2 * sgen-debug.c: Collector debugging
5 * Paolo Molaro (lupus@ximian.com)
6 * Rodrigo Kumpera (kumpera@gmail.com)
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
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;
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.
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.
30 #include "metadata/sgen-gc.h"
31 #include "metadata/sgen-cardtable.h"
32 #include "metadata/sgen-ssb.h"
33 #include "metadata/sgen-protocol.h"
34 #include "metadata/sgen-memory-governor.h"
36 #define LOAD_VTABLE SGEN_LOAD_VTABLE
38 #define object_is_forwarded SGEN_OBJECT_IS_FORWARDED
39 #define object_is_pinned SGEN_OBJECT_IS_PINNED
40 #define safe_object_get_size sgen_safe_object_get_size
42 void describe_ptr (char *ptr);
43 void check_object (char *start);
46 * ######################################################################
47 * ######## Collector debugging
48 * ######################################################################
51 const char*descriptor_types [] = {
63 describe_ptr (char *ptr)
72 if (sgen_ptr_in_nursery (ptr)) {
73 printf ("Pointer inside nursery.\n");
75 if (sgen_ptr_is_in_los (ptr, &start)) {
77 printf ("Pointer is the start of object %p in LOS space.\n", start);
79 printf ("Pointer is at offset 0x%x of object %p in LOS space.\n", (int)(ptr - start), start);
81 } else if (major_collector.ptr_is_in_non_pinned_space (ptr, &start)) {
83 printf ("Pointer is the start of object %p in oldspace.\n", start);
85 printf ("Pointer is at offset 0x%x of object %p in oldspace.\n", (int)(ptr - start), start);
87 printf ("Pointer inside oldspace.\n");
90 } else if (major_collector.obj_is_from_pinned_alloc (ptr)) {
91 printf ("Pointer is inside a pinned chunk.\n");
93 printf ("Pointer unknown.\n");
98 if (object_is_pinned (ptr))
99 printf ("Object is pinned.\n");
101 if ((forwarded = object_is_forwarded (ptr))) {
102 printf ("Object is forwarded to %p:\n", forwarded);
107 // FIXME: Handle pointers to the inside of objects
108 vtable = (MonoVTable*)LOAD_VTABLE (ptr);
110 printf ("VTable: %p\n", vtable);
111 if (vtable == NULL) {
112 printf ("VTable is invalid (empty).\n");
115 if (sgen_ptr_in_nursery (vtable)) {
116 printf ("VTable is invalid (points inside nursery).\n");
119 printf ("Class: %s\n", vtable->klass->name);
121 desc = ((GCVTable*)vtable)->desc;
122 printf ("Descriptor: %lx\n", (long)desc);
125 printf ("Descriptor type: %d (%s)\n", type, descriptor_types [type]);
128 static gboolean missing_remsets;
131 * We let a missing remset slide if the target object is pinned,
132 * because the store might have happened but the remset not yet added,
133 * but in that case the target must be pinned. We might theoretically
134 * miss some missing remsets this way, but it's very unlikely.
137 #define HANDLE_PTR(ptr,obj) do { \
138 if (*(ptr) && sgen_ptr_in_nursery ((char*)*(ptr))) { \
139 if (!sgen_get_remset ()->find_address ((char*)(ptr))) { \
140 SGEN_LOG (1, "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); \
141 binary_protocol_missing_remset ((obj), (gpointer)LOAD_VTABLE ((obj)), (char*)(ptr) - (char*)(obj), *(ptr), (gpointer)LOAD_VTABLE(*(ptr)), object_is_pinned (*(ptr))); \
142 if (!object_is_pinned (*(ptr))) \
143 missing_remsets = TRUE; \
149 * Check that each object reference which points into the nursery can
150 * be found in the remembered sets.
153 check_consistency_callback (char *start, size_t size, void *dummy)
155 GCVTable *vt = (GCVTable*)LOAD_VTABLE (start);
156 SGEN_LOG (8, "Scanning object %p, vtable: %p (%s)", start, vt, vt->klass->name);
158 #define SCAN_OBJECT_ACTION
159 #include "sgen-scan-object.h"
163 * Perform consistency check of the heap.
165 * Assumes the world is stopped.
168 sgen_check_consistency (void)
170 // Need to add more checks
172 missing_remsets = FALSE;
174 SGEN_LOG (1, "Begin heap consistency check...");
176 // Check that oldspace->newspace pointers are registered with the collector
177 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)check_consistency_callback, NULL);
179 sgen_los_iterate_objects ((IterateObjectCallbackFunc)check_consistency_callback, NULL);
181 SGEN_LOG (1, "Heap consistency check done.");
183 if (!binary_protocol_is_enabled ())
184 g_assert (!missing_remsets);
189 #define HANDLE_PTR(ptr,obj) do { \
190 if (*(ptr) && !LOAD_VTABLE (*(ptr))) \
191 g_error ("Could not load vtable for obj %p slot %d (size %d)", obj, (char*)ptr - (char*)obj, safe_object_get_size ((MonoObject*)obj)); \
195 check_major_refs_callback (char *start, size_t size, void *dummy)
197 #define SCAN_OBJECT_ACTION
198 #include "sgen-scan-object.h"
202 sgen_check_major_refs (void)
204 major_collector.iterate_objects (TRUE, TRUE, (IterateObjectCallbackFunc)check_major_refs_callback, NULL);
205 sgen_los_iterate_objects ((IterateObjectCallbackFunc)check_major_refs_callback, NULL);
208 /* Check that the reference is valid */
210 #define HANDLE_PTR(ptr,obj) do { \
212 g_assert (sgen_safe_name (*(ptr)) != NULL); \
219 * Perform consistency check on an object. Currently we only check that the
220 * reference fields are valid.
223 check_object (char *start)
228 #include "sgen-scan-object.h"
232 static char **valid_nursery_objects;
233 static int valid_nursery_object_count;
234 static gboolean broken_heap;
237 setup_mono_sgen_scan_area_with_callback (char *object, size_t size, void *data)
239 valid_nursery_objects [valid_nursery_object_count++] = object;
243 find_object_in_nursery_dump (char *object)
245 int first = 0, last = valid_nursery_object_count;
246 while (first < last) {
247 int middle = first + ((last - first) >> 1);
248 if (object == valid_nursery_objects [middle])
251 if (object < valid_nursery_objects [middle])
256 g_assert (first == last);
261 describe_nursery_ptr (char *ptr)
265 for (i = 0; i < valid_nursery_object_count; ++i) {
266 if (valid_nursery_objects [i] >= ptr)
270 if (i >= valid_nursery_object_count || valid_nursery_objects [i] + safe_object_get_size ((MonoObject *)valid_nursery_objects [i]) < ptr) {
271 SGEN_LOG (1, "nursery-ptr (unalloc'd-memory)");
273 char *obj = valid_nursery_objects [i];
274 MonoVTable *vtable = (MonoVTable*)LOAD_VTABLE (obj);
275 int size = safe_object_get_size ((MonoObject *)obj);
278 SGEN_LOG (1, "nursery-ptr (object %s.%s size %d)",
279 vtable->klass->name_space, vtable->klass->name, size);
281 SGEN_LOG (1, "nursery-ptr (interior-ptr offset %td of %p (%s.%s) size %d)",
283 vtable->klass->name_space, vtable->klass->name, size);
288 is_valid_object_pointer (char *object)
290 if (sgen_ptr_in_nursery (object))
291 return find_object_in_nursery_dump (object);
293 if (sgen_los_is_valid_object (object))
296 if (major_collector.is_valid_object (object))
303 describe_pointer (char *ptr)
305 if (sgen_ptr_in_nursery (ptr)) {
306 describe_nursery_ptr (ptr);
307 } else if (major_collector.describe_pointer (ptr)) {
309 } else if (!mono_sgen_los_describe_pointer (ptr)) {
310 SGEN_LOG (1, "\tnon-heap-ptr");
315 bad_pointer_spew (char *obj, char **slot)
318 MonoVTable *vtable = (MonoVTable*)LOAD_VTABLE (obj);
320 SGEN_LOG (1, "Invalid object pointer %p at offset %td in object %p (%s.%s):", ptr,
322 obj, vtable->klass->name_space, vtable->klass->name);
323 describe_pointer (ptr);
328 missing_remset_spew (char *obj, char **slot)
331 MonoVTable *vtable = (MonoVTable*)LOAD_VTABLE (obj);
333 SGEN_LOG (1, "Oldspace->newspace reference %p at offset %td in object %p (%s.%s) not found in remsets.",
334 ptr, (char*)slot - obj, obj,
335 vtable->klass->name_space, vtable->klass->name);
341 FIXME Flag missing remsets due to pinning as non fatal
344 #define HANDLE_PTR(ptr,obj) do { \
345 if (*(char**)ptr) { \
346 if (!is_valid_object_pointer (*(char**)ptr)) { \
347 bad_pointer_spew ((char*)obj, (char**)ptr); \
348 } else if (!sgen_ptr_in_nursery (obj) && sgen_ptr_in_nursery ((char*)*ptr)) { \
349 if (!sgen_get_remset ()->find_address ((char*)(ptr))) \
350 missing_remset_spew ((char*)obj, (char**)ptr); \
356 verify_object_pointers_callback (char *start, size_t size, void *dummy)
358 #define SCAN_OBJECT_ACTION
359 #include "sgen-scan-object.h"
364 -This heap checker is racy regarding inlined write barriers and other JIT tricks that
365 depend on OP_DUMMY_USE.
368 sgen_check_whole_heap (void)
370 /*setup valid_nursery_objects*/
371 if (!valid_nursery_objects)
372 valid_nursery_objects = sgen_alloc_os_memory (DEFAULT_NURSERY_SIZE, SGEN_ALLOC_INTERNAL | SGEN_ALLOC_ACTIVATE, "debugging data");
373 valid_nursery_object_count = 0;
374 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, setup_mono_sgen_scan_area_with_callback, NULL, FALSE);
377 sgen_scan_area_with_callback (nursery_section->data, nursery_section->end_data, verify_object_pointers_callback, NULL, FALSE);
378 major_collector.iterate_objects (TRUE, TRUE, verify_object_pointers_callback, NULL);
379 sgen_los_iterate_objects (verify_object_pointers_callback, NULL);
381 g_assert (!broken_heap);
385 ptr_in_heap (char *object)
387 if (sgen_ptr_in_nursery (object))
390 if (sgen_los_is_valid_object (object))
393 if (major_collector.is_valid_object (object))
400 * Do consistency checks on the object reference OBJ. Assert on failure.
403 sgen_check_objref (char *obj)
405 g_assert (ptr_in_heap (obj));
409 find_pinning_ref_from_thread (char *obj, size_t size)
412 SgenThreadInfo *info;
413 char *endobj = obj + size;
415 FOREACH_THREAD (info) {
416 char **start = (char**)info->stack_start;
419 while (start < (char**)info->stack_end) {
420 if (*start >= obj && *start < endobj) {
421 SGEN_LOG (1, "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);
426 for (j = 0; j < ARCH_NUM_REGS; ++j) {
428 mword w = ((mword*)&info->ctx) [j];
430 mword w = (mword)&info->regs [j];
433 if (w >= (mword)obj && w < (mword)obj + size)
434 SGEN_LOG (1, "Object %p referenced in saved reg %d of thread %p (id %p)", obj, j, info, (gpointer)mono_thread_info_get_tid (info));
440 * Debugging function: find in the conservative roots where @obj is being pinned.
442 static G_GNUC_UNUSED void
443 find_pinning_reference (char *obj, size_t size)
447 char *endobj = obj + size;
449 SGEN_HASH_TABLE_FOREACH (&roots_hash [ROOT_TYPE_NORMAL], start, root) {
450 /* if desc is non-null it has precise info */
451 if (!root->root_desc) {
452 while (start < (char**)root->end_root) {
453 if (*start >= obj && *start < endobj) {
454 SGEN_LOG (1, "Object %p referenced in pinned roots %p-%p\n", obj, start, root->end_root);
459 } SGEN_HASH_TABLE_FOREACH_END;
461 find_pinning_ref_from_thread (obj, size);
464 #endif /*HAVE_SGEN_GC*/