Mercurial > hg > graal-compiler
annotate src/share/vm/memory/genMarkSweep.cpp @ 367:194b8e3a2fc4
6384206: Phis which are later unneeded are impairing our ability to inline based on static types
Reviewed-by: rasbold, jrose
author | never |
---|---|
date | Wed, 17 Sep 2008 12:59:52 -0700 |
parents | 850fdf70db2b |
children | 1ee8caae33af |
rev | line source |
---|---|
0 | 1 /* |
196 | 2 * Copyright 2001-2008 Sun Microsystems, Inc. All Rights Reserved. |
0 | 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/_genMarkSweep.cpp.incl" | |
27 | |
28 void GenMarkSweep::invoke_at_safepoint(int level, ReferenceProcessor* rp, | |
29 bool clear_all_softrefs) { | |
30 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint"); | |
31 | |
32 // hook up weak ref data so it can be used during Mark-Sweep | |
33 assert(ref_processor() == NULL, "no stomping"); | |
34 _ref_processor = rp; | |
35 assert(rp != NULL, "should be non-NULL"); | |
36 | |
37 TraceTime t1("Full GC", PrintGC && !PrintGCDetails, true, gclog_or_tty); | |
38 | |
39 // When collecting the permanent generation methodOops may be moving, | |
40 // so we either have to flush all bcp data or convert it into bci. | |
41 CodeCache::gc_prologue(); | |
42 Threads::gc_prologue(); | |
43 | |
44 // Increment the invocation count for the permanent generation, since it is | |
45 // implicitly collected whenever we do a full mark sweep collection. | |
46 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
47 gch->perm_gen()->stat_record()->invocations++; | |
48 | |
49 // Capture heap size before collection for printing. | |
50 size_t gch_prev_used = gch->used(); | |
51 | |
52 // Some of the card table updates below assume that the perm gen is | |
53 // also being collected. | |
54 assert(level == gch->n_gens() - 1, | |
55 "All generations are being collected, ergo perm gen too."); | |
56 | |
57 // Capture used regions for each generation that will be | |
58 // subject to collection, so that card table adjustments can | |
59 // be made intelligently (see clear / invalidate further below). | |
60 gch->save_used_regions(level, true /* perm */); | |
61 | |
62 allocate_stacks(); | |
63 | |
64 mark_sweep_phase1(level, clear_all_softrefs); | |
65 | |
66 mark_sweep_phase2(); | |
67 | |
68 // Don't add any more derived pointers during phase3 | |
69 COMPILER2_PRESENT(assert(DerivedPointerTable::is_active(), "Sanity")); | |
70 COMPILER2_PRESENT(DerivedPointerTable::set_active(false)); | |
71 | |
72 mark_sweep_phase3(level); | |
73 | |
74 VALIDATE_MARK_SWEEP_ONLY( | |
75 if (ValidateMarkSweep) { | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
76 guarantee(_root_refs_stack->length() == 0, "should be empty by now"); |
0 | 77 } |
78 ) | |
79 | |
80 mark_sweep_phase4(); | |
81 | |
82 VALIDATE_MARK_SWEEP_ONLY( | |
83 if (ValidateMarkSweep) { | |
84 guarantee(_live_oops->length() == _live_oops_moved_to->length(), | |
85 "should be the same size"); | |
86 } | |
87 ) | |
88 | |
89 restore_marks(); | |
90 | |
91 // Set saved marks for allocation profiler (and other things? -- dld) | |
92 // (Should this be in general part?) | |
93 gch->save_marks(); | |
94 | |
95 deallocate_stacks(); | |
96 | |
97 // If compaction completely evacuated all generations younger than this | |
98 // one, then we can clear the card table. Otherwise, we must invalidate | |
99 // it (consider all cards dirty). In the future, we might consider doing | |
100 // compaction within generations only, and doing card-table sliding. | |
101 bool all_empty = true; | |
102 for (int i = 0; all_empty && i < level; i++) { | |
103 Generation* g = gch->get_gen(i); | |
104 all_empty = all_empty && gch->get_gen(i)->used() == 0; | |
105 } | |
106 GenRemSet* rs = gch->rem_set(); | |
107 // Clear/invalidate below make use of the "prev_used_regions" saved earlier. | |
108 if (all_empty) { | |
109 // We've evacuated all generations below us. | |
110 Generation* g = gch->get_gen(level); | |
111 rs->clear_into_younger(g, true /* perm */); | |
112 } else { | |
113 // Invalidate the cards corresponding to the currently used | |
114 // region and clear those corresponding to the evacuated region | |
115 // of all generations just collected (i.e. level and younger). | |
116 rs->invalidate_or_clear(gch->get_gen(level), | |
117 true /* younger */, | |
118 true /* perm */); | |
119 } | |
120 | |
121 Threads::gc_epilogue(); | |
122 CodeCache::gc_epilogue(); | |
123 | |
124 if (PrintGC && !PrintGCDetails) { | |
125 gch->print_heap_change(gch_prev_used); | |
126 } | |
127 | |
128 // refs processing: clean slate | |
129 _ref_processor = NULL; | |
130 | |
131 // Update heap occupancy information which is used as | |
132 // input to soft ref clearing policy at the next gc. | |
133 Universe::update_heap_info_at_gc(); | |
134 | |
135 // Update time of last gc for all generations we collected | |
136 // (which curently is all the generations in the heap). | |
137 gch->update_time_of_last_gc(os::javaTimeMillis()); | |
138 } | |
139 | |
140 void GenMarkSweep::allocate_stacks() { | |
141 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
142 // Scratch request on behalf of oldest generation; will do no | |
143 // allocation. | |
144 ScratchBlock* scratch = gch->gather_scratch(gch->_gens[gch->_n_gens-1], 0); | |
145 | |
146 // $$$ To cut a corner, we'll only use the first scratch block, and then | |
147 // revert to malloc. | |
148 if (scratch != NULL) { | |
149 _preserved_count_max = | |
150 scratch->num_words * HeapWordSize / sizeof(PreservedMark); | |
151 } else { | |
152 _preserved_count_max = 0; | |
153 } | |
154 | |
155 _preserved_marks = (PreservedMark*)scratch; | |
156 _preserved_count = 0; | |
157 _preserved_mark_stack = NULL; | |
158 _preserved_oop_stack = NULL; | |
159 | |
160 _marking_stack = new (ResourceObj::C_HEAP) GrowableArray<oop>(4000, true); | |
161 | |
162 int size = SystemDictionary::number_of_classes() * 2; | |
163 _revisit_klass_stack = new (ResourceObj::C_HEAP) GrowableArray<Klass*>(size, true); | |
164 | |
165 #ifdef VALIDATE_MARK_SWEEP | |
166 if (ValidateMarkSweep) { | |
113
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
167 _root_refs_stack = new (ResourceObj::C_HEAP) GrowableArray<void*>(100, true); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
168 _other_refs_stack = new (ResourceObj::C_HEAP) GrowableArray<void*>(100, true); |
ba764ed4b6f2
6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
coleenp
parents:
0
diff
changeset
|
169 _adjusted_pointers = new (ResourceObj::C_HEAP) GrowableArray<void*>(100, true); |
0 | 170 _live_oops = new (ResourceObj::C_HEAP) GrowableArray<oop>(100, true); |
171 _live_oops_moved_to = new (ResourceObj::C_HEAP) GrowableArray<oop>(100, true); | |
172 _live_oops_size = new (ResourceObj::C_HEAP) GrowableArray<size_t>(100, true); | |
173 } | |
174 if (RecordMarkSweepCompaction) { | |
175 if (_cur_gc_live_oops == NULL) { | |
176 _cur_gc_live_oops = new(ResourceObj::C_HEAP) GrowableArray<HeapWord*>(100, true); | |
177 _cur_gc_live_oops_moved_to = new(ResourceObj::C_HEAP) GrowableArray<HeapWord*>(100, true); | |
178 _cur_gc_live_oops_size = new(ResourceObj::C_HEAP) GrowableArray<size_t>(100, true); | |
179 _last_gc_live_oops = new(ResourceObj::C_HEAP) GrowableArray<HeapWord*>(100, true); | |
180 _last_gc_live_oops_moved_to = new(ResourceObj::C_HEAP) GrowableArray<HeapWord*>(100, true); | |
181 _last_gc_live_oops_size = new(ResourceObj::C_HEAP) GrowableArray<size_t>(100, true); | |
182 } else { | |
183 _cur_gc_live_oops->clear(); | |
184 _cur_gc_live_oops_moved_to->clear(); | |
185 _cur_gc_live_oops_size->clear(); | |
186 } | |
187 } | |
188 #endif | |
189 } | |
190 | |
191 | |
192 void GenMarkSweep::deallocate_stacks() { | |
263
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
193 |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
194 GenCollectedHeap* gch = GenCollectedHeap::heap(); |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
195 gch->release_scratch(); |
12eea04c8b06
6672698: mangle_unused_area() should not remangle the entire heap at each collection.
jmasa
parents:
113
diff
changeset
|
196 |
0 | 197 if (_preserved_oop_stack) { |
198 delete _preserved_mark_stack; | |
199 _preserved_mark_stack = NULL; | |
200 delete _preserved_oop_stack; | |
201 _preserved_oop_stack = NULL; | |
202 } | |
203 | |
204 delete _marking_stack; | |
205 delete _revisit_klass_stack; | |
206 | |
207 #ifdef VALIDATE_MARK_SWEEP | |
208 if (ValidateMarkSweep) { | |
209 delete _root_refs_stack; | |
210 delete _other_refs_stack; | |
211 delete _adjusted_pointers; | |
212 delete _live_oops; | |
213 delete _live_oops_size; | |
214 delete _live_oops_moved_to; | |
215 _live_oops_index = 0; | |
216 _live_oops_index_at_perm = 0; | |
217 } | |
218 #endif | |
219 } | |
220 | |
221 void GenMarkSweep::mark_sweep_phase1(int level, | |
222 bool clear_all_softrefs) { | |
223 // Recursively traverse all live objects and mark them | |
224 EventMark m("1 mark object"); | |
225 TraceTime tm("phase 1", PrintGC && Verbose, true, gclog_or_tty); | |
226 trace(" 1"); | |
227 | |
228 VALIDATE_MARK_SWEEP_ONLY(reset_live_oop_tracking(false)); | |
229 | |
230 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
231 | |
232 // Because follow_root_closure is created statically, cannot | |
233 // use OopsInGenClosure constructor which takes a generation, | |
234 // as the Universe has not been created when the static constructors | |
235 // are run. | |
236 follow_root_closure.set_orig_generation(gch->get_gen(level)); | |
237 | |
238 gch->gen_process_strong_roots(level, | |
239 false, // Younger gens are not roots. | |
240 true, // Collecting permanent generation. | |
241 SharedHeap::SO_SystemClasses, | |
242 &follow_root_closure, &follow_root_closure); | |
243 | |
244 // Process reference objects found during marking | |
245 { | |
246 ReferencePolicy *soft_ref_policy; | |
247 if (clear_all_softrefs) { | |
248 soft_ref_policy = new AlwaysClearPolicy(); | |
249 } else { | |
250 #ifdef COMPILER2 | |
251 soft_ref_policy = new LRUMaxHeapPolicy(); | |
252 #else | |
253 soft_ref_policy = new LRUCurrentHeapPolicy(); | |
254 #endif // COMPILER2 | |
255 } | |
256 assert(soft_ref_policy != NULL,"No soft reference policy"); | |
257 ref_processor()->process_discovered_references( | |
258 soft_ref_policy, &is_alive, &keep_alive, | |
259 &follow_stack_closure, NULL); | |
260 } | |
261 | |
262 // Follow system dictionary roots and unload classes | |
263 bool purged_class = SystemDictionary::do_unloading(&is_alive); | |
264 | |
265 // Follow code cache roots | |
266 CodeCache::do_unloading(&is_alive, &keep_alive, purged_class); | |
267 follow_stack(); // Flush marking stack | |
268 | |
269 // Update subklass/sibling/implementor links of live klasses | |
270 follow_weak_klass_links(); | |
271 assert(_marking_stack->is_empty(), "just drained"); | |
272 | |
273 // Visit symbol and interned string tables and delete unmarked oops | |
274 SymbolTable::unlink(&is_alive); | |
275 StringTable::unlink(&is_alive); | |
276 | |
277 assert(_marking_stack->is_empty(), "stack should be empty by now"); | |
278 } | |
279 | |
280 | |
281 void GenMarkSweep::mark_sweep_phase2() { | |
282 // Now all live objects are marked, compute the new object addresses. | |
283 | |
284 // It is imperative that we traverse perm_gen LAST. If dead space is | |
285 // allowed a range of dead object may get overwritten by a dead int | |
286 // array. If perm_gen is not traversed last a klassOop may get | |
287 // overwritten. This is fine since it is dead, but if the class has dead | |
288 // instances we have to skip them, and in order to find their size we | |
289 // need the klassOop! | |
290 // | |
291 // It is not required that we traverse spaces in the same order in | |
292 // phase2, phase3 and phase4, but the ValidateMarkSweep live oops | |
293 // tracking expects us to do so. See comment under phase4. | |
294 | |
295 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
296 Generation* pg = gch->perm_gen(); | |
297 | |
298 EventMark m("2 compute new addresses"); | |
299 TraceTime tm("phase 2", PrintGC && Verbose, true, gclog_or_tty); | |
300 trace("2"); | |
301 | |
302 VALIDATE_MARK_SWEEP_ONLY(reset_live_oop_tracking(false)); | |
303 | |
304 gch->prepare_for_compaction(); | |
305 | |
306 VALIDATE_MARK_SWEEP_ONLY(_live_oops_index_at_perm = _live_oops_index); | |
307 CompactPoint perm_cp(pg, NULL, NULL); | |
308 pg->prepare_for_compaction(&perm_cp); | |
309 } | |
310 | |
311 class GenAdjustPointersClosure: public GenCollectedHeap::GenClosure { | |
312 public: | |
313 void do_generation(Generation* gen) { | |
314 gen->adjust_pointers(); | |
315 } | |
316 }; | |
317 | |
318 void GenMarkSweep::mark_sweep_phase3(int level) { | |
319 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
320 Generation* pg = gch->perm_gen(); | |
321 | |
322 // Adjust the pointers to reflect the new locations | |
323 EventMark m("3 adjust pointers"); | |
324 TraceTime tm("phase 3", PrintGC && Verbose, true, gclog_or_tty); | |
325 trace("3"); | |
326 | |
327 VALIDATE_MARK_SWEEP_ONLY(reset_live_oop_tracking(false)); | |
328 | |
329 // Needs to be done before the system dictionary is adjusted. | |
330 pg->pre_adjust_pointers(); | |
331 | |
332 // Because the two closures below are created statically, cannot | |
333 // use OopsInGenClosure constructor which takes a generation, | |
334 // as the Universe has not been created when the static constructors | |
335 // are run. | |
336 adjust_root_pointer_closure.set_orig_generation(gch->get_gen(level)); | |
337 adjust_pointer_closure.set_orig_generation(gch->get_gen(level)); | |
338 | |
339 gch->gen_process_strong_roots(level, | |
340 false, // Younger gens are not roots. | |
341 true, // Collecting permanent generation. | |
342 SharedHeap::SO_AllClasses, | |
343 &adjust_root_pointer_closure, | |
344 &adjust_root_pointer_closure); | |
345 | |
346 // Now adjust pointers in remaining weak roots. (All of which should | |
347 // have been cleared if they pointed to non-surviving objects.) | |
348 gch->gen_process_weak_roots(&adjust_root_pointer_closure, | |
349 &adjust_pointer_closure); | |
350 | |
351 adjust_marks(); | |
352 GenAdjustPointersClosure blk; | |
353 gch->generation_iterate(&blk, true); | |
354 pg->adjust_pointers(); | |
355 } | |
356 | |
357 class GenCompactClosure: public GenCollectedHeap::GenClosure { | |
358 public: | |
359 void do_generation(Generation* gen) { | |
360 gen->compact(); | |
361 } | |
362 }; | |
363 | |
364 void GenMarkSweep::mark_sweep_phase4() { | |
365 // All pointers are now adjusted, move objects accordingly | |
366 | |
367 // It is imperative that we traverse perm_gen first in phase4. All | |
368 // classes must be allocated earlier than their instances, and traversing | |
369 // perm_gen first makes sure that all klassOops have moved to their new | |
370 // location before any instance does a dispatch through it's klass! | |
371 | |
372 // The ValidateMarkSweep live oops tracking expects us to traverse spaces | |
373 // in the same order in phase2, phase3 and phase4. We don't quite do that | |
374 // here (perm_gen first rather than last), so we tell the validate code | |
375 // to use a higher index (saved from phase2) when verifying perm_gen. | |
376 GenCollectedHeap* gch = GenCollectedHeap::heap(); | |
377 Generation* pg = gch->perm_gen(); | |
378 | |
379 EventMark m("4 compact heap"); | |
380 TraceTime tm("phase 4", PrintGC && Verbose, true, gclog_or_tty); | |
381 trace("4"); | |
382 | |
383 VALIDATE_MARK_SWEEP_ONLY(reset_live_oop_tracking(true)); | |
384 | |
385 pg->compact(); | |
386 | |
387 VALIDATE_MARK_SWEEP_ONLY(reset_live_oop_tracking(false)); | |
388 | |
389 GenCompactClosure blk; | |
390 gch->generation_iterate(&blk, true); | |
391 | |
392 VALIDATE_MARK_SWEEP_ONLY(compaction_complete()); | |
393 | |
394 pg->post_compact(); // Shared spaces verification. | |
395 } |