mono/metadata/boehm-gc.c

   1 /*
   2  * boehm-gc.c: GC implementation using either the installed or included Boehm GC.
   3  *
   4  * Copyright 2001-2003 Ximian, Inc (http://www.ximian.com)
   5  * Copyright 2004-2009 Novell, Inc (http://www.novell.com)
   6  */
   7
   8 #include "config.h"
   9 #define GC_I_HIDE_POINTERS
  10 #include <mono/metadata/gc-internal.h>
  11 #include <mono/metadata/mono-gc.h>
  12 #include <mono/metadata/gc-internal.h>
  13 #include <mono/metadata/profiler-private.h>
  14 #include <mono/metadata/class-internals.h>
  15 #include <mono/metadata/method-builder.h>
  16 #include <mono/metadata/opcodes.h>
  17 #include <mono/metadata/domain-internals.h>
  18 #include <mono/metadata/metadata-internals.h>
  19 #include <mono/utils/mono-logger.h>
  20 #include <mono/utils/mono-time.h>
  21 #include <mono/utils/dtrace.h>
  22
  23 #if HAVE_BOEHM_GC
  24
  25 #ifdef USE_INCLUDED_LIBGC
  26 #undef TRUE
  27 #undef FALSE
  28 #define THREAD_LOCAL_ALLOC 1
  29 #include "private/pthread_support.h"
  30 #endif
  31
  32 #define GC_NO_DESCRIPTOR ((gpointer)(0 | GC_DS_LENGTH))
  33
  34 static gboolean gc_initialized = FALSE;
  35
  36 static void
  37 mono_gc_warning (char *msg, GC_word arg)
  38 {
  39         mono_trace (G_LOG_LEVEL_WARNING, MONO_TRACE_GC, msg, (unsigned long)arg);
  40 }
  41
  42 void
  43 mono_gc_base_init (void)
  44 {
  45         if (gc_initialized)
  46                 return;
  47
  48         /*
  49          * Handle the case when we are called from a thread different from the main thread,
  50          * confusing libgc.
  51          * FIXME: Move this to libgc where it belongs.
  52          *
  53          * we used to do this only when running on valgrind,
  54          * but it happens also in other setups.
  55          */
  56 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
  57         {
  58                 size_t size;
  59                 void *sstart;
  60                 pthread_attr_t attr;
  61                 pthread_getattr_np (pthread_self (), &attr);
  62                 pthread_attr_getstack (&attr, &sstart, &size);
  63                 pthread_attr_destroy (&attr);
  64                 /*g_print ("stackbottom pth is: %p\n", (char*)sstart + size);*/
  65 #ifdef __ia64__
  66                 /*
  67                  * The calculation above doesn't seem to work on ia64, also we need to set
  68                  * GC_register_stackbottom as well, but don't know how.
  69                  */
  70 #else
  71                 /* apparently with some linuxthreads implementations sstart can be NULL,
  72                  * fallback to the more imprecise method (bug# 78096).
  73                  */
  74                 if (sstart) {
  75                         GC_stackbottom = (char*)sstart + size;
  76                 } else {
  77                         int dummy;
  78                         gsize stack_bottom = (gsize)&dummy;
  79                         stack_bottom += 4095;
  80                         stack_bottom &= ~4095;
  81                         GC_stackbottom = (char*)stack_bottom;
  82                 }
  83 #endif
  84         }
  85 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
  86                 GC_stackbottom = (char*)pthread_get_stackaddr_np (pthread_self ());
  87 #else
  88         {
  89                 int dummy;
  90                 gsize stack_bottom = (gsize)&dummy;
  91                 stack_bottom += 4095;
  92                 stack_bottom &= ~4095;
  93                 /*g_print ("stackbottom is: %p\n", (char*)stack_bottom);*/
  94                 GC_stackbottom = (char*)stack_bottom;
  95         }
  96 #endif
  97
  98 #if !defined(PLATFORM_ANDROID)
  99         /* If GC_no_dls is set to true, GC_find_limit is not called. This causes a seg fault on Android. */
 100         GC_no_dls = TRUE;
 101 #endif
 102         GC_init ();
 103         GC_oom_fn = mono_gc_out_of_memory;
 104         GC_set_warn_proc (mono_gc_warning);
 105         GC_finalize_on_demand = 1;
 106         GC_finalizer_notifier = mono_gc_finalize_notify;
 107
 108 #ifdef HAVE_GC_GCJ_MALLOC
 109         GC_init_gcj_malloc (5, NULL);
 110 #endif
 111         mono_gc_enable_events ();
 112         gc_initialized = TRUE;
 113 }
 114
 115 void
 116 mono_gc_collect (int generation)
 117 {
 118         MONO_PROBE_GC_BEGIN (generation);
 119
 120         mono_perfcounters->gc_induced++;
 121         GC_gcollect ();
 122
 123         MONO_PROBE_GC_END (generation);
 124 #if defined(ENABLE_DTRACE) && defined(__sun__)
 125         /* This works around a dtrace -G problem on Solaris.
 126            Limit its actual use to when the probe is enabled. */
 127         if (MONO_PROBE_GC_END_ENABLED ())
 128                 sleep(0);
 129 #endif
 130 }
 131
 132 int
 133 mono_gc_max_generation (void)
 134 {
 135         return 0;
 136 }
 137
 138 int
 139 mono_gc_get_generation  (MonoObject *object)
 140 {
 141         return 0;
 142 }
 143
 144 int
 145 mono_gc_collection_count (int generation)
 146 {
 147         return GC_gc_no;
 148 }
 149
 150 void
 151 mono_gc_add_memory_pressure (gint64 value)
 152 {
 153 }
 154
 155 gint64
 156 mono_gc_get_used_size (void)
 157 {
 158         return GC_get_heap_size () - GC_get_free_bytes ();
 159 }
 160
 161 gint64
 162 mono_gc_get_heap_size (void)
 163 {
 164         return GC_get_heap_size ();
 165 }
 166
 167 void
 168 mono_gc_disable (void)
 169 {
 170 #ifdef HAVE_GC_ENABLE
 171         GC_disable ();
 172 #else
 173         g_assert_not_reached ();
 174 #endif
 175 }
 176
 177 void
 178 mono_gc_enable (void)
 179 {
 180 #ifdef HAVE_GC_ENABLE
 181         GC_enable ();
 182 #else
 183         g_assert_not_reached ();
 184 #endif
 185 }
 186
 187 gboolean
 188 mono_gc_is_gc_thread (void)
 189 {
 190 #if GC_VERSION_MAJOR >= 7
 191         return TRUE;
 192 #elif defined(USE_INCLUDED_LIBGC)
 193         return GC_thread_is_registered ();
 194 #else
 195         return TRUE;
 196 #endif
 197 }
 198
 199 extern int GC_thread_register_foreign (void *base_addr);
 200
 201 gboolean
 202 mono_gc_register_thread (void *baseptr)
 203 {
 204 #if GC_VERSION_MAJOR >= 7
 205         struct GC_stack_base sb;
 206         int res;
 207
 208         res = GC_get_stack_base (&sb);
 209         if (res != GC_SUCCESS) {
 210                 sb.mem_base = baseptr;
 211 #ifdef __ia64__
 212                 /* Can't determine the register stack bounds */
 213                 g_error ("mono_gc_register_thread failed ().\n");
 214 #endif
 215         }
 216         res = GC_register_my_thread (&sb);
 217         if ((res != GC_SUCCESS) && (res != GC_DUPLICATE)) {
 218                 g_warning ("GC_register_my_thread () failed.\n");
 219                 return FALSE;
 220         }
 221         return TRUE;
 222 #else
 223         if (mono_gc_is_gc_thread())
 224                 return TRUE;
 225 #if defined(USE_INCLUDED_LIBGC) && !defined(HOST_WIN32)
 226         return GC_thread_register_foreign (baseptr);
 227 #else
 228         return FALSE;
 229 #endif
 230 #endif
 231 }
 232
 233 gboolean
 234 mono_object_is_alive (MonoObject* o)
 235 {
 236 #ifdef USE_INCLUDED_LIBGC
 237         return GC_is_marked ((gpointer)o);
 238 #else
 239         return TRUE;
 240 #endif
 241 }
 242
 243 #ifdef USE_INCLUDED_LIBGC
 244
 245 static gint64 gc_start_time;
 246
 247 static void
 248 on_gc_notification (GCEventType event)
 249 {
 250         if (event == MONO_GC_EVENT_START) {
 251                 mono_perfcounters->gc_collections0++;
 252                 mono_stats.major_gc_count ++;
 253                 gc_start_time = mono_100ns_ticks ();
 254         } else if (event == MONO_GC_EVENT_END) {
 255                 guint64 heap_size = GC_get_heap_size ();
 256                 guint64 used_size = heap_size - GC_get_free_bytes ();
 257                 mono_perfcounters->gc_total_bytes = used_size;
 258                 mono_perfcounters->gc_committed_bytes = heap_size;
 259                 mono_perfcounters->gc_reserved_bytes = heap_size;
 260                 mono_perfcounters->gc_gen0size = heap_size;
 261                 mono_stats.major_gc_time_usecs += (mono_100ns_ticks () - gc_start_time) / 10;
 262                 mono_trace_message (MONO_TRACE_GC, "gc took %d usecs", (mono_100ns_ticks () - gc_start_time) / 10);
 263         }
 264         mono_profiler_gc_event ((MonoGCEvent) event, 0);
 265 }
 266
 267 static void
 268 on_gc_heap_resize (size_t new_size)
 269 {
 270         guint64 heap_size = GC_get_heap_size ();
 271         mono_perfcounters->gc_committed_bytes = heap_size;
 272         mono_perfcounters->gc_reserved_bytes = heap_size;
 273         mono_perfcounters->gc_gen0size = heap_size;
 274         mono_profiler_gc_heap_resize (new_size);
 275 }
 276
 277 void
 278 mono_gc_enable_events (void)
 279 {
 280         GC_notify_event = on_gc_notification;
 281         GC_on_heap_resize = on_gc_heap_resize;
 282 }
 283
 284 #else
 285
 286 void
 287 mono_gc_enable_events (void)
 288 {
 289 }
 290
 291 #endif
 292
 293 int
 294 mono_gc_register_root (char *start, size_t size, void *descr)
 295 {
 296         /* for some strange reason, they want one extra byte on the end */
 297         GC_add_roots (start, start + size + 1);
 298
 299         return TRUE;
 300 }
 301
 302 void
 303 mono_gc_deregister_root (char* addr)
 304 {
 305 #ifndef HOST_WIN32
 306         /* FIXME: libgc doesn't define this work win32 for some reason */
 307         /* FIXME: No size info */
 308         GC_remove_roots (addr, addr + sizeof (gpointer) + 1);
 309 #endif
 310 }
 311
 312 void
 313 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
 314 {
 315         /* libgc requires that we use HIDE_POINTER... */
 316         *link_addr = (void*)HIDE_POINTER (obj);
 317         GC_GENERAL_REGISTER_DISAPPEARING_LINK (link_addr, obj);
 318 }
 319
 320 void
 321 mono_gc_weak_link_remove (void **link_addr)
 322 {
 323         GC_unregister_disappearing_link (link_addr);
 324         *link_addr = NULL;
 325 }
 326
 327 MonoObject*
 328 mono_gc_weak_link_get (void **link_addr)
 329 {
 330         MonoObject *obj = REVEAL_POINTER (*link_addr);
 331         if (obj == (MonoObject *) -1)
 332                 return NULL;
 333         return obj;
 334 }
 335
 336 void*
 337 mono_gc_make_descr_for_string (gsize *bitmap, int numbits)
 338 {
 339         return mono_gc_make_descr_from_bitmap (bitmap, numbits);
 340 }
 341
 342 void*
 343 mono_gc_make_descr_for_object (gsize *bitmap, int numbits, size_t obj_size)
 344 {
 345         return mono_gc_make_descr_from_bitmap (bitmap, numbits);
 346 }
 347
 348 void*
 349 mono_gc_make_descr_for_array (int vector, gsize *elem_bitmap, int numbits, size_t elem_size)
 350 {
 351         /* libgc has no usable support for arrays... */
 352         return GC_NO_DESCRIPTOR;
 353 }
 354
 355 void*
 356 mono_gc_make_descr_from_bitmap (gsize *bitmap, int numbits)
 357 {
 358 #ifdef HAVE_GC_GCJ_MALLOC
 359         /* It seems there are issues when the bitmap doesn't fit: play it safe */
 360         if (numbits >= 30)
 361                 return GC_NO_DESCRIPTOR;
 362         else
 363                 return (gpointer)GC_make_descriptor ((GC_bitmap)bitmap, numbits);
 364 #else
 365         return NULL;
 366 #endif
 367 }
 368
 369 void*
 370 mono_gc_alloc_fixed (size_t size, void *descr)
 371 {
 372         /* To help track down typed allocation bugs */
 373         /*
 374         static int count;
 375         count ++;
 376         if (count == atoi (getenv ("COUNT2")))
 377                 printf ("HIT!\n");
 378         if (count > atoi (getenv ("COUNT2")))
 379                 return GC_MALLOC (size);
 380         */
 381
 382         if (descr)
 383                 return GC_MALLOC_EXPLICITLY_TYPED (size, (GC_descr)descr);
 384         else
 385                 return GC_MALLOC (size);
 386 }
 387
 388 void
 389 mono_gc_free_fixed (void* addr)
 390 {
 391 }
 392
 393 int
 394 mono_gc_invoke_finalizers (void)
 395 {
 396         /* There is a bug in GC_invoke_finalizer () in versions <= 6.2alpha4:
 397          * the 'mem_freed' variable is not initialized when there are no
 398          * objects to finalize, which leads to strange behavior later on.
 399          * The check is necessary to work around that bug.
 400          */
 401         if (GC_should_invoke_finalizers ())
 402                 return GC_invoke_finalizers ();
 403         return 0;
 404 }
 405
 406 gboolean
 407 mono_gc_pending_finalizers (void)
 408 {
 409         return GC_should_invoke_finalizers ();
 410 }
 411
 412 /*
 413  * LOCKING: Assumes the domain_finalizers lock is held.
 414  */
 415 static void
 416 add_weak_track_handle_internal (MonoDomain *domain, MonoObject *obj, guint32 gchandle)
 417 {
 418         GSList *refs;
 419
 420         if (!domain->track_resurrection_objects_hash)
 421                 domain->track_resurrection_objects_hash = g_hash_table_new (mono_aligned_addr_hash, NULL);
 422
 423         refs = g_hash_table_lookup (domain->track_resurrection_objects_hash, obj);
 424         refs = g_slist_prepend (refs, GUINT_TO_POINTER (gchandle));
 425         g_hash_table_insert (domain->track_resurrection_objects_hash, obj, refs);
 426 }
 427
 428 void
 429 mono_gc_add_weak_track_handle (MonoObject *obj, guint32 handle)
 430 {
 431         MonoDomain *domain;
 432
 433         if (!obj)
 434                 return;
 435
 436         domain = mono_object_get_domain (obj);
 437
 438         mono_domain_finalizers_lock (domain);
 439
 440         add_weak_track_handle_internal (domain, obj, handle);
 441
 442         g_hash_table_insert (domain->track_resurrection_handles_hash, GUINT_TO_POINTER (handle), obj);
 443
 444         mono_domain_finalizers_unlock (domain);
 445 }
 446
 447 /*
 448  * LOCKING: Assumes the domain_finalizers lock is held.
 449  */
 450 static void
 451 remove_weak_track_handle_internal (MonoDomain *domain, MonoObject *obj, guint32 gchandle)
 452 {
 453         GSList *refs;
 454
 455         if (!domain->track_resurrection_objects_hash)
 456                 return;
 457
 458         refs = g_hash_table_lookup (domain->track_resurrection_objects_hash, obj);
 459         refs = g_slist_remove (refs, GUINT_TO_POINTER (gchandle));
 460         g_hash_table_insert (domain->track_resurrection_objects_hash, obj, refs);
 461 }
 462
 463 void
 464 mono_gc_change_weak_track_handle (MonoObject *old_obj, MonoObject *obj, guint32 gchandle)
 465 {
 466         MonoDomain *domain = mono_domain_get ();
 467
 468         mono_domain_finalizers_lock (domain);
 469
 470         if (old_obj)
 471                 remove_weak_track_handle_internal (domain, old_obj, gchandle);
 472         if (obj)
 473                 add_weak_track_handle_internal (domain, obj, gchandle);
 474
 475         mono_domain_finalizers_unlock (domain);
 476 }
 477
 478 void
 479 mono_gc_remove_weak_track_handle (guint32 gchandle)
 480 {
 481         MonoDomain *domain = mono_domain_get ();
 482         MonoObject *obj;
 483
 484         /* Clean our entries in the two hashes in MonoDomain */
 485
 486         mono_domain_finalizers_lock (domain);
 487
 488         /* Get the original object this handle pointed to */
 489         obj = g_hash_table_lookup (domain->track_resurrection_handles_hash, GUINT_TO_POINTER (gchandle));
 490         if (obj) {
 491                 g_hash_table_remove (domain->track_resurrection_handles_hash, GUINT_TO_POINTER (gchandle));
 492
 493                 remove_weak_track_handle_internal (domain, obj, gchandle);
 494         }
 495
 496         mono_domain_finalizers_unlock (domain);
 497 }
 498
 499 GSList*
 500 mono_gc_remove_weak_track_object (MonoDomain *domain, MonoObject *obj)
 501 {
 502         GSList *refs = NULL;
 503
 504         if (domain->track_resurrection_objects_hash) {
 505                 refs = g_hash_table_lookup (domain->track_resurrection_objects_hash, obj);
 506
 507                 if (refs)
 508                         /*
 509                          * Since we don't run finalizers again for resurrected objects,
 510                          * no need to keep these around.
 511                          */
 512                         g_hash_table_remove (domain->track_resurrection_objects_hash, obj);
 513         }
 514
 515         return refs;
 516 }
 517
 518 void
 519 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
 520 {
 521         *(void**)field_ptr = value;
 522 }
 523
 524 void
 525 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
 526 {
 527         *(void**)slot_ptr = value;
 528 }
 529
 530 void
 531 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
 532 {
 533         memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
 534 }
 535
 536 void
 537 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
 538 {
 539         *(void**)ptr = value;
 540 }
 541
 542 void
 543 mono_gc_wbarrier_generic_nostore (gpointer ptr)
 544 {
 545 }
 546
 547 void
 548 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
 549 {
 550         memmove (dest, src, count * mono_class_value_size (klass, NULL));
 551 }
 552
 553 void
 554 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
 555 {
 556         /* do not copy the sync state */
 557         memcpy ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
 558                         mono_object_class (obj)->instance_size - sizeof (MonoObject));
 559 }
 560
 561 void
 562 mono_gc_clear_domain (MonoDomain *domain)
 563 {
 564 }
 565
 566 int
 567 mono_gc_get_suspend_signal (void)
 568 {
 569 #ifdef USE_INCLUDED_GC
 570         return GC_get_suspend_signal ();
 571 #else
 572         return -1;
 573 #endif
 574 }
 575
 576 #if defined(USE_INCLUDED_LIBGC) && defined(USE_COMPILER_TLS) && defined(__linux__) && (defined(__i386__) || defined(__x86_64__))
 577 extern __thread MONO_TLS_FAST void* GC_thread_tls;
 578 #include "metadata-internals.h"
 579
 580 static int
 581 shift_amount (int v)
 582 {
 583         int i = 0;
 584         while (!(v & (1 << i)))
 585                 i++;
 586         return i;
 587 }
 588
 589 enum {
 590         ATYPE_FREEPTR,
 591         ATYPE_FREEPTR_FOR_BOX,
 592         ATYPE_NORMAL,
 593         ATYPE_GCJ,
 594         ATYPE_STRING,
 595         ATYPE_NUM
 596 };
 597
 598 static MonoMethod*
 599 create_allocator (int atype, int offset)
 600 {
 601         int index_var, bytes_var, my_fl_var, my_entry_var;
 602         guint32 no_freelist_branch, not_small_enough_branch = 0;
 603         guint32 size_overflow_branch = 0;
 604         MonoMethodBuilder *mb;
 605         MonoMethod *res;
 606         MonoMethodSignature *csig;
 607
 608         if (atype == ATYPE_STRING) {
 609                 csig = mono_metadata_signature_alloc (mono_defaults.corlib, 2);
 610                 csig->ret = &mono_defaults.string_class->byval_arg;
 611                 csig->params [0] = &mono_defaults.int_class->byval_arg;
 612                 csig->params [1] = &mono_defaults.int32_class->byval_arg;
 613         } else {
 614                 csig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
 615                 csig->ret = &mono_defaults.object_class->byval_arg;
 616                 csig->params [0] = &mono_defaults.int_class->byval_arg;
 617         }
 618
 619         mb = mono_mb_new (mono_defaults.object_class, "Alloc", MONO_WRAPPER_ALLOC);
 620         bytes_var = mono_mb_add_local (mb, &mono_defaults.int32_class->byval_arg);
 621         if (atype == ATYPE_STRING) {
 622                 /* a string alloator method takes the args: (vtable, len) */
 623                 /* bytes = (sizeof (MonoString) + ((len + 1) * 2)); */
 624                 mono_mb_emit_ldarg (mb, 1);
 625                 mono_mb_emit_icon (mb, 1);
 626                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 627                 mono_mb_emit_icon (mb, 1);
 628                 mono_mb_emit_byte (mb, MONO_CEE_SHL);
 629                 // sizeof (MonoString) might include padding
 630                 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoString, chars));
 631                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 632                 mono_mb_emit_stloc (mb, bytes_var);
 633         } else {
 634                 /* bytes = vtable->klass->instance_size */
 635                 mono_mb_emit_ldarg (mb, 0);
 636                 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoVTable, klass));
 637                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 638                 mono_mb_emit_byte (mb, MONO_CEE_LDIND_I);
 639                 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoClass, instance_size));
 640                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 641                 /* FIXME: assert instance_size stays a 4 byte integer */
 642                 mono_mb_emit_byte (mb, MONO_CEE_LDIND_U4);
 643                 mono_mb_emit_stloc (mb, bytes_var);
 644         }
 645
 646         /* this is needed for strings/arrays only as the other big types are never allocated with this method */
 647         if (atype == ATYPE_STRING) {
 648                 /* check for size */
 649                 /* if (!SMALL_ENOUGH (bytes)) jump slow_path;*/
 650                 mono_mb_emit_ldloc (mb, bytes_var);
 651                 mono_mb_emit_icon (mb, (NFREELISTS-1) * GRANULARITY);
 652                 not_small_enough_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BGT_UN_S);
 653                 /* check for overflow */
 654                 mono_mb_emit_ldloc (mb, bytes_var);
 655                 mono_mb_emit_icon (mb, sizeof (MonoString));
 656                 size_overflow_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BLE_UN_S);
 657         }
 658
 659         /* int index = INDEX_FROM_BYTES(bytes); */
 660         index_var = mono_mb_add_local (mb, &mono_defaults.int32_class->byval_arg);
 661
 662         mono_mb_emit_ldloc (mb, bytes_var);
 663         mono_mb_emit_icon (mb, GRANULARITY - 1);
 664         mono_mb_emit_byte (mb, MONO_CEE_ADD);
 665         mono_mb_emit_icon (mb, shift_amount (GRANULARITY));
 666         mono_mb_emit_byte (mb, MONO_CEE_SHR_UN);
 667         mono_mb_emit_icon (mb, shift_amount (sizeof (gpointer)));
 668         mono_mb_emit_byte (mb, MONO_CEE_SHL);
 669         /* index var is already adjusted into bytes */
 670         mono_mb_emit_stloc (mb, index_var);
 671
 672         my_fl_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
 673         my_entry_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
 674         /* my_fl = ((GC_thread)tsd) -> ptrfree_freelists + index; */
 675         mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
 676         mono_mb_emit_byte (mb, 0x0D); /* CEE_MONO_TLS */
 677         mono_mb_emit_i4 (mb, offset);
 678         if (atype == ATYPE_FREEPTR || atype == ATYPE_FREEPTR_FOR_BOX || atype == ATYPE_STRING)
 679                 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (struct GC_Thread_Rep, ptrfree_freelists));
 680         else if (atype == ATYPE_NORMAL)
 681                 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (struct GC_Thread_Rep, normal_freelists));
 682         else if (atype == ATYPE_GCJ)
 683                 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (struct GC_Thread_Rep, gcj_freelists));
 684         else
 685                 g_assert_not_reached ();
 686         mono_mb_emit_byte (mb, MONO_CEE_ADD);
 687         mono_mb_emit_ldloc (mb, index_var);
 688         mono_mb_emit_byte (mb, MONO_CEE_ADD);
 689         mono_mb_emit_stloc (mb, my_fl_var);
 690
 691         /* my_entry = *my_fl; */
 692         mono_mb_emit_ldloc (mb, my_fl_var);
 693         mono_mb_emit_byte (mb, MONO_CEE_LDIND_I);
 694         mono_mb_emit_stloc (mb, my_entry_var);
 695
 696         /* if (EXPECT((word)my_entry >= HBLKSIZE, 1)) { */
 697         mono_mb_emit_ldloc (mb, my_entry_var);
 698         mono_mb_emit_icon (mb, HBLKSIZE);
 699         no_freelist_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BLT_UN_S);
 700
 701         /* ptr_t next = obj_link(my_entry); *my_fl = next; */
 702         mono_mb_emit_ldloc (mb, my_fl_var);
 703         mono_mb_emit_ldloc (mb, my_entry_var);
 704         mono_mb_emit_byte (mb, MONO_CEE_LDIND_I);
 705         mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
 706
 707         /* set the vtable and clear the words in the object */
 708         mono_mb_emit_ldloc (mb, my_entry_var);
 709         mono_mb_emit_ldarg (mb, 0);
 710         mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
 711
 712         if (atype == ATYPE_FREEPTR) {
 713                 int start_var, end_var, start_loop;
 714                 /* end = my_entry + bytes; start = my_entry + sizeof (gpointer);
 715                  */
 716                 start_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
 717                 end_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
 718                 mono_mb_emit_ldloc (mb, my_entry_var);
 719                 mono_mb_emit_ldloc (mb, bytes_var);
 720                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 721                 mono_mb_emit_stloc (mb, end_var);
 722                 mono_mb_emit_ldloc (mb, my_entry_var);
 723                 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoObject, synchronisation));
 724                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 725                 mono_mb_emit_stloc (mb, start_var);
 726                 /*
 727                  * do {
 728                  *      *start++ = NULL;
 729                  * } while (start < end);
 730                  */
 731                 start_loop = mono_mb_get_label (mb);
 732                 mono_mb_emit_ldloc (mb, start_var);
 733                 mono_mb_emit_icon (mb, 0);
 734                 mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
 735                 mono_mb_emit_ldloc (mb, start_var);
 736                 mono_mb_emit_icon (mb, sizeof (gpointer));
 737                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 738                 mono_mb_emit_stloc (mb, start_var);
 739
 740                 mono_mb_emit_ldloc (mb, start_var);
 741                 mono_mb_emit_ldloc (mb, end_var);
 742                 mono_mb_emit_byte (mb, MONO_CEE_BLT_UN_S);
 743                 mono_mb_emit_byte (mb, start_loop - (mono_mb_get_label (mb) + 1));
 744         } else if (atype == ATYPE_FREEPTR_FOR_BOX || atype == ATYPE_STRING) {
 745                 /* need to clear just the sync pointer */
 746                 mono_mb_emit_ldloc (mb, my_entry_var);
 747                 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoObject, synchronisation));
 748                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 749                 mono_mb_emit_icon (mb, 0);
 750                 mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
 751         }
 752
 753         if (atype == ATYPE_STRING) {
 754                 /* need to set length and clear the last char */
 755                 /* s->length = len; */
 756                 mono_mb_emit_ldloc (mb, my_entry_var);
 757                 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoString, length));
 758                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 759                 mono_mb_emit_ldarg (mb, 1);
 760                 mono_mb_emit_byte (mb, MONO_CEE_STIND_I4);
 761                 /* s->chars [len] = 0; */
 762                 mono_mb_emit_ldloc (mb, my_entry_var);
 763                 mono_mb_emit_ldloc (mb, bytes_var);
 764                 mono_mb_emit_icon (mb, 2);
 765                 mono_mb_emit_byte (mb, MONO_CEE_SUB);
 766                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 767                 mono_mb_emit_icon (mb, 0);
 768                 mono_mb_emit_byte (mb, MONO_CEE_STIND_I2);
 769         }
 770
 771         /* return my_entry; */
 772         mono_mb_emit_ldloc (mb, my_entry_var);
 773         mono_mb_emit_byte (mb, MONO_CEE_RET);
 774
 775         mono_mb_patch_short_branch (mb, no_freelist_branch);
 776         if (not_small_enough_branch > 0)
 777                 mono_mb_patch_short_branch (mb, not_small_enough_branch);
 778         if (size_overflow_branch > 0)
 779                 mono_mb_patch_short_branch (mb, size_overflow_branch);
 780         /* the slow path: we just call back into the runtime */
 781         if (atype == ATYPE_STRING) {
 782                 mono_mb_emit_ldarg (mb, 1);
 783                 mono_mb_emit_icall (mb, mono_string_alloc);
 784         } else {
 785                 mono_mb_emit_ldarg (mb, 0);
 786                 mono_mb_emit_icall (mb, mono_object_new_specific);
 787         }
 788
 789         mono_mb_emit_byte (mb, MONO_CEE_RET);
 790
 791         res = mono_mb_create_method (mb, csig, 8);
 792         mono_mb_free (mb);
 793         mono_method_get_header (res)->init_locals = FALSE;
 794         return res;
 795 }
 796
 797 static MonoMethod* alloc_method_cache [ATYPE_NUM];
 798
 799 /*
 800  * If possible, generate a managed method that can quickly allocate objects in class
 801  * @klass. The method will typically have an thread-local inline allocation sequence.
 802  * The signature of the called method is:
 803  *      object allocate (MonoVTable *vtable)
 804  * Some of the logic here is similar to mono_class_get_allocation_ftn () i object.c,
 805  * keep in sync.
 806  * The thread local alloc logic is taken from libgc/pthread_support.c.
 807  */
 808
 809 MonoMethod*
 810 mono_gc_get_managed_allocator (MonoVTable *vtable, gboolean for_box)
 811 {
 812         int offset = -1;
 813         int atype;
 814         MonoClass *klass = vtable->klass;
 815         MONO_THREAD_VAR_OFFSET (GC_thread_tls, offset);
 816
 817         /*g_print ("thread tls: %d\n", offset);*/
 818         if (offset == -1)
 819                 return NULL;
 820         if (!SMALL_ENOUGH (klass->instance_size))
 821                 return NULL;
 822         if (klass->has_finalize || klass->marshalbyref || (mono_profiler_get_events () & MONO_PROFILE_ALLOCATIONS))
 823                 return NULL;
 824         if (klass->rank)
 825                 return NULL;
 826         if (klass->byval_arg.type == MONO_TYPE_STRING) {
 827                 atype = ATYPE_STRING;
 828         } else if (!klass->has_references) {
 829                 if (for_box)
 830                         atype = ATYPE_FREEPTR_FOR_BOX;
 831                 else
 832                         atype = ATYPE_FREEPTR;
 833         } else {
 834                 return NULL;
 835                 /*
 836                  * disabled because we currently do a runtime choice anyway, to
 837                  * deal with multiple appdomains.
 838                 if (vtable->gc_descr != GC_NO_DESCRIPTOR)
 839                         atype = ATYPE_GCJ;
 840                 else
 841                         atype = ATYPE_NORMAL;
 842                 */
 843         }
 844         return mono_gc_get_managed_allocator_by_type (atype);
 845 }
 846
 847 MonoMethod*
 848 mono_gc_get_managed_array_allocator (MonoVTable *vtable, int rank)
 849 {
 850         return NULL;
 851 }
 852
 853 /**
 854  * mono_gc_get_managed_allocator_id:
 855  *
 856  *   Return a type for the managed allocator method MANAGED_ALLOC which can later be passed
 857  * to mono_gc_get_managed_allocator_by_type () to get back this allocator method. This can be
 858  * used by the AOT code to encode references to managed allocator methods.
 859  */
 860 int
 861 mono_gc_get_managed_allocator_type (MonoMethod *managed_alloc)
 862 {
 863         int i;
 864
 865         mono_loader_lock ();
 866         for (i = 0; i < ATYPE_NUM; ++i) {
 867                 if (alloc_method_cache [i] == managed_alloc) {
 868                         mono_loader_unlock ();
 869                         return i;
 870                 }
 871         }
 872         mono_loader_unlock ();
 873
 874         return -1;
 875 }
 876
 877 /**
 878  * mono_gc_get_managed_allocator_by_type:
 879  *
 880  *   Return a managed allocator method corresponding to allocator type ATYPE.
 881  */
 882 MonoMethod*
 883 mono_gc_get_managed_allocator_by_type (int atype)
 884 {
 885         int offset = -1;
 886         MonoMethod *res;
 887         MONO_THREAD_VAR_OFFSET (GC_thread_tls, offset);
 888
 889         mono_loader_lock ();
 890         res = alloc_method_cache [atype];
 891         if (!res)
 892                 res = alloc_method_cache [atype] = create_allocator (atype, offset);
 893         mono_loader_unlock ();
 894         return res;
 895 }
 896
 897 guint32
 898 mono_gc_get_managed_allocator_types (void)
 899 {
 900         return ATYPE_NUM;
 901 }
 902
 903 #else
 904
 905 MonoMethod*
 906 mono_gc_get_managed_allocator (MonoVTable *vtable, gboolean for_box)
 907 {
 908         return NULL;
 909 }
 910
 911 MonoMethod*
 912 mono_gc_get_managed_array_allocator (MonoVTable *vtable, int rank)
 913 {
 914         return NULL;
 915 }
 916
 917 int
 918 mono_gc_get_managed_allocator_type (MonoMethod *managed_alloc)
 919 {
 920         return -1;
 921 }
 922
 923 MonoMethod*
 924 mono_gc_get_managed_allocator_by_type (int atype)
 925 {
 926         return NULL;
 927 }
 928
 929 guint32
 930 mono_gc_get_managed_allocator_types (void)
 931 {
 932         return 0;
 933 }
 934
 935 #endif
 936
 937 #endif /* no Boehm GC */
 938