Mercurial > hg > graal-jvmci-8
annotate src/share/vm/gc_implementation/g1/g1MarkSweep.cpp @ 941:8b46c4d82093
4957990: Perm heap bloat in JVM
Summary: Treat ProfileData in MDO's as a source of weak, not strong, roots. Fixes the bug for stop-world collection -- the case of concurrent collection will be fixed separately.
Reviewed-by: jcoomes, jmasa, kvn, never
author | ysr |
---|---|
date | Wed, 02 Sep 2009 00:04:29 -0700 |
parents | bd02caa94611 |
children | 54b3b351d6f9 |
rev | line source |
---|---|
342 | 1 /* |
844 | 2 * Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved. |
342 | 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
4 * | |
5 * This code is free software; you can redistribute it and/or modify it | |
6 * under the terms of the GNU General Public License version 2 only, as | |
7 * published by the Free Software Foundation. | |
8 * | |
9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
12 * version 2 for more details (a copy is included in the LICENSE file that | |
13 * accompanied this code). | |
14 * | |
15 * You should have received a copy of the GNU General Public License version | |
16 * 2 along with this work; if not, write to the Free Software Foundation, | |
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
18 * | |
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
21 * have any questions. | |
22 * | |
23 */ | |
24 | |
25 #include "incls/_precompiled.incl" | |
26 #include "incls/_g1MarkSweep.cpp.incl" | |
27 | |
28 class HeapRegion; | |
29 | |
30 void G1MarkSweep::invoke_at_safepoint(ReferenceProcessor* rp, | |
31 bool clear_all_softrefs) { | |
32 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint"); | |
33 | |
34 // hook up weak ref data so it can be used during Mark-Sweep | |
35 assert(GenMarkSweep::ref_processor() == NULL, "no stomping"); | |
453
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
358
diff
changeset
|
36 assert(rp != NULL, "should be non-NULL"); |
342 | 37 GenMarkSweep::_ref_processor = rp; |
457
27a80744a83b
6778647: snap(), snap_policy() should be renamed setup(), setup_policy()
ysr
parents:
453
diff
changeset
|
38 rp->setup_policy(clear_all_softrefs); |
342 | 39 |
40 // When collecting the permanent generation methodOops may be moving, | |
41 // so we either have to flush all bcp data or convert it into bci. | |
42 CodeCache::gc_prologue(); | |
43 Threads::gc_prologue(); | |
44 | |
45 // Increment the invocation count for the permanent generation, since it is | |
46 // implicitly collected whenever we do a full mark sweep collection. | |
47 SharedHeap* sh = SharedHeap::heap(); | |
48 sh->perm_gen()->stat_record()->invocations++; | |
49 | |
50 bool marked_for_unloading = false; | |
51 | |
52 allocate_stacks(); | |
53 | |
358
8651a65ac4b4
6735416: G1: runThese javasoft.sqe.tests.lang.thrd011.thrd01101.thrd01101 fails
iveresov
parents:
342
diff
changeset
|
54 // We should save the marks of the currently locked biased monitors. |
8651a65ac4b4
6735416: G1: runThese javasoft.sqe.tests.lang.thrd011.thrd01101.thrd01101 fails
iveresov
parents:
342
diff
changeset
|
55 // The marking doesn't preserve the marks of biased objects. |
8651a65ac4b4
6735416: G1: runThese javasoft.sqe.tests.lang.thrd011.thrd01101.thrd01101 fails
iveresov
parents:
342
diff
changeset
|
56 BiasedLocking::preserve_marks(); |
8651a65ac4b4
6735416: G1: runThese javasoft.sqe.tests.lang.thrd011.thrd01101.thrd01101 fails
iveresov
parents:
342
diff
changeset
|
57 |
342 | 58 mark_sweep_phase1(marked_for_unloading, clear_all_softrefs); |
59 | |
751 | 60 if (VerifyDuringGC) { |
342 | 61 G1CollectedHeap* g1h = G1CollectedHeap::heap(); |
62 g1h->checkConcurrentMark(); | |
63 } | |
64 | |
65 mark_sweep_phase2(); | |
66 | |
67 // Don't add any more derived pointers during phase3 | |
68 COMPILER2_PRESENT(DerivedPointerTable::set_active(false)); | |
69 | |
70 mark_sweep_phase3(); | |
71 | |
72 mark_sweep_phase4(); | |
73 | |
74 GenMarkSweep::restore_marks(); | |
358
8651a65ac4b4
6735416: G1: runThese javasoft.sqe.tests.lang.thrd011.thrd01101.thrd01101 fails
iveresov
parents:
342
diff
changeset
|
75 BiasedLocking::restore_marks(); |
342 | 76 GenMarkSweep::deallocate_stacks(); |
77 | |
78 // We must invalidate the perm-gen rs, so that it gets rebuilt. | |
79 GenRemSet* rs = sh->rem_set(); | |
80 rs->invalidate(sh->perm_gen()->used_region(), true /*whole_heap*/); | |
81 | |
82 // "free at last gc" is calculated from these. | |
83 // CHF: cheating for now!!! | |
84 // Universe::set_heap_capacity_at_last_gc(Universe::heap()->capacity()); | |
85 // Universe::set_heap_used_at_last_gc(Universe::heap()->used()); | |
86 | |
87 Threads::gc_epilogue(); | |
88 CodeCache::gc_epilogue(); | |
89 | |
90 // refs processing: clean slate | |
91 GenMarkSweep::_ref_processor = NULL; | |
92 } | |
93 | |
94 | |
95 void G1MarkSweep::allocate_stacks() { | |
96 GenMarkSweep::_preserved_count_max = 0; | |
97 GenMarkSweep::_preserved_marks = NULL; | |
98 GenMarkSweep::_preserved_count = 0; | |
99 GenMarkSweep::_preserved_mark_stack = NULL; | |
100 GenMarkSweep::_preserved_oop_stack = NULL; | |
101 | |
102 GenMarkSweep::_marking_stack = | |
103 new (ResourceObj::C_HEAP) GrowableArray<oop>(4000, true); | |
104 | |
941 | 105 int size = SystemDictionary::number_of_classes() * 2; |
342 | 106 GenMarkSweep::_revisit_klass_stack = |
941 | 107 new (ResourceObj::C_HEAP) GrowableArray<Klass*>(size, true); |
108 // (#klass/k)^2 for k ~ 10 appears a better fit, but this will have to do | |
109 // for now until we have a chance to work out a more optimal setting. | |
110 GenMarkSweep::_revisit_mdo_stack = | |
111 new (ResourceObj::C_HEAP) GrowableArray<DataLayout*>(size*2, true); | |
112 | |
342 | 113 } |
114 | |
115 void G1MarkSweep::mark_sweep_phase1(bool& marked_for_unloading, | |
116 bool clear_all_softrefs) { | |
117 // Recursively traverse all live objects and mark them | |
118 EventMark m("1 mark object"); | |
119 TraceTime tm("phase 1", PrintGC && Verbose, true, gclog_or_tty); | |
120 GenMarkSweep::trace(" 1"); | |
121 | |
122 SharedHeap* sh = SharedHeap::heap(); | |
123 | |
124 sh->process_strong_roots(true, // Collecting permanent generation. | |
125 SharedHeap::SO_SystemClasses, | |
126 &GenMarkSweep::follow_root_closure, | |
127 &GenMarkSweep::follow_root_closure); | |
128 | |
129 // Process reference objects found during marking | |
453
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
358
diff
changeset
|
130 ReferenceProcessor* rp = GenMarkSweep::ref_processor(); |
457
27a80744a83b
6778647: snap(), snap_policy() should be renamed setup(), setup_policy()
ysr
parents:
453
diff
changeset
|
131 rp->setup_policy(clear_all_softrefs); |
453
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
358
diff
changeset
|
132 rp->process_discovered_references(&GenMarkSweep::is_alive, |
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
358
diff
changeset
|
133 &GenMarkSweep::keep_alive, |
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
358
diff
changeset
|
134 &GenMarkSweep::follow_stack_closure, |
c96030fff130
6684579: SoftReference processing can be made more efficient
ysr
parents:
358
diff
changeset
|
135 NULL); |
342 | 136 |
137 // Follow system dictionary roots and unload classes | |
138 bool purged_class = SystemDictionary::do_unloading(&GenMarkSweep::is_alive); | |
139 assert(GenMarkSweep::_marking_stack->is_empty(), | |
140 "stack should be empty by now"); | |
141 | |
142 // Follow code cache roots (has to be done after system dictionary, | |
143 // assumes all live klasses are marked) | |
144 CodeCache::do_unloading(&GenMarkSweep::is_alive, | |
145 &GenMarkSweep::keep_alive, | |
146 purged_class); | |
941 | 147 GenMarkSweep::follow_stack(); |
342 | 148 |
149 // Update subklass/sibling/implementor links of live klasses | |
150 GenMarkSweep::follow_weak_klass_links(); | |
151 assert(GenMarkSweep::_marking_stack->is_empty(), | |
152 "stack should be empty by now"); | |
153 | |
941 | 154 // Visit memoized MDO's and clear any unmarked weak refs |
155 GenMarkSweep::follow_mdo_weak_refs(); | |
156 assert(GenMarkSweep::_marking_stack->is_empty(), "just drained"); | |
157 | |
158 | |
342 | 159 // Visit symbol and interned string tables and delete unmarked oops |
160 SymbolTable::unlink(&GenMarkSweep::is_alive); | |
161 StringTable::unlink(&GenMarkSweep::is_alive); | |
162 | |
163 assert(GenMarkSweep::_marking_stack->is_empty(), | |
164 "stack should be empty by now"); | |
165 } | |
166 | |
167 class G1PrepareCompactClosure: public HeapRegionClosure { | |
168 ModRefBarrierSet* _mrbs; | |
169 CompactPoint _cp; | |
170 | |
171 void free_humongous_region(HeapRegion* hr) { | |
172 HeapWord* bot = hr->bottom(); | |
173 HeapWord* end = hr->end(); | |
174 assert(hr->startsHumongous(), | |
175 "Only the start of a humongous region should be freed."); | |
176 G1CollectedHeap::heap()->free_region(hr); | |
177 hr->prepare_for_compaction(&_cp); | |
178 // Also clear the part of the card table that will be unused after | |
179 // compaction. | |
180 _mrbs->clear(MemRegion(hr->compaction_top(), hr->end())); | |
181 } | |
182 | |
183 public: | |
677 | 184 G1PrepareCompactClosure(CompactibleSpace* cs) : |
342 | 185 _cp(NULL, cs, cs->initialize_threshold()), |
677 | 186 _mrbs(G1CollectedHeap::heap()->mr_bs()) |
342 | 187 {} |
188 bool doHeapRegion(HeapRegion* hr) { | |
189 if (hr->isHumongous()) { | |
190 if (hr->startsHumongous()) { | |
191 oop obj = oop(hr->bottom()); | |
192 if (obj->is_gc_marked()) { | |
193 obj->forward_to(obj); | |
194 } else { | |
195 free_humongous_region(hr); | |
196 } | |
197 } else { | |
198 assert(hr->continuesHumongous(), "Invalid humongous."); | |
199 } | |
200 } else { | |
201 hr->prepare_for_compaction(&_cp); | |
202 // Also clear the part of the card table that will be unused after | |
203 // compaction. | |
204 _mrbs->clear(MemRegion(hr->compaction_top(), hr->end())); | |
205 } | |
206 return false; | |
207 } | |
208 }; | |
677 | 209 |
210 // Finds the first HeapRegion. | |
342 | 211 class FindFirstRegionClosure: public HeapRegionClosure { |
212 HeapRegion* _a_region; | |
213 public: | |
677 | 214 FindFirstRegionClosure() : _a_region(NULL) {} |
342 | 215 bool doHeapRegion(HeapRegion* r) { |
677 | 216 _a_region = r; |
217 return true; | |
342 | 218 } |
219 HeapRegion* result() { return _a_region; } | |
220 }; | |
221 | |
222 void G1MarkSweep::mark_sweep_phase2() { | |
223 // Now all live objects are marked, compute the new object addresses. | |
224 | |
225 // It is imperative that we traverse perm_gen LAST. If dead space is | |
226 // allowed a range of dead object may get overwritten by a dead int | |
227 // array. If perm_gen is not traversed last a klassOop may get | |
228 // overwritten. This is fine since it is dead, but if the class has dead | |
229 // instances we have to skip them, and in order to find their size we | |
230 // need the klassOop! | |
231 // | |
232 // It is not required that we traverse spaces in the same order in | |
233 // phase2, phase3 and phase4, but the ValidateMarkSweep live oops | |
234 // tracking expects us to do so. See comment under phase4. | |
235 | |
236 G1CollectedHeap* g1h = G1CollectedHeap::heap(); | |
237 Generation* pg = g1h->perm_gen(); | |
238 | |
239 EventMark m("2 compute new addresses"); | |
240 TraceTime tm("phase 2", PrintGC && Verbose, true, gclog_or_tty); | |
241 GenMarkSweep::trace("2"); | |
242 | |
677 | 243 FindFirstRegionClosure cl; |
342 | 244 g1h->heap_region_iterate(&cl); |
245 HeapRegion *r = cl.result(); | |
246 CompactibleSpace* sp = r; | |
247 if (r->isHumongous() && oop(r->bottom())->is_gc_marked()) { | |
248 sp = r->next_compaction_space(); | |
249 } | |
250 | |
677 | 251 G1PrepareCompactClosure blk(sp); |
342 | 252 g1h->heap_region_iterate(&blk); |
253 | |
254 CompactPoint perm_cp(pg, NULL, NULL); | |
255 pg->prepare_for_compaction(&perm_cp); | |
256 } | |
257 | |
258 class G1AdjustPointersClosure: public HeapRegionClosure { | |
259 public: | |
260 bool doHeapRegion(HeapRegion* r) { | |
261 if (r->isHumongous()) { | |
262 if (r->startsHumongous()) { | |
263 // We must adjust the pointers on the single H object. | |
264 oop obj = oop(r->bottom()); | |
265 debug_only(GenMarkSweep::track_interior_pointers(obj)); | |
266 // point all the oops to the new location | |
267 obj->adjust_pointers(); | |
268 debug_only(GenMarkSweep::check_interior_pointers()); | |
269 } | |
270 } else { | |
271 // This really ought to be "as_CompactibleSpace"... | |
272 r->adjust_pointers(); | |
273 } | |
274 return false; | |
275 } | |
276 }; | |
277 | |
278 void G1MarkSweep::mark_sweep_phase3() { | |
279 G1CollectedHeap* g1h = G1CollectedHeap::heap(); | |
280 Generation* pg = g1h->perm_gen(); | |
281 | |
282 // Adjust the pointers to reflect the new locations | |
283 EventMark m("3 adjust pointers"); | |
284 TraceTime tm("phase 3", PrintGC && Verbose, true, gclog_or_tty); | |
285 GenMarkSweep::trace("3"); | |
286 | |
287 SharedHeap* sh = SharedHeap::heap(); | |
288 | |
289 sh->process_strong_roots(true, // Collecting permanent generation. | |
290 SharedHeap::SO_AllClasses, | |
291 &GenMarkSweep::adjust_root_pointer_closure, | |
292 &GenMarkSweep::adjust_pointer_closure); | |
293 | |
294 g1h->ref_processor()->weak_oops_do(&GenMarkSweep::adjust_root_pointer_closure); | |
295 | |
296 // Now adjust pointers in remaining weak roots. (All of which should | |
297 // have been cleared if they pointed to non-surviving objects.) | |
298 g1h->g1_process_weak_roots(&GenMarkSweep::adjust_root_pointer_closure, | |
299 &GenMarkSweep::adjust_pointer_closure); | |
300 | |
301 GenMarkSweep::adjust_marks(); | |
302 | |
303 G1AdjustPointersClosure blk; | |
304 g1h->heap_region_iterate(&blk); | |
305 pg->adjust_pointers(); | |
306 } | |
307 | |
308 class G1SpaceCompactClosure: public HeapRegionClosure { | |
309 public: | |
310 G1SpaceCompactClosure() {} | |
311 | |
312 bool doHeapRegion(HeapRegion* hr) { | |
313 if (hr->isHumongous()) { | |
314 if (hr->startsHumongous()) { | |
315 oop obj = oop(hr->bottom()); | |
316 if (obj->is_gc_marked()) { | |
317 obj->init_mark(); | |
318 } else { | |
319 assert(hr->is_empty(), "Should have been cleared in phase 2."); | |
320 } | |
321 hr->reset_during_compaction(); | |
322 } | |
323 } else { | |
324 hr->compact(); | |
325 } | |
326 return false; | |
327 } | |
328 }; | |
329 | |
330 void G1MarkSweep::mark_sweep_phase4() { | |
331 // All pointers are now adjusted, move objects accordingly | |
332 | |
333 // It is imperative that we traverse perm_gen first in phase4. All | |
334 // classes must be allocated earlier than their instances, and traversing | |
335 // perm_gen first makes sure that all klassOops have moved to their new | |
336 // location before any instance does a dispatch through it's klass! | |
337 | |
338 // The ValidateMarkSweep live oops tracking expects us to traverse spaces | |
339 // in the same order in phase2, phase3 and phase4. We don't quite do that | |
340 // here (perm_gen first rather than last), so we tell the validate code | |
341 // to use a higher index (saved from phase2) when verifying perm_gen. | |
342 G1CollectedHeap* g1h = G1CollectedHeap::heap(); | |
343 Generation* pg = g1h->perm_gen(); | |
344 | |
345 EventMark m("4 compact heap"); | |
346 TraceTime tm("phase 4", PrintGC && Verbose, true, gclog_or_tty); | |
347 GenMarkSweep::trace("4"); | |
348 | |
349 pg->compact(); | |
350 | |
351 G1SpaceCompactClosure blk; | |
352 g1h->heap_region_iterate(&blk); | |
353 | |
354 } | |
355 | |
356 // Local Variables: *** | |
357 // c-indentation-style: gnu *** | |
358 // End: *** |