mono/metadata/sgen-debug.c

   1 /*
   2  * sgen-debug.c: Collector debugging
   3  *
   4  * Author:
   5  *      Paolo Molaro (lupus@ximian.com)
   6  *  Rodrigo Kumpera (kumpera@gmail.com)
   7  *
   8  * Copyright 2005-2011 Novell, Inc (http://www.novell.com)
   9  * Copyright 2011 Xamarin Inc (http://www.xamarin.com)
  10  * Copyright 2011 Xamarin, Inc.
  11  * Copyright (C) 2012 Xamarin Inc
  12  *
  13  * This library is free software; you can redistribute it and/or
  14  * modify it under the terms of the GNU Library General Public
  15  * License 2.0 as published by the Free Software Foundation;
  16  *
  17  * This library is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  * Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License 2.0 along with this library; if not, write to the Free
  24  * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25  */
  26
  27 #include "config.h"
  28 #ifdef HAVE_SGEN_GC
  29
  30 #include "metadata/sgen-gc.h"
  31 #include "metadata/sgen-cardtable.h"
  32 #include "metadata/sgen-protocol.h"
  33 #include "metadata/sgen-memory-governor.h"
  34 #include "metadata/sgen-pinning.h"
  35 #include "metadata/threadpool-internals.h"
  36
  37 #define LOAD_VTABLE     SGEN_LOAD_VTABLE
  38
  39 #define object_is_forwarded     SGEN_OBJECT_IS_FORWARDED
  40 #define object_is_pinned        SGEN_OBJECT_IS_PINNED
  41 #define safe_object_get_size    sgen_safe_object_get_size
  42
  43 void describe_ptr (char *ptr);
  44 void check_object (char *start);
  45
  46 /*
  47  * ######################################################################
  48  * ########  Collector debugging
  49  * ######################################################################
  50  */
  51
  52 const char*descriptor_types [] = {
  53         "INVALID",
  54         "run_length",
  55         "small_bitmap",
  56         "complex",
  57         "vector",
  58         "large_bitmap",
  59         "complex_arr",
  60         "complex_ptrfree"
  61 };
  62
  63 static char* describe_nursery_ptr (char *ptr, gboolean need_setup);
  64
  65 static void
  66 describe_pointer (char *ptr, gboolean need_setup)
  67 {
  68         MonoVTable *vtable;
  69         mword desc;
  70         int type;
  71         char *start;
  72         char *forwarded;
  73         mword size;
  74
  75  restart:
  76         if (sgen_ptr_in_nursery (ptr)) {
  77                 start = describe_nursery_ptr (ptr, need_setup);
  78                 if (!start)
  79                         return;
  80                 ptr = start;
  81                 vtable = (MonoVTable*)LOAD_VTABLE (ptr);
  82         } else {
  83                 if (sgen_ptr_is_in_los (ptr, &start)) {
  84                         if (ptr == start)
  85                                 printf ("Pointer is the start of object %p in LOS space.\n", start);
  86                         else
  87                                 printf ("Pointer is at offset 0x%x of object %p in LOS space.\n", (int)(ptr - start), start);
  88                         ptr = start;
  89                         mono_sgen_los_describe_pointer (ptr);
  90                         vtable = (MonoVTable*)LOAD_VTABLE (ptr);
  91                 } else if (major_collector.ptr_is_in_non_pinned_space (ptr, &start)) {
  92                         if (ptr == start)
  93                                 printf ("Pointer is the start of object %p in oldspace.\n", start);
  94                         else if (start)
  95                                 printf ("Pointer is at offset 0x%x of object %p in oldspace.\n", (int)(ptr - start), start);
  96                         else
  97                                 printf ("Pointer inside oldspace.\n");
  98                         if (start)
  99                                 ptr = start;
 100                         vtable = major_collector.describe_pointer (ptr);
 101                 } else if (major_collector.obj_is_from_pinned_alloc (ptr)) {
 102                         // FIXME: Handle pointers to the inside of objects
 103                         printf ("Pointer is inside a pinned chunk.\n");
 104                         vtable = (MonoVTable*)LOAD_VTABLE (ptr);
 105                 } else {
 106                         printf ("Pointer unknown.\n");
 107                         return;
 108                 }
 109         }
 110
 111         if (object_is_pinned (ptr))
 112                 printf ("Object is pinned.\n");
 113
 114         if ((forwarded = object_is_forwarded (ptr))) {
 115                 printf ("Object is forwarded to %p:\n", forwarded);
 116                 ptr = forwarded;
 117                 goto restart;
 118         }
 119
 120         printf ("VTable: %p\n", vtable);
 121         if (vtable == NULL) {
 122                 printf ("VTable is invalid (empty).\n");
 123                 goto bridge;
 124         }
 125         if (sgen_ptr_in_nursery (vtable)) {
 126                 printf ("VTable is invalid (points inside nursery).\n");
 127                 goto bridge;
 128         }
 129         printf ("Class: %s\n", vtable->klass->name);
 130
 131         desc = ((GCVTable*)vtable)->desc;
 132         printf ("Descriptor: %lx\n", (long)desc);
 133
 134         type = desc & 0x7;
 135         printf ("Descriptor type: %d (%s)\n", type, descriptor_types [type]);
 136
 137         size = sgen_safe_object_get_size ((MonoObject*)ptr);
 138         printf ("Size: %d\n", (int)size);
 139
 140  bridge:
 141         sgen_bridge_describe_pointer ((MonoObject*)ptr);
 142 }
 143
 144 void
 145 describe_ptr (char *ptr)
 146 {
 147         describe_pointer (ptr, TRUE);
 148 }
 149
 150 static gboolean missing_remsets;
 151
 152 /*
 153  * We let a missing remset slide if the target object is pinned,
 154  * because the store might have happened but the remset not yet added,
 155  * but in that case the target must be pinned.  We might theoretically
 156  * miss some missing remsets this way, but it's very unlikely.
 157  */
 158 #undef HANDLE_PTR
 159 #define HANDLE_PTR(ptr,obj)     do {    \
 160         if (*(ptr) && sgen_ptr_in_nursery ((char*)*(ptr))) { \
 161                 if (!sgen_get_remset ()->find_address ((char*)(ptr)) && !sgen_cement_lookup (*(ptr))) { \
 162                         SGEN_LOG (0, "Oldspace->newspace reference %p at offset %td in object %p (%s.%s) not found in remsets.", *(ptr), (char*)(ptr) - (char*)(obj), (obj), ((MonoObject*)(obj))->vtable->klass->name_space, ((MonoObject*)(obj))->vtable->klass->name); \
 163                         binary_protocol_missing_remset ((obj), (gpointer)LOAD_VTABLE ((obj)), (int) ((char*)(ptr) - (char*)(obj)), *(ptr), (gpointer)LOAD_VTABLE(*(ptr)), object_is_pinned (*(ptr))); \
 164                         if (!object_is_pinned (*(ptr)))                                                         \
 165                                 missing_remsets = TRUE;                                                                 \
 166                 }                                                                                                                               \
 167         }                                                                                                                                       \
 168         } while (0)
 169
 170 /*
 171  * Check that each object reference which points into the nursery can
 172  * be found in the remembered sets.
 173  */
 174 static void
 175 check_consistency_callback (char *start, size_t size, void *dummy)
 176 {
 177         GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
 178         SGEN_LOG (8, "Scanning object %p, vtable: %p (%s)", start, vt, vt->klass->name);
 179
 180 #include "sgen-scan-object.h"
 181 }
 182
 183 /*
 184  * Perform consistency check of the heap.
 185  *
 186  * Assumes the world is stopped.
 187  */
 188 void
 189 sgen_check_consistency (void)
 190 {
 191         // Need to add more checks
 192
 193         missing_remsets = FALSE;
 194
 195         SGEN_LOG (1, "Begin heap consistency check...");
 196
 197         // Check that oldspace->newspace pointers are registered with the collector
 198         major_collector.iterate_objects (ITERATE_OBJECTS_SWEEP_ALL, (IterateObjectCallbackFunc)check_consistency_callback, NULL);
 199
 200         sgen_los_iterate_objects ((IterateObjectCallbackFunc)check_consistency_callback, NULL);
 201
 202         SGEN_LOG (1, "Heap consistency check done.");
 203
 204         if (!binary_protocol_is_enabled ())
 205                 g_assert (!missing_remsets);
 206 }
 207
 208 static gboolean
 209 is_major_or_los_object_marked (char *obj)
 210 {
 211         if (sgen_safe_object_get_size ((MonoObject*)obj) > SGEN_MAX_SMALL_OBJ_SIZE) {
 212                 return sgen_los_object_is_pinned (obj);
 213         } else {
 214                 return sgen_get_major_collector ()->is_object_live (obj);
 215         }
 216 }
 217
 218 #undef HANDLE_PTR
 219 #define HANDLE_PTR(ptr,obj)     do {    \
 220         if (*(ptr) && !sgen_ptr_in_nursery ((char*)*(ptr)) && !is_major_or_los_object_marked ((char*)*(ptr))) { \
 221                 if (!sgen_get_remset ()->find_address_with_cards (start, cards, (char*)(ptr))) { \
 222                         SGEN_LOG (0, "major->major reference %p at offset %td in object %p (%s.%s) not found in remsets.", *(ptr), (char*)(ptr) - (char*)(obj), (obj), ((MonoObject*)(obj))->vtable->klass->name_space, ((MonoObject*)(obj))->vtable->klass->name); \
 223                         binary_protocol_missing_remset ((obj), (gpointer)LOAD_VTABLE ((obj)), (int) ((char*)(ptr) - (char*)(obj)), *(ptr), (gpointer)LOAD_VTABLE(*(ptr)), object_is_pinned (*(ptr))); \
 224                         missing_remsets = TRUE;                         \
 225                 }                                                                                                                               \
 226         }                                                                                                                                       \
 227         } while (0)
 228
 229 static void
 230 check_mod_union_callback (char *start, size_t size, void *dummy)
 231 {
 232         gboolean in_los = (gboolean) (size_t) dummy;
 233         GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
 234         guint8 *cards;
 235         SGEN_LOG (8, "Scanning object %p, vtable: %p (%s)", start, vt, vt->klass->name);
 236
 237         if (!is_major_or_los_object_marked (start))
 238                 return;
 239
 240         if (in_los)
 241                 cards = sgen_los_header_for_object (start)->cardtable_mod_union;
 242         else
 243                 cards = sgen_get_major_collector ()->get_cardtable_mod_union_for_object (start);
 244
 245         SGEN_ASSERT (0, cards, "we must have mod union for marked major objects");
 246
 247 #include "sgen-scan-object.h"
 248 }
 249
 250 void
 251 sgen_check_mod_union_consistency (void)
 252 {
 253         missing_remsets = FALSE;
 254
 255         major_collector.iterate_objects (ITERATE_OBJECTS_ALL, (IterateObjectCallbackFunc)check_mod_union_callback, (void*)FALSE);
 256
 257         sgen_los_iterate_objects ((IterateObjectCallbackFunc)check_mod_union_callback, (void*)TRUE);
 258
 259         if (!binary_protocol_is_enabled ())
 260                 g_assert (!missing_remsets);
 261 }
 262
 263 #undef HANDLE_PTR
 264 #define HANDLE_PTR(ptr,obj)     do {                                    \
 265                 if (*(ptr) && !LOAD_VTABLE (*(ptr)))                                            \
 266                         g_error ("Could not load vtable for obj %p slot %d (size %d)", obj, (char*)ptr - (char*)obj, safe_object_get_size ((MonoObject*)obj));          \
 267         } while (0)
 268
 269 static void
 270 check_major_refs_callback (char *start, size_t size, void *dummy)
 271 {
 272 #include "sgen-scan-object.h"
 273 }
 274
 275 void
 276 sgen_check_major_refs (void)
 277 {
 278         major_collector.iterate_objects (ITERATE_OBJECTS_SWEEP_ALL, (IterateObjectCallbackFunc)check_major_refs_callback, NULL);
 279         sgen_los_iterate_objects ((IterateObjectCallbackFunc)check_major_refs_callback, NULL);
 280 }
 281
 282 /* Check that the reference is valid */
 283 #undef HANDLE_PTR
 284 #define HANDLE_PTR(ptr,obj)     do {    \
 285                 if (*(ptr)) {   \
 286                         g_assert (sgen_safe_name (*(ptr)) != NULL);     \
 287                 }       \
 288         } while (0)
 289
 290 /*
 291  * check_object:
 292  *
 293  *   Perform consistency check on an object. Currently we only check that the
 294  * reference fields are valid.
 295  */
 296 void
 297 check_object (char *start)
 298 {
 299         if (!start)
 300                 return;
 301
 302 #include "sgen-scan-object.h"
 303 }
 304
 305
 306 static char **valid_nursery_objects;
 307 static int valid_nursery_object_count;
 308 static gboolean broken_heap;
 309
 310 static void
 311 setup_mono_sgen_scan_area_with_callback (char *object, size_t size, void *data)
 312 {
 313         valid_nursery_objects [valid_nursery_object_count++] = object;
 314 }
 315
 316 static void
 317 setup_valid_nursery_objects (void)
 318 {
 319         if (!valid_nursery_objects)
 320                 valid_nursery_objects = sgen_alloc_os_memory (DEFAULT_NURSERY_SIZE, SGEN_ALLOC_INTERNAL | SGEN_ALLOC_ACTIVATE, "debugging data");
 321         valid_nursery_object_count = 0;
 322         sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, setup_mono_sgen_scan_area_with_callback, NULL, FALSE);
 323 }
 324
 325 static gboolean
 326 find_object_in_nursery_dump (char *object)
 327 {
 328         int first = 0, last = valid_nursery_object_count;
 329         while (first < last) {
 330                 int middle = first + ((last - first) >> 1);
 331                 if (object == valid_nursery_objects [middle])
 332                         return TRUE;
 333
 334                 if (object < valid_nursery_objects [middle])
 335                         last = middle;
 336                 else
 337                         first = middle + 1;
 338         }
 339         g_assert (first == last);
 340         return FALSE;
 341 }
 342
 343 static char*
 344 describe_nursery_ptr (char *ptr, gboolean need_setup)
 345 {
 346         int i;
 347
 348         if (need_setup)
 349                 setup_valid_nursery_objects ();
 350
 351         for (i = 0; i < valid_nursery_object_count; ++i) {
 352                 if (valid_nursery_objects [i] >= ptr)
 353                         break;
 354         }
 355
 356         if (i >= valid_nursery_object_count || valid_nursery_objects [i] + safe_object_get_size ((MonoObject *)valid_nursery_objects [i]) < ptr) {
 357                 SGEN_LOG (0, "nursery-ptr (unalloc'd-memory)\n");
 358                 return NULL;
 359         } else {
 360                 char *obj = valid_nursery_objects [i];
 361                 if (obj == ptr)
 362                         SGEN_LOG (0, "nursery-ptr\n");
 363                 else
 364                         SGEN_LOG (0, "nursery-ptr (interior-ptr offset %td)\n", ptr - obj);
 365                 return obj;
 366         }
 367 }
 368
 369 static gboolean
 370 is_valid_object_pointer (char *object)
 371 {
 372         if (sgen_ptr_in_nursery (object))
 373                 return find_object_in_nursery_dump (object);
 374
 375         if (sgen_los_is_valid_object (object))
 376                 return TRUE;
 377
 378         if (major_collector.is_valid_object (object))
 379                 return TRUE;
 380         return FALSE;
 381 }
 382
 383 static void
 384 bad_pointer_spew (char *obj, char **slot)
 385 {
 386         char *ptr = *slot;
 387         MonoVTable *vtable = (MonoVTable*)LOAD_VTABLE (obj);
 388
 389         SGEN_LOG (0, "Invalid object pointer %p at offset %td in object %p (%s.%s):", ptr,
 390                 (char*)slot - obj,
 391                 obj, vtable->klass->name_space, vtable->klass->name);
 392         describe_pointer (ptr, FALSE);
 393         broken_heap = TRUE;
 394 }
 395
 396 static void
 397 missing_remset_spew (char *obj, char **slot)
 398 {
 399         char *ptr = *slot;
 400         MonoVTable *vtable = (MonoVTable*)LOAD_VTABLE (obj);
 401
 402         SGEN_LOG (0, "Oldspace->newspace reference %p at offset %td in object %p (%s.%s) not found in remsets.",
 403                 ptr, (char*)slot - obj, obj,
 404                 vtable->klass->name_space, vtable->klass->name);
 405
 406         broken_heap = TRUE;
 407 }
 408
 409 /*
 410 FIXME Flag missing remsets due to pinning as non fatal
 411 */
 412 #undef HANDLE_PTR
 413 #define HANDLE_PTR(ptr,obj)     do {    \
 414                 if (*(char**)ptr) {     \
 415                         if (!is_valid_object_pointer (*(char**)ptr)) {  \
 416                                 bad_pointer_spew ((char*)obj, (char**)ptr);     \
 417                         } else if (!sgen_ptr_in_nursery (obj) && sgen_ptr_in_nursery ((char*)*ptr)) {   \
 418                                 if (!sgen_get_remset ()->find_address ((char*)(ptr)) && !sgen_cement_lookup ((char*)*(ptr)) && (!allow_missing_pinned || !SGEN_OBJECT_IS_PINNED ((char*)*(ptr)))) \
 419                                 missing_remset_spew ((char*)obj, (char**)ptr);  \
 420                         }       \
 421         } \
 422         } while (0)
 423
 424 static void
 425 verify_object_pointers_callback (char *start, size_t size, void *data)
 426 {
 427         gboolean allow_missing_pinned = (gboolean) (size_t) data;
 428
 429 #include "sgen-scan-object.h"
 430 }
 431
 432 /*
 433 FIXME:
 434 -This heap checker is racy regarding inlined write barriers and other JIT tricks that
 435 depend on OP_DUMMY_USE.
 436 */
 437 void
 438 sgen_check_whole_heap (gboolean allow_missing_pinned)
 439 {
 440         setup_valid_nursery_objects ();
 441
 442         broken_heap = FALSE;
 443         sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, verify_object_pointers_callback, (void*) (size_t) allow_missing_pinned, FALSE);
 444         major_collector.iterate_objects (ITERATE_OBJECTS_SWEEP_ALL, verify_object_pointers_callback, (void*) (size_t) allow_missing_pinned);
 445         sgen_los_iterate_objects (verify_object_pointers_callback, (void*) (size_t) allow_missing_pinned);
 446
 447         g_assert (!broken_heap);
 448 }
 449
 450 static gboolean
 451 ptr_in_heap (char *object)
 452 {
 453         if (sgen_ptr_in_nursery (object))
 454                 return TRUE;
 455
 456         if (sgen_los_is_valid_object (object))
 457                 return TRUE;
 458
 459         if (major_collector.is_valid_object (object))
 460                 return TRUE;
 461         return FALSE;
 462 }
 463
 464 /*
 465  * sgen_check_objref:
 466  *   Do consistency checks on the object reference OBJ. Assert on failure.
 467  */
 468 void
 469 sgen_check_objref (char *obj)
 470 {
 471         g_assert (ptr_in_heap (obj));
 472 }
 473
 474 static void
 475 find_pinning_ref_from_thread (char *obj, size_t size)
 476 {
 477         int j;
 478         SgenThreadInfo *info;
 479         char *endobj = obj + size;
 480
 481         FOREACH_THREAD (info) {
 482                 char **start = (char**)info->stack_start;
 483                 if (info->skip)
 484                         continue;
 485                 while (start < (char**)info->stack_end) {
 486                         if (*start >= obj && *start < endobj) {
 487                                 SGEN_LOG (0, "Object %p referenced in thread %p (id %p) at %p, stack: %p-%p", obj, info, (gpointer)mono_thread_info_get_tid (info), start, info->stack_start, info->stack_end);
 488                         }
 489                         start++;
 490                 }
 491
 492                 for (j = 0; j < ARCH_NUM_REGS; ++j) {
 493 #ifdef USE_MONO_CTX
 494                         mword w = ((mword*)&info->ctx) [j];
 495 #else
 496                         mword w = (mword)&info->regs [j];
 497 #endif
 498
 499                         if (w >= (mword)obj && w < (mword)obj + size)
 500                                 SGEN_LOG (0, "Object %p referenced in saved reg %d of thread %p (id %p)", obj, j, info, (gpointer)mono_thread_info_get_tid (info));
 501                 } END_FOREACH_THREAD
 502         }
 503 }
 504
 505 /*
 506  * Debugging function: find in the conservative roots where @obj is being pinned.
 507  */
 508 static G_GNUC_UNUSED void
 509 find_pinning_reference (char *obj, size_t size)
 510 {
 511         char **start;
 512         RootRecord *root;
 513         char *endobj = obj + size;
 514
 515         SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_NORMAL], start, root) {
 516                 /* if desc is non-null it has precise info */
 517                 if (!root->root_desc) {
 518                         while (start < (char**)root->end_root) {
 519                                 if (*start >= obj && *start < endobj) {
 520                                         SGEN_LOG (0, "Object %p referenced in pinned roots %p-%p\n", obj, start, root->end_root);
 521                                 }
 522                                 start++;
 523                         }
 524                 }
 525         } SGEN_HASH_TABLE_FOREACH_END;
 526
 527         find_pinning_ref_from_thread (obj, size);
 528 }
 529
 530 #undef HANDLE_PTR
 531 #define HANDLE_PTR(ptr,obj)     do {                                    \
 532                 char* __target = *(char**)ptr;                          \
 533                 if (__target) {                                         \
 534                         g_assert (is_valid_object_pointer (__target));  \
 535                         if (sgen_ptr_in_nursery (__target)) {           \
 536                                 g_assert (SGEN_OBJECT_IS_PINNED (__target)); \
 537                         } else if (sgen_los_is_valid_object (__target)) { \
 538                                 g_assert (sgen_los_object_is_pinned (__target)); \
 539                         } else if (major_collector.is_valid_object (__target)) { \
 540                                 g_assert (major_collector.is_object_live (__target)); \
 541                         } else {                                        \
 542                                 g_assert_not_reached ();                \
 543                         }                                               \
 544                 }                                                       \
 545         } while (0)
 546
 547 static void
 548 check_marked_callback (char *start, size_t size, void *dummy)
 549 {
 550         gboolean is_los = (gboolean) (size_t) dummy;
 551
 552         if (is_los) {
 553                 if (!sgen_los_object_is_pinned (start))
 554                         return;
 555         } else {
 556                 if (!major_collector.is_object_live (start))
 557                         return;
 558         }
 559
 560 #include "sgen-scan-object.h"
 561 }
 562
 563 void
 564 sgen_check_major_heap_marked (void)
 565 {
 566         setup_valid_nursery_objects ();
 567
 568         major_collector.iterate_objects (ITERATE_OBJECTS_SWEEP_ALL, check_marked_callback, (void*)FALSE);
 569         sgen_los_iterate_objects (check_marked_callback, (void*)TRUE);
 570 }
 571
 572 static void
 573 check_nursery_objects_pinned_callback (char *obj, size_t size, void *data /* ScanCopyContext *ctx */)
 574 {
 575         gboolean pinned = (gboolean) (size_t) data;
 576
 577         g_assert (!SGEN_OBJECT_IS_FORWARDED (obj));
 578         if (pinned)
 579                 g_assert (SGEN_OBJECT_IS_PINNED (obj));
 580         else
 581                 g_assert (!SGEN_OBJECT_IS_PINNED (obj));
 582 }
 583
 584 void
 585 sgen_check_nursery_objects_pinned (gboolean pinned)
 586 {
 587         sgen_clear_nursery_fragments ();
 588         sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
 589                         (IterateObjectCallbackFunc)check_nursery_objects_pinned_callback, (void*) (size_t) pinned /* (void*)&ctx */, FALSE);
 590 }
 591
 592 static gboolean scan_object_for_specific_ref_precise = TRUE;
 593
 594 #undef HANDLE_PTR
 595 #define HANDLE_PTR(ptr,obj) do {                \
 596         if ((MonoObject*)*(ptr) == key) {       \
 597         g_print ("found ref to %p in object %p (%s) at offset %td\n",   \
 598                         key, (obj), sgen_safe_name ((obj)), ((char*)(ptr) - (char*)(obj))); \
 599         }                                                               \
 600         } while (0)
 601
 602 static void
 603 scan_object_for_specific_ref (char *start, MonoObject *key)
 604 {
 605         char *forwarded;
 606
 607         if ((forwarded = SGEN_OBJECT_IS_FORWARDED (start)))
 608                 start = forwarded;
 609
 610         if (scan_object_for_specific_ref_precise) {
 611                 #include "sgen-scan-object.h"
 612         } else {
 613                 mword *words = (mword*)start;
 614                 size_t size = safe_object_get_size ((MonoObject*)start);
 615                 int i;
 616                 for (i = 0; i < size / sizeof (mword); ++i) {
 617                         if (words [i] == (mword)key) {
 618                                 g_print ("found possible ref to %p in object %p (%s) at offset %td\n",
 619                                                 key, start, sgen_safe_name (start), i * sizeof (mword));
 620                         }
 621                 }
 622         }
 623 }
 624
 625 static void
 626 scan_object_for_specific_ref_callback (char *obj, size_t size, MonoObject *key)
 627 {
 628         scan_object_for_specific_ref (obj, key);
 629 }
 630
 631 static void
 632 check_root_obj_specific_ref (RootRecord *root, MonoObject *key, MonoObject *obj)
 633 {
 634         if (key != obj)
 635                 return;
 636         g_print ("found ref to %p in root record %p\n", key, root);
 637 }
 638
 639 static MonoObject *check_key = NULL;
 640 static RootRecord *check_root = NULL;
 641
 642 static void
 643 check_root_obj_specific_ref_from_marker (void **obj)
 644 {
 645         check_root_obj_specific_ref (check_root, check_key, *obj);
 646 }
 647
 648 static void
 649 scan_roots_for_specific_ref (MonoObject *key, int root_type)
 650 {
 651         void **start_root;
 652         RootRecord *root;
 653         check_key = key;
 654
 655         SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
 656                 mword desc = root->root_desc;
 657
 658                 check_root = root;
 659
 660                 switch (desc & ROOT_DESC_TYPE_MASK) {
 661                 case ROOT_DESC_BITMAP:
 662                         desc >>= ROOT_DESC_TYPE_SHIFT;
 663                         while (desc) {
 664                                 if (desc & 1)
 665                                         check_root_obj_specific_ref (root, key, *start_root);
 666                                 desc >>= 1;
 667                                 start_root++;
 668                         }
 669                         return;
 670                 case ROOT_DESC_COMPLEX: {
 671                         gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
 672                         int bwords = (int) ((*bitmap_data) - 1);
 673                         void **start_run = start_root;
 674                         bitmap_data++;
 675                         while (bwords-- > 0) {
 676                                 gsize bmap = *bitmap_data++;
 677                                 void **objptr = start_run;
 678                                 while (bmap) {
 679                                         if (bmap & 1)
 680                                                 check_root_obj_specific_ref (root, key, *objptr);
 681                                         bmap >>= 1;
 682                                         ++objptr;
 683                                 }
 684                                 start_run += GC_BITS_PER_WORD;
 685                         }
 686                         break;
 687                 }
 688                 case ROOT_DESC_USER: {
 689                         MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
 690                         marker (start_root, check_root_obj_specific_ref_from_marker);
 691                         break;
 692                 }
 693                 case ROOT_DESC_RUN_LEN:
 694                         g_assert_not_reached ();
 695                 default:
 696                         g_assert_not_reached ();
 697                 }
 698         } SGEN_HASH_TABLE_FOREACH_END;
 699
 700         check_key = NULL;
 701         check_root = NULL;
 702 }
 703
 704 void
 705 mono_gc_scan_for_specific_ref (MonoObject *key, gboolean precise)
 706 {
 707         void **ptr;
 708         RootRecord *root;
 709
 710         scan_object_for_specific_ref_precise = precise;
 711
 712         sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
 713                         (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key, TRUE);
 714
 715         major_collector.iterate_objects (ITERATE_OBJECTS_SWEEP_ALL, (IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
 716
 717         sgen_los_iterate_objects ((IterateObjectCallbackFunc)scan_object_for_specific_ref_callback, key);
 718
 719         scan_roots_for_specific_ref (key, ROOT_TYPE_NORMAL);
 720         scan_roots_for_specific_ref (key, ROOT_TYPE_WBARRIER);
 721
 722         SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_PINNED], ptr, root) {
 723                 while (ptr < (void**)root->end_root) {
 724                         check_root_obj_specific_ref (root, *ptr, key);
 725                         ++ptr;
 726                 }
 727         } SGEN_HASH_TABLE_FOREACH_END;
 728 }
 729
 730 static MonoDomain *check_domain = NULL;
 731
 732 static void
 733 check_obj_not_in_domain (void **o)
 734 {
 735         g_assert (((MonoObject*)(*o))->vtable->domain != check_domain);
 736 }
 737
 738 void
 739 sgen_scan_for_registered_roots_in_domain (MonoDomain *domain, int root_type)
 740 {
 741         void **start_root;
 742         RootRecord *root;
 743         check_domain = domain;
 744         SGEN_HASH_TABLE_FOREACH (&roots_hash [root_type], start_root, root) {
 745                 mword desc = root->root_desc;
 746
 747                 /* The MonoDomain struct is allowed to hold
 748                    references to objects in its own domain. */
 749                 if (start_root == (void**)domain)
 750                         continue;
 751
 752                 switch (desc & ROOT_DESC_TYPE_MASK) {
 753                 case ROOT_DESC_BITMAP:
 754                         desc >>= ROOT_DESC_TYPE_SHIFT;
 755                         while (desc) {
 756                                 if ((desc & 1) && *start_root)
 757                                         check_obj_not_in_domain (*start_root);
 758                                 desc >>= 1;
 759                                 start_root++;
 760                         }
 761                         break;
 762                 case ROOT_DESC_COMPLEX: {
 763                         gsize *bitmap_data = sgen_get_complex_descriptor_bitmap (desc);
 764                         int bwords = (int)((*bitmap_data) - 1);
 765                         void **start_run = start_root;
 766                         bitmap_data++;
 767                         while (bwords-- > 0) {
 768                                 gsize bmap = *bitmap_data++;
 769                                 void **objptr = start_run;
 770                                 while (bmap) {
 771                                         if ((bmap & 1) && *objptr)
 772                                                 check_obj_not_in_domain (*objptr);
 773                                         bmap >>= 1;
 774                                         ++objptr;
 775                                 }
 776                                 start_run += GC_BITS_PER_WORD;
 777                         }
 778                         break;
 779                 }
 780                 case ROOT_DESC_USER: {
 781                         MonoGCRootMarkFunc marker = sgen_get_user_descriptor_func (desc);
 782                         marker (start_root, check_obj_not_in_domain);
 783                         break;
 784                 }
 785                 case ROOT_DESC_RUN_LEN:
 786                         g_assert_not_reached ();
 787                 default:
 788                         g_assert_not_reached ();
 789                 }
 790         } SGEN_HASH_TABLE_FOREACH_END;
 791
 792         check_domain = NULL;
 793 }
 794
 795 static gboolean
 796 is_xdomain_ref_allowed (gpointer *ptr, char *obj, MonoDomain *domain)
 797 {
 798         MonoObject *o = (MonoObject*)(obj);
 799         MonoObject *ref = (MonoObject*)*(ptr);
 800         size_t offset = (char*)(ptr) - (char*)o;
 801
 802         if (o->vtable->klass == mono_defaults.thread_class && offset == G_STRUCT_OFFSET (MonoThread, internal_thread))
 803                 return TRUE;
 804         if (o->vtable->klass == mono_defaults.internal_thread_class && offset == G_STRUCT_OFFSET (MonoInternalThread, current_appcontext))
 805                 return TRUE;
 806
 807 #ifndef DISABLE_REMOTING
 808         if (mono_defaults.real_proxy_class->supertypes && mono_class_has_parent_fast (o->vtable->klass, mono_defaults.real_proxy_class) &&
 809                         offset == G_STRUCT_OFFSET (MonoRealProxy, unwrapped_server))
 810                 return TRUE;
 811 #endif
 812         /* Thread.cached_culture_info */
 813         if (!strcmp (ref->vtable->klass->name_space, "System.Globalization") &&
 814                         !strcmp (ref->vtable->klass->name, "CultureInfo") &&
 815                         !strcmp(o->vtable->klass->name_space, "System") &&
 816                         !strcmp(o->vtable->klass->name, "Object[]"))
 817                 return TRUE;
 818         /*
 819          *  at System.IO.MemoryStream.InternalConstructor (byte[],int,int,bool,bool) [0x0004d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:121
 820          * at System.IO.MemoryStream..ctor (byte[]) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.IO/MemoryStream.cs:81
 821          * at (wrapper remoting-invoke-with-check) System.IO.MemoryStream..ctor (byte[]) <IL 0x00020, 0xffffffff>
 822          * at System.Runtime.Remoting.Messaging.CADMethodCallMessage.GetArguments () [0x0000d] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/CADMessages.cs:327
 823          * at System.Runtime.Remoting.Messaging.MethodCall..ctor (System.Runtime.Remoting.Messaging.CADMethodCallMessage) [0x00017] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Messaging/MethodCall.cs:87
 824          * at System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) [0x00018] in /home/schani/Work/novell/trunk/mcs/class/corlib/System/AppDomain.cs:1213
 825          * at (wrapper remoting-invoke-with-check) System.AppDomain.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage,byte[]&,System.Runtime.Remoting.Messaging.CADMethodReturnMessage&) <IL 0x0003d, 0xffffffff>
 826          * at System.Runtime.Remoting.Channels.CrossAppDomainSink.ProcessMessageInDomain (byte[],System.Runtime.Remoting.Messaging.CADMethodCallMessage) [0x00008] in /home/schani/Work/novell/trunk/mcs/class/corlib/System.Runtime.Remoting.Channels/CrossAppDomainChannel.cs:198
 827          * at (wrapper runtime-invoke) object.runtime_invoke_CrossAppDomainSink/ProcessMessageRes_object_object (object,intptr,intptr,intptr) <IL 0x0004c, 0xffffffff>
 828          */
 829         if (!strcmp (ref->vtable->klass->name_space, "System") &&
 830                         !strcmp (ref->vtable->klass->name, "Byte[]") &&
 831                         !strcmp (o->vtable->klass->name_space, "System.IO") &&
 832                         !strcmp (o->vtable->klass->name, "MemoryStream"))
 833                 return TRUE;
 834         /* append_job() in threadpool.c */
 835         if (!strcmp (ref->vtable->klass->name_space, "System.Runtime.Remoting.Messaging") &&
 836                         !strcmp (ref->vtable->klass->name, "AsyncResult") &&
 837                         !strcmp (o->vtable->klass->name_space, "System") &&
 838                         !strcmp (o->vtable->klass->name, "Object[]") &&
 839                         mono_thread_pool_is_queue_array ((MonoArray*) o))
 840                 return TRUE;
 841         return FALSE;
 842 }
 843
 844 static void
 845 check_reference_for_xdomain (gpointer *ptr, char *obj, MonoDomain *domain)
 846 {
 847         MonoObject *o = (MonoObject*)(obj);
 848         MonoObject *ref = (MonoObject*)*(ptr);
 849         size_t offset = (char*)(ptr) - (char*)o;
 850         MonoClass *class;
 851         MonoClassField *field;
 852         char *str;
 853
 854         if (!ref || ref->vtable->domain == domain)
 855                 return;
 856         if (is_xdomain_ref_allowed (ptr, obj, domain))
 857                 return;
 858
 859         field = NULL;
 860         for (class = o->vtable->klass; class; class = class->parent) {
 861                 int i;
 862
 863                 for (i = 0; i < class->field.count; ++i) {
 864                         if (class->fields[i].offset == offset) {
 865                                 field = &class->fields[i];
 866                                 break;
 867                         }
 868                 }
 869                 if (field)
 870                         break;
 871         }
 872
 873         if (ref->vtable->klass == mono_defaults.string_class)
 874                 str = mono_string_to_utf8 ((MonoString*)ref);
 875         else
 876                 str = NULL;
 877         g_print ("xdomain reference in %p (%s.%s) at offset %d (%s) to %p (%s.%s) (%s)  -  pointed to by:\n",
 878                         o, o->vtable->klass->name_space, o->vtable->klass->name,
 879                         offset, field ? field->name : "",
 880                         ref, ref->vtable->klass->name_space, ref->vtable->klass->name, str ? str : "");
 881         mono_gc_scan_for_specific_ref (o, TRUE);
 882         if (str)
 883                 g_free (str);
 884 }
 885
 886 #undef HANDLE_PTR
 887 #define HANDLE_PTR(ptr,obj)     check_reference_for_xdomain ((ptr), (obj), domain)
 888
 889 static void
 890 scan_object_for_xdomain_refs (char *start, mword size, void *data)
 891 {
 892         MonoDomain *domain = ((MonoObject*)start)->vtable->domain;
 893
 894         #include "sgen-scan-object.h"
 895 }
 896
 897 void
 898 sgen_check_for_xdomain_refs (void)
 899 {
 900         LOSObject *bigobj;
 901
 902         sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data,
 903                         (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL, FALSE);
 904
 905         major_collector.iterate_objects (ITERATE_OBJECTS_SWEEP_ALL, (IterateObjectCallbackFunc)scan_object_for_xdomain_refs, NULL);
 906
 907         for (bigobj = los_object_list; bigobj; bigobj = bigobj->next)
 908                 scan_object_for_xdomain_refs (bigobj->data, sgen_los_object_size (bigobj), NULL);
 909 }
 910
 911 static int
 912 compare_xrefs (const void *a_ptr, const void *b_ptr)
 913 {
 914         const MonoGCBridgeXRef *a = a_ptr;
 915         const MonoGCBridgeXRef *b = b_ptr;
 916
 917         if (a->src_scc_index < b->src_scc_index)
 918                 return -1;
 919         if (a->src_scc_index > b->src_scc_index)
 920                 return 1;
 921
 922         if (a->dst_scc_index < b->dst_scc_index)
 923                 return -1;
 924         if (a->dst_scc_index > b->dst_scc_index)
 925                 return 1;
 926
 927         return 0;
 928 }
 929
 930 /*
 931 static void
 932 dump_processor_state (SgenBridgeProcessor *p)
 933 {
 934         int i;
 935
 936         printf ("------\n");
 937         printf ("SCCS %d\n", p->num_sccs);
 938         for (i = 0; i < p->num_sccs; ++i) {
 939                 int j;
 940                 MonoGCBridgeSCC *scc = p->api_sccs [i];
 941                 printf ("\tSCC %d:", i);
 942                 for (j = 0; j < scc->num_objs; ++j) {
 943                         MonoObject *obj = scc->objs [j];
 944                         printf (" %p", obj);
 945                 }
 946                 printf ("\n");
 947         }
 948
 949         printf ("XREFS %d\n", p->num_xrefs);
 950         for (i = 0; i < p->num_xrefs; ++i)
 951                 printf ("\t%d -> %d\n", p->api_xrefs [i].src_scc_index, p->api_xrefs [i].dst_scc_index);
 952
 953         printf ("-------\n");
 954 }
 955 */
 956
 957 gboolean
 958 sgen_compare_bridge_processor_results (SgenBridgeProcessor *a, SgenBridgeProcessor *b)
 959 {
 960         int i;
 961         SgenHashTable obj_to_a_scc = SGEN_HASH_TABLE_INIT (INTERNAL_MEM_BRIDGE_DEBUG, INTERNAL_MEM_BRIDGE_DEBUG, sizeof (int), mono_aligned_addr_hash, NULL);
 962         SgenHashTable b_scc_to_a_scc = SGEN_HASH_TABLE_INIT (INTERNAL_MEM_BRIDGE_DEBUG, INTERNAL_MEM_BRIDGE_DEBUG, sizeof (int), g_direct_hash, NULL);
 963         MonoGCBridgeXRef *a_xrefs, *b_xrefs;
 964         size_t xrefs_alloc_size;
 965
 966         // dump_processor_state (a);
 967         // dump_processor_state (b);
 968
 969         if (a->num_sccs != b->num_sccs)
 970                 g_error ("SCCS count expected %d but got %d", a->num_sccs, b->num_sccs);
 971         if (a->num_xrefs != b->num_xrefs)
 972                 g_error ("SCCS count expected %d but got %d", a->num_xrefs, b->num_xrefs);
 973
 974         /*
 975          * First we build a hash of each object in `a` to its respective SCC index within
 976          * `a`.  Along the way we also assert that no object is more than one SCC.
 977          */
 978         for (i = 0; i < a->num_sccs; ++i) {
 979                 int j;
 980                 MonoGCBridgeSCC *scc = a->api_sccs [i];
 981
 982                 g_assert (scc->num_objs > 0);
 983
 984                 for (j = 0; j < scc->num_objs; ++j) {
 985                         MonoObject *obj = scc->objs [j];
 986                         gboolean new_entry = sgen_hash_table_replace (&obj_to_a_scc, obj, &i, NULL);
 987                         g_assert (new_entry);
 988                 }
 989         }
 990
 991         /*
 992          * Now we check whether each of the objects in `b` are in `a`, and whether the SCCs
 993          * of `b` contain the same sets of objects as those of `a`.
 994          *
 995          * While we're doing this, build a hash table to map from `b` SCC indexes to `a` SCC
 996          * indexes.
 997          */
 998         for (i = 0; i < b->num_sccs; ++i) {
 999                 MonoGCBridgeSCC *scc = b->api_sccs [i];
1000                 MonoGCBridgeSCC *a_scc;
1001                 int *a_scc_index_ptr;
1002                 int a_scc_index;
1003                 int j;
1004                 gboolean new_entry;
1005
1006                 g_assert (scc->num_objs > 0);
1007                 a_scc_index_ptr = sgen_hash_table_lookup (&obj_to_a_scc, scc->objs [0]);
1008                 g_assert (a_scc_index_ptr);
1009                 a_scc_index = *a_scc_index_ptr;
1010
1011                 //g_print ("A SCC %d -> B SCC %d\n", a_scc_index, i);
1012
1013                 a_scc = a->api_sccs [a_scc_index];
1014                 g_assert (a_scc->num_objs == scc->num_objs);
1015
1016                 for (j = 1; j < scc->num_objs; ++j) {
1017                         a_scc_index_ptr = sgen_hash_table_lookup (&obj_to_a_scc, scc->objs [j]);
1018                         g_assert (a_scc_index_ptr);
1019                         g_assert (*a_scc_index_ptr == a_scc_index);
1020                 }
1021
1022                 new_entry = sgen_hash_table_replace (&b_scc_to_a_scc, GINT_TO_POINTER (i), &a_scc_index, NULL);
1023                 g_assert (new_entry);
1024         }
1025
1026         /*
1027          * Finally, check that we have the same xrefs.  We do this by making copies of both
1028          * xref arrays, and replacing the SCC indexes in the copy for `b` with the
1029          * corresponding indexes in `a`.  Then we sort both arrays and assert that they're
1030          * the same.
1031          *
1032          * At the same time, check that no xref is self-referential and that there are no
1033          * duplicate ones.
1034          */
1035
1036         xrefs_alloc_size = a->num_xrefs * sizeof (MonoGCBridgeXRef);
1037         a_xrefs = sgen_alloc_internal_dynamic (xrefs_alloc_size, INTERNAL_MEM_BRIDGE_DEBUG, TRUE);
1038         b_xrefs = sgen_alloc_internal_dynamic (xrefs_alloc_size, INTERNAL_MEM_BRIDGE_DEBUG, TRUE);
1039
1040         memcpy (a_xrefs, a->api_xrefs, xrefs_alloc_size);
1041         for (i = 0; i < b->num_xrefs; ++i) {
1042                 MonoGCBridgeXRef *xref = &b->api_xrefs [i];
1043                 int *scc_index_ptr;
1044
1045                 g_assert (xref->src_scc_index != xref->dst_scc_index);
1046
1047                 scc_index_ptr = sgen_hash_table_lookup (&b_scc_to_a_scc, GINT_TO_POINTER (xref->src_scc_index));
1048                 g_assert (scc_index_ptr);
1049                 b_xrefs [i].src_scc_index = *scc_index_ptr;
1050
1051                 scc_index_ptr = sgen_hash_table_lookup (&b_scc_to_a_scc, GINT_TO_POINTER (xref->dst_scc_index));
1052                 g_assert (scc_index_ptr);
1053                 b_xrefs [i].dst_scc_index = *scc_index_ptr;
1054         }
1055
1056         qsort (a_xrefs, a->num_xrefs, sizeof (MonoGCBridgeXRef), compare_xrefs);
1057         qsort (b_xrefs, a->num_xrefs, sizeof (MonoGCBridgeXRef), compare_xrefs);
1058
1059         for (i = 0; i < a->num_xrefs; ++i) {
1060                 g_assert (a_xrefs [i].src_scc_index == b_xrefs [i].src_scc_index);
1061                 g_assert (a_xrefs [i].dst_scc_index == b_xrefs [i].dst_scc_index);
1062         }
1063
1064         sgen_hash_table_clean (&obj_to_a_scc);
1065         sgen_hash_table_clean (&b_scc_to_a_scc);
1066         sgen_free_internal_dynamic (a_xrefs, xrefs_alloc_size, INTERNAL_MEM_BRIDGE_DEBUG);
1067         sgen_free_internal_dynamic (b_xrefs, xrefs_alloc_size, INTERNAL_MEM_BRIDGE_DEBUG);
1068
1069         return TRUE;
1070 }
1071
1072 #endif /*HAVE_SGEN_GC*/