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 2004-2011 Novell, Inc (http://www.novell.com)
   6  * Copyright 2011-2012 Xamarin, Inc (http://www.xamarin.com)
   7  */
   8
   9 #include "config.h"
  10
  11 #include <string.h>
  12
  13 #define GC_I_HIDE_POINTERS
  14 #include <mono/metadata/gc-internal.h>
  15 #include <mono/metadata/mono-gc.h>
  16 #include <mono/metadata/gc-internal.h>
  17 #include <mono/metadata/profiler-private.h>
  18 #include <mono/metadata/class-internals.h>
  19 #include <mono/metadata/method-builder.h>
  20 #include <mono/metadata/opcodes.h>
  21 #include <mono/metadata/domain-internals.h>
  22 #include <mono/metadata/metadata-internals.h>
  23 #include <mono/metadata/marshal.h>
  24 #include <mono/metadata/runtime.h>
  25 #include <mono/utils/mono-logger-internal.h>
  26 #include <mono/utils/mono-time.h>
  27 #include <mono/utils/mono-threads.h>
  28 #include <mono/utils/dtrace.h>
  29 #include <mono/utils/gc_wrapper.h>
  30
  31 #if HAVE_BOEHM_GC
  32
  33 #ifdef USE_INCLUDED_LIBGC
  34 #undef TRUE
  35 #undef FALSE
  36 #define THREAD_LOCAL_ALLOC 1
  37 #include "private/pthread_support.h"
  38 #endif
  39
  40 #if defined(PLATFORM_MACOSX) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
  41 void *pthread_get_stackaddr_np(pthread_t);
  42 #endif
  43
  44 #define GC_NO_DESCRIPTOR ((gpointer)(0 | GC_DS_LENGTH))
  45 /*Boehm max heap cannot be smaller than 16MB*/
  46 #define MIN_BOEHM_MAX_HEAP_SIZE_IN_MB 16
  47 #define MIN_BOEHM_MAX_HEAP_SIZE (MIN_BOEHM_MAX_HEAP_SIZE_IN_MB << 20)
  48
  49 static gboolean gc_initialized = FALSE;
  50
  51 static void*
  52 boehm_thread_register (MonoThreadInfo* info, void *baseptr);
  53
  54 static void
  55 mono_gc_warning (char *msg, GC_word arg)
  56 {
  57         mono_trace (G_LOG_LEVEL_WARNING, MONO_TRACE_GC, msg, (unsigned long)arg);
  58 }
  59
  60 void
  61 mono_gc_base_init (void)
  62 {
  63         MonoThreadInfoCallbacks cb;
  64         char *env;
  65
  66         if (gc_initialized)
  67                 return;
  68
  69         /*
  70          * Handle the case when we are called from a thread different from the main thread,
  71          * confusing libgc.
  72          * FIXME: Move this to libgc where it belongs.
  73          *
  74          * we used to do this only when running on valgrind,
  75          * but it happens also in other setups.
  76          */
  77 #if defined(HAVE_PTHREAD_GETATTR_NP) && defined(HAVE_PTHREAD_ATTR_GETSTACK)
  78         {
  79                 size_t size;
  80                 void *sstart;
  81                 pthread_attr_t attr;
  82                 pthread_getattr_np (pthread_self (), &attr);
  83                 pthread_attr_getstack (&attr, &sstart, &size);
  84                 pthread_attr_destroy (&attr);
  85                 /*g_print ("stackbottom pth is: %p\n", (char*)sstart + size);*/
  86 #ifdef __ia64__
  87                 /*
  88                  * The calculation above doesn't seem to work on ia64, also we need to set
  89                  * GC_register_stackbottom as well, but don't know how.
  90                  */
  91 #else
  92                 /* apparently with some linuxthreads implementations sstart can be NULL,
  93                  * fallback to the more imprecise method (bug# 78096).
  94                  */
  95                 if (sstart) {
  96                         GC_stackbottom = (char*)sstart + size;
  97                 } else {
  98                         int dummy;
  99                         gsize stack_bottom = (gsize)&dummy;
 100                         stack_bottom += 4095;
 101                         stack_bottom &= ~4095;
 102                         GC_stackbottom = (char*)stack_bottom;
 103                 }
 104 #endif
 105         }
 106 #elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP) && defined(HAVE_PTHREAD_GET_STACKADDR_NP)
 107                 GC_stackbottom = (char*)pthread_get_stackaddr_np (pthread_self ());
 108 #elif defined(__OpenBSD__)
 109 #  include <pthread_np.h>
 110         {
 111                 stack_t ss;
 112                 int rslt;
 113
 114                 rslt = pthread_stackseg_np(pthread_self(), &ss);
 115                 g_assert (rslt == 0);
 116
 117                 GC_stackbottom = (char*)ss.ss_sp;
 118         }
 119 #elif defined(__native_client__)
 120         /* Do nothing, GC_stackbottom is set correctly in libgc */
 121 #else
 122         {
 123                 int dummy;
 124                 gsize stack_bottom = (gsize)&dummy;
 125                 stack_bottom += 4095;
 126                 stack_bottom &= ~4095;
 127                 /*g_print ("stackbottom is: %p\n", (char*)stack_bottom);*/
 128                 GC_stackbottom = (char*)stack_bottom;
 129         }
 130 #endif
 131
 132 #if !defined(PLATFORM_ANDROID)
 133         /* If GC_no_dls is set to true, GC_find_limit is not called. This causes a seg fault on Android. */
 134         GC_no_dls = TRUE;
 135 #endif
 136         GC_init ();
 137         GC_oom_fn = mono_gc_out_of_memory;
 138         GC_set_warn_proc (mono_gc_warning);
 139         GC_finalize_on_demand = 1;
 140         GC_finalizer_notifier = mono_gc_finalize_notify;
 141
 142 #ifdef HAVE_GC_GCJ_MALLOC
 143         GC_init_gcj_malloc (5, NULL);
 144 #endif
 145
 146 #ifdef HAVE_GC_ALLOW_REGISTER_THREADS
 147         GC_allow_register_threads();
 148 #endif
 149
 150         if ((env = getenv ("MONO_GC_PARAMS"))) {
 151                 char **ptr, **opts = g_strsplit (env, ",", -1);
 152                 for (ptr = opts; *ptr; ++ptr) {
 153                         char *opt = *ptr;
 154                         if (g_str_has_prefix (opt, "max-heap-size=")) {
 155                                 glong max_heap;
 156
 157                                 opt = strchr (opt, '=') + 1;
 158                                 if (*opt && mono_gc_parse_environment_string_extract_number (opt, &max_heap)) {
 159                                         if (max_heap < MIN_BOEHM_MAX_HEAP_SIZE) {
 160                                                 fprintf (stderr, "max-heap-size must be at least %dMb.\n", MIN_BOEHM_MAX_HEAP_SIZE_IN_MB);
 161                                                 exit (1);
 162                                         }
 163                                         GC_set_max_heap_size (max_heap);
 164                                 } else {
 165                                         fprintf (stderr, "max-heap-size must be an integer.\n");
 166                                         exit (1);
 167                                 }
 168                                 continue;
 169                         } else {
 170                                 /* Could be a parameter for sgen */
 171                                 /*
 172                                 fprintf (stderr, "MONO_GC_PARAMS must be a comma-delimited list of one or more of the following:\n");
 173                                 fprintf (stderr, "  max-heap-size=N (where N is an integer, possibly with a k, m or a g suffix)\n");
 174                                 exit (1);
 175                                 */
 176                         }
 177                 }
 178                 g_strfreev (opts);
 179         }
 180
 181         memset (&cb, 0, sizeof (cb));
 182         cb.thread_register = boehm_thread_register;
 183         cb.mono_method_is_critical = (gpointer)mono_runtime_is_critical_method;
 184 #ifndef HOST_WIN32
 185         cb.mono_gc_pthread_create = (gpointer)mono_gc_pthread_create;
 186 #endif
 187
 188         mono_threads_init (&cb, sizeof (MonoThreadInfo));
 189
 190         mono_gc_enable_events ();
 191         gc_initialized = TRUE;
 192 }
 193
 194 /**
 195  * mono_gc_collect:
 196  * @generation: GC generation identifier
 197  *
 198  * Perform a garbage collection for the given generation, higher numbers
 199  * mean usually older objects. Collecting a high-numbered generation
 200  * implies collecting also the lower-numbered generations.
 201  * The maximum value for @generation can be retrieved with a call to
 202  * mono_gc_max_generation(), so this function is usually called as:
 203  *
 204  *      mono_gc_collect (mono_gc_max_generation ());
 205  */
 206 void
 207 mono_gc_collect (int generation)
 208 {
 209 #ifndef DISABLE_PERFCOUNTERS
 210         mono_perfcounters->gc_induced++;
 211 #endif
 212         GC_gcollect ();
 213 }
 214
 215 /**
 216  * mono_gc_max_generation:
 217  *
 218  * Get the maximum generation number used by the current garbage
 219  * collector. The value will be 0 for the Boehm collector, 1 or more
 220  * for the generational collectors.
 221  *
 222  * Returns: the maximum generation number.
 223  */
 224 int
 225 mono_gc_max_generation (void)
 226 {
 227         return 0;
 228 }
 229
 230 /**
 231  * mono_gc_get_generation:
 232  * @object: a managed object
 233  *
 234  * Get the garbage collector's generation that @object belongs to.
 235  * Use this has a hint only.
 236  *
 237  * Returns: a garbage collector generation number
 238  */
 239 int
 240 mono_gc_get_generation  (MonoObject *object)
 241 {
 242         return 0;
 243 }
 244
 245 /**
 246  * mono_gc_collection_count:
 247  * @generation: a GC generation number
 248  *
 249  * Get how many times a garbage collection has been performed
 250  * for the given @generation number.
 251  *
 252  * Returns: the number of garbage collections
 253  */
 254 int
 255 mono_gc_collection_count (int generation)
 256 {
 257         return GC_gc_no;
 258 }
 259
 260 /**
 261  * mono_gc_add_memory_pressure:
 262  * @value: amount of bytes
 263  *
 264  * Adjust the garbage collector's view of how many bytes of memory
 265  * are indirectly referenced by managed objects (for example unmanaged
 266  * memory holding image or other binary data).
 267  * This is a hint only to the garbage collector algorithm.
 268  * Note that negative amounts of @value will decrease the memory
 269  * pressure.
 270  */
 271 void
 272 mono_gc_add_memory_pressure (gint64 value)
 273 {
 274 }
 275
 276 /**
 277  * mono_gc_get_used_size:
 278  *
 279  * Get the approximate amount of memory used by managed objects.
 280  *
 281  * Returns: the amount of memory used in bytes
 282  */
 283 int64_t
 284 mono_gc_get_used_size (void)
 285 {
 286         return GC_get_heap_size () - GC_get_free_bytes ();
 287 }
 288
 289 /**
 290  * mono_gc_get_heap_size:
 291  *
 292  * Get the amount of memory used by the garbage collector.
 293  *
 294  * Returns: the size of the heap in bytes
 295  */
 296 int64_t
 297 mono_gc_get_heap_size (void)
 298 {
 299         return GC_get_heap_size ();
 300 }
 301
 302 gboolean
 303 mono_gc_is_gc_thread (void)
 304 {
 305 #if GC_VERSION_MAJOR >= 7
 306         return TRUE;
 307 #elif defined(USE_INCLUDED_LIBGC)
 308         return GC_thread_is_registered ();
 309 #else
 310         return TRUE;
 311 #endif
 312 }
 313
 314 extern int GC_thread_register_foreign (void *base_addr);
 315
 316 gboolean
 317 mono_gc_register_thread (void *baseptr)
 318 {
 319         return mono_thread_info_attach (baseptr) != NULL;
 320 }
 321
 322 static void*
 323 boehm_thread_register (MonoThreadInfo* info, void *baseptr)
 324 {
 325 #if GC_VERSION_MAJOR >= 7
 326         struct GC_stack_base sb;
 327         int res;
 328
 329         res = GC_get_stack_base (&sb);
 330         if (res != GC_SUCCESS) {
 331                 sb.mem_base = baseptr;
 332 #ifdef __ia64__
 333                 /* Can't determine the register stack bounds */
 334                 g_error ("mono_gc_register_thread failed ().\n");
 335 #endif
 336         }
 337         res = GC_register_my_thread (&sb);
 338         if ((res != GC_SUCCESS) && (res != GC_DUPLICATE)) {
 339                 g_warning ("GC_register_my_thread () failed.\n");
 340                 return NULL;
 341         }
 342         return info;
 343 #else
 344         if (mono_gc_is_gc_thread())
 345                 return info;
 346 #if defined(USE_INCLUDED_LIBGC) && !defined(HOST_WIN32)
 347         return GC_thread_register_foreign (baseptr) ? info : NULL;
 348 #else
 349         return NULL;
 350 #endif
 351 #endif
 352 }
 353
 354 gboolean
 355 mono_object_is_alive (MonoObject* o)
 356 {
 357 #ifdef USE_INCLUDED_LIBGC
 358         return GC_is_marked ((gpointer)o);
 359 #else
 360         return TRUE;
 361 #endif
 362 }
 363
 364 int
 365 mono_gc_walk_heap (int flags, MonoGCReferences callback, void *data)
 366 {
 367         return 1;
 368 }
 369
 370 #ifdef USE_INCLUDED_LIBGC
 371
 372 static gint64 gc_start_time;
 373
 374 static void
 375 on_gc_notification (GCEventType event)
 376 {
 377         MonoGCEvent e = (MonoGCEvent)event;
 378
 379         switch (e) {
 380         case MONO_GC_EVENT_PRE_STOP_WORLD:
 381                 MONO_GC_WORLD_STOP_BEGIN ();
 382                 mono_thread_info_suspend_lock ();
 383                 break;
 384
 385         case MONO_GC_EVENT_POST_STOP_WORLD:
 386                 MONO_GC_WORLD_STOP_END ();
 387                 break;
 388
 389         case MONO_GC_EVENT_PRE_START_WORLD:
 390                 MONO_GC_WORLD_RESTART_BEGIN (1);
 391                 break;
 392
 393         case MONO_GC_EVENT_POST_START_WORLD:
 394                 MONO_GC_WORLD_RESTART_END (1);
 395                 mono_thread_info_suspend_unlock ();
 396                 break;
 397
 398         case MONO_GC_EVENT_START:
 399                 MONO_GC_BEGIN (1);
 400 #ifndef DISABLE_PERFCOUNTERS
 401                 if (mono_perfcounters)
 402                         mono_perfcounters->gc_collections0++;
 403 #endif
 404                 gc_stats.major_gc_count ++;
 405                 gc_start_time = mono_100ns_ticks ();
 406                 break;
 407
 408         case MONO_GC_EVENT_END:
 409                 MONO_GC_END (1);
 410 #if defined(ENABLE_DTRACE) && defined(__sun__)
 411                 /* This works around a dtrace -G problem on Solaris.
 412                    Limit its actual use to when the probe is enabled. */
 413                 if (MONO_GC_END_ENABLED ())
 414                         sleep(0);
 415 #endif
 416
 417 #ifndef DISABLE_PERFCOUNTERS
 418                 if (mono_perfcounters) {
 419                         guint64 heap_size = GC_get_heap_size ();
 420                         guint64 used_size = heap_size - GC_get_free_bytes ();
 421                         mono_perfcounters->gc_total_bytes = used_size;
 422                         mono_perfcounters->gc_committed_bytes = heap_size;
 423                         mono_perfcounters->gc_reserved_bytes = heap_size;
 424                         mono_perfcounters->gc_gen0size = heap_size;
 425                 }
 426 #endif
 427                 gc_stats.major_gc_time_usecs += (mono_100ns_ticks () - gc_start_time) / 10;
 428                 mono_trace_message (MONO_TRACE_GC, "gc took %d usecs", (mono_100ns_ticks () - gc_start_time) / 10);
 429                 break;
 430         }
 431
 432         mono_profiler_gc_event (e, 0);
 433 }
 434
 435 static void
 436 on_gc_heap_resize (size_t new_size)
 437 {
 438         guint64 heap_size = GC_get_heap_size ();
 439 #ifndef DISABLE_PERFCOUNTERS
 440         if (mono_perfcounters) {
 441                 mono_perfcounters->gc_committed_bytes = heap_size;
 442                 mono_perfcounters->gc_reserved_bytes = heap_size;
 443                 mono_perfcounters->gc_gen0size = heap_size;
 444         }
 445 #endif
 446         mono_profiler_gc_heap_resize (new_size);
 447 }
 448
 449 void
 450 mono_gc_enable_events (void)
 451 {
 452         GC_notify_event = on_gc_notification;
 453         GC_on_heap_resize = on_gc_heap_resize;
 454 }
 455
 456 #else
 457
 458 void
 459 mono_gc_enable_events (void)
 460 {
 461 }
 462
 463 #endif
 464
 465 int
 466 mono_gc_register_root (char *start, size_t size, void *descr)
 467 {
 468         /* for some strange reason, they want one extra byte on the end */
 469         GC_add_roots (start, start + size + 1);
 470
 471         return TRUE;
 472 }
 473
 474 void
 475 mono_gc_deregister_root (char* addr)
 476 {
 477 #ifndef HOST_WIN32
 478         /* FIXME: libgc doesn't define this work win32 for some reason */
 479         /* FIXME: No size info */
 480         GC_remove_roots (addr, addr + sizeof (gpointer) + 1);
 481 #endif
 482 }
 483
 484 void
 485 mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
 486 {
 487         /* libgc requires that we use HIDE_POINTER... */
 488         *link_addr = (void*)HIDE_POINTER (obj);
 489         if (track)
 490                 GC_REGISTER_LONG_LINK (link_addr, obj);
 491         else
 492                 GC_GENERAL_REGISTER_DISAPPEARING_LINK (link_addr, obj);
 493 }
 494
 495 void
 496 mono_gc_weak_link_remove (void **link_addr, gboolean track)
 497 {
 498         if (track)
 499                 GC_unregister_long_link (link_addr);
 500         else
 501                 GC_unregister_disappearing_link (link_addr);
 502         *link_addr = NULL;
 503 }
 504
 505 static gpointer
 506 reveal_link (gpointer link_addr)
 507 {
 508         void **link_a = link_addr;
 509         return REVEAL_POINTER (*link_a);
 510 }
 511
 512 MonoObject*
 513 mono_gc_weak_link_get (void **link_addr)
 514 {
 515         MonoObject *obj = GC_call_with_alloc_lock (reveal_link, link_addr);
 516         if (obj == (MonoObject *) -1)
 517                 return NULL;
 518         return obj;
 519 }
 520
 521 void*
 522 mono_gc_make_descr_for_string (gsize *bitmap, int numbits)
 523 {
 524         return mono_gc_make_descr_from_bitmap (bitmap, numbits);
 525 }
 526
 527 void*
 528 mono_gc_make_descr_for_object (gsize *bitmap, int numbits, size_t obj_size)
 529 {
 530         return mono_gc_make_descr_from_bitmap (bitmap, numbits);
 531 }
 532
 533 void*
 534 mono_gc_make_descr_for_array (int vector, gsize *elem_bitmap, int numbits, size_t elem_size)
 535 {
 536         /* libgc has no usable support for arrays... */
 537         return GC_NO_DESCRIPTOR;
 538 }
 539
 540 void*
 541 mono_gc_make_descr_from_bitmap (gsize *bitmap, int numbits)
 542 {
 543 #ifdef HAVE_GC_GCJ_MALLOC
 544         /* It seems there are issues when the bitmap doesn't fit: play it safe */
 545         if (numbits >= 30)
 546                 return GC_NO_DESCRIPTOR;
 547         else
 548                 return (gpointer)GC_make_descriptor ((GC_bitmap)bitmap, numbits);
 549 #else
 550         return NULL;
 551 #endif
 552 }
 553
 554 void*
 555 mono_gc_make_root_descr_all_refs (int numbits)
 556 {
 557         return NULL;
 558 }
 559
 560 void*
 561 mono_gc_alloc_fixed (size_t size, void *descr)
 562 {
 563         /* To help track down typed allocation bugs */
 564         /*
 565         static int count;
 566         count ++;
 567         if (count == atoi (getenv ("COUNT2")))
 568                 printf ("HIT!\n");
 569         if (count > atoi (getenv ("COUNT2")))
 570                 return GC_MALLOC (size);
 571         */
 572
 573         if (descr)
 574                 return GC_MALLOC_EXPLICITLY_TYPED (size, (GC_descr)descr);
 575         else
 576                 return GC_MALLOC (size);
 577 }
 578
 579 void
 580 mono_gc_free_fixed (void* addr)
 581 {
 582 }
 583
 584 int
 585 mono_gc_invoke_finalizers (void)
 586 {
 587         /* There is a bug in GC_invoke_finalizer () in versions <= 6.2alpha4:
 588          * the 'mem_freed' variable is not initialized when there are no
 589          * objects to finalize, which leads to strange behavior later on.
 590          * The check is necessary to work around that bug.
 591          */
 592         if (GC_should_invoke_finalizers ())
 593                 return GC_invoke_finalizers ();
 594         return 0;
 595 }
 596
 597 gboolean
 598 mono_gc_pending_finalizers (void)
 599 {
 600         return GC_should_invoke_finalizers ();
 601 }
 602
 603 void
 604 mono_gc_wbarrier_set_field (MonoObject *obj, gpointer field_ptr, MonoObject* value)
 605 {
 606         *(void**)field_ptr = value;
 607 }
 608
 609 void
 610 mono_gc_wbarrier_set_arrayref (MonoArray *arr, gpointer slot_ptr, MonoObject* value)
 611 {
 612         *(void**)slot_ptr = value;
 613 }
 614
 615 void
 616 mono_gc_wbarrier_arrayref_copy (gpointer dest_ptr, gpointer src_ptr, int count)
 617 {
 618         mono_gc_memmove (dest_ptr, src_ptr, count * sizeof (gpointer));
 619 }
 620
 621 void
 622 mono_gc_wbarrier_generic_store (gpointer ptr, MonoObject* value)
 623 {
 624         *(void**)ptr = value;
 625 }
 626
 627 void
 628 mono_gc_wbarrier_generic_nostore (gpointer ptr)
 629 {
 630 }
 631
 632 void
 633 mono_gc_wbarrier_value_copy (gpointer dest, gpointer src, int count, MonoClass *klass)
 634 {
 635         mono_gc_memmove (dest, src, count * mono_class_value_size (klass, NULL));
 636 }
 637
 638 void
 639 mono_gc_wbarrier_object_copy (MonoObject* obj, MonoObject *src)
 640 {
 641         /* do not copy the sync state */
 642         mono_gc_memmove ((char*)obj + sizeof (MonoObject), (char*)src + sizeof (MonoObject),
 643                         mono_object_class (obj)->instance_size - sizeof (MonoObject));
 644 }
 645
 646 void
 647 mono_gc_clear_domain (MonoDomain *domain)
 648 {
 649 }
 650
 651 int
 652 mono_gc_get_suspend_signal (void)
 653 {
 654 #ifdef USE_INCLUDED_GC
 655         return GC_get_suspend_signal ();
 656 #else
 657         return -1;
 658 #endif
 659 }
 660
 661 #if defined(USE_INCLUDED_LIBGC) && defined(USE_COMPILER_TLS) && defined(__linux__) && (defined(__i386__) || defined(__x86_64__))
 662 extern __thread MONO_TLS_FAST void* GC_thread_tls;
 663 #include "metadata-internals.h"
 664
 665 static int
 666 shift_amount (int v)
 667 {
 668         int i = 0;
 669         while (!(v & (1 << i)))
 670                 i++;
 671         return i;
 672 }
 673
 674 enum {
 675         ATYPE_FREEPTR,
 676         ATYPE_FREEPTR_FOR_BOX,
 677         ATYPE_NORMAL,
 678         ATYPE_GCJ,
 679         ATYPE_STRING,
 680         ATYPE_NUM
 681 };
 682
 683 static MonoMethod*
 684 create_allocator (int atype, int offset)
 685 {
 686         int index_var, bytes_var, my_fl_var, my_entry_var;
 687         guint32 no_freelist_branch, not_small_enough_branch = 0;
 688         guint32 size_overflow_branch = 0;
 689         MonoMethodBuilder *mb;
 690         MonoMethod *res;
 691         MonoMethodSignature *csig;
 692         AllocatorWrapperInfo *info;
 693
 694         if (atype == ATYPE_STRING) {
 695                 csig = mono_metadata_signature_alloc (mono_defaults.corlib, 2);
 696                 csig->ret = &mono_defaults.string_class->byval_arg;
 697                 csig->params [0] = &mono_defaults.int_class->byval_arg;
 698                 csig->params [1] = &mono_defaults.int32_class->byval_arg;
 699         } else {
 700                 csig = mono_metadata_signature_alloc (mono_defaults.corlib, 1);
 701                 csig->ret = &mono_defaults.object_class->byval_arg;
 702                 csig->params [0] = &mono_defaults.int_class->byval_arg;
 703         }
 704
 705         mb = mono_mb_new (mono_defaults.object_class, "Alloc", MONO_WRAPPER_ALLOC);
 706         bytes_var = mono_mb_add_local (mb, &mono_defaults.int32_class->byval_arg);
 707         if (atype == ATYPE_STRING) {
 708                 /* a string alloator method takes the args: (vtable, len) */
 709                 /* bytes = (sizeof (MonoString) + ((len + 1) * 2)); */
 710                 mono_mb_emit_ldarg (mb, 1);
 711                 mono_mb_emit_icon (mb, 1);
 712                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 713                 mono_mb_emit_icon (mb, 1);
 714                 mono_mb_emit_byte (mb, MONO_CEE_SHL);
 715                 // sizeof (MonoString) might include padding
 716                 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoString, chars));
 717                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 718                 mono_mb_emit_stloc (mb, bytes_var);
 719         } else {
 720                 /* bytes = vtable->klass->instance_size */
 721                 mono_mb_emit_ldarg (mb, 0);
 722                 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoVTable, klass));
 723                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 724                 mono_mb_emit_byte (mb, MONO_CEE_LDIND_I);
 725                 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoClass, instance_size));
 726                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 727                 /* FIXME: assert instance_size stays a 4 byte integer */
 728                 mono_mb_emit_byte (mb, MONO_CEE_LDIND_U4);
 729                 mono_mb_emit_stloc (mb, bytes_var);
 730         }
 731
 732         /* this is needed for strings/arrays only as the other big types are never allocated with this method */
 733         if (atype == ATYPE_STRING) {
 734                 /* check for size */
 735                 /* if (!SMALL_ENOUGH (bytes)) jump slow_path;*/
 736                 mono_mb_emit_ldloc (mb, bytes_var);
 737                 mono_mb_emit_icon (mb, (NFREELISTS-1) * GRANULARITY);
 738                 not_small_enough_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BGT_UN_S);
 739                 /* check for overflow */
 740                 mono_mb_emit_ldloc (mb, bytes_var);
 741                 mono_mb_emit_icon (mb, sizeof (MonoString));
 742                 size_overflow_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BLE_UN_S);
 743         }
 744
 745         /* int index = INDEX_FROM_BYTES(bytes); */
 746         index_var = mono_mb_add_local (mb, &mono_defaults.int32_class->byval_arg);
 747
 748         mono_mb_emit_ldloc (mb, bytes_var);
 749         mono_mb_emit_icon (mb, GRANULARITY - 1);
 750         mono_mb_emit_byte (mb, MONO_CEE_ADD);
 751         mono_mb_emit_icon (mb, shift_amount (GRANULARITY));
 752         mono_mb_emit_byte (mb, MONO_CEE_SHR_UN);
 753         mono_mb_emit_icon (mb, shift_amount (sizeof (gpointer)));
 754         mono_mb_emit_byte (mb, MONO_CEE_SHL);
 755         /* index var is already adjusted into bytes */
 756         mono_mb_emit_stloc (mb, index_var);
 757
 758         my_fl_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
 759         my_entry_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
 760         /* my_fl = ((GC_thread)tsd) -> ptrfree_freelists + index; */
 761         mono_mb_emit_byte (mb, MONO_CUSTOM_PREFIX);
 762         mono_mb_emit_byte (mb, 0x0D); /* CEE_MONO_TLS */
 763         mono_mb_emit_i4 (mb, offset);
 764         if (atype == ATYPE_FREEPTR || atype == ATYPE_FREEPTR_FOR_BOX || atype == ATYPE_STRING)
 765                 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (struct GC_Thread_Rep, ptrfree_freelists));
 766         else if (atype == ATYPE_NORMAL)
 767                 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (struct GC_Thread_Rep, normal_freelists));
 768         else if (atype == ATYPE_GCJ)
 769                 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (struct GC_Thread_Rep, gcj_freelists));
 770         else
 771                 g_assert_not_reached ();
 772         mono_mb_emit_byte (mb, MONO_CEE_ADD);
 773         mono_mb_emit_ldloc (mb, index_var);
 774         mono_mb_emit_byte (mb, MONO_CEE_ADD);
 775         mono_mb_emit_stloc (mb, my_fl_var);
 776
 777         /* my_entry = *my_fl; */
 778         mono_mb_emit_ldloc (mb, my_fl_var);
 779         mono_mb_emit_byte (mb, MONO_CEE_LDIND_I);
 780         mono_mb_emit_stloc (mb, my_entry_var);
 781
 782         /* if (EXPECT((word)my_entry >= HBLKSIZE, 1)) { */
 783         mono_mb_emit_ldloc (mb, my_entry_var);
 784         mono_mb_emit_icon (mb, HBLKSIZE);
 785         no_freelist_branch = mono_mb_emit_short_branch (mb, MONO_CEE_BLT_UN_S);
 786
 787         /* ptr_t next = obj_link(my_entry); *my_fl = next; */
 788         mono_mb_emit_ldloc (mb, my_fl_var);
 789         mono_mb_emit_ldloc (mb, my_entry_var);
 790         mono_mb_emit_byte (mb, MONO_CEE_LDIND_I);
 791         mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
 792
 793         /* set the vtable and clear the words in the object */
 794         mono_mb_emit_ldloc (mb, my_entry_var);
 795         mono_mb_emit_ldarg (mb, 0);
 796         mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
 797
 798         if (atype == ATYPE_FREEPTR) {
 799                 int start_var, end_var, start_loop;
 800                 /* end = my_entry + bytes; start = my_entry + sizeof (gpointer);
 801                  */
 802                 start_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
 803                 end_var = mono_mb_add_local (mb, &mono_defaults.int_class->byval_arg);
 804                 mono_mb_emit_ldloc (mb, my_entry_var);
 805                 mono_mb_emit_ldloc (mb, bytes_var);
 806                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 807                 mono_mb_emit_stloc (mb, end_var);
 808                 mono_mb_emit_ldloc (mb, my_entry_var);
 809                 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoObject, synchronisation));
 810                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 811                 mono_mb_emit_stloc (mb, start_var);
 812                 /*
 813                  * do {
 814                  *      *start++ = NULL;
 815                  * } while (start < end);
 816                  */
 817                 start_loop = mono_mb_get_label (mb);
 818                 mono_mb_emit_ldloc (mb, start_var);
 819                 mono_mb_emit_icon (mb, 0);
 820                 mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
 821                 mono_mb_emit_ldloc (mb, start_var);
 822                 mono_mb_emit_icon (mb, sizeof (gpointer));
 823                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 824                 mono_mb_emit_stloc (mb, start_var);
 825
 826                 mono_mb_emit_ldloc (mb, start_var);
 827                 mono_mb_emit_ldloc (mb, end_var);
 828                 mono_mb_emit_byte (mb, MONO_CEE_BLT_UN_S);
 829                 mono_mb_emit_byte (mb, start_loop - (mono_mb_get_label (mb) + 1));
 830         } else if (atype == ATYPE_FREEPTR_FOR_BOX || atype == ATYPE_STRING) {
 831                 /* need to clear just the sync pointer */
 832                 mono_mb_emit_ldloc (mb, my_entry_var);
 833                 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoObject, synchronisation));
 834                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 835                 mono_mb_emit_icon (mb, 0);
 836                 mono_mb_emit_byte (mb, MONO_CEE_STIND_I);
 837         }
 838
 839         if (atype == ATYPE_STRING) {
 840                 /* need to set length and clear the last char */
 841                 /* s->length = len; */
 842                 mono_mb_emit_ldloc (mb, my_entry_var);
 843                 mono_mb_emit_icon (mb, G_STRUCT_OFFSET (MonoString, length));
 844                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 845                 mono_mb_emit_ldarg (mb, 1);
 846                 mono_mb_emit_byte (mb, MONO_CEE_STIND_I4);
 847                 /* s->chars [len] = 0; */
 848                 mono_mb_emit_ldloc (mb, my_entry_var);
 849                 mono_mb_emit_ldloc (mb, bytes_var);
 850                 mono_mb_emit_icon (mb, 2);
 851                 mono_mb_emit_byte (mb, MONO_CEE_SUB);
 852                 mono_mb_emit_byte (mb, MONO_CEE_ADD);
 853                 mono_mb_emit_icon (mb, 0);
 854                 mono_mb_emit_byte (mb, MONO_CEE_STIND_I2);
 855         }
 856
 857         /* return my_entry; */
 858         mono_mb_emit_ldloc (mb, my_entry_var);
 859         mono_mb_emit_byte (mb, MONO_CEE_RET);
 860
 861         mono_mb_patch_short_branch (mb, no_freelist_branch);
 862         if (not_small_enough_branch > 0)
 863                 mono_mb_patch_short_branch (mb, not_small_enough_branch);
 864         if (size_overflow_branch > 0)
 865                 mono_mb_patch_short_branch (mb, size_overflow_branch);
 866         /* the slow path: we just call back into the runtime */
 867         if (atype == ATYPE_STRING) {
 868                 mono_mb_emit_ldarg (mb, 1);
 869                 mono_mb_emit_icall (mb, mono_string_alloc);
 870         } else {
 871                 mono_mb_emit_ldarg (mb, 0);
 872                 mono_mb_emit_icall (mb, mono_object_new_specific);
 873         }
 874
 875         mono_mb_emit_byte (mb, MONO_CEE_RET);
 876
 877         res = mono_mb_create_method (mb, csig, 8);
 878         mono_mb_free (mb);
 879         mono_method_get_header (res)->init_locals = FALSE;
 880
 881         info = mono_image_alloc0 (mono_defaults.corlib, sizeof (AllocatorWrapperInfo));
 882         info->gc_name = "boehm";
 883         info->alloc_type = atype;
 884         mono_marshal_set_wrapper_info (res, info);
 885
 886         return res;
 887 }
 888
 889 static MonoMethod* alloc_method_cache [ATYPE_NUM];
 890
 891 static G_GNUC_UNUSED gboolean
 892 mono_gc_is_critical_method (MonoMethod *method)
 893 {
 894         int i;
 895
 896         for (i = 0; i < ATYPE_NUM; ++i)
 897                 if (method == alloc_method_cache [i])
 898                         return TRUE;
 899
 900         return FALSE;
 901 }
 902
 903 /*
 904  * If possible, generate a managed method that can quickly allocate objects in class
 905  * @klass. The method will typically have an thread-local inline allocation sequence.
 906  * The signature of the called method is:
 907  *      object allocate (MonoVTable *vtable)
 908  * Some of the logic here is similar to mono_class_get_allocation_ftn () i object.c,
 909  * keep in sync.
 910  * The thread local alloc logic is taken from libgc/pthread_support.c.
 911  */
 912
 913 MonoMethod*
 914 mono_gc_get_managed_allocator (MonoVTable *vtable, gboolean for_box)
 915 {
 916         int offset = -1;
 917         int atype;
 918         MonoClass *klass = vtable->klass;
 919         MONO_THREAD_VAR_OFFSET (GC_thread_tls, offset);
 920
 921         /*g_print ("thread tls: %d\n", offset);*/
 922         if (offset == -1)
 923                 return NULL;
 924         if (!SMALL_ENOUGH (klass->instance_size))
 925                 return NULL;
 926         if (mono_class_has_finalizer (klass) || klass->marshalbyref || (mono_profiler_get_events () & MONO_PROFILE_ALLOCATIONS))
 927                 return NULL;
 928         if (klass->rank)
 929                 return NULL;
 930         if (klass->byval_arg.type == MONO_TYPE_STRING) {
 931                 atype = ATYPE_STRING;
 932         } else if (!klass->has_references) {
 933                 if (for_box)
 934                         atype = ATYPE_FREEPTR_FOR_BOX;
 935                 else
 936                         atype = ATYPE_FREEPTR;
 937         } else {
 938                 return NULL;
 939                 /*
 940                  * disabled because we currently do a runtime choice anyway, to
 941                  * deal with multiple appdomains.
 942                 if (vtable->gc_descr != GC_NO_DESCRIPTOR)
 943                         atype = ATYPE_GCJ;
 944                 else
 945                         atype = ATYPE_NORMAL;
 946                 */
 947         }
 948         return mono_gc_get_managed_allocator_by_type (atype);
 949 }
 950
 951 MonoMethod*
 952 mono_gc_get_managed_array_allocator (MonoClass *klass)
 953 {
 954         return NULL;
 955 }
 956
 957 /**
 958  * mono_gc_get_managed_allocator_by_type:
 959  *
 960  *   Return a managed allocator method corresponding to allocator type ATYPE.
 961  */
 962 MonoMethod*
 963 mono_gc_get_managed_allocator_by_type (int atype)
 964 {
 965         int offset = -1;
 966         MonoMethod *res;
 967         MONO_THREAD_VAR_OFFSET (GC_thread_tls, offset);
 968
 969         mono_loader_lock ();
 970         res = alloc_method_cache [atype];
 971         if (!res)
 972                 res = alloc_method_cache [atype] = create_allocator (atype, offset);
 973         mono_loader_unlock ();
 974         return res;
 975 }
 976
 977 guint32
 978 mono_gc_get_managed_allocator_types (void)
 979 {
 980         return ATYPE_NUM;
 981 }
 982
 983 MonoMethod*
 984 mono_gc_get_write_barrier (void)
 985 {
 986         g_assert_not_reached ();
 987         return NULL;
 988 }
 989
 990 #else
 991
 992 static G_GNUC_UNUSED gboolean
 993 mono_gc_is_critical_method (MonoMethod *method)
 994 {
 995         return FALSE;
 996 }
 997
 998 MonoMethod*
 999 mono_gc_get_managed_allocator (MonoVTable *vtable, gboolean for_box)
1000 {
1001         return NULL;
1002 }
1003
1004 MonoMethod*
1005 mono_gc_get_managed_array_allocator (MonoClass *klass)
1006 {
1007         return NULL;
1008 }
1009
1010 MonoMethod*
1011 mono_gc_get_managed_allocator_by_type (int atype)
1012 {
1013         return NULL;
1014 }
1015
1016 guint32
1017 mono_gc_get_managed_allocator_types (void)
1018 {
1019         return 0;
1020 }
1021
1022 MonoMethod*
1023 mono_gc_get_write_barrier (void)
1024 {
1025         g_assert_not_reached ();
1026         return NULL;
1027 }
1028
1029 #endif
1030
1031 const char *
1032 mono_gc_get_gc_name (void)
1033 {
1034         return "boehm";
1035 }
1036
1037 void*
1038 mono_gc_invoke_with_gc_lock (MonoGCLockedCallbackFunc func, void *data)
1039 {
1040         return GC_call_with_alloc_lock (func, data);
1041 }
1042
1043 char*
1044 mono_gc_get_description (void)
1045 {
1046         return g_strdup (DEFAULT_GC_NAME);
1047 }
1048
1049 void
1050 mono_gc_set_desktop_mode (void)
1051 {
1052         GC_dont_expand = 1;
1053 }
1054
1055 gboolean
1056 mono_gc_is_moving (void)
1057 {
1058         return FALSE;
1059 }
1060
1061 gboolean
1062 mono_gc_is_disabled (void)
1063 {
1064         if (GC_dont_gc || g_getenv ("GC_DONT_GC"))
1065                 return TRUE;
1066         else
1067                 return FALSE;
1068 }
1069
1070 void
1071 mono_gc_wbarrier_value_copy_bitmap (gpointer _dest, gpointer _src, int size, unsigned bitmap)
1072 {
1073         g_assert_not_reached ();
1074 }
1075
1076
1077 guint8*
1078 mono_gc_get_card_table (int *shift_bits, gpointer *card_mask)
1079 {
1080         g_assert_not_reached ();
1081         return NULL;
1082 }
1083
1084 gboolean
1085 mono_gc_card_table_nursery_check (void)
1086 {
1087         g_assert_not_reached ();
1088         return TRUE;
1089 }
1090
1091 void*
1092 mono_gc_get_nursery (int *shift_bits, size_t *size)
1093 {
1094         return NULL;
1095 }
1096
1097 void
1098 mono_gc_set_current_thread_appdomain (MonoDomain *domain)
1099 {
1100 }
1101
1102 gboolean
1103 mono_gc_precise_stack_mark_enabled (void)
1104 {
1105         return FALSE;
1106 }
1107
1108 FILE *
1109 mono_gc_get_logfile (void)
1110 {
1111         return NULL;
1112 }
1113
1114 void
1115 mono_gc_conservatively_scan_area (void *start, void *end)
1116 {
1117         g_assert_not_reached ();
1118 }
1119
1120 void *
1121 mono_gc_scan_object (void *obj)
1122 {
1123         g_assert_not_reached ();
1124         return NULL;
1125 }
1126
1127 gsize*
1128 mono_gc_get_bitmap_for_descr (void *descr, int *numbits)
1129 {
1130         g_assert_not_reached ();
1131         return NULL;
1132 }
1133
1134 void
1135 mono_gc_set_gc_callbacks (MonoGCCallbacks *callbacks)
1136 {
1137 }
1138
1139 void
1140 mono_gc_set_stack_end (void *stack_end)
1141 {
1142 }
1143
1144 void mono_gc_set_skip_thread (gboolean value)
1145 {
1146 }
1147
1148 /*
1149  * These will call the redefined versions in libgc.
1150  */
1151
1152 #ifndef HOST_WIN32
1153
1154 int
1155 mono_gc_pthread_create (pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
1156 {
1157         return pthread_create (new_thread, attr, start_routine, arg);
1158 }
1159
1160 int
1161 mono_gc_pthread_join (pthread_t thread, void **retval)
1162 {
1163         return pthread_join (thread, retval);
1164 }
1165
1166 int
1167 mono_gc_pthread_detach (pthread_t thread)
1168 {
1169         return pthread_detach (thread);
1170 }
1171
1172 void
1173 mono_gc_pthread_exit (void *retval)
1174 {
1175         pthread_exit (retval);
1176 }
1177
1178 #endif
1179
1180 #ifdef HOST_WIN32
1181 BOOL APIENTRY mono_gc_dllmain (HMODULE module_handle, DWORD reason, LPVOID reserved)
1182 {
1183 #ifdef USE_INCLUDED_LIBGC
1184         return GC_DllMain (module_handle, reason, reserved);
1185 #else
1186         return TRUE;
1187 #endif
1188 }
1189 #endif
1190
1191 guint
1192 mono_gc_get_vtable_bits (MonoClass *class)
1193 {
1194         return 0;
1195 }
1196
1197 /*
1198  * mono_gc_register_altstack:
1199  *
1200  *   Register the dimensions of the normal stack and altstack with the collector.
1201  * Currently, STACK/STACK_SIZE is only used when the thread is suspended while it is on an altstack.
1202  */
1203 void
1204 mono_gc_register_altstack (gpointer stack, gint32 stack_size, gpointer altstack, gint32 altstack_size)
1205 {
1206 #ifdef USE_INCLUDED_LIBGC
1207         GC_register_altstack (stack, stack_size, altstack, altstack_size);
1208 #endif
1209 }
1210
1211 int
1212 mono_gc_get_los_limit (void)
1213 {
1214         return G_MAXINT;
1215 }
1216
1217 gboolean
1218 mono_gc_user_markers_supported (void)
1219 {
1220         return FALSE;
1221 }
1222
1223 void *
1224 mono_gc_make_root_descr_user (MonoGCRootMarkFunc marker)
1225 {
1226         g_assert_not_reached ();
1227         return NULL;
1228 }
1229
1230 gboolean
1231 mono_gc_set_allow_synchronous_major (gboolean flag)
1232 {
1233         return flag;
1234 }
1235
1236 #endif /* no Boehm GC */