1 /*
2 * Copyright (c) 2000, 2011, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/symbolTable.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "classfile/vmSymbols.hpp"
29 #include "code/icBuffer.hpp"
30 #include "gc_implementation/shared/collectorCounters.hpp"
31 #include "gc_implementation/shared/vmGCOperations.hpp"
32 #include "gc_interface/collectedHeap.inline.hpp"
33 #include "memory/compactPermGen.hpp"
34 #include "memory/filemap.hpp"
35 #include "memory/gcLocker.inline.hpp"
36 #include "memory/genCollectedHeap.hpp"
37 #include "memory/genOopClosures.inline.hpp"
38 #include "memory/generation.inline.hpp"
39 #include "memory/generationSpec.hpp"
40 #include "memory/permGen.hpp"
41 #include "memory/resourceArea.hpp"
42 #include "memory/sharedHeap.hpp"
43 #include "memory/space.hpp"
44 #include "oops/oop.inline.hpp"
45 #include "oops/oop.inline2.hpp"
46 #include "runtime/aprofiler.hpp"
47 #include "runtime/biasedLocking.hpp"
48 #include "runtime/fprofiler.hpp"
49 #include "runtime/handles.hpp"
50 #include "runtime/handles.inline.hpp"
51 #include "runtime/java.hpp"
52 #include "runtime/vmThread.hpp"
53 #include "services/memoryService.hpp"
54 #include "utilities/vmError.hpp"
55 #include "utilities/workgroup.hpp"
56 #ifndef SERIALGC
57 #include "gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp"
58 #include "gc_implementation/concurrentMarkSweep/vmCMSOperations.hpp"
59 #endif
60
61 GenCollectedHeap* GenCollectedHeap::_gch;
62 NOT_PRODUCT(size_t GenCollectedHeap::_skip_header_HeapWords = 0;)
63
64 // The set of potentially parallel tasks in strong root scanning.
65 enum GCH_process_strong_roots_tasks {
66 // We probably want to parallelize both of these internally, but for now...
67 GCH_PS_younger_gens,
68 // Leave this one last.
69 GCH_PS_NumElements
70 };
71
72 GenCollectedHeap::GenCollectedHeap(GenCollectorPolicy *policy) :
73 SharedHeap(policy),
74 _gen_policy(policy),
75 _gen_process_strong_tasks(new SubTasksDone(GCH_PS_NumElements)),
76 _full_collections_completed(0)
77 {
78 if (_gen_process_strong_tasks == NULL ||
79 !_gen_process_strong_tasks->valid()) {
80 vm_exit_during_initialization("Failed necessary allocation.");
81 }
82 assert(policy != NULL, "Sanity check");
83 _preloading_shared_classes = false;
84 }
85
86 jint GenCollectedHeap::initialize() {
87 CollectedHeap::pre_initialize();
88
89 int i;
90 _n_gens = gen_policy()->number_of_generations();
91
92 // While there are no constraints in the GC code that HeapWordSize
93 // be any particular value, there are multiple other areas in the
94 // system which believe this to be true (e.g. oop->object_size in some
95 // cases incorrectly returns the size in wordSize units rather than
96 // HeapWordSize).
97 guarantee(HeapWordSize == wordSize, "HeapWordSize must equal wordSize");
98
99 // The heap must be at least as aligned as generations.
100 size_t alignment = Generation::GenGrain;
101
102 _gen_specs = gen_policy()->generations();
103 PermanentGenerationSpec *perm_gen_spec =
104 collector_policy()->permanent_generation();
105
106 // Make sure the sizes are all aligned.
107 for (i = 0; i < _n_gens; i++) {
108 _gen_specs[i]->align(alignment);
109 }
110 perm_gen_spec->align(alignment);
111
112 // If we are dumping the heap, then allocate a wasted block of address
113 // space in order to push the heap to a lower address. This extra
114 // address range allows for other (or larger) libraries to be loaded
115 // without them occupying the space required for the shared spaces.
116
117 if (DumpSharedSpaces) {
118 uintx reserved = 0;
119 uintx block_size = 64*1024*1024;
120 while (reserved < SharedDummyBlockSize) {
121 char* dummy = os::reserve_memory(block_size);
122 reserved += block_size;
123 }
124 }
125
126 // Allocate space for the heap.
127
128 char* heap_address;
129 size_t total_reserved = 0;
130 int n_covered_regions = 0;
131 ReservedSpace heap_rs(0);
132
133 heap_address = allocate(alignment, perm_gen_spec, &total_reserved,
134 &n_covered_regions, &heap_rs);
135
136 if (UseSharedSpaces) {
137 if (!heap_rs.is_reserved() || heap_address != heap_rs.base()) {
138 if (heap_rs.is_reserved()) {
139 heap_rs.release();
140 }
141 FileMapInfo* mapinfo = FileMapInfo::current_info();
142 mapinfo->fail_continue("Unable to reserve shared region.");
143 allocate(alignment, perm_gen_spec, &total_reserved, &n_covered_regions,
144 &heap_rs);
145 }
146 }
147
148 if (!heap_rs.is_reserved()) {
149 vm_shutdown_during_initialization(
150 "Could not reserve enough space for object heap");
151 return JNI_ENOMEM;
152 }
153
154 _reserved = MemRegion((HeapWord*)heap_rs.base(),
155 (HeapWord*)(heap_rs.base() + heap_rs.size()));
156
157 // It is important to do this in a way such that concurrent readers can't
158 // temporarily think somethings in the heap. (Seen this happen in asserts.)
159 _reserved.set_word_size(0);
160 _reserved.set_start((HeapWord*)heap_rs.base());
161 size_t actual_heap_size = heap_rs.size() - perm_gen_spec->misc_data_size()
162 - perm_gen_spec->misc_code_size();
163 _reserved.set_end((HeapWord*)(heap_rs.base() + actual_heap_size));
164
165 _rem_set = collector_policy()->create_rem_set(_reserved, n_covered_regions);
166 set_barrier_set(rem_set()->bs());
167
168 _gch = this;
169
170 for (i = 0; i < _n_gens; i++) {
171 ReservedSpace this_rs = heap_rs.first_part(_gen_specs[i]->max_size(),
172 UseSharedSpaces, UseSharedSpaces);
173 _gens[i] = _gen_specs[i]->init(this_rs, i, rem_set());
174 heap_rs = heap_rs.last_part(_gen_specs[i]->max_size());
175 }
176 _perm_gen = perm_gen_spec->init(heap_rs, PermSize, rem_set());
177
178 clear_incremental_collection_failed();
179
180 #ifndef SERIALGC
181 // If we are running CMS, create the collector responsible
182 // for collecting the CMS generations.
183 if (collector_policy()->is_concurrent_mark_sweep_policy()) {
184 bool success = create_cms_collector();
185 if (!success) return JNI_ENOMEM;
186 }
187 #endif // SERIALGC
188
189 return JNI_OK;
190 }
191
192
193 char* GenCollectedHeap::allocate(size_t alignment,
194 PermanentGenerationSpec* perm_gen_spec,
195 size_t* _total_reserved,
196 int* _n_covered_regions,
197 ReservedSpace* heap_rs){
198 const char overflow_msg[] = "The size of the object heap + VM data exceeds "
199 "the maximum representable size";
200
201 // Now figure out the total size.
202 size_t total_reserved = 0;
203 int n_covered_regions = 0;
204 const size_t pageSize = UseLargePages ?
205 os::large_page_size() : os::vm_page_size();
206
207 for (int i = 0; i < _n_gens; i++) {
208 total_reserved += _gen_specs[i]->max_size();
209 if (total_reserved < _gen_specs[i]->max_size()) {
210 vm_exit_during_initialization(overflow_msg);
211 }
212 n_covered_regions += _gen_specs[i]->n_covered_regions();
213 }
214 assert(total_reserved % pageSize == 0,
215 err_msg("Gen size; total_reserved=" SIZE_FORMAT ", pageSize="
216 SIZE_FORMAT, total_reserved, pageSize));
217 total_reserved += perm_gen_spec->max_size();
218 assert(total_reserved % pageSize == 0,
219 err_msg("Perm size; total_reserved=" SIZE_FORMAT ", pageSize="
220 SIZE_FORMAT ", perm gen max=" SIZE_FORMAT, total_reserved,
221 pageSize, perm_gen_spec->max_size()));
222
223 if (total_reserved < perm_gen_spec->max_size()) {
224 vm_exit_during_initialization(overflow_msg);
225 }
226 n_covered_regions += perm_gen_spec->n_covered_regions();
227
228 // Add the size of the data area which shares the same reserved area
229 // as the heap, but which is not actually part of the heap.
230 size_t s = perm_gen_spec->misc_data_size() + perm_gen_spec->misc_code_size();
231
232 total_reserved += s;
233 if (total_reserved < s) {
234 vm_exit_during_initialization(overflow_msg);
235 }
236
237 if (UseLargePages) {
238 assert(total_reserved != 0, "total_reserved cannot be 0");
239 total_reserved = round_to(total_reserved, os::large_page_size());
240 if (total_reserved < os::large_page_size()) {
241 vm_exit_during_initialization(overflow_msg);
242 }
243 }
244
245 // Calculate the address at which the heap must reside in order for
246 // the shared data to be at the required address.
247
248 char* heap_address;
249 if (UseSharedSpaces) {
250
251 // Calculate the address of the first word beyond the heap.
252 FileMapInfo* mapinfo = FileMapInfo::current_info();
253 int lr = CompactingPermGenGen::n_regions - 1;
254 size_t capacity = align_size_up(mapinfo->space_capacity(lr), alignment);
255 heap_address = mapinfo->region_base(lr) + capacity;
256
257 // Calculate the address of the first word of the heap.
258 heap_address -= total_reserved;
259 } else {
260 heap_address = NULL; // any address will do.
261 if (UseCompressedOops) {
262 heap_address = Universe::preferred_heap_base(total_reserved, Universe::UnscaledNarrowOop);
263 *_total_reserved = total_reserved;
264 *_n_covered_regions = n_covered_regions;
265 *heap_rs = ReservedHeapSpace(total_reserved, alignment,
266 UseLargePages, heap_address);
267
268 if (heap_address != NULL && !heap_rs->is_reserved()) {
269 // Failed to reserve at specified address - the requested memory
270 // region is taken already, for example, by 'java' launcher.
271 // Try again to reserver heap higher.
272 heap_address = Universe::preferred_heap_base(total_reserved, Universe::ZeroBasedNarrowOop);
273 *heap_rs = ReservedHeapSpace(total_reserved, alignment,
274 UseLargePages, heap_address);
275
276 if (heap_address != NULL && !heap_rs->is_reserved()) {
277 // Failed to reserve at specified address again - give up.
278 heap_address = Universe::preferred_heap_base(total_reserved, Universe::HeapBasedNarrowOop);
279 assert(heap_address == NULL, "");
280 *heap_rs = ReservedHeapSpace(total_reserved, alignment,
281 UseLargePages, heap_address);
282 }
283 }
284 return heap_address;
285 }
286 }
287
288 *_total_reserved = total_reserved;
289 *_n_covered_regions = n_covered_regions;
290 *heap_rs = ReservedHeapSpace(total_reserved, alignment,
291 UseLargePages, heap_address);
292
293 return heap_address;
294 }
295
296
297 void GenCollectedHeap::post_initialize() {
298 SharedHeap::post_initialize();
299 TwoGenerationCollectorPolicy *policy =
300 (TwoGenerationCollectorPolicy *)collector_policy();
301 guarantee(policy->is_two_generation_policy(), "Illegal policy type");
302 DefNewGeneration* def_new_gen = (DefNewGeneration*) get_gen(0);
303 assert(def_new_gen->kind() == Generation::DefNew ||
304 def_new_gen->kind() == Generation::ParNew ||
305 def_new_gen->kind() == Generation::ASParNew,
306 "Wrong generation kind");
307
308 Generation* old_gen = get_gen(1);
309 assert(old_gen->kind() == Generation::ConcurrentMarkSweep ||
310 old_gen->kind() == Generation::ASConcurrentMarkSweep ||
311 old_gen->kind() == Generation::MarkSweepCompact,
312 "Wrong generation kind");
313
314 policy->initialize_size_policy(def_new_gen->eden()->capacity(),
315 old_gen->capacity(),
316 def_new_gen->from()->capacity());
317 policy->initialize_gc_policy_counters();
318 }
319
320 void GenCollectedHeap::ref_processing_init() {
321 SharedHeap::ref_processing_init();
322 for (int i = 0; i < _n_gens; i++) {
323 _gens[i]->ref_processor_init();
324 }
325 }
326
327 size_t GenCollectedHeap::capacity() const {
328 size_t res = 0;
329 for (int i = 0; i < _n_gens; i++) {
330 res += _gens[i]->capacity();
331 }
332 return res;
333 }
334
335 size_t GenCollectedHeap::used() const {
336 size_t res = 0;
337 for (int i = 0; i < _n_gens; i++) {
338 res += _gens[i]->used();
339 }
340 return res;
341 }
342
343 // Save the "used_region" for generations level and lower,
344 // and, if perm is true, for perm gen.
345 void GenCollectedHeap::save_used_regions(int level, bool perm) {
346 assert(level < _n_gens, "Illegal level parameter");
347 for (int i = level; i >= 0; i--) {
348 _gens[i]->save_used_region();
349 }
350 if (perm) {
351 perm_gen()->save_used_region();
352 }
353 }
354
355 size_t GenCollectedHeap::max_capacity() const {
356 size_t res = 0;
357 for (int i = 0; i < _n_gens; i++) {
358 res += _gens[i]->max_capacity();
359 }
360 return res;
361 }
362
363 // Update the _full_collections_completed counter
364 // at the end of a stop-world full GC.
365 unsigned int GenCollectedHeap::update_full_collections_completed() {
366 MonitorLockerEx ml(FullGCCount_lock, Mutex::_no_safepoint_check_flag);
367 assert(_full_collections_completed <= _total_full_collections,
368 "Can't complete more collections than were started");
369 _full_collections_completed = _total_full_collections;
370 ml.notify_all();
371 return _full_collections_completed;
372 }
373
374 // Update the _full_collections_completed counter, as appropriate,
375 // at the end of a concurrent GC cycle. Note the conditional update
376 // below to allow this method to be called by a concurrent collector
377 // without synchronizing in any manner with the VM thread (which
378 // may already have initiated a STW full collection "concurrently").
379 unsigned int GenCollectedHeap::update_full_collections_completed(unsigned int count) {
380 MonitorLockerEx ml(FullGCCount_lock, Mutex::_no_safepoint_check_flag);
381 assert((_full_collections_completed <= _total_full_collections) &&
382 (count <= _total_full_collections),
383 "Can't complete more collections than were started");
384 if (count > _full_collections_completed) {
385 _full_collections_completed = count;
386 ml.notify_all();
387 }
388 return _full_collections_completed;
389 }
390
391
392 #ifndef PRODUCT
393 // Override of memory state checking method in CollectedHeap:
394 // Some collectors (CMS for example) can't have badHeapWordVal written
395 // in the first two words of an object. (For instance , in the case of
396 // CMS these words hold state used to synchronize between certain
397 // (concurrent) GC steps and direct allocating mutators.)
398 // The skip_header_HeapWords() method below, allows us to skip
399 // over the requisite number of HeapWord's. Note that (for
400 // generational collectors) this means that those many words are
401 // skipped in each object, irrespective of the generation in which
402 // that object lives. The resultant loss of precision seems to be
403 // harmless and the pain of avoiding that imprecision appears somewhat
404 // higher than we are prepared to pay for such rudimentary debugging
405 // support.
406 void GenCollectedHeap::check_for_non_bad_heap_word_value(HeapWord* addr,
407 size_t size) {
408 if (CheckMemoryInitialization && ZapUnusedHeapArea) {
409 // We are asked to check a size in HeapWords,
410 // but the memory is mangled in juint words.
411 juint* start = (juint*) (addr + skip_header_HeapWords());
412 juint* end = (juint*) (addr + size);
413 for (juint* slot = start; slot < end; slot += 1) {
414 assert(*slot == badHeapWordVal,
415 "Found non badHeapWordValue in pre-allocation check");
416 }
417 }
418 }
419 #endif
420
421 HeapWord* GenCollectedHeap::attempt_allocation(size_t size,
422 bool is_tlab,
423 bool first_only) {
424 HeapWord* res;
425 for (int i = 0; i < _n_gens; i++) {
426 if (_gens[i]->should_allocate(size, is_tlab)) {
427 res = _gens[i]->allocate(size, is_tlab);
428 if (res != NULL) return res;
429 else if (first_only) break;
430 }
431 }
432 // Otherwise...
433 return NULL;
434 }
435
436 HeapWord* GenCollectedHeap::mem_allocate(size_t size,
437 bool* gc_overhead_limit_was_exceeded) {
438 return collector_policy()->mem_allocate_work(size,
439 false /* is_tlab */,
440 gc_overhead_limit_was_exceeded);
441 }
442
443 bool GenCollectedHeap::must_clear_all_soft_refs() {
444 return _gc_cause == GCCause::_last_ditch_collection;
445 }
446
447 bool GenCollectedHeap::should_do_concurrent_full_gc(GCCause::Cause cause) {
448 return UseConcMarkSweepGC &&
449 ((cause == GCCause::_gc_locker && GCLockerInvokesConcurrent) ||
450 (cause == GCCause::_java_lang_system_gc && ExplicitGCInvokesConcurrent));
451 }
452
453 void GenCollectedHeap::do_collection(bool full,
454 bool clear_all_soft_refs,
455 size_t size,
456 bool is_tlab,
457 int max_level) {
458 bool prepared_for_verification = false;
459 ResourceMark rm;
460 DEBUG_ONLY(Thread* my_thread = Thread::current();)
461
462 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
463 assert(my_thread->is_VM_thread() ||
464 my_thread->is_ConcurrentGC_thread(),
465 "incorrect thread type capability");
466 assert(Heap_lock->is_locked(),
467 "the requesting thread should have the Heap_lock");
468 guarantee(!is_gc_active(), "collection is not reentrant");
469 assert(max_level < n_gens(), "sanity check");
470
471 if (GC_locker::check_active_before_gc()) {
472 return; // GC is disabled (e.g. JNI GetXXXCritical operation)
473 }
474
475 const bool do_clear_all_soft_refs = clear_all_soft_refs ||
476 collector_policy()->should_clear_all_soft_refs();
477
478 ClearedAllSoftRefs casr(do_clear_all_soft_refs, collector_policy());
479
480 const size_t perm_prev_used = perm_gen()->used();
481
482 if (PrintHeapAtGC) {
483 Universe::print_heap_before_gc();
484 if (Verbose) {
485 gclog_or_tty->print_cr("GC Cause: %s", GCCause::to_string(gc_cause()));
486 }
487 }
488
489 {
490 FlagSetting fl(_is_gc_active, true);
491
492 bool complete = full && (max_level == (n_gens()-1));
493 const char* gc_cause_str = "GC ";
494 if (complete) {
495 GCCause::Cause cause = gc_cause();
496 if (cause == GCCause::_java_lang_system_gc) {
497 gc_cause_str = "Full GC (System) ";
498 } else {
499 gc_cause_str = "Full GC ";
500 }
501 }
502 gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
503 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
504 TraceTime t(gc_cause_str, PrintGCDetails, false, gclog_or_tty);
505
506 gc_prologue(complete);
507 increment_total_collections(complete);
508
509 size_t gch_prev_used = used();
510
511 int starting_level = 0;
512 if (full) {
513 // Search for the oldest generation which will collect all younger
514 // generations, and start collection loop there.
515 for (int i = max_level; i >= 0; i--) {
516 if (_gens[i]->full_collects_younger_generations()) {
517 starting_level = i;
518 break;
519 }
520 }
521 }
522
523 bool must_restore_marks_for_biased_locking = false;
524
525 int max_level_collected = starting_level;
526 for (int i = starting_level; i <= max_level; i++) {
527 if (_gens[i]->should_collect(full, size, is_tlab)) {
528 if (i == n_gens() - 1) { // a major collection is to happen
529 if (!complete) {
530 // The full_collections increment was missed above.
531 increment_total_full_collections();
532 }
533 pre_full_gc_dump(); // do any pre full gc dumps
534 }
535 // Timer for individual generations. Last argument is false: no CR
536 TraceTime t1(_gens[i]->short_name(), PrintGCDetails, false, gclog_or_tty);
537 TraceCollectorStats tcs(_gens[i]->counters());
538 TraceMemoryManagerStats tmms(_gens[i]->kind(),gc_cause());
539
540 size_t prev_used = _gens[i]->used();
541 _gens[i]->stat_record()->invocations++;
542 _gens[i]->stat_record()->accumulated_time.start();
543
544 // Must be done anew before each collection because
545 // a previous collection will do mangling and will
546 // change top of some spaces.
547 record_gen_tops_before_GC();
548
549 if (PrintGC && Verbose) {
550 gclog_or_tty->print("level=%d invoke=%d size=" SIZE_FORMAT,
551 i,
552 _gens[i]->stat_record()->invocations,
553 size*HeapWordSize);
554 }
555
556 if (VerifyBeforeGC && i >= VerifyGCLevel &&
557 total_collections() >= VerifyGCStartAt) {
558 HandleMark hm; // Discard invalid handles created during verification
559 if (!prepared_for_verification) {
560 prepare_for_verify();
561 prepared_for_verification = true;
562 }
563 gclog_or_tty->print(" VerifyBeforeGC:");
564 Universe::verify(true);
565 }
566 COMPILER2_PRESENT(DerivedPointerTable::clear());
567
568 if (!must_restore_marks_for_biased_locking &&
569 _gens[i]->performs_in_place_marking()) {
570 // We perform this mark word preservation work lazily
571 // because it's only at this point that we know whether we
572 // absolutely have to do it; we want to avoid doing it for
573 // scavenge-only collections where it's unnecessary
574 must_restore_marks_for_biased_locking = true;
575 BiasedLocking::preserve_marks();
576 }
577
578 // Do collection work
579 {
580 // Note on ref discovery: For what appear to be historical reasons,
581 // GCH enables and disabled (by enqueing) refs discovery.
582 // In the future this should be moved into the generation's
583 // collect method so that ref discovery and enqueueing concerns
584 // are local to a generation. The collect method could return
585 // an appropriate indication in the case that notification on
586 // the ref lock was needed. This will make the treatment of
587 // weak refs more uniform (and indeed remove such concerns
588 // from GCH). XXX
589
590 HandleMark hm; // Discard invalid handles created during gc
591 save_marks(); // save marks for all gens
592 // We want to discover references, but not process them yet.
593 // This mode is disabled in process_discovered_references if the
594 // generation does some collection work, or in
595 // enqueue_discovered_references if the generation returns
596 // without doing any work.
597 ReferenceProcessor* rp = _gens[i]->ref_processor();
598 // If the discovery of ("weak") refs in this generation is
599 // atomic wrt other collectors in this configuration, we
600 // are guaranteed to have empty discovered ref lists.
601 if (rp->discovery_is_atomic()) {
602 rp->enable_discovery(true /*verify_disabled*/, true /*verify_no_refs*/);
603 rp->setup_policy(do_clear_all_soft_refs);
604 } else {
605 // collect() below will enable discovery as appropriate
606 }
607 _gens[i]->collect(full, do_clear_all_soft_refs, size, is_tlab);
608 if (!rp->enqueuing_is_done()) {
609 rp->enqueue_discovered_references();
610 } else {
611 rp->set_enqueuing_is_done(false);
612 }
613 rp->verify_no_references_recorded();
614 }
615 max_level_collected = i;
616
617 // Determine if allocation request was met.
618 if (size > 0) {
619 if (!is_tlab || _gens[i]->supports_tlab_allocation()) {
620 if (size*HeapWordSize <= _gens[i]->unsafe_max_alloc_nogc()) {
621 size = 0;
622 }
623 }
624 }
625
626 COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
627
628 _gens[i]->stat_record()->accumulated_time.stop();
629
630 update_gc_stats(i, full);
631
632 if (VerifyAfterGC && i >= VerifyGCLevel &&
633 total_collections() >= VerifyGCStartAt) {
634 HandleMark hm; // Discard invalid handles created during verification
635 gclog_or_tty->print(" VerifyAfterGC:");
636 Universe::verify(false);
637 }
638
639 if (PrintGCDetails) {
640 gclog_or_tty->print(":");
641 _gens[i]->print_heap_change(prev_used);
642 }
643 }
644 }
645
646 // Update "complete" boolean wrt what actually transpired --
647 // for instance, a promotion failure could have led to
648 // a whole heap collection.
649 complete = complete || (max_level_collected == n_gens() - 1);
650
651 if (complete) { // We did a "major" collection
652 post_full_gc_dump(); // do any post full gc dumps
653 }
654
655 if (PrintGCDetails) {
656 print_heap_change(gch_prev_used);
657
658 // Print perm gen info for full GC with PrintGCDetails flag.
659 if (complete) {
660 print_perm_heap_change(perm_prev_used);
661 }
662 }
663
664 for (int j = max_level_collected; j >= 0; j -= 1) {
665 // Adjust generation sizes.
666 _gens[j]->compute_new_size();
667 }
668
669 if (complete) {
670 // Ask the permanent generation to adjust size for full collections
671 perm()->compute_new_size();
672 update_full_collections_completed();
673 }
674
675 // Track memory usage and detect low memory after GC finishes
676 MemoryService::track_memory_usage();
677
678 gc_epilogue(complete);
679
680 if (must_restore_marks_for_biased_locking) {
681 BiasedLocking::restore_marks();
682 }
683 }
684
685 AdaptiveSizePolicy* sp = gen_policy()->size_policy();
686 AdaptiveSizePolicyOutput(sp, total_collections());
687
688 if (PrintHeapAtGC) {
689 Universe::print_heap_after_gc();
690 }
691
692 #ifdef TRACESPINNING
693 ParallelTaskTerminator::print_termination_counts();
694 #endif
695
696 if (ExitAfterGCNum > 0 && total_collections() == ExitAfterGCNum) {
697 tty->print_cr("Stopping after GC #%d", ExitAfterGCNum);
698 vm_exit(-1);
699 }
700 }
701
702 HeapWord* GenCollectedHeap::satisfy_failed_allocation(size_t size, bool is_tlab) {
703 return collector_policy()->satisfy_failed_allocation(size, is_tlab);
704 }
705
706 void GenCollectedHeap::set_par_threads(int t) {
707 SharedHeap::set_par_threads(t);
708 _gen_process_strong_tasks->set_n_threads(t);
709 }
710
711 void GenCollectedHeap::
712 gen_process_strong_roots(int level,
713 bool younger_gens_as_roots,
714 bool activate_scope,
715 bool collecting_perm_gen,
716 SharedHeap::ScanningOption so,
717 OopsInGenClosure* not_older_gens,
718 bool do_code_roots,
719 OopsInGenClosure* older_gens) {
720 // General strong roots.
721
722 if (!do_code_roots) {
723 SharedHeap::process_strong_roots(activate_scope, collecting_perm_gen, so,
724 not_older_gens, NULL, older_gens);
725 } else {
726 bool do_code_marking = (activate_scope || nmethod::oops_do_marking_is_active());
727 CodeBlobToOopClosure code_roots(not_older_gens, /*do_marking=*/ do_code_marking);
728 SharedHeap::process_strong_roots(activate_scope, collecting_perm_gen, so,
729 not_older_gens, &code_roots, older_gens);
730 }
731
732 if (younger_gens_as_roots) {
733 if (!_gen_process_strong_tasks->is_task_claimed(GCH_PS_younger_gens)) {
734 for (int i = 0; i < level; i++) {
735 not_older_gens->set_generation(_gens[i]);
736 _gens[i]->oop_iterate(not_older_gens);
737 }
738 not_older_gens->reset_generation();
739 }
740 }
741 // When collection is parallel, all threads get to cooperate to do
742 // older-gen scanning.
743 for (int i = level+1; i < _n_gens; i++) {
744 older_gens->set_generation(_gens[i]);
745 rem_set()->younger_refs_iterate(_gens[i], older_gens);
746 older_gens->reset_generation();
747 }
748
749 _gen_process_strong_tasks->all_tasks_completed();
750 }
751
752 void GenCollectedHeap::gen_process_weak_roots(OopClosure* root_closure,
753 CodeBlobClosure* code_roots,
754 OopClosure* non_root_closure) {
755 SharedHeap::process_weak_roots(root_closure, code_roots, non_root_closure);
756 // "Local" "weak" refs
757 for (int i = 0; i < _n_gens; i++) {
758 _gens[i]->ref_processor()->weak_oops_do(root_closure);
759 }
760 }
761
762 #define GCH_SINCE_SAVE_MARKS_ITERATE_DEFN(OopClosureType, nv_suffix) \
763 void GenCollectedHeap:: \
764 oop_since_save_marks_iterate(int level, \
765 OopClosureType* cur, \
766 OopClosureType* older) { \
767 _gens[level]->oop_since_save_marks_iterate##nv_suffix(cur); \
768 for (int i = level+1; i < n_gens(); i++) { \
769 _gens[i]->oop_since_save_marks_iterate##nv_suffix(older); \
770 } \
771 perm_gen()->oop_since_save_marks_iterate##nv_suffix(older); \
772 }
773
774 ALL_SINCE_SAVE_MARKS_CLOSURES(GCH_SINCE_SAVE_MARKS_ITERATE_DEFN)
775
776 #undef GCH_SINCE_SAVE_MARKS_ITERATE_DEFN
777
778 bool GenCollectedHeap::no_allocs_since_save_marks(int level) {
779 for (int i = level; i < _n_gens; i++) {
780 if (!_gens[i]->no_allocs_since_save_marks()) return false;
781 }
782 return perm_gen()->no_allocs_since_save_marks();
783 }
784
785 bool GenCollectedHeap::supports_inline_contig_alloc() const {
786 return _gens[0]->supports_inline_contig_alloc();
787 }
788
789 HeapWord** GenCollectedHeap::top_addr() const {
790 return _gens[0]->top_addr();
791 }
792
793 HeapWord** GenCollectedHeap::end_addr() const {
794 return _gens[0]->end_addr();
795 }
796
797 size_t GenCollectedHeap::unsafe_max_alloc() {
798 return _gens[0]->unsafe_max_alloc_nogc();
799 }
800
801 // public collection interfaces
802
803 void GenCollectedHeap::collect(GCCause::Cause cause) {
804 if (should_do_concurrent_full_gc(cause)) {
805 #ifndef SERIALGC
806 // mostly concurrent full collection
807 collect_mostly_concurrent(cause);
808 #else // SERIALGC
809 ShouldNotReachHere();
810 #endif // SERIALGC
811 } else {
812 #ifdef ASSERT
813 if (cause == GCCause::_scavenge_alot) {
814 // minor collection only
815 collect(cause, 0);
816 } else {
817 // Stop-the-world full collection
818 collect(cause, n_gens() - 1);
819 }
820 #else
821 // Stop-the-world full collection
822 collect(cause, n_gens() - 1);
823 #endif
824 }
825 }
826
827 void GenCollectedHeap::collect(GCCause::Cause cause, int max_level) {
828 // The caller doesn't have the Heap_lock
829 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
830 MutexLocker ml(Heap_lock);
831 collect_locked(cause, max_level);
832 }
833
834 // This interface assumes that it's being called by the
835 // vm thread. It collects the heap assuming that the
836 // heap lock is already held and that we are executing in
837 // the context of the vm thread.
838 void GenCollectedHeap::collect_as_vm_thread(GCCause::Cause cause) {
839 assert(Thread::current()->is_VM_thread(), "Precondition#1");
840 assert(Heap_lock->is_locked(), "Precondition#2");
841 GCCauseSetter gcs(this, cause);
842 switch (cause) {
843 case GCCause::_heap_inspection:
844 case GCCause::_heap_dump: {
845 HandleMark hm;
846 do_full_collection(false, // don't clear all soft refs
847 n_gens() - 1);
848 break;
849 }
850 default: // XXX FIX ME
851 ShouldNotReachHere(); // Unexpected use of this function
852 }
853 }
854
855 void GenCollectedHeap::collect_locked(GCCause::Cause cause) {
856 // The caller has the Heap_lock
857 assert(Heap_lock->owned_by_self(), "this thread should own the Heap_lock");
858 collect_locked(cause, n_gens() - 1);
859 }
860
861 // this is the private collection interface
862 // The Heap_lock is expected to be held on entry.
863
864 void GenCollectedHeap::collect_locked(GCCause::Cause cause, int max_level) {
865 if (_preloading_shared_classes) {
866 report_out_of_shared_space(SharedPermGen);
867 }
868 // Read the GC count while holding the Heap_lock
869 unsigned int gc_count_before = total_collections();
870 unsigned int full_gc_count_before = total_full_collections();
871 {
872 MutexUnlocker mu(Heap_lock); // give up heap lock, execute gets it back
873 VM_GenCollectFull op(gc_count_before, full_gc_count_before,
874 cause, max_level);
875 VMThread::execute(&op);
876 }
877 }
878
879 #ifndef SERIALGC
880 bool GenCollectedHeap::create_cms_collector() {
881
882 assert(((_gens[1]->kind() == Generation::ConcurrentMarkSweep) ||
883 (_gens[1]->kind() == Generation::ASConcurrentMarkSweep)) &&
884 _perm_gen->as_gen()->kind() == Generation::ConcurrentMarkSweep,
885 "Unexpected generation kinds");
886 // Skip two header words in the block content verification
887 NOT_PRODUCT(_skip_header_HeapWords = CMSCollector::skip_header_HeapWords();)
888 CMSCollector* collector = new CMSCollector(
889 (ConcurrentMarkSweepGeneration*)_gens[1],
890 (ConcurrentMarkSweepGeneration*)_perm_gen->as_gen(),
891 _rem_set->as_CardTableRS(),
892 (ConcurrentMarkSweepPolicy*) collector_policy());
893
894 if (collector == NULL || !collector->completed_initialization()) {
895 if (collector) {
896 delete collector; // Be nice in embedded situation
897 }
898 vm_shutdown_during_initialization("Could not create CMS collector");
899 return false;
900 }
901 return true; // success
902 }
903
904 void GenCollectedHeap::collect_mostly_concurrent(GCCause::Cause cause) {
905 assert(!Heap_lock->owned_by_self(), "Should not own Heap_lock");
906
907 MutexLocker ml(Heap_lock);
908 // Read the GC counts while holding the Heap_lock
909 unsigned int full_gc_count_before = total_full_collections();
910 unsigned int gc_count_before = total_collections();
911 {
912 MutexUnlocker mu(Heap_lock);
913 VM_GenCollectFullConcurrent op(gc_count_before, full_gc_count_before, cause);
914 VMThread::execute(&op);
915 }
916 }
917 #endif // SERIALGC
918
919
920 void GenCollectedHeap::do_full_collection(bool clear_all_soft_refs,
921 int max_level) {
922 int local_max_level;
923 if (!incremental_collection_will_fail(false /* don't consult_young */) &&
924 gc_cause() == GCCause::_gc_locker) {
925 local_max_level = 0;
926 } else {
927 local_max_level = max_level;
928 }
929
930 do_collection(true /* full */,
931 clear_all_soft_refs /* clear_all_soft_refs */,
932 0 /* size */,
933 false /* is_tlab */,
934 local_max_level /* max_level */);
935 // Hack XXX FIX ME !!!
936 // A scavenge may not have been attempted, or may have
937 // been attempted and failed, because the old gen was too full
938 if (local_max_level == 0 && gc_cause() == GCCause::_gc_locker &&
939 incremental_collection_will_fail(false /* don't consult_young */)) {
940 if (PrintGCDetails) {
941 gclog_or_tty->print_cr("GC locker: Trying a full collection "
942 "because scavenge failed");
943 }
944 // This time allow the old gen to be collected as well
945 do_collection(true /* full */,
946 clear_all_soft_refs /* clear_all_soft_refs */,
947 0 /* size */,
948 false /* is_tlab */,
949 n_gens() - 1 /* max_level */);
950 }
951 }
952
953 bool GenCollectedHeap::is_in_young(oop p) {
954 bool result = ((HeapWord*)p) < _gens[_n_gens - 1]->reserved().start();
955 assert(result == _gens[0]->is_in_reserved(p),
956 err_msg("incorrect test - result=%d, p=" PTR_FORMAT, result, (void*)p));
957 return result;
958 }
959
960 // Returns "TRUE" iff "p" points into the allocated area of the heap.
961 bool GenCollectedHeap::is_in(const void* p) const {
962 #ifndef ASSERT
963 guarantee(VerifyBeforeGC ||
964 VerifyDuringGC ||
965 VerifyBeforeExit ||
966 PrintAssembly ||
967 tty->count() != 0 || // already printing
968 VerifyAfterGC ||
969 VMError::fatal_error_in_progress(), "too expensive");
970
971 #endif
972 // This might be sped up with a cache of the last generation that
973 // answered yes.
974 for (int i = 0; i < _n_gens; i++) {
975 if (_gens[i]->is_in(p)) return true;
976 }
977 if (_perm_gen->as_gen()->is_in(p)) return true;
978 // Otherwise...
979 return false;
980 }
981
982 #ifdef ASSERT
983 // Don't implement this by using is_in_young(). This method is used
984 // in some cases to check that is_in_young() is correct.
985 bool GenCollectedHeap::is_in_partial_collection(const void* p) {
986 assert(is_in_reserved(p) || p == NULL,
987 "Does not work if address is non-null and outside of the heap");
988 // The order of the generations is young (low addr), old, perm (high addr)
989 return p < _gens[_n_gens - 2]->reserved().end() && p != NULL;
990 }
991 #endif
992
993 void GenCollectedHeap::oop_iterate(OopClosure* cl) {
994 for (int i = 0; i < _n_gens; i++) {
995 _gens[i]->oop_iterate(cl);
996 }
997 }
998
999 void GenCollectedHeap::oop_iterate(MemRegion mr, OopClosure* cl) {
1000 for (int i = 0; i < _n_gens; i++) {
1001 _gens[i]->oop_iterate(mr, cl);
1002 }
1003 }
1004
1005 void GenCollectedHeap::object_iterate(ObjectClosure* cl) {
1006 for (int i = 0; i < _n_gens; i++) {
1007 _gens[i]->object_iterate(cl);
1008 }
1009 perm_gen()->object_iterate(cl);
1010 }
1011
1012 void GenCollectedHeap::safe_object_iterate(ObjectClosure* cl) {
1013 for (int i = 0; i < _n_gens; i++) {
1014 _gens[i]->safe_object_iterate(cl);
1015 }
1016 perm_gen()->safe_object_iterate(cl);
1017 }
1018
1019 void GenCollectedHeap::object_iterate_since_last_GC(ObjectClosure* cl) {
1020 for (int i = 0; i < _n_gens; i++) {
1021 _gens[i]->object_iterate_since_last_GC(cl);
1022 }
1023 }
1024
1025 Space* GenCollectedHeap::space_containing(const void* addr) const {
1026 for (int i = 0; i < _n_gens; i++) {
1027 Space* res = _gens[i]->space_containing(addr);
1028 if (res != NULL) return res;
1029 }
1030 Space* res = perm_gen()->space_containing(addr);
1031 if (res != NULL) return res;
1032 // Otherwise...
1033 assert(false, "Could not find containing space");
1034 return NULL;
1035 }
1036
1037
1038 HeapWord* GenCollectedHeap::block_start(const void* addr) const {
1039 assert(is_in_reserved(addr), "block_start of address outside of heap");
1040 for (int i = 0; i < _n_gens; i++) {
1041 if (_gens[i]->is_in_reserved(addr)) {
1042 assert(_gens[i]->is_in(addr),
1043 "addr should be in allocated part of generation");
1044 return _gens[i]->block_start(addr);
1045 }
1046 }
1047 if (perm_gen()->is_in_reserved(addr)) {
1048 assert(perm_gen()->is_in(addr),
1049 "addr should be in allocated part of perm gen");
1050 return perm_gen()->block_start(addr);
1051 }
1052 assert(false, "Some generation should contain the address");
1053 return NULL;
1054 }
1055
1056 size_t GenCollectedHeap::block_size(const HeapWord* addr) const {
1057 assert(is_in_reserved(addr), "block_size of address outside of heap");
1058 for (int i = 0; i < _n_gens; i++) {
1059 if (_gens[i]->is_in_reserved(addr)) {
1060 assert(_gens[i]->is_in(addr),
1061 "addr should be in allocated part of generation");
1062 return _gens[i]->block_size(addr);
1063 }
1064 }
1065 if (perm_gen()->is_in_reserved(addr)) {
1066 assert(perm_gen()->is_in(addr),
1067 "addr should be in allocated part of perm gen");
1068 return perm_gen()->block_size(addr);
1069 }
1070 assert(false, "Some generation should contain the address");
1071 return 0;
1072 }
1073
1074 bool GenCollectedHeap::block_is_obj(const HeapWord* addr) const {
1075 assert(is_in_reserved(addr), "block_is_obj of address outside of heap");
1076 assert(block_start(addr) == addr, "addr must be a block start");
1077 for (int i = 0; i < _n_gens; i++) {
1078 if (_gens[i]->is_in_reserved(addr)) {
1079 return _gens[i]->block_is_obj(addr);
1080 }
1081 }
1082 if (perm_gen()->is_in_reserved(addr)) {
1083 return perm_gen()->block_is_obj(addr);
1084 }
1085 assert(false, "Some generation should contain the address");
1086 return false;
1087 }
1088
1089 bool GenCollectedHeap::supports_tlab_allocation() const {
1090 for (int i = 0; i < _n_gens; i += 1) {
1091 if (_gens[i]->supports_tlab_allocation()) {
1092 return true;
1093 }
1094 }
1095 return false;
1096 }
1097
1098 size_t GenCollectedHeap::tlab_capacity(Thread* thr) const {
1099 size_t result = 0;
1100 for (int i = 0; i < _n_gens; i += 1) {
1101 if (_gens[i]->supports_tlab_allocation()) {
1102 result += _gens[i]->tlab_capacity();
1103 }
1104 }
1105 return result;
1106 }
1107
1108 size_t GenCollectedHeap::unsafe_max_tlab_alloc(Thread* thr) const {
1109 size_t result = 0;
1110 for (int i = 0; i < _n_gens; i += 1) {
1111 if (_gens[i]->supports_tlab_allocation()) {
1112 result += _gens[i]->unsafe_max_tlab_alloc();
1113 }
1114 }
1115 return result;
1116 }
1117
1118 HeapWord* GenCollectedHeap::allocate_new_tlab(size_t size) {
1119 bool gc_overhead_limit_was_exceeded;
1120 return collector_policy()->mem_allocate_work(size /* size */,
1121 true /* is_tlab */,
1122 &gc_overhead_limit_was_exceeded);
1123 }
1124
1125 // Requires "*prev_ptr" to be non-NULL. Deletes and a block of minimal size
1126 // from the list headed by "*prev_ptr".
1127 static ScratchBlock *removeSmallestScratch(ScratchBlock **prev_ptr) {
1128 bool first = true;
1129 size_t min_size = 0; // "first" makes this conceptually infinite.
1130 ScratchBlock **smallest_ptr, *smallest;
1131 ScratchBlock *cur = *prev_ptr;
1132 while (cur) {
1133 assert(*prev_ptr == cur, "just checking");
1134 if (first || cur->num_words < min_size) {
1135 smallest_ptr = prev_ptr;
1136 smallest = cur;
1137 min_size = smallest->num_words;
1138 first = false;
1139 }
1140 prev_ptr = &cur->next;
1141 cur = cur->next;
1142 }
1143 smallest = *smallest_ptr;
1144 *smallest_ptr = smallest->next;
1145 return smallest;
1146 }
1147
1148 // Sort the scratch block list headed by res into decreasing size order,
1149 // and set "res" to the result.
1150 static void sort_scratch_list(ScratchBlock*& list) {
1151 ScratchBlock* sorted = NULL;
1152 ScratchBlock* unsorted = list;
1153 while (unsorted) {
1154 ScratchBlock *smallest = removeSmallestScratch(&unsorted);
1155 smallest->next = sorted;
1156 sorted = smallest;
1157 }
1158 list = sorted;
1159 }
1160
1161 ScratchBlock* GenCollectedHeap::gather_scratch(Generation* requestor,
1162 size_t max_alloc_words) {
1163 ScratchBlock* res = NULL;
1164 for (int i = 0; i < _n_gens; i++) {
1165 _gens[i]->contribute_scratch(res, requestor, max_alloc_words);
1166 }
1167 sort_scratch_list(res);
1168 return res;
1169 }
1170
1171 void GenCollectedHeap::release_scratch() {
1172 for (int i = 0; i < _n_gens; i++) {
1173 _gens[i]->reset_scratch();
1174 }
1175 }
1176
1177 class GenPrepareForVerifyClosure: public GenCollectedHeap::GenClosure {
1178 void do_generation(Generation* gen) {
1179 gen->prepare_for_verify();
1180 }
1181 };
1182
1183 void GenCollectedHeap::prepare_for_verify() {
1184 ensure_parsability(false); // no need to retire TLABs
1185 GenPrepareForVerifyClosure blk;
1186 generation_iterate(&blk, false);
1187 perm_gen()->prepare_for_verify();
1188 }
1189
1190
1191 void GenCollectedHeap::generation_iterate(GenClosure* cl,
1192 bool old_to_young) {
1193 if (old_to_young) {
1194 for (int i = _n_gens-1; i >= 0; i--) {
1195 cl->do_generation(_gens[i]);
1196 }
1197 } else {
1198 for (int i = 0; i < _n_gens; i++) {
1199 cl->do_generation(_gens[i]);
1200 }
1201 }
1202 }
1203
1204 void GenCollectedHeap::space_iterate(SpaceClosure* cl) {
1205 for (int i = 0; i < _n_gens; i++) {
1206 _gens[i]->space_iterate(cl, true);
1207 }
1208 perm_gen()->space_iterate(cl, true);
1209 }
1210
1211 bool GenCollectedHeap::is_maximal_no_gc() const {
1212 for (int i = 0; i < _n_gens; i++) { // skip perm gen
1213 if (!_gens[i]->is_maximal_no_gc()) {
1214 return false;
1215 }
1216 }
1217 return true;
1218 }
1219
1220 void GenCollectedHeap::save_marks() {
1221 for (int i = 0; i < _n_gens; i++) {
1222 _gens[i]->save_marks();
1223 }
1224 perm_gen()->save_marks();
1225 }
1226
1227 void GenCollectedHeap::compute_new_generation_sizes(int collectedGen) {
1228 for (int i = 0; i <= collectedGen; i++) {
1229 _gens[i]->compute_new_size();
1230 }
1231 }
1232
1233 GenCollectedHeap* GenCollectedHeap::heap() {
1234 assert(_gch != NULL, "Uninitialized access to GenCollectedHeap::heap()");
1235 assert(_gch->kind() == CollectedHeap::GenCollectedHeap, "not a generational heap");
1236 return _gch;
1237 }
1238
1239
1240 void GenCollectedHeap::prepare_for_compaction() {
1241 Generation* scanning_gen = _gens[_n_gens-1];
1242 // Start by compacting into same gen.
1243 CompactPoint cp(scanning_gen, NULL, NULL);
1244 while (scanning_gen != NULL) {
1245 scanning_gen->prepare_for_compaction(&cp);
1246 scanning_gen = prev_gen(scanning_gen);
1247 }
1248 }
1249
1250 GCStats* GenCollectedHeap::gc_stats(int level) const {
1251 return _gens[level]->gc_stats();
1252 }
1253
1254 void GenCollectedHeap::verify(bool allow_dirty, bool silent, VerifyOption option /* ignored */) {
1255 if (!silent) {
1256 gclog_or_tty->print("permgen ");
1257 }
1258 perm_gen()->verify(allow_dirty);
1259 for (int i = _n_gens-1; i >= 0; i--) {
1260 Generation* g = _gens[i];
1261 if (!silent) {
1262 gclog_or_tty->print(g->name());
1263 gclog_or_tty->print(" ");
1264 }
1265 g->verify(allow_dirty);
1266 }
1267 if (!silent) {
1268 gclog_or_tty->print("remset ");
1269 }
1270 rem_set()->verify();
1271 }
1272
1273 void GenCollectedHeap::print_on(outputStream* st) const {
1274 for (int i = 0; i < _n_gens; i++) {
1275 _gens[i]->print_on(st);
1276 }
1277 perm_gen()->print_on(st);
1278 }
1279
1280 void GenCollectedHeap::gc_threads_do(ThreadClosure* tc) const {
1281 if (workers() != NULL) {
1282 workers()->threads_do(tc);
1283 }
1284 #ifndef SERIALGC
1285 if (UseConcMarkSweepGC) {
1286 ConcurrentMarkSweepThread::threads_do(tc);
1287 }
1288 #endif // SERIALGC
1289 }
1290
1291 void GenCollectedHeap::print_gc_threads_on(outputStream* st) const {
1292 #ifndef SERIALGC
1293 if (UseParNewGC) {
1294 workers()->print_worker_threads_on(st);
1295 }
1296 if (UseConcMarkSweepGC) {
1297 ConcurrentMarkSweepThread::print_all_on(st);
1298 }
1299 #endif // SERIALGC
1300 }
1301
1302 void GenCollectedHeap::print_tracing_info() const {
1303 if (TraceGen0Time) {
1304 get_gen(0)->print_summary_info();
1305 }
1306 if (TraceGen1Time) {
1307 get_gen(1)->print_summary_info();
1308 }
1309 }
1310
1311 void GenCollectedHeap::print_heap_change(size_t prev_used) const {
1312 if (PrintGCDetails && Verbose) {
1313 gclog_or_tty->print(" " SIZE_FORMAT
1314 "->" SIZE_FORMAT
1315 "(" SIZE_FORMAT ")",
1316 prev_used, used(), capacity());
1317 } else {
1318 gclog_or_tty->print(" " SIZE_FORMAT "K"
1319 "->" SIZE_FORMAT "K"
1320 "(" SIZE_FORMAT "K)",
1321 prev_used / K, used() / K, capacity() / K);
1322 }
1323 }
1324
1325 //New method to print perm gen info with PrintGCDetails flag
1326 void GenCollectedHeap::print_perm_heap_change(size_t perm_prev_used) const {
1327 gclog_or_tty->print(", [%s :", perm_gen()->short_name());
1328 perm_gen()->print_heap_change(perm_prev_used);
1329 gclog_or_tty->print("]");
1330 }
1331
1332 class GenGCPrologueClosure: public GenCollectedHeap::GenClosure {
1333 private:
1334 bool _full;
1335 public:
1336 void do_generation(Generation* gen) {
1337 gen->gc_prologue(_full);
1338 }
1339 GenGCPrologueClosure(bool full) : _full(full) {};
1340 };
1341
1342 void GenCollectedHeap::gc_prologue(bool full) {
1343 assert(InlineCacheBuffer::is_empty(), "should have cleaned up ICBuffer");
1344
1345 always_do_update_barrier = false;
1346 // Fill TLAB's and such
1347 CollectedHeap::accumulate_statistics_all_tlabs();
1348 ensure_parsability(true); // retire TLABs
1349
1350 // Call allocation profiler
1351 AllocationProfiler::iterate_since_last_gc();
1352 // Walk generations
1353 GenGCPrologueClosure blk(full);
1354 generation_iterate(&blk, false); // not old-to-young.
1355 perm_gen()->gc_prologue(full);
1356 };
1357
1358 class GenGCEpilogueClosure: public GenCollectedHeap::GenClosure {
1359 private:
1360 bool _full;
1361 public:
1362 void do_generation(Generation* gen) {
1363 gen->gc_epilogue(_full);
1364 }
1365 GenGCEpilogueClosure(bool full) : _full(full) {};
1366 };
1367
1368 void GenCollectedHeap::gc_epilogue(bool full) {
1369 #ifdef COMPILER2
1370 assert(DerivedPointerTable::is_empty(), "derived pointer present");
1371 size_t actual_gap = pointer_delta((HeapWord*) (max_uintx-3), *(end_addr()));
1372 guarantee(actual_gap > (size_t)FastAllocateSizeLimit, "inline allocation wraps");
1373 #endif /* COMPILER2 */
1374
1375 resize_all_tlabs();
1376
1377 GenGCEpilogueClosure blk(full);
1378 generation_iterate(&blk, false); // not old-to-young.
1379 perm_gen()->gc_epilogue(full);
1380
1381 if (!CleanChunkPoolAsync) {
1382 Chunk::clean_chunk_pool();
1383 }
1384
1385 always_do_update_barrier = UseConcMarkSweepGC;
1386 };
1387
1388 #ifndef PRODUCT
1389 class GenGCSaveTopsBeforeGCClosure: public GenCollectedHeap::GenClosure {
1390 private:
1391 public:
1392 void do_generation(Generation* gen) {
1393 gen->record_spaces_top();
1394 }
1395 };
1396
1397 void GenCollectedHeap::record_gen_tops_before_GC() {
1398 if (ZapUnusedHeapArea) {
1399 GenGCSaveTopsBeforeGCClosure blk;
1400 generation_iterate(&blk, false); // not old-to-young.
1401 perm_gen()->record_spaces_top();
1402 }
1403 }
1404 #endif // not PRODUCT
1405
1406 class GenEnsureParsabilityClosure: public GenCollectedHeap::GenClosure {
1407 public:
1408 void do_generation(Generation* gen) {
1409 gen->ensure_parsability();
1410 }
1411 };
1412
1413 void GenCollectedHeap::ensure_parsability(bool retire_tlabs) {
1414 CollectedHeap::ensure_parsability(retire_tlabs);
1415 GenEnsureParsabilityClosure ep_cl;
1416 generation_iterate(&ep_cl, false);
1417 perm_gen()->ensure_parsability();
1418 }
1419
1420 oop GenCollectedHeap::handle_failed_promotion(Generation* gen,
1421 oop obj,
1422 size_t obj_size) {
1423 assert(obj_size == (size_t)obj->size(), "bad obj_size passed in");
1424 HeapWord* result = NULL;
1425
1426 // First give each higher generation a chance to allocate the promoted object.
1427 Generation* allocator = next_gen(gen);
1428 if (allocator != NULL) {
1429 do {
1430 result = allocator->allocate(obj_size, false);
1431 } while (result == NULL && (allocator = next_gen(allocator)) != NULL);
1432 }
1433
1434 if (result == NULL) {
1435 // Then give gen and higher generations a chance to expand and allocate the
1436 // object.
1437 do {
1438 result = gen->expand_and_allocate(obj_size, false);
1439 } while (result == NULL && (gen = next_gen(gen)) != NULL);
1440 }
1441
1442 if (result != NULL) {
1443 Copy::aligned_disjoint_words((HeapWord*)obj, result, obj_size);
1444 }
1445 return oop(result);
1446 }
1447
1448 class GenTimeOfLastGCClosure: public GenCollectedHeap::GenClosure {
1449 jlong _time; // in ms
1450 jlong _now; // in ms
1451
1452 public:
1453 GenTimeOfLastGCClosure(jlong now) : _time(now), _now(now) { }
1454
1455 jlong time() { return _time; }
1456
1457 void do_generation(Generation* gen) {
1458 _time = MIN2(_time, gen->time_of_last_gc(_now));
1459 }
1460 };
1461
1462 jlong GenCollectedHeap::millis_since_last_gc() {
1463 jlong now = os::javaTimeMillis();
1464 GenTimeOfLastGCClosure tolgc_cl(now);
1465 // iterate over generations getting the oldest
1466 // time that a generation was collected
1467 generation_iterate(&tolgc_cl, false);
1468 tolgc_cl.do_generation(perm_gen());
1469 // XXX Despite the assert above, since javaTimeMillis()
1470 // doesnot guarantee monotonically increasing return
1471 // values (note, i didn't say "strictly monotonic"),
1472 // we need to guard against getting back a time
1473 // later than now. This should be fixed by basing
1474 // on someting like gethrtime() which guarantees
1475 // monotonicity. Note that cond_wait() is susceptible
1476 // to a similar problem, because its interface is
1477 // based on absolute time in the form of the
1478 // system time's notion of UCT. See also 4506635
1479 // for yet another problem of similar nature. XXX
1480 jlong retVal = now - tolgc_cl.time();
1481 if (retVal < 0) {
1482 NOT_PRODUCT(warning("time warp: %d", retVal);)
1483 return 0;
1484 }
1485 return retVal;
1486 }