Mercurial > hg > graal-compiler
annotate src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.cpp @ 62:cd0742ba123c
Merge
author | kamg |
---|---|
date | Thu, 20 Mar 2008 09:17:30 -0500 |
parents | 183f41cf8bfe |
children | c0492d52d55b |
rev | line source |
---|---|
0 | 1 /* |
2 * Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved. | |
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/_parallelScavengeHeap.cpp.incl" | |
27 | |
28 PSYoungGen* ParallelScavengeHeap::_young_gen = NULL; | |
29 PSOldGen* ParallelScavengeHeap::_old_gen = NULL; | |
30 PSPermGen* ParallelScavengeHeap::_perm_gen = NULL; | |
31 PSAdaptiveSizePolicy* ParallelScavengeHeap::_size_policy = NULL; | |
32 PSGCAdaptivePolicyCounters* ParallelScavengeHeap::_gc_policy_counters = NULL; | |
33 ParallelScavengeHeap* ParallelScavengeHeap::_psh = NULL; | |
34 GCTaskManager* ParallelScavengeHeap::_gc_task_manager = NULL; | |
35 | |
36 static void trace_gen_sizes(const char* const str, | |
37 size_t pg_min, size_t pg_max, | |
38 size_t og_min, size_t og_max, | |
39 size_t yg_min, size_t yg_max) | |
40 { | |
41 if (TracePageSizes) { | |
42 tty->print_cr("%s: " SIZE_FORMAT "," SIZE_FORMAT " " | |
43 SIZE_FORMAT "," SIZE_FORMAT " " | |
44 SIZE_FORMAT "," SIZE_FORMAT " " | |
45 SIZE_FORMAT, | |
46 str, pg_min / K, pg_max / K, | |
47 og_min / K, og_max / K, | |
48 yg_min / K, yg_max / K, | |
49 (pg_max + og_max + yg_max) / K); | |
50 } | |
51 } | |
52 | |
53 jint ParallelScavengeHeap::initialize() { | |
54 // Cannot be initialized until after the flags are parsed | |
55 GenerationSizer flag_parser; | |
56 | |
57 size_t yg_min_size = flag_parser.min_young_gen_size(); | |
58 size_t yg_max_size = flag_parser.max_young_gen_size(); | |
59 size_t og_min_size = flag_parser.min_old_gen_size(); | |
60 size_t og_max_size = flag_parser.max_old_gen_size(); | |
61 // Why isn't there a min_perm_gen_size()? | |
62 size_t pg_min_size = flag_parser.perm_gen_size(); | |
63 size_t pg_max_size = flag_parser.max_perm_gen_size(); | |
64 | |
65 trace_gen_sizes("ps heap raw", | |
66 pg_min_size, pg_max_size, | |
67 og_min_size, og_max_size, | |
68 yg_min_size, yg_max_size); | |
69 | |
70 // The ReservedSpace ctor used below requires that the page size for the perm | |
71 // gen is <= the page size for the rest of the heap (young + old gens). | |
72 const size_t og_page_sz = os::page_size_for_region(yg_min_size + og_min_size, | |
73 yg_max_size + og_max_size, | |
74 8); | |
75 const size_t pg_page_sz = MIN2(os::page_size_for_region(pg_min_size, | |
76 pg_max_size, 16), | |
77 og_page_sz); | |
78 | |
79 const size_t pg_align = set_alignment(_perm_gen_alignment, pg_page_sz); | |
80 const size_t og_align = set_alignment(_old_gen_alignment, og_page_sz); | |
81 const size_t yg_align = set_alignment(_young_gen_alignment, og_page_sz); | |
82 | |
83 // Update sizes to reflect the selected page size(s). | |
84 // | |
85 // NEEDS_CLEANUP. The default TwoGenerationCollectorPolicy uses NewRatio; it | |
86 // should check UseAdaptiveSizePolicy. Changes from generationSizer could | |
87 // move to the common code. | |
88 yg_min_size = align_size_up(yg_min_size, yg_align); | |
89 yg_max_size = align_size_up(yg_max_size, yg_align); | |
90 size_t yg_cur_size = align_size_up(flag_parser.young_gen_size(), yg_align); | |
91 yg_cur_size = MAX2(yg_cur_size, yg_min_size); | |
92 | |
93 og_min_size = align_size_up(og_min_size, og_align); | |
94 og_max_size = align_size_up(og_max_size, og_align); | |
95 size_t og_cur_size = align_size_up(flag_parser.old_gen_size(), og_align); | |
96 og_cur_size = MAX2(og_cur_size, og_min_size); | |
97 | |
98 pg_min_size = align_size_up(pg_min_size, pg_align); | |
99 pg_max_size = align_size_up(pg_max_size, pg_align); | |
100 size_t pg_cur_size = pg_min_size; | |
101 | |
102 trace_gen_sizes("ps heap rnd", | |
103 pg_min_size, pg_max_size, | |
104 og_min_size, og_max_size, | |
105 yg_min_size, yg_max_size); | |
106 | |
107 // The main part of the heap (old gen + young gen) can often use a larger page | |
108 // size than is needed or wanted for the perm gen. Use the "compound | |
109 // alignment" ReservedSpace ctor to avoid having to use the same page size for | |
110 // all gens. | |
111 ReservedSpace heap_rs(pg_max_size, pg_align, og_max_size + yg_max_size, | |
112 og_align); | |
113 os::trace_page_sizes("ps perm", pg_min_size, pg_max_size, pg_page_sz, | |
114 heap_rs.base(), pg_max_size); | |
115 os::trace_page_sizes("ps main", og_min_size + yg_min_size, | |
116 og_max_size + yg_max_size, og_page_sz, | |
117 heap_rs.base() + pg_max_size, | |
118 heap_rs.size() - pg_max_size); | |
119 if (!heap_rs.is_reserved()) { | |
120 vm_shutdown_during_initialization( | |
121 "Could not reserve enough space for object heap"); | |
122 return JNI_ENOMEM; | |
123 } | |
124 | |
125 _reserved = MemRegion((HeapWord*)heap_rs.base(), | |
126 (HeapWord*)(heap_rs.base() + heap_rs.size())); | |
127 | |
128 CardTableExtension* const barrier_set = new CardTableExtension(_reserved, 3); | |
129 _barrier_set = barrier_set; | |
130 oopDesc::set_bs(_barrier_set); | |
131 if (_barrier_set == NULL) { | |
132 vm_shutdown_during_initialization( | |
133 "Could not reserve enough space for barrier set"); | |
134 return JNI_ENOMEM; | |
135 } | |
136 | |
137 // Initial young gen size is 4 Mb | |
138 // | |
139 // XXX - what about flag_parser.young_gen_size()? | |
140 const size_t init_young_size = align_size_up(4 * M, yg_align); | |
141 yg_cur_size = MAX2(MIN2(init_young_size, yg_max_size), yg_cur_size); | |
142 | |
143 // Split the reserved space into perm gen and the main heap (everything else). | |
144 // The main heap uses a different alignment. | |
145 ReservedSpace perm_rs = heap_rs.first_part(pg_max_size); | |
146 ReservedSpace main_rs = heap_rs.last_part(pg_max_size, og_align); | |
147 | |
148 // Make up the generations | |
149 // Calculate the maximum size that a generation can grow. This | |
150 // includes growth into the other generation. Note that the | |
151 // parameter _max_gen_size is kept as the maximum | |
152 // size of the generation as the boundaries currently stand. | |
153 // _max_gen_size is still used as that value. | |
154 double max_gc_pause_sec = ((double) MaxGCPauseMillis)/1000.0; | |
155 double max_gc_minor_pause_sec = ((double) MaxGCMinorPauseMillis)/1000.0; | |
156 | |
157 _gens = new AdjoiningGenerations(main_rs, | |
158 og_cur_size, | |
159 og_min_size, | |
160 og_max_size, | |
161 yg_cur_size, | |
162 yg_min_size, | |
163 yg_max_size, | |
164 yg_align); | |
165 | |
166 _old_gen = _gens->old_gen(); | |
167 _young_gen = _gens->young_gen(); | |
168 | |
169 const size_t eden_capacity = _young_gen->eden_space()->capacity_in_bytes(); | |
170 const size_t old_capacity = _old_gen->capacity_in_bytes(); | |
171 const size_t initial_promo_size = MIN2(eden_capacity, old_capacity); | |
172 _size_policy = | |
173 new PSAdaptiveSizePolicy(eden_capacity, | |
174 initial_promo_size, | |
175 young_gen()->to_space()->capacity_in_bytes(), | |
13
183f41cf8bfe
6557851: CMS: ergonomics defaults are not set with FLAG_SET_ERGO
jmasa
parents:
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changeset
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176 intra_heap_alignment(), |
0 | 177 max_gc_pause_sec, |
178 max_gc_minor_pause_sec, | |
179 GCTimeRatio | |
180 ); | |
181 | |
182 _perm_gen = new PSPermGen(perm_rs, | |
183 pg_align, | |
184 pg_cur_size, | |
185 pg_cur_size, | |
186 pg_max_size, | |
187 "perm", 2); | |
188 | |
189 assert(!UseAdaptiveGCBoundary || | |
190 (old_gen()->virtual_space()->high_boundary() == | |
191 young_gen()->virtual_space()->low_boundary()), | |
192 "Boundaries must meet"); | |
193 // initialize the policy counters - 2 collectors, 3 generations | |
194 _gc_policy_counters = | |
195 new PSGCAdaptivePolicyCounters("ParScav:MSC", 2, 3, _size_policy); | |
196 _psh = this; | |
197 | |
198 // Set up the GCTaskManager | |
199 _gc_task_manager = GCTaskManager::create(ParallelGCThreads); | |
200 | |
201 if (UseParallelOldGC && !PSParallelCompact::initialize()) { | |
202 return JNI_ENOMEM; | |
203 } | |
204 | |
205 return JNI_OK; | |
206 } | |
207 | |
208 void ParallelScavengeHeap::post_initialize() { | |
209 // Need to init the tenuring threshold | |
210 PSScavenge::initialize(); | |
211 if (UseParallelOldGC) { | |
212 PSParallelCompact::post_initialize(); | |
213 if (VerifyParallelOldWithMarkSweep) { | |
214 // Will be used for verification of par old. | |
215 PSMarkSweep::initialize(); | |
216 } | |
217 } else { | |
218 PSMarkSweep::initialize(); | |
219 } | |
220 PSPromotionManager::initialize(); | |
221 } | |
222 | |
223 void ParallelScavengeHeap::update_counters() { | |
224 young_gen()->update_counters(); | |
225 old_gen()->update_counters(); | |
226 perm_gen()->update_counters(); | |
227 } | |
228 | |
229 size_t ParallelScavengeHeap::capacity() const { | |
230 size_t value = young_gen()->capacity_in_bytes() + old_gen()->capacity_in_bytes(); | |
231 return value; | |
232 } | |
233 | |
234 size_t ParallelScavengeHeap::used() const { | |
235 size_t value = young_gen()->used_in_bytes() + old_gen()->used_in_bytes(); | |
236 return value; | |
237 } | |
238 | |
239 bool ParallelScavengeHeap::is_maximal_no_gc() const { | |
240 return old_gen()->is_maximal_no_gc() && young_gen()->is_maximal_no_gc(); | |
241 } | |
242 | |
243 | |
244 size_t ParallelScavengeHeap::permanent_capacity() const { | |
245 return perm_gen()->capacity_in_bytes(); | |
246 } | |
247 | |
248 size_t ParallelScavengeHeap::permanent_used() const { | |
249 return perm_gen()->used_in_bytes(); | |
250 } | |
251 | |
252 size_t ParallelScavengeHeap::max_capacity() const { | |
253 size_t estimated = reserved_region().byte_size(); | |
254 estimated -= perm_gen()->reserved().byte_size(); | |
255 if (UseAdaptiveSizePolicy) { | |
256 estimated -= _size_policy->max_survivor_size(young_gen()->max_size()); | |
257 } else { | |
258 estimated -= young_gen()->to_space()->capacity_in_bytes(); | |
259 } | |
260 return MAX2(estimated, capacity()); | |
261 } | |
262 | |
263 bool ParallelScavengeHeap::is_in(const void* p) const { | |
264 if (young_gen()->is_in(p)) { | |
265 return true; | |
266 } | |
267 | |
268 if (old_gen()->is_in(p)) { | |
269 return true; | |
270 } | |
271 | |
272 if (perm_gen()->is_in(p)) { | |
273 return true; | |
274 } | |
275 | |
276 return false; | |
277 } | |
278 | |
279 bool ParallelScavengeHeap::is_in_reserved(const void* p) const { | |
280 if (young_gen()->is_in_reserved(p)) { | |
281 return true; | |
282 } | |
283 | |
284 if (old_gen()->is_in_reserved(p)) { | |
285 return true; | |
286 } | |
287 | |
288 if (perm_gen()->is_in_reserved(p)) { | |
289 return true; | |
290 } | |
291 | |
292 return false; | |
293 } | |
294 | |
295 // Static method | |
296 bool ParallelScavengeHeap::is_in_young(oop* p) { | |
297 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); | |
298 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, | |
299 "Must be ParallelScavengeHeap"); | |
300 | |
301 PSYoungGen* young_gen = heap->young_gen(); | |
302 | |
303 if (young_gen->is_in_reserved(p)) { | |
304 return true; | |
305 } | |
306 | |
307 return false; | |
308 } | |
309 | |
310 // Static method | |
311 bool ParallelScavengeHeap::is_in_old_or_perm(oop* p) { | |
312 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); | |
313 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, | |
314 "Must be ParallelScavengeHeap"); | |
315 | |
316 PSOldGen* old_gen = heap->old_gen(); | |
317 PSPermGen* perm_gen = heap->perm_gen(); | |
318 | |
319 if (old_gen->is_in_reserved(p)) { | |
320 return true; | |
321 } | |
322 | |
323 if (perm_gen->is_in_reserved(p)) { | |
324 return true; | |
325 } | |
326 | |
327 return false; | |
328 } | |
329 | |
330 // There are two levels of allocation policy here. | |
331 // | |
332 // When an allocation request fails, the requesting thread must invoke a VM | |
333 // operation, transfer control to the VM thread, and await the results of a | |
334 // garbage collection. That is quite expensive, and we should avoid doing it | |
335 // multiple times if possible. | |
336 // | |
337 // To accomplish this, we have a basic allocation policy, and also a | |
338 // failed allocation policy. | |
339 // | |
340 // The basic allocation policy controls how you allocate memory without | |
341 // attempting garbage collection. It is okay to grab locks and | |
342 // expand the heap, if that can be done without coming to a safepoint. | |
343 // It is likely that the basic allocation policy will not be very | |
344 // aggressive. | |
345 // | |
346 // The failed allocation policy is invoked from the VM thread after | |
347 // the basic allocation policy is unable to satisfy a mem_allocate | |
348 // request. This policy needs to cover the entire range of collection, | |
349 // heap expansion, and out-of-memory conditions. It should make every | |
350 // attempt to allocate the requested memory. | |
351 | |
352 // Basic allocation policy. Should never be called at a safepoint, or | |
353 // from the VM thread. | |
354 // | |
355 // This method must handle cases where many mem_allocate requests fail | |
356 // simultaneously. When that happens, only one VM operation will succeed, | |
357 // and the rest will not be executed. For that reason, this method loops | |
358 // during failed allocation attempts. If the java heap becomes exhausted, | |
359 // we rely on the size_policy object to force a bail out. | |
360 HeapWord* ParallelScavengeHeap::mem_allocate( | |
361 size_t size, | |
362 bool is_noref, | |
363 bool is_tlab, | |
364 bool* gc_overhead_limit_was_exceeded) { | |
365 assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint"); | |
366 assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread"); | |
367 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock"); | |
368 | |
369 HeapWord* result = young_gen()->allocate(size, is_tlab); | |
370 | |
371 uint loop_count = 0; | |
372 uint gc_count = 0; | |
373 | |
374 while (result == NULL) { | |
375 // We don't want to have multiple collections for a single filled generation. | |
376 // To prevent this, each thread tracks the total_collections() value, and if | |
377 // the count has changed, does not do a new collection. | |
378 // | |
379 // The collection count must be read only while holding the heap lock. VM | |
380 // operations also hold the heap lock during collections. There is a lock | |
381 // contention case where thread A blocks waiting on the Heap_lock, while | |
382 // thread B is holding it doing a collection. When thread A gets the lock, | |
383 // the collection count has already changed. To prevent duplicate collections, | |
384 // The policy MUST attempt allocations during the same period it reads the | |
385 // total_collections() value! | |
386 { | |
387 MutexLocker ml(Heap_lock); | |
388 gc_count = Universe::heap()->total_collections(); | |
389 | |
390 result = young_gen()->allocate(size, is_tlab); | |
391 | |
392 // (1) If the requested object is too large to easily fit in the | |
393 // young_gen, or | |
394 // (2) If GC is locked out via GCLocker, young gen is full and | |
395 // the need for a GC already signalled to GCLocker (done | |
396 // at a safepoint), | |
397 // ... then, rather than force a safepoint and (a potentially futile) | |
398 // collection (attempt) for each allocation, try allocation directly | |
399 // in old_gen. For case (2) above, we may in the future allow | |
400 // TLAB allocation directly in the old gen. | |
401 if (result != NULL) { | |
402 return result; | |
403 } | |
404 if (!is_tlab && | |
405 size >= (young_gen()->eden_space()->capacity_in_words() / 2)) { | |
406 result = old_gen()->allocate(size, is_tlab); | |
407 if (result != NULL) { | |
408 return result; | |
409 } | |
410 } | |
411 if (GC_locker::is_active_and_needs_gc()) { | |
412 // GC is locked out. If this is a TLAB allocation, | |
413 // return NULL; the requestor will retry allocation | |
414 // of an idividual object at a time. | |
415 if (is_tlab) { | |
416 return NULL; | |
417 } | |
418 | |
419 // If this thread is not in a jni critical section, we stall | |
420 // the requestor until the critical section has cleared and | |
421 // GC allowed. When the critical section clears, a GC is | |
422 // initiated by the last thread exiting the critical section; so | |
423 // we retry the allocation sequence from the beginning of the loop, | |
424 // rather than causing more, now probably unnecessary, GC attempts. | |
425 JavaThread* jthr = JavaThread::current(); | |
426 if (!jthr->in_critical()) { | |
427 MutexUnlocker mul(Heap_lock); | |
428 GC_locker::stall_until_clear(); | |
429 continue; | |
430 } else { | |
431 if (CheckJNICalls) { | |
432 fatal("Possible deadlock due to allocating while" | |
433 " in jni critical section"); | |
434 } | |
435 return NULL; | |
436 } | |
437 } | |
438 } | |
439 | |
440 if (result == NULL) { | |
441 | |
442 // Exit the loop if if the gc time limit has been exceeded. | |
443 // The allocation must have failed above (result must be NULL), | |
444 // and the most recent collection must have exceeded the | |
445 // gc time limit. Exit the loop so that an out-of-memory | |
446 // will be thrown (returning a NULL will do that), but | |
447 // clear gc_time_limit_exceeded so that the next collection | |
448 // will succeeded if the applications decides to handle the | |
449 // out-of-memory and tries to go on. | |
450 *gc_overhead_limit_was_exceeded = size_policy()->gc_time_limit_exceeded(); | |
451 if (size_policy()->gc_time_limit_exceeded()) { | |
452 size_policy()->set_gc_time_limit_exceeded(false); | |
453 if (PrintGCDetails && Verbose) { | |
454 gclog_or_tty->print_cr("ParallelScavengeHeap::mem_allocate: " | |
455 "return NULL because gc_time_limit_exceeded is set"); | |
456 } | |
457 return NULL; | |
458 } | |
459 | |
460 // Generate a VM operation | |
461 VM_ParallelGCFailedAllocation op(size, is_tlab, gc_count); | |
462 VMThread::execute(&op); | |
463 | |
464 // Did the VM operation execute? If so, return the result directly. | |
465 // This prevents us from looping until time out on requests that can | |
466 // not be satisfied. | |
467 if (op.prologue_succeeded()) { | |
468 assert(Universe::heap()->is_in_or_null(op.result()), | |
469 "result not in heap"); | |
470 | |
471 // If GC was locked out during VM operation then retry allocation | |
472 // and/or stall as necessary. | |
473 if (op.gc_locked()) { | |
474 assert(op.result() == NULL, "must be NULL if gc_locked() is true"); | |
475 continue; // retry and/or stall as necessary | |
476 } | |
477 // If a NULL result is being returned, an out-of-memory | |
478 // will be thrown now. Clear the gc_time_limit_exceeded | |
479 // flag to avoid the following situation. | |
480 // gc_time_limit_exceeded is set during a collection | |
481 // the collection fails to return enough space and an OOM is thrown | |
482 // the next GC is skipped because the gc_time_limit_exceeded | |
483 // flag is set and another OOM is thrown | |
484 if (op.result() == NULL) { | |
485 size_policy()->set_gc_time_limit_exceeded(false); | |
486 } | |
487 return op.result(); | |
488 } | |
489 } | |
490 | |
491 // The policy object will prevent us from looping forever. If the | |
492 // time spent in gc crosses a threshold, we will bail out. | |
493 loop_count++; | |
494 if ((result == NULL) && (QueuedAllocationWarningCount > 0) && | |
495 (loop_count % QueuedAllocationWarningCount == 0)) { | |
496 warning("ParallelScavengeHeap::mem_allocate retries %d times \n\t" | |
497 " size=%d %s", loop_count, size, is_tlab ? "(TLAB)" : ""); | |
498 } | |
499 } | |
500 | |
501 return result; | |
502 } | |
503 | |
504 // Failed allocation policy. Must be called from the VM thread, and | |
505 // only at a safepoint! Note that this method has policy for allocation | |
506 // flow, and NOT collection policy. So we do not check for gc collection | |
507 // time over limit here, that is the responsibility of the heap specific | |
508 // collection methods. This method decides where to attempt allocations, | |
509 // and when to attempt collections, but no collection specific policy. | |
510 HeapWord* ParallelScavengeHeap::failed_mem_allocate(size_t size, bool is_tlab) { | |
511 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); | |
512 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread"); | |
513 assert(!Universe::heap()->is_gc_active(), "not reentrant"); | |
514 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock"); | |
515 | |
516 size_t mark_sweep_invocation_count = total_invocations(); | |
517 | |
518 // We assume (and assert!) that an allocation at this point will fail | |
519 // unless we collect. | |
520 | |
521 // First level allocation failure, scavenge and allocate in young gen. | |
522 GCCauseSetter gccs(this, GCCause::_allocation_failure); | |
523 PSScavenge::invoke(); | |
524 HeapWord* result = young_gen()->allocate(size, is_tlab); | |
525 | |
526 // Second level allocation failure. | |
527 // Mark sweep and allocate in young generation. | |
528 if (result == NULL) { | |
529 // There is some chance the scavenge method decided to invoke mark_sweep. | |
530 // Don't mark sweep twice if so. | |
531 if (mark_sweep_invocation_count == total_invocations()) { | |
532 invoke_full_gc(false); | |
533 result = young_gen()->allocate(size, is_tlab); | |
534 } | |
535 } | |
536 | |
537 // Third level allocation failure. | |
538 // After mark sweep and young generation allocation failure, | |
539 // allocate in old generation. | |
540 if (result == NULL && !is_tlab) { | |
541 result = old_gen()->allocate(size, is_tlab); | |
542 } | |
543 | |
544 // Fourth level allocation failure. We're running out of memory. | |
545 // More complete mark sweep and allocate in young generation. | |
546 if (result == NULL) { | |
547 invoke_full_gc(true); | |
548 result = young_gen()->allocate(size, is_tlab); | |
549 } | |
550 | |
551 // Fifth level allocation failure. | |
552 // After more complete mark sweep, allocate in old generation. | |
553 if (result == NULL && !is_tlab) { | |
554 result = old_gen()->allocate(size, is_tlab); | |
555 } | |
556 | |
557 return result; | |
558 } | |
559 | |
560 // | |
561 // This is the policy loop for allocating in the permanent generation. | |
562 // If the initial allocation fails, we create a vm operation which will | |
563 // cause a collection. | |
564 HeapWord* ParallelScavengeHeap::permanent_mem_allocate(size_t size) { | |
565 assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint"); | |
566 assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread"); | |
567 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock"); | |
568 | |
569 HeapWord* result; | |
570 | |
571 uint loop_count = 0; | |
572 uint gc_count = 0; | |
573 uint full_gc_count = 0; | |
574 | |
575 do { | |
576 // We don't want to have multiple collections for a single filled generation. | |
577 // To prevent this, each thread tracks the total_collections() value, and if | |
578 // the count has changed, does not do a new collection. | |
579 // | |
580 // The collection count must be read only while holding the heap lock. VM | |
581 // operations also hold the heap lock during collections. There is a lock | |
582 // contention case where thread A blocks waiting on the Heap_lock, while | |
583 // thread B is holding it doing a collection. When thread A gets the lock, | |
584 // the collection count has already changed. To prevent duplicate collections, | |
585 // The policy MUST attempt allocations during the same period it reads the | |
586 // total_collections() value! | |
587 { | |
588 MutexLocker ml(Heap_lock); | |
589 gc_count = Universe::heap()->total_collections(); | |
590 full_gc_count = Universe::heap()->total_full_collections(); | |
591 | |
592 result = perm_gen()->allocate_permanent(size); | |
593 } | |
594 | |
595 if (result == NULL) { | |
596 | |
597 // Exit the loop if the gc time limit has been exceeded. | |
598 // The allocation must have failed above (result must be NULL), | |
599 // and the most recent collection must have exceeded the | |
600 // gc time limit. Exit the loop so that an out-of-memory | |
601 // will be thrown (returning a NULL will do that), but | |
602 // clear gc_time_limit_exceeded so that the next collection | |
603 // will succeeded if the applications decides to handle the | |
604 // out-of-memory and tries to go on. | |
605 if (size_policy()->gc_time_limit_exceeded()) { | |
606 size_policy()->set_gc_time_limit_exceeded(false); | |
607 if (PrintGCDetails && Verbose) { | |
608 gclog_or_tty->print_cr("ParallelScavengeHeap::permanent_mem_allocate: " | |
609 "return NULL because gc_time_limit_exceeded is set"); | |
610 } | |
611 assert(result == NULL, "Allocation did not fail"); | |
612 return NULL; | |
613 } | |
614 | |
615 // Generate a VM operation | |
616 VM_ParallelGCFailedPermanentAllocation op(size, gc_count, full_gc_count); | |
617 VMThread::execute(&op); | |
618 | |
619 // Did the VM operation execute? If so, return the result directly. | |
620 // This prevents us from looping until time out on requests that can | |
621 // not be satisfied. | |
622 if (op.prologue_succeeded()) { | |
623 assert(Universe::heap()->is_in_permanent_or_null(op.result()), | |
624 "result not in heap"); | |
625 // If a NULL results is being returned, an out-of-memory | |
626 // will be thrown now. Clear the gc_time_limit_exceeded | |
627 // flag to avoid the following situation. | |
628 // gc_time_limit_exceeded is set during a collection | |
629 // the collection fails to return enough space and an OOM is thrown | |
630 // the next GC is skipped because the gc_time_limit_exceeded | |
631 // flag is set and another OOM is thrown | |
632 if (op.result() == NULL) { | |
633 size_policy()->set_gc_time_limit_exceeded(false); | |
634 } | |
635 return op.result(); | |
636 } | |
637 } | |
638 | |
639 // The policy object will prevent us from looping forever. If the | |
640 // time spent in gc crosses a threshold, we will bail out. | |
641 loop_count++; | |
642 if ((QueuedAllocationWarningCount > 0) && | |
643 (loop_count % QueuedAllocationWarningCount == 0)) { | |
644 warning("ParallelScavengeHeap::permanent_mem_allocate retries %d times \n\t" | |
645 " size=%d", loop_count, size); | |
646 } | |
647 } while (result == NULL); | |
648 | |
649 return result; | |
650 } | |
651 | |
652 // | |
653 // This is the policy code for permanent allocations which have failed | |
654 // and require a collection. Note that just as in failed_mem_allocate, | |
655 // we do not set collection policy, only where & when to allocate and | |
656 // collect. | |
657 HeapWord* ParallelScavengeHeap::failed_permanent_mem_allocate(size_t size) { | |
658 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint"); | |
659 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread"); | |
660 assert(!Universe::heap()->is_gc_active(), "not reentrant"); | |
661 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock"); | |
662 assert(size > perm_gen()->free_in_words(), "Allocation should fail"); | |
663 | |
664 // We assume (and assert!) that an allocation at this point will fail | |
665 // unless we collect. | |
666 | |
667 // First level allocation failure. Mark-sweep and allocate in perm gen. | |
668 GCCauseSetter gccs(this, GCCause::_allocation_failure); | |
669 invoke_full_gc(false); | |
670 HeapWord* result = perm_gen()->allocate_permanent(size); | |
671 | |
672 // Second level allocation failure. We're running out of memory. | |
673 if (result == NULL) { | |
674 invoke_full_gc(true); | |
675 result = perm_gen()->allocate_permanent(size); | |
676 } | |
677 | |
678 return result; | |
679 } | |
680 | |
681 void ParallelScavengeHeap::ensure_parsability(bool retire_tlabs) { | |
682 CollectedHeap::ensure_parsability(retire_tlabs); | |
683 young_gen()->eden_space()->ensure_parsability(); | |
684 } | |
685 | |
686 size_t ParallelScavengeHeap::unsafe_max_alloc() { | |
687 return young_gen()->eden_space()->free_in_bytes(); | |
688 } | |
689 | |
690 size_t ParallelScavengeHeap::tlab_capacity(Thread* thr) const { | |
691 return young_gen()->eden_space()->tlab_capacity(thr); | |
692 } | |
693 | |
694 size_t ParallelScavengeHeap::unsafe_max_tlab_alloc(Thread* thr) const { | |
695 return young_gen()->eden_space()->unsafe_max_tlab_alloc(thr); | |
696 } | |
697 | |
698 HeapWord* ParallelScavengeHeap::allocate_new_tlab(size_t size) { | |
699 return young_gen()->allocate(size, true); | |
700 } | |
701 | |
702 void ParallelScavengeHeap::fill_all_tlabs(bool retire) { | |
703 CollectedHeap::fill_all_tlabs(retire); | |
704 } | |
705 | |
706 void ParallelScavengeHeap::accumulate_statistics_all_tlabs() { | |
707 CollectedHeap::accumulate_statistics_all_tlabs(); | |
708 } | |
709 | |
710 void ParallelScavengeHeap::resize_all_tlabs() { | |
711 CollectedHeap::resize_all_tlabs(); | |
712 } | |
713 | |
714 // This method is used by System.gc() and JVMTI. | |
715 void ParallelScavengeHeap::collect(GCCause::Cause cause) { | |
716 assert(!Heap_lock->owned_by_self(), | |
717 "this thread should not own the Heap_lock"); | |
718 | |
719 unsigned int gc_count = 0; | |
720 unsigned int full_gc_count = 0; | |
721 { | |
722 MutexLocker ml(Heap_lock); | |
723 // This value is guarded by the Heap_lock | |
724 gc_count = Universe::heap()->total_collections(); | |
725 full_gc_count = Universe::heap()->total_full_collections(); | |
726 } | |
727 | |
728 VM_ParallelGCSystemGC op(gc_count, full_gc_count, cause); | |
729 VMThread::execute(&op); | |
730 } | |
731 | |
732 // This interface assumes that it's being called by the | |
733 // vm thread. It collects the heap assuming that the | |
734 // heap lock is already held and that we are executing in | |
735 // the context of the vm thread. | |
736 void ParallelScavengeHeap::collect_as_vm_thread(GCCause::Cause cause) { | |
737 assert(Thread::current()->is_VM_thread(), "Precondition#1"); | |
738 assert(Heap_lock->is_locked(), "Precondition#2"); | |
739 GCCauseSetter gcs(this, cause); | |
740 switch (cause) { | |
741 case GCCause::_heap_inspection: | |
742 case GCCause::_heap_dump: { | |
743 HandleMark hm; | |
744 invoke_full_gc(false); | |
745 break; | |
746 } | |
747 default: // XXX FIX ME | |
748 ShouldNotReachHere(); | |
749 } | |
750 } | |
751 | |
752 | |
753 void ParallelScavengeHeap::oop_iterate(OopClosure* cl) { | |
754 Unimplemented(); | |
755 } | |
756 | |
757 void ParallelScavengeHeap::object_iterate(ObjectClosure* cl) { | |
758 young_gen()->object_iterate(cl); | |
759 old_gen()->object_iterate(cl); | |
760 perm_gen()->object_iterate(cl); | |
761 } | |
762 | |
763 void ParallelScavengeHeap::permanent_oop_iterate(OopClosure* cl) { | |
764 Unimplemented(); | |
765 } | |
766 | |
767 void ParallelScavengeHeap::permanent_object_iterate(ObjectClosure* cl) { | |
768 perm_gen()->object_iterate(cl); | |
769 } | |
770 | |
771 HeapWord* ParallelScavengeHeap::block_start(const void* addr) const { | |
772 if (young_gen()->is_in_reserved(addr)) { | |
773 assert(young_gen()->is_in(addr), | |
774 "addr should be in allocated part of young gen"); | |
775 Unimplemented(); | |
776 } else if (old_gen()->is_in_reserved(addr)) { | |
777 assert(old_gen()->is_in(addr), | |
778 "addr should be in allocated part of old gen"); | |
779 return old_gen()->start_array()->object_start((HeapWord*)addr); | |
780 } else if (perm_gen()->is_in_reserved(addr)) { | |
781 assert(perm_gen()->is_in(addr), | |
782 "addr should be in allocated part of perm gen"); | |
783 return perm_gen()->start_array()->object_start((HeapWord*)addr); | |
784 } | |
785 return 0; | |
786 } | |
787 | |
788 size_t ParallelScavengeHeap::block_size(const HeapWord* addr) const { | |
789 return oop(addr)->size(); | |
790 } | |
791 | |
792 bool ParallelScavengeHeap::block_is_obj(const HeapWord* addr) const { | |
793 return block_start(addr) == addr; | |
794 } | |
795 | |
796 jlong ParallelScavengeHeap::millis_since_last_gc() { | |
797 return UseParallelOldGC ? | |
798 PSParallelCompact::millis_since_last_gc() : | |
799 PSMarkSweep::millis_since_last_gc(); | |
800 } | |
801 | |
802 void ParallelScavengeHeap::prepare_for_verify() { | |
803 ensure_parsability(false); // no need to retire TLABs for verification | |
804 } | |
805 | |
806 void ParallelScavengeHeap::print() const { print_on(tty); } | |
807 | |
808 void ParallelScavengeHeap::print_on(outputStream* st) const { | |
809 young_gen()->print_on(st); | |
810 old_gen()->print_on(st); | |
811 perm_gen()->print_on(st); | |
812 } | |
813 | |
814 void ParallelScavengeHeap::gc_threads_do(ThreadClosure* tc) const { | |
815 PSScavenge::gc_task_manager()->threads_do(tc); | |
816 } | |
817 | |
818 void ParallelScavengeHeap::print_gc_threads_on(outputStream* st) const { | |
819 PSScavenge::gc_task_manager()->print_threads_on(st); | |
820 } | |
821 | |
822 void ParallelScavengeHeap::print_tracing_info() const { | |
823 if (TraceGen0Time) { | |
824 double time = PSScavenge::accumulated_time()->seconds(); | |
825 tty->print_cr("[Accumulated GC generation 0 time %3.7f secs]", time); | |
826 } | |
827 if (TraceGen1Time) { | |
828 double time = PSMarkSweep::accumulated_time()->seconds(); | |
829 tty->print_cr("[Accumulated GC generation 1 time %3.7f secs]", time); | |
830 } | |
831 } | |
832 | |
833 | |
834 void ParallelScavengeHeap::verify(bool allow_dirty, bool silent) { | |
835 // Why do we need the total_collections()-filter below? | |
836 if (total_collections() > 0) { | |
837 if (!silent) { | |
838 gclog_or_tty->print("permanent "); | |
839 } | |
840 perm_gen()->verify(allow_dirty); | |
841 | |
842 if (!silent) { | |
843 gclog_or_tty->print("tenured "); | |
844 } | |
845 old_gen()->verify(allow_dirty); | |
846 | |
847 if (!silent) { | |
848 gclog_or_tty->print("eden "); | |
849 } | |
850 young_gen()->verify(allow_dirty); | |
851 } | |
852 if (!silent) { | |
853 gclog_or_tty->print("ref_proc "); | |
854 } | |
855 ReferenceProcessor::verify(); | |
856 } | |
857 | |
858 void ParallelScavengeHeap::print_heap_change(size_t prev_used) { | |
859 if (PrintGCDetails && Verbose) { | |
860 gclog_or_tty->print(" " SIZE_FORMAT | |
861 "->" SIZE_FORMAT | |
862 "(" SIZE_FORMAT ")", | |
863 prev_used, used(), capacity()); | |
864 } else { | |
865 gclog_or_tty->print(" " SIZE_FORMAT "K" | |
866 "->" SIZE_FORMAT "K" | |
867 "(" SIZE_FORMAT "K)", | |
868 prev_used / K, used() / K, capacity() / K); | |
869 } | |
870 } | |
871 | |
872 ParallelScavengeHeap* ParallelScavengeHeap::heap() { | |
873 assert(_psh != NULL, "Uninitialized access to ParallelScavengeHeap::heap()"); | |
874 assert(_psh->kind() == CollectedHeap::ParallelScavengeHeap, "not a parallel scavenge heap"); | |
875 return _psh; | |
876 } | |
877 | |
878 // Before delegating the resize to the young generation, | |
879 // the reserved space for the young and old generations | |
880 // may be changed to accomodate the desired resize. | |
881 void ParallelScavengeHeap::resize_young_gen(size_t eden_size, | |
882 size_t survivor_size) { | |
883 if (UseAdaptiveGCBoundary) { | |
884 if (size_policy()->bytes_absorbed_from_eden() != 0) { | |
885 size_policy()->reset_bytes_absorbed_from_eden(); | |
886 return; // The generation changed size already. | |
887 } | |
888 gens()->adjust_boundary_for_young_gen_needs(eden_size, survivor_size); | |
889 } | |
890 | |
891 // Delegate the resize to the generation. | |
892 _young_gen->resize(eden_size, survivor_size); | |
893 } | |
894 | |
895 // Before delegating the resize to the old generation, | |
896 // the reserved space for the young and old generations | |
897 // may be changed to accomodate the desired resize. | |
898 void ParallelScavengeHeap::resize_old_gen(size_t desired_free_space) { | |
899 if (UseAdaptiveGCBoundary) { | |
900 if (size_policy()->bytes_absorbed_from_eden() != 0) { | |
901 size_policy()->reset_bytes_absorbed_from_eden(); | |
902 return; // The generation changed size already. | |
903 } | |
904 gens()->adjust_boundary_for_old_gen_needs(desired_free_space); | |
905 } | |
906 | |
907 // Delegate the resize to the generation. | |
908 _old_gen->resize(desired_free_space); | |
909 } |