 if (!strcmp (minor_collector_opt, "simple")) {
4924                 use_simple_nursery:
4925                         sgen_simple_nursery_init (&sgen_minor_collector);
4926                 } else if (!strcmp (minor_collector_opt, "split")) {
4927                         sgen_split_nursery_init (&sgen_minor_collector);
4928                         have_split_nursery = TRUE;
4929                 } else {
4930                         sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using `simple` instead.", "Unknown minor collector `%s'.", minor_collector_opt);
4931                         goto use_simple_nursery;
4932                 }
4933         }
4934
4935         if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep")) {
4936         use_marksweep_major:
4937                 sgen_marksweep_init (&major_collector);
4938         } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed")) {
4939                 sgen_marksweep_fixed_init (&major_collector);
4940         } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-par")) {
4941                 sgen_marksweep_par_init (&major_collector);
4942         } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-fixed-par")) {
4943                 sgen_marksweep_fixed_par_init (&major_collector);
4944         } else if (!major_collector_opt || !strcmp (major_collector_opt, "marksweep-conc")) {
4945                 sgen_marksweep_conc_init (&major_collector);
4946         } else {
4947                 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using `marksweep` instead.", "Unknown major collector `%s'.", major_collector_opt);
4948                 goto use_marksweep_major;
4949         }
4950
4951         if (have_split_nursery && major_collector.is_parallel) {
4952                 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Disabling split minor collector.", "`minor=split` is not supported with the parallel collector yet.");
4953                 have_split_nursery = FALSE;
4954         }
4955
4956         num_workers = mono_cpu_count ();
4957         g_assert (num_workers > 0);
4958         if (num_workers > 16)
4959                 num_workers = 16;
4960
4961         ///* Keep this the default for now */
4962         /* Precise marking is broken on all supported targets. Disable until fixed. */
4963         conservative_stack_mark = TRUE;
4964
4965         sgen_nursery_size = DEFAULT_NURSERY_SIZE;
4966
4967         if (opts) {
4968                 gboolean usage_printed = FALSE;
4969
4970                 for (ptr = opts; *ptr; ++ptr) {
4971                         char *opt = *ptr;
4972                         if (!strcmp (opt, ""))
4973                                 continue;
4974                         if (g_str_has_prefix (opt, "major="))
4975                                 continue;
4976                         if (g_str_has_prefix (opt, "minor="))
4977                                 continue;
4978                         if (g_str_has_prefix (opt, "max-heap-size=")) {
4979                                 glong max_heap_candidate = 0;
4980                                 opt = strchr (opt, '=') + 1;
4981                                 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap_candidate)) {
4982                                         max_heap = (max_heap_candidate + mono_pagesize () - 1) & ~(glong)(mono_pagesize () - 1);
4983                                         if (max_heap != max_heap_candidate)
4984                                                 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Rounding up.", "`max-heap-size` size must be a multiple of %d.", mono_pagesize ());
4985                                 } else {
4986                                         sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`max-heap-size` must be an integer.");
4987                                 }
4988                                 continue;
4989                         }
4990                         if (g_str_has_prefix (opt, "soft-heap-limit=")) {
4991                                 opt = strchr (opt, '=') + 1;
4992                                 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &soft_limit)) {
4993                                         if (soft_limit <= 0) {
4994                                                 sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`soft-heap-limit` must be positive.");
4995                                                 soft_limit = 0;
4996                                         }
4997                                 } else {
4998                                         sgen_env_var_error (MONO_GC_PARAMS_NAME, NULL, "`soft-heap-limit` must be an integer.");
4999                                 }
5000                                 continue;
5001                         }
5002                         if (g_str_has_prefix (opt, "workers=")) {
5003                                 long val;
5004                                 char *endptr;
5005                                 if (!major_collector.is_parallel) {
5006                                         sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "The `workers` option can only be used for parallel collectors.");
5007                                         continue;
5008                                 }
5009                                 opt = strchr (opt, '=') + 1;
5010                                 val = strtol (opt, &endptr, 10);
5011                                 if (!*opt || *endptr) {
5012                                         sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "Cannot parse the `workers` option value.");
5013                                         continue;
5014                                 }
5015                                 if (val <= 0 || val > 16) {
5016                                         sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "The number of `workers` must be in the range 1 to 16.");
5017                                         continue;
5018                                 }
5019                                 num_workers = (int)val;
5020                                 continue;
5021                         }
5022                         if (g_str_has_prefix (opt, "stack-mark=")) {
5023                                 opt = strchr (opt, '=') + 1;
5024                                 if (!strcmp (opt, "precise")) {
5025                                         conservative_stack_mark = FALSE;
5026                                 } else if (!strcmp (opt, "conservative")) {
5027                                         conservative_stack_mark = TRUE;
5028                                 } else {
5029                                         sgen_env_var_error (MONO_GC_PARAMS_NAME, conservative_stack_mark ? "Using `conservative`." : "Using `precise`.",
5030                                                         "Invalid value `%s` for `stack-mark` option, possible values are: `precise`, `conservative`.", opt);
5031                                 }
5032                                 continue;
5033                         }
5034                         if (g_str_has_prefix (opt, "bridge=")) {
5035                                 opt = strchr (opt, '=') + 1;
5036                                 sgen_register_test_bridge_callbacks (g_strdup (opt));
5037                                 continue;
5038                         }
5039 #ifdef USER_CONFIG
5040                         if (g_str_has_prefix (opt, "nursery-size=")) {
5041                                 long val;
5042                                 opt = strchr (opt, '=') + 1;
5043                                 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &val)) {
5044 #ifdef SGEN_ALIGN_NURSERY
5045                                         if ((val & (val - 1))) {
5046                                                 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "`nursery-size` must be a power of two.");
5047                                                 continue;
5048                                         }
5049
5050                                         if (val < SGEN_MAX_NURSERY_WASTE) {
5051                                                 sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.",
5052                                                                 "`nursery-size` must be at least %d bytes.\n", SGEN_MAX_NURSERY_WASTE);
5053                                                 continue;
5054                                         }
5055
5056                                         sgen_nursery_size = val;
5057                                         sgen_nursery_bits = 0;
5058                                         while (1 << (++ sgen_nursery_bits) != sgen_nursery_size)
5059                                                 ;
5060 #else
5061                                         sgen_nursery_size = val;
5062 #endif
5063                                 } else {
5064                                         sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "`nursery-size` must be an integer.");
5065                                         continue;
5066                                 }
5067                                 continue;
5068                         }
5069 #endif
5070                         if (g_str_has_prefix (opt, "save-target-ratio=")) {
5071                                 double val;
5072                                 opt = strchr (opt, '=') + 1;
5073                                 if (parse_double_in_interval (MONO_GC_PARAMS_NAME, "save-target-ratio", opt,
5074                                                 SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO, &val)) {
5075                                         save_target = val;
5076                                 }
5077                                 continue;
5078                         }
5079                         if (g_str_has_prefix (opt, "default-allowance-ratio=")) {
5080                                 double val;
5081                                 opt = strchr (opt, '=') + 1;
5082                                 if (parse_double_in_interval (MONO_GC_PARAMS_NAME, "default-allowance-ratio", opt,
5083                                                 SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, SGEN_MIN_ALLOWANCE_NURSERY_SIZE_RATIO, &val)) {
5084                                         allowance_ratio = val;
5085                                 }
5086                                 continue;
5087                         }
5088                         if (g_str_has_prefix (opt, "allow-synchronous-major=")) {
5089                                 if (!major_collector.is_concurrent) {
5090                                         sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "`allow-synchronous-major` is only valid for the concurrent major collector.");
5091                                         continue;
5092                                 }
5093
5094                                 opt = strchr (opt, '=') + 1;
5095
5096                                 if (!strcmp (opt, "yes")) {
5097                                         allow_synchronous_major = TRUE;
5098                                 } else if (!strcmp (opt, "no")) {
5099                                         allow_synchronous_major = FALSE;
5100                                 } else {
5101                                         sgen_env_var_error (MONO_GC_PARAMS_NAME, "Using default value.", "`allow-synchronous-major` must be either `yes' or `no'.");
5102                                         continue;
5103                                 }
5104                         }
5105
5106                         if (!strcmp (opt, "cementing")) {
5107                                 if (major_collector.is_parallel) {
5108                                         sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "`cementing` is not supported for the parallel major collector.");
5109                                         continue;
5110                                 }
5111                                 cement_enabled = TRUE;
5112                                 continue;
5113                         }
5114                         if (!strcmp (opt, "no-cementing")) {
5115                                 cement_enabled = FALSE;
5116                                 continue;
5117                         }
5118
5119                         if (major_collector.handle_gc_param && major_collector.handle_gc_param (opt))
5120                                 continue;
5121
5122                         if (sgen_minor_collector.handle_gc_param && sgen_minor_collector.handle_gc_param (opt))
5123                                 continue;
5124
5125                         sgen_env_var_error (MONO_GC_PARAMS_NAME, "Ignoring.", "Unknown option `%s`.", opt);
5126
5127                         if (usage_printed)
5128                                 continue;
5129
5130                         fprintf (stderr, "\n%s must be a comma-delimited list of one or more of the following:\n", MONO_GC_PARAMS_NAME);
5131                         fprintf (stderr, "  max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
5132                         fprintf (stderr, "  soft-heap-limit=n (where N is an integer, possibly with a k, m or a g suffix)\n");
5133                         fprintf (stderr, "  nursery-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
5134                         fprintf (stderr, "  major=COLLECTOR (where COLLECTOR is `marksweep', `marksweep-conc', `marksweep-par', 'marksweep-fixed' or 'marksweep-fixed-par')\n");
5135                         fprintf (stderr, "  minor=COLLECTOR (where COLLECTOR is `simple' or `split')\n");
5136                         fprintf (stderr, "  wbarrier=WBARRIER (where WBARRIER is `remset' or `cardtable')\n");
5137                         fprintf (stderr, "  stack-mark=MARK-METHOD (where MARK-METHOD is 'precise' or 'conservative')\n");
5138                         fprintf (stderr, "  [no-]cementing\n");
5139                         if (major_collector.is_concurrent)
5140                                 fprintf (stderr, "  allow-synchronous-major=FLAG (where FLAG is `yes' or `no')\n");
5141                         if (major_collector.print_gc_param_usage)
5142                                 major_collector.print_gc_param_usage ();
5143                         if (sgen_minor_collector.print_gc_param_usage)
5144                                 sgen_minor_collector.print_gc_param_usage ();
5145                         fprintf (stderr, " Experimental options:\n");
5146                         fprintf (stderr, "  save-target-ratio=R (where R must be between %.2f - %.2f).\n", SGEN_MIN_SAVE_TARGET_RATIO, SGEN_MAX_SAVE_TARGET_RATIO);
5147                         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);
5148                         fprintf (stderr, "\n");
5149
5150                         usage_printed = TRUE;
5151                 }
5152                 g_strfreev (opts);
5153         }
5154
5155         if (major_collector.is_parallel) {
5156                 cement_enabled = FALSE;
5157                 sgen_workers_init (num_workers);
5158         } else if (major_collector.is_concurrent) {
5159                 sgen_workers_init (1);
5160         }
5161
5162         if (major_collector_opt)
5163                 g_free (major_collector_opt);
5164
5165         if (minor_collector_opt)
5166                 g_free (minor_collector_opt);
5167
5168         alloc_nursery ();
5169
5170         sgen_cement_init (cement_enabled);
5171
5172         if ((env = g_getenv (MONO_GC_DEBUG_NAME))) {
5173                 gboolean usage_printed = FALSE;
5174
5175                 opts = g_strsplit (env, ",", -1);
5176                 for (ptr = opts; ptr && *ptr; ptr ++) {
5177                         char *opt = *ptr;
5178                         if (!strcmp (opt, ""))
5179                                 continue;
5180                         if (opt [0] >= '0' && opt [0] <= '9') {
5181                                 gc_debug_level = atoi (opt);
5182                                 opt++;
5183                                 if (opt [0] == ':')
5184                                         opt++;
5185                                 if (opt [0]) {
5186 #ifdef HOST_WIN32
5187                                         char *rf = g_strdup_printf ("%s.%d", opt, GetCurrentProcessId ());
5188 #else
5189                                         char *rf = g_strdup_printf ("%s.%d", opt, getpid ());
5190 #endif
5191                                         gc_debug_file = fopen (rf, "wb");
5192                                         if (!gc_debug_file)
5193                                                 gc_debug_file = stderr;
5194                                         g_free (rf);
5195                                 }
5196                         } else if (!strcmp (opt, "print-allowance")) {
5197                                 debug_print_allowance = TRUE;
5198                         } else if (!strcmp (opt, "print-pinning")) {
5199                                 do_pin_stats = TRUE;
5200                         } else if (!strcmp (opt, "verify-before-allocs")) {
5201                                 verify_before_allocs = 1;
5202                                 has_per_allocation_action = TRUE;
5203                         } else if (g_str_has_prefix (opt, "verify-before-allocs=")) {
5204                                 char *arg = strchr (opt, '=') + 1;
5205                                 verify_before_allocs = atoi (arg);
5206                                 has_per_allocation_action = TRUE;
5207                         } else if (!strcmp (opt, "collect-before-allocs")) {
5208                                 collect_before_allocs = 1;
5209                                 has_per_allocation_action = TRUE;
5210                         } else if (g_str_has_prefix (opt, "collect-before-allocs=")) {
5211                                 char *arg = strchr (opt, '=') + 1;
5212                                 has_per_allocation_action = TRUE;
5213                                 collect_before_allocs = atoi (arg);
5214                         } else if (!strcmp (opt, "verify-before-collections")) {
5215                                 whole_heap_check_before_collection = TRUE;
5216                         } else if (!strcmp (opt, "check-at-minor-collections")) {
5217                                 consistency_check_at_minor_collection = TRUE;
5218                                 nursery_clear_policy = CLEAR_AT_GC;
5219                         } else if (!strcmp (opt, "mod-union-consistency-check")) {
5220                                 if (!major_collector.is_concurrent) {
5221                                         sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "`mod-union-consistency-check` only works with concurrent major collector.");
5222                                         continue;
5223                                 }
5224                                 mod_union_consistency_check = TRUE;
5225                         } else if (!strcmp (opt, "check-mark-bits")) {
5226                                 check_mark_bits_after_major_collection = TRUE;
5227                         } else if (!strcmp (opt, "check-nursery-pinned")) {
5228                                 check_nursery_objects_pinned = TRUE;
5229                         } else if (!strcmp (opt, "xdomain-checks")) {
5230                                 xdomain_checks = TRUE;
5231                         } else if (!strcmp (opt, "clear-at-gc")) {
5232                                 nursery_clear_policy = CLEAR_AT_GC;
5233                         } else if (!strcmp (opt, "clear-nursery-at-gc")) {
5234                                 nursery_clear_policy = CLEAR_AT_GC;
5235                         } else if (!strcmp (opt, "check-scan-starts")) {
5236                                 do_scan_starts_check = TRUE;
5237                         } else if (!strcmp (opt, "verify-nursery-at-minor-gc")) {
5238                                 do_verify_nursery = TRUE;
5239                         } else if (!strcmp (opt, "check-concurrent")) {
5240                                 if (!major_collector.is_concurrent) {
5241                                         sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "`check-concurrent` only works with concurrent major collectors.");
5242                                         continue;
5243                                 }
5244                                 do_concurrent_checks = TRUE;
5245                         } else if (!strcmp (opt, "dump-nursery-at-minor-gc")) {
5246                                 do_dump_nursery_content = TRUE;
5247                         } else if (!strcmp (opt, "no-managed-allocator")) {
5248                                 sgen_set_use_managed_allocator (FALSE);
5249                         } else if (!strcmp (opt, "disable-minor")) {
5250                                 disable_minor_collections = TRUE;
5251                         } else if (!strcmp (opt, "disable-major")) {
5252                                 disable_major_collections = TRUE;
5253                         } else if (g_str_has_prefix (opt, "heap-dump=")) {
5254                                 char *filename = strchr (opt, '=') + 1;
5255                                 nursery_clear_policy = CLEAR_AT_GC;
5256                                 heap_dump_file = fopen (filename, "w");
5257                                 if (heap_dump_file) {
5258                                         fprintf (heap_dump_file, "<sgen-dump>\n");
5259                                         do_pin_stats = TRUE;
5260                                 }
5261 #ifdef SGEN_BINARY_PROTOCOL
5262                         } else if (g_str_has_prefix (opt, "binary-protocol=")) {
5263                                 char *filename = strchr (opt, '=') + 1;
5264                                 binary_protocol_init (filename);
5265 #endif
5266                         } else {
5267                                 sgen_env_var_error (MONO_GC_DEBUG_NAME, "Ignoring.", "Unknown option `%s`.", opt);
5268
5269                                 if (usage_printed)
5270                                         continue;
5271
5272                                 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);
5273                                 fprintf (stderr, "Valid <option>s are:\n");
5274                                 fprintf (stderr, "  collect-before-allocs[=<n>]\n");
5275                                 fprintf (stderr, "  verify-before-allocs[=<n>]\n");
5276                                 fprintf (stderr, "  check-at-minor-collections\n");
5277                                 fprintf (stderr, "  check-mark-bits\n");
5278                                 fprintf (stderr, "  check-nursery-pinned\n");
5279                                 fprintf (stderr, "  verify-before-collections\n");
5280                                 fprintf (stderr, "  verify-nursery-at-minor-gc\n");
5281                                 fprintf (stderr, "  dump-nursery-at-minor-gc\n");
5282                                 fprintf (stderr, "  disable-minor\n");
5283                                 fprintf (stderr, "  disable-major\n");
5284                                 fprintf (stderr, "  xdomain-checks\n");
5285                                 fprintf (stderr, "  check-concurrent\n");
5286                                 fprintf (stderr, "  clear-at-gc\n");
5287                                 fprintf (stderr, "  clear-nursery-at-gc\n");
5288                                 fprintf (stderr, "  check-scan-starts\n");
5289                                 fprintf (stderr, "  no-managed-allocator\n");
5290                                 fprintf (stderr, "  print-allowance\n");
5291                                 fprintf (stderr, "  print-pinning\n");
5292                                 fprintf (stderr, "  heap-dump=<filename>\n");
5293 #ifdef SGEN_BINARY_PROTOCOL
5294                                 fprintf (stderr, "  binary-protocol=<filename>\n");
5295 #endif
5296                                 fprintf (stderr, "\n");
5297
5298                                 usage_printed = TRUE;
5299                         }
5300                 }
5301                 g_strfreev (opts);
5302         }
5303
5304         if (major_collector.is_parallel) {
5305                 if (heap_dump_file) {
5306                         sgen_env_var_error (MONO_GC_DEBUG_NAME, "Disabling.", "Cannot do `heap-dump` with the parallel collector.");
5307                         fclose (heap_dump_file);
5308                         heap_dump_file = NULL;
5309                 }
5310                 if (do_pin_stats) {
5311                         sgen_env_var_error (MONO_GC_DEBUG_NAME, "Disabling.", "`print-pinning` is not supported with the parallel collector.");
5312                         do_pin_stats = FALSE;
5313                 }
5314         }
5315
5316         if (major_collector.post_param_init)
5317                 major_collector.post_param_init (&major_collector);
5318
5319         sgen_memgov_init (max_heap, soft_limit, debug_print_allowance, allowance_ratio, save_target);
5320
5321         memset (&remset, 0, sizeof (remset));
5322
5323         sgen_card_table_init (&remset);
5324
5325         gc_initialized = 1;
5326 }
5327
5328 const char *
5329 mono_gc_get_gc_name (void)
5330 {
5331         return "sgen";
5332 }
5333
5334 static MonoMethod *write_barrier_method;
5335
5336 gboolean
5337 sgen_is_critical_method (MonoMethod *method)
5338 {
5339         return (method == write_barrier_method || sgen_is_managed_allocator (method));
5340 }
5341
5342 gboolean
5343 sgen_has_critical_method (void)
5344 {
5345         return write_barrier_method || sgen_has_managed_allocator ();
5346 }
5347
5348 #ifndef DISABLE_JIT
5349
5350 static void
5351 emit_nursery_check (MonoMethodBuilder *mb, int *nursery_check_return_labels)
5352 {
5353         memset (nursery_check_return_labels, 0, sizeof (int) * 3);
5354 #ifdef SGEN_ALIGN_NURSERY
5355         // if (ptr_in_nursery (ptr)) return;
5356         /*
5357          * Masking out the bits might be faster, but we would have to use 64 bit
5358          * immediates, which might be slower.
5359          */
5360         mono_mb_emit_ldarg (mb, 0);
5361         mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5362         mono_mb_emit_byte (mb, CEE_SHR_UN);
5363         mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5364         nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BEQ);
5365
5366         if (!major_collector.is_concurrent) {
5367                 // if (!ptr_in_nursery (*ptr)) return;
5368                 mono_mb_emit_ldarg (mb, 0);
5369                 mono_mb_emit_byte (mb, CEE_LDIND_I);
5370                 mono_mb_emit_icon (mb, DEFAULT_NURSERY_BITS);
5371                 mono_mb_emit_byte (mb, CEE_SHR_UN);
5372                 mono_mb_emit_icon (mb, (mword)sgen_get_nursery_start () >> DEFAULT_NURSERY_BITS);
5373                 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BNE_UN);
5374         }
5375 #else
5376         int label_continue1, label_continue2;
5377         int dereferenced_var;
5378
5379         // if (ptr < (sgen_get_nursery_start ())) goto continue;
5380         mono_mb_emit_ldarg (mb, 0);
5381         mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5382         label_continue_1 = mono_mb_emit_branch (mb, CEE_BLT);
5383
5384         // if (ptr >= sgen_get_nursery_end ())) goto continue;
5385         mono_mb_emit_ldarg (mb, 0);
5386         mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5387         label_continue_2 = mono_mb_emit_branch (mb, CEE_BGE);
5388
5389         // Otherwise return
5390         nursery_check_return_labels [0] = mono_mb_emit_branch (mb, CEE_BR);
5391
5392         // continue:
5393         mono_mb_patch_branch (mb, label_continue_1);
5394         mono_mb_patch_branch (mb, label_continue_2);
5395
5396         // Dereference and store in local var
5397         dereferenced_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
5398         mono_mb_emit_ldarg (mb, 0);
5399         mono_mb_emit_byte (mb, CEE_LDIND_I);
5400         mono_mb_emit_stloc (mb, dereferenced_var);
5401
5402         if (!major_collector.is_concurrent) {
5403                 // if (*ptr < sgen_get_nursery_start ()) return;
5404                 mono_mb_emit_ldloc (mb, dereferenced_var);
5405                 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_start ());
5406                 nursery_check_return_labels [1] = mono_mb_emit_branch (mb, CEE_BLT);
5407
5408                 // if (*ptr >= sgen_get_nursery_end ()) return;
5409                 mono_mb_emit_ldloc (mb, dereferenced_var);
5410                 mono_mb_emit_ptr (mb, (gpointer) sgen_get_nursery_end ());
5411                 nursery_check_return_labels [2] = mono_mb_emit_branch (mb, CEE_BGE);
5412         }
5413 #endif
5414 }
5415 #endif
5416
5417 MonoMethod*
5418 mono_gc_get_write_barrier (void)
5419 {
5420         MonoMethod *res;
5421         MonoMethodBuilder *mb;
5422         MonoMethodSignature *sig;
5423 #ifdef MANAGED_WBARRIER
5424         int i, nursery_check_labels [3];
5425
5426 #ifdef HAVE_KW_THREAD
5427         int stack_end_offset = -1;
5428
5429         MONO_THREAD_VAR_OFFSET (stack_end, stack_end_offset);
5430         g_assert (stack_end_offset != -1);
5431 #endif
5432 #endif
5433
5434         // FIXME: Maybe create a separate version for ctors (the branch would be
5435         // correctly predicted more times)
5436         if (write_barrier_method)
5437                 return write_barrier_method;
5438
5439         /* Create the IL version of mono_gc_barrier_generic_store () */
5440         sig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
5441         sig->ret = &mono_defaults.void_class->byval_arg;
5442         sig->params [0] = &mono_defaults.int_class->byval_arg;
5443
5444         mb = mono_mb_new (mono_defaults.object_class, "wbarrier", MONO_WRAPPER_WRITE_BARRIER);
5445
5446 #ifndef DISABLE_JIT
5447 #ifdef MANAGED_WBARRIER
5448         emit_nursery_check (mb, nursery_check_labels);
5449         /*
5450         addr = sgen_cardtable + ((address >> CARD_BITS) & CARD_MASK)
5451         *addr = 1;
5452
5453         sgen_cardtable:
5454                 LDC_PTR sgen_cardtable
5455
5456         address >> CARD_BITS
5457                 LDARG_0
5458                 LDC_I4 CARD_BITS
5459                 SHR_UN
5460         if (SGEN_HAVE_OVERLAPPING_CARDS) {
5461                 LDC_PTR card_table_mask
5462                 AND
5463         }
5464         AND
5465         ldc_i4_1
5466         stind_i1
5467         */
5468         mono_mb_emit_ptr (mb, sgen_cardtable);
5469         mono_mb_emit_ldarg (mb, 0);
5470         mono_mb_emit_icon (mb, CARD_BITS);
5471         mono_mb_emit_byte (mb, CEE_SHR_UN);
5472 #ifdef SGEN_HAVE_OVERLAPPING_CARDS
5473         mono_mb_emit_ptr (mb, (gpointer)CARD_MASK);
5474         mono_mb_emit_byte (mb, CEE_AND);
5475 #endif
5476         mono_mb_emit_byte (mb, CEE_ADD);
5477         mono_mb_emit_icon (mb, 1);
5478         mono_mb_emit_byte (mb, CEE_STIND_I1);
5479
5480         // return;
5481         for (i = 0; i < 3; ++i) {
5482                 if (nursery_check_labels [i])
5483                         mono_mb_patch_branch (mb, nursery_check_labels [i]);
5484         }
5485         mono_mb_emit_byte (mb, CEE_RET);
5486 #else
5487         mono_mb_emit_ldarg (mb, 0);
5488         mono_mb_emit_icall (mb, mono_gc_wbarrier_generic_nostore);
5489         mono_mb_emit_byte (mb, CEE_RET);
5490 #endif
5491 #endif
5492         res = mono_mb_create_method (mb, sig, 16);
5493         mono_mb_free (mb);
5494
5495         LOCK_GC;
5496         if (write_barrier_method) {
5497                 /* Already created */
5498                 mono_free_method (res);
5499         } else {
5500                 /* double-checked locking */
5501                 mono_memory_barrier ();
5502                 write_barrier_method = res;
5503         }
5504         UNLOCK_GC;
5505
5506         return write_barrier_method;
5507 }
5508
5509 char*
5510 mono_gc_get_description (void)
5511 {
5512         return g_strdup ("sgen");
5513 }
5514
5515 void
5516 mono_gc_set_desktop_mode (void)
5517 {
5518 }
5519
5520 gboolean
5521 mono_gc_is_moving (void)
5522 {
5523         return TRUE;
5524 }
5525
5526 gboolean
5527 mono_gc_is_disabled (void)
5528 {
5529         return FALSE;
5530 }
5531
5532 #ifdef HOST_WIN32
5533 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
5534 {
5535         return TRUE;
5536 }
5537 #endif
5538
5539 NurseryClearPolicy
5540 sgen_get_nursery_clear_policy (void)
5541 {
5542         return nursery_clear_policy;
5543 }
5544
5545 MonoVTable*
5546 sgen_get_array_fill_vtable (void)
5547 {
5548         if (!array_fill_vtable) {
5549                 static MonoClass klass;
5550                 static MonoVTable vtable;
5551                 gsize bmap;
5552
5553                 MonoDomain *domain = mono_get_root_domain ();
5554                 g_assert (domain);
5555
5556                 klass.element_class = mono_defaults.byte_class;
5557                 klass.rank = 1;
5558                 klass.instance_size = sizeof (MonoArray);
5559                 klass.sizes.element_size = 1;
5560                 klass.name = "array_filler_type";
5561
5562                 vtable.klass = &klass;
5563                 bmap = 0;
5564                 vtable.gc_descr = mono_gc_make_descr_for_array (TRUE, &bmap, 0, 1);
5565                 vtable.rank = 1;
5566
5567                 array_fill_vtable = &vtable;
5568         }
5569         return array_fill_vtable;
5570 }
5571
5572 void
5573 sgen_gc_lock (void)
5574 {
5575         LOCK_GC;
5576 }
5577
5578 void
5579 sgen_gc_unlock (void)
5580 {
5581         gboolean try_free = sgen_try_free_some_memory;
5582         sgen_try_free_some_memory = FALSE;
5583         mono_mutex_unlock (&gc_mutex);
5584         MONO_GC_UNLOCKED ();
5585         if (try_free)
5586                 mono_thread_hazardous_try_free_some ();
5587 }
5588
5589 void
5590 sgen_major_collector_iterate_live_block_ranges (sgen_cardtable_block_callback callback)
5591 {
5592         major_collector.iterate_live_block_ranges (callback);
5593 }
5594
5595 void
5596 sgen_major_collector_scan_card_table (SgenGrayQueue *queue)
5597 {
5598         major_collector.scan_card_table (FALSE, queue);
5599 }
5600
5601 SgenMajorCollector*
5602 sgen_get_major_collector (void)
5603 {
5604         return &major_collector;
5605 }
5606
5607 void mono_gc_set_skip_thread (gboolean skip)
5608 {
5609         SgenThreadInfo *info = mono_thread_info_current ();
5610
5611         LOCK_GC;
5612         info->gc_disabled = skip;
5613         UNLOCK_GC;
5614 }
5615
5616 SgenRemeberedSet*
5617 sgen_get_remset (void)
5618 {
5619         return &remset;
5620 }
5621
5622 guint
5623 mono_gc_get_vtable_bits (MonoClass *class)
5624 {
5625         if (sgen_need_bridge_processing () && sgen_is_bridge_class (class))
5626                 return SGEN_GC_BIT_BRIDGE_OBJECT;
5627         return 0;
5628 }
5629
5630 void
5631 mono_gc_register_altstack (gpointer stack, gint32 stack_size, gpointer altstack, gint32 altstack_size)
5632 {
5633         // FIXME:
5634 }
5635
5636
5637 void
5638 sgen_check_whole_heap_stw (void)
5639 {
5640         sgen_stop_world (0);
5641         sgen_clear_nursery_fragments ();
5642         sgen_check_whole_heap (FALSE);
5643         sgen_restart_world (0, NULL);
5644 }
5645
5646 void
5647 sgen_gc_event_moves (void)
5648 {
5649         if (moved_objects_idx) {
5650                 mono_profiler_gc_moves (moved_objects, moved_objects_idx);
5651                 moved_objects_idx = 0;
5652         }
5653 }
5654
5655 #endif /* HAVE_SGEN_GC */