mono/metadata/gc.c

   1 /*
   2  * metadata/gc.c: GC icalls.
   3  *
   4  * Author: Paolo Molaro <lupus@ximian.com>
   5  *
   6  * (C) 2002 Ximian, Inc.
   7  */
   8
   9 #include <config.h>
  10 #include <glib.h>
  11 #include <string.h>
  12
  13 #include <mono/metadata/gc-internal.h>
  14 #include <mono/metadata/mono-gc.h>
  15 #include <mono/metadata/threads.h>
  16 #include <mono/metadata/tabledefs.h>
  17 #include <mono/metadata/exception.h>
  18 #include <mono/metadata/profiler-private.h>
  19 #include <mono/metadata/domain-internals.h>
  20 #include <mono/metadata/class-internals.h>
  21 #include <mono/utils/mono-logger.h>
  22 #define GC_I_HIDE_POINTERS
  23 #include <mono/os/gc_wrapper.h>
  24
  25 #ifndef HIDE_POINTER
  26 #define HIDE_POINTER(v)         (v)
  27 #define REVEAL_POINTER(v)       (v)
  28 #endif
  29
  30 typedef struct DomainFinalizationReq {
  31         MonoDomain *domain;
  32         HANDLE done_event;
  33 } DomainFinalizationReq;
  34
  35 #ifdef PLATFORM_WINCE /* FIXME: add accessors to gc.dll API */
  36 extern void (*__imp_GC_finalizer_notifier)(void);
  37 #define GC_finalizer_notifier __imp_GC_finalizer_notifier
  38 extern int __imp_GC_finalize_on_demand;
  39 #define GC_finalize_on_demand __imp_GC_finalize_on_demand
  40 #endif
  41
  42 static int finalize_slot = -1;
  43
  44 static gboolean gc_disabled = FALSE;
  45
  46 static CRITICAL_SECTION finalizer_mutex;
  47
  48 static GSList *domains_to_finalize= NULL;
  49
  50 static MonoThread *gc_thread;
  51
  52 static void object_register_finalizer (MonoObject *obj, void (*callback)(void *, void*));
  53
  54 #if HAVE_BOEHM_GC
  55 static void finalize_notify (void);
  56 static HANDLE pending_done_event;
  57 static HANDLE shutdown_event;
  58 static HANDLE thread_started_event;
  59 #endif
  60
  61 /*
  62  * actually, we might want to queue the finalize requests in a separate thread,
  63  * but we need to be careful about the execution domain of the thread...
  64  */
  65 static void
  66 run_finalize (void *obj, void *data)
  67 {
  68         MonoObject *exc = NULL;
  69         MonoObject *o, *o2;
  70         o = (MonoObject*)((char*)obj + GPOINTER_TO_UINT (data));
  71
  72         if (finalize_slot < 0) {
  73                 int i;
  74                 MonoClass* obj_class = mono_get_object_class ();
  75                 for (i = 0; i < obj_class->vtable_size; ++i) {
  76                         MonoMethod *cm = obj_class->vtable [i];
  77
  78                         if (!strcmp (mono_method_get_name (cm), "Finalize")) {
  79                                 finalize_slot = i;
  80                                 break;
  81                         }
  82                 }
  83         }
  84
  85         mono_domain_lock (o->vtable->domain);
  86
  87         o2 = g_hash_table_lookup (o->vtable->domain->finalizable_objects_hash, o);
  88
  89         mono_domain_unlock (o->vtable->domain);
  90
  91         if (!o2)
  92                 /* Already finalized somehow */
  93                 return;
  94
  95         /* make sure the finalizer is not called again if the object is resurrected */
  96         object_register_finalizer (obj, NULL);
  97
  98         if (o->vtable->klass == mono_get_thread_class ())
  99                 if (mono_gc_is_finalizer_thread ((MonoThread*)o))
 100                         /* Avoid finalizing ourselves */
 101                         return;
 102
 103         /* speedup later... and use a timeout */
 104         /* g_print ("Finalize run on %p %s.%s\n", o, mono_object_class (o)->name_space, mono_object_class (o)->name); */
 105
 106         /* Use _internal here, since this thread can enter a doomed appdomain */
 107         mono_domain_set_internal (mono_object_domain (o));
 108
 109         mono_runtime_invoke (o->vtable->klass->vtable [finalize_slot], o, NULL, &exc);
 110
 111         if (exc) {
 112                 /* fixme: do something useful */
 113         }
 114 }
 115
 116 gpointer
 117 mono_gc_out_of_memory (size_t size)
 118 {
 119         /*
 120          * we could allocate at program startup some memory that we could release
 121          * back to the system at this point if we're really low on memory (ie, size is
 122          * lower than the memory we set apart)
 123          */
 124         mono_raise_exception (mono_domain_get ()->out_of_memory_ex);
 125
 126         return NULL;
 127 }
 128
 129 /*
 130  * Some of our objects may point to a different address than the address returned by GC_malloc()
 131  * (because of the GetHashCode hack), but we need to pass the real address to register_finalizer.
 132  * This also means that in the callback we need to adjust the pointer to get back the real
 133  * MonoObject*.
 134  * We also need to be consistent in the use of the GC_debug* variants of malloc and register_finalizer,
 135  * since that, too, can cause the underlying pointer to be offset.
 136  */
 137 static void
 138 object_register_finalizer (MonoObject *obj, void (*callback)(void *, void*))
 139 {
 140 #if HAVE_BOEHM_GC
 141         guint offset = 0;
 142
 143 #ifndef GC_DEBUG
 144         /* This assertion is not valid when GC_DEBUG is defined */
 145         g_assert (GC_base (obj) == (char*)obj - offset);
 146 #endif
 147
 148         if (mono_domain_is_unloading (obj->vtable->domain) && (callback != NULL))
 149                 /*
 150                  * Can't register finalizers in a dying appdomain, since they
 151                  * could be invoked after the appdomain has been unloaded.
 152                  */
 153                 return;
 154
 155         mono_domain_lock (obj->vtable->domain);
 156
 157         if (callback)
 158                 g_hash_table_insert (obj->vtable->domain->finalizable_objects_hash, obj,
 159                                                          obj);
 160         else
 161                 g_hash_table_remove (obj->vtable->domain->finalizable_objects_hash, obj);
 162
 163         mono_domain_unlock (obj->vtable->domain);
 164
 165         GC_REGISTER_FINALIZER_NO_ORDER ((char*)obj - offset, callback, GUINT_TO_POINTER (offset), NULL, NULL);
 166 #endif
 167 }
 168
 169 void
 170 mono_object_register_finalizer (MonoObject *obj)
 171 {
 172         /* g_print ("Registered finalizer on %p %s.%s\n", obj, mono_object_class (obj)->name_space, mono_object_class (obj)->name); */
 173         object_register_finalizer (obj, run_finalize);
 174 }
 175
 176 /*
 177  * mono_domain_finalize:
 178  *
 179  *  Request finalization of all finalizable objects inside @domain. Wait
 180  * @timeout msecs for the finalization to complete.
 181  * Returns: TRUE if succeeded, FALSE if there was a timeout
 182  */
 183
 184 gboolean
 185 mono_domain_finalize (MonoDomain *domain, guint32 timeout)
 186 {
 187         DomainFinalizationReq *req;
 188         guint32 res;
 189         HANDLE done_event;
 190
 191         if (mono_thread_current () == gc_thread)
 192                 /* We are called from inside a finalizer, not much we can do here */
 193                 return FALSE;
 194
 195         mono_profiler_appdomain_event (domain, MONO_PROFILE_START_UNLOAD);
 196
 197         /*
 198          * No need to create another thread 'cause the finalizer thread
 199          * is still working and will take care of running the finalizers
 200          */
 201
 202 #if HAVE_BOEHM_GC
 203         if (gc_disabled)
 204                 return TRUE;
 205
 206         GC_gcollect ();
 207
 208         done_event = CreateEvent (NULL, TRUE, FALSE, NULL);
 209
 210         req = g_new0 (DomainFinalizationReq, 1);
 211         req->domain = domain;
 212         req->done_event = done_event;
 213
 214         EnterCriticalSection (&finalizer_mutex);
 215
 216         domains_to_finalize = g_slist_append (domains_to_finalize, req);
 217
 218         LeaveCriticalSection (&finalizer_mutex);
 219
 220         /* Tell the finalizer thread to finalize this appdomain */
 221         finalize_notify ();
 222
 223         res = WaitForSingleObjectEx (done_event, timeout, TRUE);
 224
 225         /* printf ("WAIT RES: %d.\n", res); */
 226         if (res == WAIT_TIMEOUT) {
 227                 /* We leak the handle here */
 228                 return FALSE;
 229         }
 230
 231         CloseHandle (done_event);
 232         return TRUE;
 233 #else
 234         /* We don't support domain finalization without a GC */
 235         return FALSE;
 236 #endif
 237 }
 238
 239 void
 240 ves_icall_System_GC_InternalCollect (int generation)
 241 {
 242         MONO_ARCH_SAVE_REGS;
 243
 244 #if HAVE_BOEHM_GC
 245         GC_gcollect ();
 246 #endif
 247 }
 248
 249 gint64
 250 ves_icall_System_GC_GetTotalMemory (MonoBoolean forceCollection)
 251 {
 252         MONO_ARCH_SAVE_REGS;
 253
 254         if (forceCollection)
 255                 mono_gc_collect (mono_gc_max_generation ());
 256         return mono_gc_get_used_size ();
 257 }
 258
 259 void
 260 ves_icall_System_GC_KeepAlive (MonoObject *obj)
 261 {
 262         MONO_ARCH_SAVE_REGS;
 263
 264         /*
 265          * Does nothing.
 266          */
 267 }
 268
 269 void
 270 ves_icall_System_GC_ReRegisterForFinalize (MonoObject *obj)
 271 {
 272         MONO_ARCH_SAVE_REGS;
 273
 274         object_register_finalizer (obj, run_finalize);
 275 }
 276
 277 void
 278 ves_icall_System_GC_SuppressFinalize (MonoObject *obj)
 279 {
 280         MONO_ARCH_SAVE_REGS;
 281
 282         object_register_finalizer (obj, NULL);
 283 }
 284
 285 void
 286 ves_icall_System_GC_WaitForPendingFinalizers (void)
 287 {
 288         MONO_ARCH_SAVE_REGS;
 289
 290 #if HAVE_BOEHM_GC
 291         if (!GC_should_invoke_finalizers ())
 292                 return;
 293
 294         if (mono_thread_current () == gc_thread)
 295                 /* Avoid deadlocks */
 296                 return;
 297
 298         ResetEvent (pending_done_event);
 299         finalize_notify ();
 300         /* g_print ("Waiting for pending finalizers....\n"); */
 301         WaitForSingleObjectEx (pending_done_event, INFINITE, TRUE);
 302         /* g_print ("Done pending....\n"); */
 303 #else
 304 #endif
 305 }
 306
 307 static CRITICAL_SECTION allocator_section;
 308 static CRITICAL_SECTION handle_section;
 309 static guint32 next_handle = 0;
 310 static gpointer *gc_handles = NULL;
 311 static guint8 *gc_handle_types = NULL;
 312 static guint32 array_size = 0;
 313
 314 /*
 315  * The handle type is encoded in the lower two bits of the handle value:
 316  * 0 -> normal
 317  * 1 -> pinned
 318  * 2 -> weak
 319  */
 320
 321 typedef enum {
 322         HANDLE_WEAK,
 323         HANDLE_WEAK_TRACK,
 324         HANDLE_NORMAL,
 325         HANDLE_PINNED
 326 } HandleType;
 327
 328 /*
 329  * FIXME: make thread safe and reuse the array entries.
 330  */
 331 MonoObject *
 332 ves_icall_System_GCHandle_GetTarget (guint32 handle)
 333 {
 334         MonoObject *obj;
 335         gint32 type;
 336
 337         MONO_ARCH_SAVE_REGS;
 338
 339         if (gc_handles) {
 340                 type = handle & 0x3;
 341                 EnterCriticalSection (&handle_section);
 342                 g_assert (type == gc_handle_types [handle >> 2]);
 343                 obj = gc_handles [handle >> 2];
 344                 LeaveCriticalSection (&handle_section);
 345                 if (!obj)
 346                         return NULL;
 347
 348                 if ((type == HANDLE_WEAK) || (type == HANDLE_WEAK_TRACK))
 349                         return REVEAL_POINTER (obj);
 350                 else
 351                         return obj;
 352         }
 353         return NULL;
 354 }
 355
 356 guint32
 357 ves_icall_System_GCHandle_GetTargetHandle (MonoObject *obj, guint32 handle, gint32 type)
 358 {
 359         gpointer val = obj;
 360         guint32 h, idx;
 361
 362         MONO_ARCH_SAVE_REGS;
 363
 364         EnterCriticalSection (&handle_section);
 365         /* Indexes start from 1 since 0 means the handle is not allocated */
 366         idx = ++next_handle;
 367         if (idx >= array_size) {
 368                 gpointer *new_array;
 369                 guint8 *new_type_array;
 370                 if (!array_size)
 371                         array_size = 16;
 372 #if HAVE_BOEHM_GC
 373                 new_array = GC_MALLOC (sizeof (gpointer) * (array_size * 2));
 374                 new_type_array = GC_MALLOC (sizeof (guint8) * (array_size * 2));
 375 #else
 376                 new_array = g_malloc0 (sizeof (gpointer) * (array_size * 2));
 377                 new_type_array = g_malloc0 (sizeof (guint8) * (array_size * 2));
 378 #endif
 379                 if (gc_handles) {
 380                         int i;
 381                         memcpy (new_array, gc_handles, sizeof (gpointer) * array_size);
 382                         memcpy (new_type_array, gc_handle_types, sizeof (guint8) * array_size);
 383                         /* need to re-register links for weak refs. test if GC_realloc needs the same */
 384                         for (i = 0; i < array_size; ++i) {
 385 #if 0 /* This breaks the threaded finalizer, by causing segfaults deep
 386        * inside libgc.  I assume it will also break without the
 387        * threaded finalizer, just that the stress test (bug 31333)
 388        * deadlocks too early without it.  Reverting to the previous
 389        * version here stops the segfault.
 390        */
 391                                 if ((gc_handle_types[i] == HANDLE_WEAK) || (gc_handle_types[i] == HANDLE_WEAK_TRACK)) { /* all and only disguised pointers have it set */
 392 #else
 393                                 if (((gulong)new_array [i]) & 0x1) {
 394 #endif
 395 #if HAVE_BOEHM_GC
 396                                         if (gc_handles [i] != (gpointer)-1)
 397                                                 GC_unregister_disappearing_link (&(gc_handles [i]));
 398                                         if (new_array [i] != (gpointer)-1)
 399                                                 GC_GENERAL_REGISTER_DISAPPEARING_LINK (&(new_array [i]), REVEAL_POINTER (new_array [i]));
 400 #endif
 401                                 }
 402                         }
 403                 }
 404                 array_size *= 2;
 405 #ifndef HAVE_BOEHM_GC
 406                 g_free (gc_handles);
 407                 g_free (gc_handle_types);
 408 #endif
 409                 gc_handles = new_array;
 410                 gc_handle_types = new_type_array;
 411         }
 412
 413         /* resuse the type from the old target */
 414         if (type == -1)
 415                 type =  handle & 0x3;
 416         h = (idx << 2) | type;
 417         switch (type) {
 418         case HANDLE_WEAK:
 419         case HANDLE_WEAK_TRACK:
 420                 val = (gpointer)HIDE_POINTER (val);
 421                 gc_handles [idx] = val;
 422                 gc_handle_types [idx] = type;
 423 #if HAVE_BOEHM_GC
 424                 if (gc_handles [idx] != (gpointer)-1)
 425                         GC_GENERAL_REGISTER_DISAPPEARING_LINK (&(gc_handles [idx]), obj);
 426 #endif
 427                 break;
 428         default:
 429                 gc_handles [idx] = val;
 430                 gc_handle_types [idx] = type;
 431                 break;
 432         }
 433         LeaveCriticalSection (&handle_section);
 434         return h;
 435 }
 436
 437 void
 438 ves_icall_System_GCHandle_FreeHandle (guint32 handle)
 439 {
 440         int idx = handle >> 2;
 441         int type = handle & 0x3;
 442
 443         MONO_ARCH_SAVE_REGS;
 444
 445         EnterCriticalSection (&handle_section);
 446
 447 #ifdef HAVE_BOEHM_GC
 448         g_assert (type == gc_handle_types [idx]);
 449         if ((type == HANDLE_WEAK) || (type == HANDLE_WEAK_TRACK)) {
 450                 if (gc_handles [idx] != (gpointer)-1)
 451                         GC_unregister_disappearing_link (&(gc_handles [idx]));
 452         }
 453 #endif
 454
 455         gc_handles [idx] = (gpointer)-1;
 456         gc_handle_types [idx] = (guint8)-1;
 457         LeaveCriticalSection (&handle_section);
 458 }
 459
 460 gpointer
 461 ves_icall_System_GCHandle_GetAddrOfPinnedObject (guint32 handle)
 462 {
 463         MonoObject *obj;
 464         int type = handle & 0x3;
 465
 466         MONO_ARCH_SAVE_REGS;
 467
 468         if (gc_handles) {
 469                 EnterCriticalSection (&handle_section);
 470                 obj = gc_handles [handle >> 2];
 471                 g_assert (gc_handle_types [handle >> 2] == type);
 472                 LeaveCriticalSection (&handle_section);
 473                 if ((type == HANDLE_WEAK) || (type == HANDLE_WEAK_TRACK)) {
 474                         obj = REVEAL_POINTER (obj);
 475                         if (obj == (MonoObject *) -1)
 476                                 return NULL;
 477                 }
 478                 if (obj) {
 479                         MonoClass *klass = mono_object_class (obj);
 480                         if (klass == mono_defaults.string_class) {
 481                                 return mono_string_chars ((MonoString*)obj);
 482                         } else if (klass->rank) {
 483                                 return mono_array_addr ((MonoArray*)obj, char, 0);
 484                         } else {
 485                                 /* the C# code will check and throw the exception */
 486                                 /* FIXME: missing !klass->blittable test, see bug #61134 */
 487                                 if ((klass->flags & TYPE_ATTRIBUTE_LAYOUT_MASK) == TYPE_ATTRIBUTE_AUTO_LAYOUT)
 488                                         return (gpointer)-1;
 489                                 return (char*)obj + sizeof (MonoObject);
 490                         }
 491                 }
 492         }
 493         return NULL;
 494 }
 495
 496 guint32
 497 mono_gchandle_new (MonoObject *obj, gboolean pinned)
 498 {
 499         return ves_icall_System_GCHandle_GetTargetHandle (obj, 0, pinned? HANDLE_PINNED: HANDLE_NORMAL);
 500 }
 501
 502 guint32
 503 mono_gchandle_new_weakref (MonoObject *obj, gboolean track_resurrection)
 504 {
 505         return ves_icall_System_GCHandle_GetTargetHandle (obj, 0, track_resurrection? HANDLE_WEAK_TRACK: HANDLE_WEAK);
 506 }
 507
 508 /* This will return NULL for a collected object if using a weakref handle */
 509 MonoObject*
 510 mono_gchandle_get_target (guint32 gchandle)
 511 {
 512         return ves_icall_System_GCHandle_GetTarget (gchandle);
 513 }
 514
 515 void
 516 mono_gchandle_free (guint32 gchandle)
 517 {
 518         ves_icall_System_GCHandle_FreeHandle (gchandle);
 519 }
 520
 521 #if HAVE_BOEHM_GC
 522
 523 static HANDLE finalizer_event;
 524 static volatile gboolean finished=FALSE;
 525
 526 static void finalize_notify (void)
 527 {
 528 #ifdef DEBUG
 529         g_message (G_GNUC_PRETTY_FUNCTION ": prodding finalizer");
 530 #endif
 531
 532         SetEvent (finalizer_event);
 533 }
 534
 535 static void
 536 collect_objects (gpointer key, gpointer value, gpointer user_data)
 537 {
 538         GPtrArray *arr = (GPtrArray*)user_data;
 539         g_ptr_array_add (arr, key);
 540 }
 541
 542 /*
 543  * finalize_domain_objects:
 544  *
 545  *  Run the finalizers of all finalizable objects in req->domain.
 546  */
 547 static void
 548 finalize_domain_objects (DomainFinalizationReq *req)
 549 {
 550         int i;
 551         GPtrArray *objs;
 552         MonoDomain *domain = req->domain;
 553
 554         while (g_hash_table_size (domain->finalizable_objects_hash) > 0) {
 555                 /*
 556                  * Since the domain is unloading, nobody is allowed to put
 557                  * new entries into the hash table. But finalize_object might
 558                  * remove entries from the hash table, so we make a copy.
 559                  */
 560                 objs = g_ptr_array_new ();
 561                 g_hash_table_foreach (domain->finalizable_objects_hash,
 562                                                           collect_objects, objs);
 563                 /* printf ("FINALIZING %d OBJECTS.\n", objs->len); */
 564
 565                 for (i = 0; i < objs->len; ++i) {
 566                         MonoObject *o = (MonoObject*)g_ptr_array_index (objs, i);
 567                         /* FIXME: Avoid finalizing threads, etc */
 568                         run_finalize (o, 0);
 569                 }
 570
 571                 g_ptr_array_free (objs, TRUE);
 572         }
 573
 574         /* Process finalizers which are already in the queue */
 575         GC_invoke_finalizers ();
 576
 577         /* printf ("DONE.\n"); */
 578         SetEvent (req->done_event);
 579
 580         /* The event is closed in mono_domain_finalize if we get here */
 581         g_free (req);
 582 }
 583
 584 static guint32 finalizer_thread (gpointer unused)
 585 {
 586         gc_thread = mono_thread_current ();
 587
 588         SetEvent (thread_started_event);
 589
 590         while(!finished) {
 591                 /* Wait to be notified that there's at least one
 592                  * finaliser to run
 593                  */
 594                 WaitForSingleObjectEx (finalizer_event, INFINITE, TRUE);
 595
 596                 if (domains_to_finalize) {
 597                         EnterCriticalSection (&finalizer_mutex);
 598                         if (domains_to_finalize) {
 599                                 DomainFinalizationReq *req = domains_to_finalize->data;
 600                                 domains_to_finalize = g_slist_remove (domains_to_finalize, req);
 601                                 LeaveCriticalSection (&finalizer_mutex);
 602
 603                                 finalize_domain_objects (req);
 604                         }
 605                         else
 606                                 LeaveCriticalSection (&finalizer_mutex);
 607                 }
 608
 609 #ifdef DEBUG
 610                 g_message (G_GNUC_PRETTY_FUNCTION ": invoking finalizers");
 611 #endif
 612
 613                 /* If finished == TRUE, mono_gc_cleanup has been called (from mono_runtime_cleanup),
 614                  * before the domain is unloaded.
 615                  *
 616                  * There is a bug in GC_invoke_finalizer () in versions <= 6.2alpha4:
 617                  * the 'mem_freed' variable is not initialized when there are no
 618                  * objects to finalize, which leads to strange behavior later on.
 619                  * The check is necessary to work around that bug.
 620                  */
 621                 if (GC_should_invoke_finalizers ()) {
 622                         GC_invoke_finalizers ();
 623                 }
 624
 625                 SetEvent (pending_done_event);
 626         }
 627
 628         SetEvent (shutdown_event);
 629         return(0);
 630 }
 631
 632 /*
 633  * Enable or disable the separate finalizer thread.
 634  * It's currently disabled because it still requires some
 635  * work in the rest of the runtime.
 636  */
 637 #define ENABLE_FINALIZER_THREAD
 638
 639 #ifdef WITH_INCLUDED_LIBGC
 640 /* from threads.c */
 641 extern void mono_gc_stop_world (void);
 642 extern void mono_gc_start_world (void);
 643 extern void mono_gc_push_all_stacks (void);
 644
 645 static void mono_gc_lock (void)
 646 {
 647         EnterCriticalSection (&allocator_section);
 648 }
 649
 650 static void mono_gc_unlock (void)
 651 {
 652         LeaveCriticalSection (&allocator_section);
 653 }
 654
 655 static GCThreadFunctions mono_gc_thread_vtable = {
 656         NULL,
 657
 658         mono_gc_lock,
 659         mono_gc_unlock,
 660
 661         mono_gc_stop_world,
 662         NULL,
 663         mono_gc_push_all_stacks,
 664         mono_gc_start_world
 665 };
 666 #endif /* WITH_INCLUDED_LIBGC */
 667
 668 static void
 669 mono_gc_warning (char *msg, GC_word arg)
 670 {
 671         mono_trace (G_LOG_LEVEL_WARNING, MONO_TRACE_GC, msg, (unsigned long)arg);
 672 }
 673
 674 void mono_gc_init (void)
 675 {
 676         InitializeCriticalSection (&handle_section);
 677         InitializeCriticalSection (&allocator_section);
 678
 679         InitializeCriticalSection (&finalizer_mutex);
 680
 681 #ifdef WITH_INCLUDED_LIBGC
 682         gc_thread_vtable = &mono_gc_thread_vtable;
 683 #endif
 684
 685         MONO_GC_REGISTER_ROOT (gc_handles);
 686         MONO_GC_REGISTER_ROOT (gc_handle_types);
 687         GC_no_dls = TRUE;
 688
 689         GC_oom_fn = mono_gc_out_of_memory;
 690
 691         GC_set_warn_proc (mono_gc_warning);
 692
 693 #ifdef ENABLE_FINALIZER_THREAD
 694
 695         if (g_getenv ("GC_DONT_GC")) {
 696                 gc_disabled = TRUE;
 697                 return;
 698         }
 699
 700         finalizer_event = CreateEvent (NULL, FALSE, FALSE, NULL);
 701         pending_done_event = CreateEvent (NULL, TRUE, FALSE, NULL);
 702         shutdown_event = CreateEvent (NULL, TRUE, FALSE, NULL);
 703         thread_started_event = CreateEvent (NULL, TRUE, FALSE, NULL);
 704         if (finalizer_event == NULL || pending_done_event == NULL || shutdown_event == NULL || thread_started_event == NULL) {
 705                 g_assert_not_reached ();
 706         }
 707
 708         GC_finalize_on_demand = 1;
 709         GC_finalizer_notifier = finalize_notify;
 710
 711         mono_thread_create (mono_domain_get (), finalizer_thread, NULL);
 712         /*
 713          * Wait until the finalizer thread sets gc_thread since its value is needed
 714          * by mono_thread_attach ()
 715          */
 716         WaitForSingleObjectEx (thread_started_event, INFINITE, FALSE);
 717 #endif
 718 }
 719
 720 void mono_gc_cleanup (void)
 721 {
 722 #ifdef DEBUG
 723         g_message (G_GNUC_PRETTY_FUNCTION ": cleaning up finalizer");
 724 #endif
 725
 726 #ifdef ENABLE_FINALIZER_THREAD
 727         if (!gc_disabled) {
 728                 ResetEvent (shutdown_event);
 729                 finished = TRUE;
 730                 if (mono_thread_current () != gc_thread) {
 731                         finalize_notify ();
 732                         /* Finishing the finalizer thread, so wait a little bit... */
 733                         /* MS seems to wait for about 2 seconds */
 734                         if (WaitForSingleObjectEx (shutdown_event, 2000000, FALSE) == WAIT_TIMEOUT) {
 735                                 mono_thread_stop (gc_thread);
 736                         }
 737                 }
 738                 gc_thread = NULL;
 739                 GC_finalizer_notifier = NULL;
 740         }
 741
 742 #endif
 743 }
 744
 745 #else
 746
 747 /* no Boehm GC support. */
 748 void mono_gc_init (void)
 749 {
 750         InitializeCriticalSection (&handle_section);
 751 }
 752
 753 void mono_gc_cleanup (void)
 754 {
 755 }
 756
 757 #endif
 758
 759 gboolean
 760 mono_gc_is_finalizer_thread (MonoThread *thread)
 761 {
 762         return thread == gc_thread;
 763 }
 764
 765