1 /*
2 * Copyright (c) 2018, Red Hat, Inc. All rights reserved.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This code is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 * version 2 for more details (a copy is included in the LICENSE file that
12 * accompanied this code).
13 *
14 * You should have received a copy of the GNU General Public License version
15 * 2 along with this work; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 * or visit www.oracle.com if you need additional information or have any
20 * questions.
21 *
22 */
23
24 #include "precompiled.hpp"
25
26 #include "gc/shenandoah/shenandoahAsserts.hpp"
27 #include "gc/shenandoah/shenandoahBrooksPointer.hpp"
28 #include "gc/shenandoah/shenandoahHeap.hpp"
29 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
30 #include "gc/shenandoah/shenandoahHeapRegionSet.inline.hpp"
31 #include "gc/shenandoah/shenandoahMarkingContext.inline.hpp"
32 #include "gc/shenandoah/shenandoahTraversalGC.hpp"
33 #include "gc/shenandoah/shenandoahUtils.hpp"
34 #include "memory/resourceArea.hpp"
35
36 void print_raw_memory(ShenandoahMessageBuffer &msg, void* loc) {
37 // Be extra safe. Only access data that is guaranteed to be safe:
38 // should be in heap, in known committed region, within that region.
39
40 ShenandoahHeap* heap = ShenandoahHeap::heap();
41 if (!heap->is_in(loc)) return;
42
43 ShenandoahHeapRegion* r = heap->heap_region_containing(loc);
44 if (r != NULL && r->is_committed()) {
45 address start = MAX2((address) r->bottom(), (address) loc - 32);
46 address end = MIN2((address) r->end(), (address) loc + 128);
47 if (start >= end) return;
48
49 stringStream ss;
50 os::print_hex_dump(&ss, start, end, 4);
51 msg.append("\n");
52 msg.append("Raw heap memory:\n%s", ss.as_string());
53 }
54 }
55
56 void ShenandoahAsserts::print_obj(ShenandoahMessageBuffer& msg, oop obj) {
57 ShenandoahHeap* heap = ShenandoahHeap::heap();
58 ShenandoahHeapRegion *r = heap->heap_region_containing(obj);
59
60 ResourceMark rm;
61 stringStream ss;
62 r->print_on(&ss);
63
64 ShenandoahMarkingContext* const ctx = heap->marking_context();
65
66 msg.append(" " PTR_FORMAT " - klass " PTR_FORMAT " %s\n", p2i(obj), p2i(obj->klass()), obj->klass()->external_name());
67 msg.append(" %3s allocated after mark start\n", ctx->allocated_after_mark_start((HeapWord *) obj) ? "" : "not");
68 msg.append(" %3s marked \n", ctx->is_marked(obj) ? "" : "not");
69 msg.append(" %3s in collection set\n", heap->in_collection_set(obj) ? "" : "not");
70 if (heap->traversal_gc() != NULL) {
71 msg.append(" %3s in traversal set\n", heap->traversal_gc()->traversal_set()->is_in((HeapWord*) obj) ? "" : "not");
72 }
73 msg.append(" region: %s", ss.as_string());
74 }
75
76 void ShenandoahAsserts::print_non_obj(ShenandoahMessageBuffer& msg, void* loc) {
77 ShenandoahHeap* heap = ShenandoahHeap::heap();
78 if (heap->is_in(loc)) {
79 msg.append(" inside Java heap\n");
80 ShenandoahHeapRegion *r = heap->heap_region_containing(loc);
81 stringStream ss;
82 r->print_on(&ss);
83
84 msg.append(" %3s in collection set\n", heap->in_collection_set(loc) ? "" : "not");
85 msg.append(" region: %s", ss.as_string());
86 } else {
87 msg.append(" outside of Java heap\n");
88 stringStream ss;
89 os::print_location(&ss, (intptr_t) loc, false);
90 msg.append(" %s", ss.as_string());
91 }
92 }
93
94 void ShenandoahAsserts::print_obj_safe(ShenandoahMessageBuffer& msg, void* loc) {
95 ShenandoahHeap* heap = ShenandoahHeap::heap();
96 msg.append(" " PTR_FORMAT " - safe print, no details\n", p2i(loc));
97 if (heap->is_in(loc)) {
98 ShenandoahHeapRegion* r = heap->heap_region_containing(loc);
99 if (r != NULL) {
100 stringStream ss;
101 r->print_on(&ss);
102 msg.append(" region: %s", ss.as_string());
103 print_raw_memory(msg, loc);
104 }
105 }
106 }
107
108 void ShenandoahAsserts::print_failure(SafeLevel level, oop obj, void* interior_loc, oop loc,
109 const char* phase, const char* label,
110 const char* file, int line) {
111 ShenandoahHeap* heap = ShenandoahHeap::heap();
112 ResourceMark rm;
113
114 bool loc_in_heap = (loc != NULL && heap->is_in(loc));
115
116 ShenandoahMessageBuffer msg("%s; %s\n\n", phase, label);
117
118 msg.append("Referenced from:\n");
119 if (interior_loc != NULL) {
120 msg.append(" interior location: " PTR_FORMAT "\n", p2i(interior_loc));
121 if (loc_in_heap) {
122 print_obj(msg, loc);
123 } else {
124 print_non_obj(msg, interior_loc);
125 }
126 } else {
127 msg.append(" no interior location recorded (probably a plain heap scan, or detached oop)\n");
128 }
129 msg.append("\n");
130
131 msg.append("Object:\n");
132 if (level >= _safe_oop) {
133 print_obj(msg, obj);
134 } else {
135 print_obj_safe(msg, obj);
136 }
137 msg.append("\n");
138
139 if (level >= _safe_oop) {
140 oop fwd = (oop) ShenandoahBrooksPointer::get_raw_unchecked(obj);
141 msg.append("Forwardee:\n");
142 if (!oopDesc::equals_raw(obj, fwd)) {
143 if (level >= _safe_oop_fwd) {
144 print_obj(msg, fwd);
145 } else {
146 print_obj_safe(msg, fwd);
147 }
148 } else {
149 msg.append(" (the object itself)");
150 }
151 msg.append("\n");
152 }
153
154 if (level >= _safe_oop_fwd) {
155 oop fwd = (oop) ShenandoahBrooksPointer::get_raw_unchecked(obj);
156 oop fwd2 = (oop) ShenandoahBrooksPointer::get_raw_unchecked(fwd);
157 if (!oopDesc::equals_raw(fwd, fwd2)) {
158 msg.append("Second forwardee:\n");
159 print_obj_safe(msg, fwd2);
160 msg.append("\n");
161 }
162 }
163
164 report_vm_error(file, line, msg.buffer());
165 }
166
167 void ShenandoahAsserts::assert_in_heap(void* interior_loc, oop obj, const char *file, int line) {
168 ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
169
170 if (!heap->is_in(obj)) {
171 print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_in_heap failed",
172 "oop must point to a heap address",
173 file, line);
174 }
175 }
176
177 void ShenandoahAsserts::assert_correct(void* interior_loc, oop obj, const char* file, int line) {
178 ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
179
180 // Step 1. Check that obj is correct.
181 // After this step, it is safe to call heap_region_containing().
182 if (!heap->is_in(obj)) {
183 print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
184 "oop must point to a heap address",
185 file, line);
186 }
187
188 Klass* obj_klass = obj->klass_or_null();
189 if (obj_klass == NULL) {
190 print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
191 "Object klass pointer should not be NULL",
192 file,line);
193 }
194
195 if (!Metaspace::contains(obj_klass)) {
196 print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
197 "Object klass pointer must go to metaspace",
198 file,line);
199 }
200
201 oop fwd = oop(ShenandoahBrooksPointer::get_raw_unchecked(obj));
202
203 if (!oopDesc::equals_raw(obj, fwd)) {
204 // When Full GC moves the objects, we cannot trust fwdptrs. If we got here, it means something
205 // tries fwdptr manipulation when Full GC is running. The only exception is using the fwdptr
206 // that still points to the object itself.
207 if (heap->is_full_gc_move_in_progress()) {
208 print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
209 "Non-trivial forwarding pointer during Full GC moves, probable bug.",
210 file, line);
211 }
212
213 // Step 2. Check that forwardee is correct
214 if (!heap->is_in(fwd)) {
215 print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
216 "Forwardee must point to a heap address",
217 file, line);
218 }
219
220 if (obj_klass != fwd->klass()) {
221 print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
222 "Forwardee klass disagrees with object class",
223 file, line);
224 }
225
226 // Step 3. Check that forwardee points to correct region
227 if (heap->heap_region_index_containing(fwd) == heap->heap_region_index_containing(obj)) {
228 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
229 "Non-trivial forwardee should in another region",
230 file, line);
231 }
232
233 // Step 4. Check for multiple forwardings
234 oop fwd2 = oop(ShenandoahBrooksPointer::get_raw_unchecked(fwd));
235 if (!oopDesc::equals_raw(fwd, fwd2)) {
236 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_correct failed",
237 "Multiple forwardings",
238 file, line);
239 }
240 }
241 }
242
243 void ShenandoahAsserts::assert_in_correct_region(void* interior_loc, oop obj, const char* file, int line) {
244 assert_correct(interior_loc, obj, file, line);
245
246 ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
247 ShenandoahHeapRegion* r = heap->heap_region_containing(obj);
248 if (!r->is_active()) {
249 print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_in_correct_region failed",
250 "Object must reside in active region",
251 file, line);
252 }
253
254 size_t alloc_size = obj->size() + ShenandoahBrooksPointer::word_size();
255 if (alloc_size > ShenandoahHeapRegion::humongous_threshold_words()) {
256 size_t idx = r->region_number();
257 size_t num_regions = ShenandoahHeapRegion::required_regions(alloc_size * HeapWordSize);
258 for (size_t i = idx; i < idx + num_regions; i++) {
259 ShenandoahHeapRegion* chain_reg = heap->get_region(i);
260 if (i == idx && !chain_reg->is_humongous_start()) {
261 print_failure(_safe_unknown, obj, interior_loc, NULL, "Shenandoah assert_in_correct_region failed",
262 "Object must reside in humongous start",
263 file, line);
264 }
265 if (i != idx && !chain_reg->is_humongous_continuation()) {
266 print_failure(_safe_oop, obj, interior_loc, NULL, "Shenandoah assert_in_correct_region failed",
267 "Humongous continuation should be of proper size",
268 file, line);
269 }
270 }
271 }
272 }
273
274 void ShenandoahAsserts::assert_forwarded(void* interior_loc, oop obj, const char* file, int line) {
275 assert_correct(interior_loc, obj, file, line);
276 oop fwd = oop(ShenandoahBrooksPointer::get_raw_unchecked(obj));
277
278 if (oopDesc::equals_raw(obj, fwd)) {
279 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_forwarded failed",
280 "Object should be forwarded",
281 file, line);
282 }
283 }
284
285 void ShenandoahAsserts::assert_not_forwarded(void* interior_loc, oop obj, const char* file, int line) {
286 assert_correct(interior_loc, obj, file, line);
287 oop fwd = oop(ShenandoahBrooksPointer::get_raw_unchecked(obj));
288
289 if (!oopDesc::equals_raw(obj, fwd)) {
290 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_not_forwarded failed",
291 "Object should not be forwarded",
292 file, line);
293 }
294 }
295
296 void ShenandoahAsserts::assert_marked(void *interior_loc, oop obj, const char *file, int line) {
297 assert_correct(interior_loc, obj, file, line);
298
299 ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
300 if (!heap->marking_context()->is_marked(obj)) {
301 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_marked failed",
302 "Object should be marked",
303 file, line);
304 }
305 }
306
307 void ShenandoahAsserts::assert_in_cset(void* interior_loc, oop obj, const char* file, int line) {
308 assert_correct(interior_loc, obj, file, line);
309
310 ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
311 if (!heap->in_collection_set(obj)) {
312 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_in_cset failed",
313 "Object should be in collection set",
314 file, line);
315 }
316 }
317
318 void ShenandoahAsserts::assert_not_in_cset(void* interior_loc, oop obj, const char* file, int line) {
319 assert_correct(interior_loc, obj, file, line);
320
321 ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
322 if (heap->in_collection_set(obj)) {
323 print_failure(_safe_all, obj, interior_loc, NULL, "Shenandoah assert_not_in_cset failed",
324 "Object should not be in collection set",
325 file, line);
326 }
327 }
328
329 void ShenandoahAsserts::assert_not_in_cset_loc(void* interior_loc, const char* file, int line) {
330 ShenandoahHeap* heap = ShenandoahHeap::heap_no_check();
331 if (heap->in_collection_set(interior_loc)) {
332 print_failure(_safe_unknown, NULL, interior_loc, NULL, "Shenandoah assert_not_in_cset_loc failed",
333 "Interior location should not be in collection set",
334 file, line);
335 }
336 }
337
338 void ShenandoahAsserts::print_rp_failure(const char *label, BoolObjectClosure* actual,
339 const char *file, int line) {
340 ShenandoahMessageBuffer msg("%s\n", label);
341 msg.append(" Actual: " PTR_FORMAT "\n", p2i(actual));
342 report_vm_error(file, line, msg.buffer());
343 }
344
345 void ShenandoahAsserts::assert_rp_isalive_not_installed(const char *file, int line) {
346 ShenandoahHeap* heap = ShenandoahHeap::heap();
347 ReferenceProcessor* rp = heap->ref_processor();
348 if (rp->is_alive_non_header() != NULL) {
349 print_rp_failure("Shenandoah assert_rp_isalive_not_installed failed", rp->is_alive_non_header(),
350 file, line);
351 }
352 }
353
354 void ShenandoahAsserts::assert_rp_isalive_installed(const char *file, int line) {
355 ShenandoahHeap* heap = ShenandoahHeap::heap();
356 ReferenceProcessor* rp = heap->ref_processor();
357 if (rp->is_alive_non_header() == NULL) {
358 print_rp_failure("Shenandoah assert_rp_isalive_installed failed", rp->is_alive_non_header(),
359 file, line);
360 }
361 }