Wed, 16 Dec 2009 12:54:49 -0500
6843629: Make current hotspot build part of jdk5 control build
Summary: Source changes for older compilers plus makefile changes.
Reviewed-by: xlu
1 /*
2 * Copyright 2000-2009 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 */
25 # include "incls/_precompiled.incl"
26 # include "incls/_genCollectedHeap.cpp.incl"
28 GenCollectedHeap* GenCollectedHeap::_gch;
29 NOT_PRODUCT(size_t GenCollectedHeap::_skip_header_HeapWords = 0;)
31 // The set of potentially parallel tasks in strong root scanning.
32 enum GCH_process_strong_roots_tasks {
33 // We probably want to parallelize both of these internally, but for now...
34 GCH_PS_younger_gens,
35 // Leave this one last.
36 GCH_PS_NumElements
37 };
39 GenCollectedHeap::GenCollectedHeap(GenCollectorPolicy *policy) :
40 SharedHeap(policy),
41 _gen_policy(policy),
42 _gen_process_strong_tasks(new SubTasksDone(GCH_PS_NumElements)),
43 _full_collections_completed(0)
44 {
45 if (_gen_process_strong_tasks == NULL ||
46 !_gen_process_strong_tasks->valid()) {
47 vm_exit_during_initialization("Failed necessary allocation.");
48 }
49 assert(policy != NULL, "Sanity check");
50 _preloading_shared_classes = false;
51 }
53 jint GenCollectedHeap::initialize() {
54 int i;
55 _n_gens = gen_policy()->number_of_generations();
57 // While there are no constraints in the GC code that HeapWordSize
58 // be any particular value, there are multiple other areas in the
59 // system which believe this to be true (e.g. oop->object_size in some
60 // cases incorrectly returns the size in wordSize units rather than
61 // HeapWordSize).
62 guarantee(HeapWordSize == wordSize, "HeapWordSize must equal wordSize");
64 // The heap must be at least as aligned as generations.
65 size_t alignment = Generation::GenGrain;
67 _gen_specs = gen_policy()->generations();
68 PermanentGenerationSpec *perm_gen_spec =
69 collector_policy()->permanent_generation();
71 // Make sure the sizes are all aligned.
72 for (i = 0; i < _n_gens; i++) {
73 _gen_specs[i]->align(alignment);
74 }
75 perm_gen_spec->align(alignment);
77 // If we are dumping the heap, then allocate a wasted block of address
78 // space in order to push the heap to a lower address. This extra
79 // address range allows for other (or larger) libraries to be loaded
80 // without them occupying the space required for the shared spaces.
82 if (DumpSharedSpaces) {
83 uintx reserved = 0;
84 uintx block_size = 64*1024*1024;
85 while (reserved < SharedDummyBlockSize) {
86 char* dummy = os::reserve_memory(block_size);
87 reserved += block_size;
88 }
89 }
91 // Allocate space for the heap.
93 char* heap_address;
94 size_t total_reserved = 0;
95 int n_covered_regions = 0;
96 ReservedSpace heap_rs(0);
98 heap_address = allocate(alignment, perm_gen_spec, &total_reserved,
99 &n_covered_regions, &heap_rs);
101 if (UseSharedSpaces) {
102 if (!heap_rs.is_reserved() || heap_address != heap_rs.base()) {
103 if (heap_rs.is_reserved()) {
104 heap_rs.release();
105 }
106 FileMapInfo* mapinfo = FileMapInfo::current_info();
107 mapinfo->fail_continue("Unable to reserve shared region.");
108 allocate(alignment, perm_gen_spec, &total_reserved, &n_covered_regions,
109 &heap_rs);
110 }
111 }
113 if (!heap_rs.is_reserved()) {
114 vm_shutdown_during_initialization(
115 "Could not reserve enough space for object heap");
116 return JNI_ENOMEM;
117 }
119 _reserved = MemRegion((HeapWord*)heap_rs.base(),
120 (HeapWord*)(heap_rs.base() + heap_rs.size()));
122 // It is important to do this in a way such that concurrent readers can't
123 // temporarily think somethings in the heap. (Seen this happen in asserts.)
124 _reserved.set_word_size(0);
125 _reserved.set_start((HeapWord*)heap_rs.base());
126 size_t actual_heap_size = heap_rs.size() - perm_gen_spec->misc_data_size()
127 - perm_gen_spec->misc_code_size();
128 _reserved.set_end((HeapWord*)(heap_rs.base() + actual_heap_size));
130 _rem_set = collector_policy()->create_rem_set(_reserved, n_covered_regions);
131 set_barrier_set(rem_set()->bs());
132 _gch = this;
134 for (i = 0; i < _n_gens; i++) {
135 ReservedSpace this_rs = heap_rs.first_part(_gen_specs[i]->max_size(),
136 UseSharedSpaces, UseSharedSpaces);
137 _gens[i] = _gen_specs[i]->init(this_rs, i, rem_set());
138 heap_rs = heap_rs.last_part(_gen_specs[i]->max_size());
139 }
140 _perm_gen = perm_gen_spec->init(heap_rs, PermSize, rem_set());
142 clear_incremental_collection_will_fail();
143 clear_last_incremental_collection_failed();
145 #ifndef SERIALGC
146 // If we are running CMS, create the collector responsible
147 // for collecting the CMS generations.
148 if (collector_policy()->is_concurrent_mark_sweep_policy()) {
149 bool success = create_cms_collector();
150 if (!success) return JNI_ENOMEM;
151 }
152 #endif // SERIALGC
154 return JNI_OK;
155 }
158 char* GenCollectedHeap::allocate(size_t alignment,
159 PermanentGenerationSpec* perm_gen_spec,
160 size_t* _total_reserved,
161 int* _n_covered_regions,
162 ReservedSpace* heap_rs){
163 const char overflow_msg[] = "The size of the object heap + VM data exceeds "
164 "the maximum representable size";
166 // Now figure out the total size.
167 size_t total_reserved = 0;
168 int n_covered_regions = 0;
169 const size_t pageSize = UseLargePages ?
170 os::large_page_size() : os::vm_page_size();
172 for (int i = 0; i < _n_gens; i++) {
173 total_reserved += _gen_specs[i]->max_size();
174 if (total_reserved < _gen_specs[i]->max_size()) {
175 vm_exit_during_initialization(overflow_msg);
176 }
177 n_covered_regions += _gen_specs[i]->n_covered_regions();
178 }
179 assert(total_reserved % pageSize == 0, "Gen size");
180 total_reserved += perm_gen_spec->max_size();
181 assert(total_reserved % pageSize == 0, "Perm Gen size");
183 if (total_reserved < perm_gen_spec->max_size()) {
184 vm_exit_during_initialization(overflow_msg);
185 }
186 n_covered_regions += perm_gen_spec->n_covered_regions();
188 // Add the size of the data area which shares the same reserved area
189 // as the heap, but which is not actually part of the heap.
190 size_t s = perm_gen_spec->misc_data_size() + perm_gen_spec->misc_code_size();
192 total_reserved += s;
193 if (total_reserved < s) {
194 vm_exit_during_initialization(overflow_msg);
195 }
197 if (UseLargePages) {
198 assert(total_reserved != 0, "total_reserved cannot be 0");
199 total_reserved = round_to(total_reserved, os::large_page_size());
200 if (total_reserved < os::large_page_size()) {
201 vm_exit_during_initialization(overflow_msg);
202 }
203 }
205 // Calculate the address at which the heap must reside in order for
206 // the shared data to be at the required address.
208 char* heap_address;
209 if (UseSharedSpaces) {
211 // Calculate the address of the first word beyond the heap.
212 FileMapInfo* mapinfo = FileMapInfo::current_info();
213 int lr = CompactingPermGenGen::n_regions - 1;
214 size_t capacity = align_size_up(mapinfo->space_capacity(lr), alignment);
215 heap_address = mapinfo->region_base(lr) + capacity;
217 // Calculate the address of the first word of the heap.
218 heap_address -= total_reserved;
219 } else {
220 heap_address = NULL; // any address will do.
221 if (UseCompressedOops) {
222 heap_address = Universe::preferred_heap_base(total_reserved, Universe::UnscaledNarrowOop);
223 *_total_reserved = total_reserved;
224 *_n_covered_regions = n_covered_regions;
225 *heap_rs = ReservedHeapSpace(total_reserved, alignment,
226 UseLargePages, heap_address);
228 if (heap_address != NULL && !heap_rs->is_reserved()) {
229 // Failed to reserve at specified address - the requested memory
230 // region is taken already, for example, by 'java' launcher.
231 // Try again to reserver heap higher.
232 heap_address = Universe::preferred_heap_base(total_reserved, Universe::ZeroBasedNarrowOop);
233 *heap_rs = ReservedHeapSpace(total_reserved, alignment,
234 UseLargePages, heap_address);
236 if (heap_address != NULL && !heap_rs->is_reserved()) {
237 // Failed to reserve at specified address again - give up.
238 heap_address = Universe::preferred_heap_base(total_reserved, Universe::HeapBasedNarrowOop);
239 assert(heap_address == NULL, "");
240 *heap_rs = ReservedHeapSpace(total_reserved, alignment,
241 UseLargePages, heap_address);
242 }
243 }
244 return heap_address;
245 }
246 }
248 *_total_reserved = total_reserved;
249 *_n_covered_regions = n_covered_regions;
250 *heap_rs = ReservedHeapSpace(total_reserved, alignment,
251 UseLargePages, heap_address);
253 return heap_address;
254 }
257 void GenCollectedHeap::post_initialize() {
258 SharedHeap::post_initialize();
259 TwoGenerationCollectorPolicy *policy =
260 (TwoGenerationCollectorPolicy *)collector_policy();
261 guarantee(policy->is_two_generation_policy(), "Illegal policy type");
262 DefNewGeneration* def_new_gen = (DefNewGeneration*) get_gen(0);
263 assert(def_new_gen->kind() == Generation::DefNew ||
264 def_new_gen->kind() == Generation::ParNew ||
265 def_new_gen->kind() == Generation::ASParNew,
266 "Wrong generation kind");
268 Generation* old_gen = get_gen(1);
269 assert(old_gen->kind() == Generation::ConcurrentMarkSweep ||
270 old_gen->kind() == Generation::ASConcurrentMarkSweep ||
271 old_gen->kind() == Generation::MarkSweepCompact,
272 "Wrong generation kind");
274 policy->initialize_size_policy(def_new_gen->eden()->capacity(),
275 old_gen->capacity(),
276 def_new_gen->from()->capacity());
277 policy->initialize_gc_policy_counters();
278 }
280 void GenCollectedHeap::ref_processing_init() {
281 SharedHeap::ref_processing_init();
282 for (int i = 0; i < _n_gens; i++) {
283 _gens[i]->ref_processor_init();
284 }
285 }
287 size_t GenCollectedHeap::capacity() const {
288 size_t res = 0;
289 for (int i = 0; i < _n_gens; i++) {
290 res += _gens[i]->capacity();
291 }
292 return res;
293 }
295 size_t GenCollectedHeap::used() const {
296 size_t res = 0;
297 for (int i = 0; i < _n_gens; i++) {
298 res += _gens[i]->used();
299 }
300 return res;
301 }
303 // Save the "used_region" for generations level and lower,
304 // and, if perm is true, for perm gen.
305 void GenCollectedHeap::save_used_regions(int level, bool perm) {
306 assert(level < _n_gens, "Illegal level parameter");
307 for (int i = level; i >= 0; i--) {
308 _gens[i]->save_used_region();
309 }
310 if (perm) {
311 perm_gen()->save_used_region();
312 }
313 }
315 size_t GenCollectedHeap::max_capacity() const {
316 size_t res = 0;
317 for (int i = 0; i < _n_gens; i++) {
318 res += _gens[i]->max_capacity();
319 }
320 return res;
321 }
323 // Update the _full_collections_completed counter
324 // at the end of a stop-world full GC.
325 unsigned int GenCollectedHeap::update_full_collections_completed() {
326 MonitorLockerEx ml(FullGCCount_lock, Mutex::_no_safepoint_check_flag);
327 assert(_full_collections_completed <= _total_full_collections,
328 "Can't complete more collections than were started");
329 _full_collections_completed = _total_full_collections;
330 ml.notify_all();
331 return _full_collections_completed;
332 }
334 // Update the _full_collections_completed counter, as appropriate,
335 // at the end of a concurrent GC cycle. Note the conditional update
336 // below to allow this method to be called by a concurrent collector
337 // without synchronizing in any manner with the VM thread (which
338 // may already have initiated a STW full collection "concurrently").
339 unsigned int GenCollectedHeap::update_full_collections_completed(unsigned int count) {
340 MonitorLockerEx ml(FullGCCount_lock, Mutex::_no_safepoint_check_flag);
341 assert((_full_collections_completed <= _total_full_collections) &&
342 (count <= _total_full_collections),
343 "Can't complete more collections than were started");
344 if (count > _full_collections_completed) {
345 _full_collections_completed = count;
346 ml.notify_all();
347 }
348 return _full_collections_completed;
349 }
352 #ifndef PRODUCT
353 // Override of memory state checking method in CollectedHeap:
354 // Some collectors (CMS for example) can't have badHeapWordVal written
355 // in the first two words of an object. (For instance , in the case of
356 // CMS these words hold state used to synchronize between certain
357 // (concurrent) GC steps and direct allocating mutators.)
358 // The skip_header_HeapWords() method below, allows us to skip
359 // over the requisite number of HeapWord's. Note that (for
360 // generational collectors) this means that those many words are
361 // skipped in each object, irrespective of the generation in which
362 // that object lives. The resultant loss of precision seems to be
363 // harmless and the pain of avoiding that imprecision appears somewhat
364 // higher than we are prepared to pay for such rudimentary debugging
365 // support.
366 void GenCollectedHeap::check_for_non_bad_heap_word_value(HeapWord* addr,
367 size_t size) {
368 if (CheckMemoryInitialization && ZapUnusedHeapArea) {
369 // We are asked to check a size in HeapWords,
370 // but the memory is mangled in juint words.
371 juint* start = (juint*) (addr + skip_header_HeapWords());
372 juint* end = (juint*) (addr + size);
373 for (juint* slot = start; slot < end; slot += 1) {
374 assert(*slot == badHeapWordVal,
375 "Found non badHeapWordValue in pre-allocation check");
376 }
377 }
378 }
379 #endif
381 HeapWord* GenCollectedHeap::attempt_allocation(size_t size,
382 bool is_tlab,
383 bool first_only) {
384 HeapWord* res;
385 for (int i = 0; i < _n_gens; i++) {
386 if (_gens[i]->should_allocate(size, is_tlab)) {
387 res = _gens[i]->allocate(size, is_tlab);
388 if (res != NULL) return res;
389 else if (first_only) break;
390 }
391 }
392 // Otherwise...
393 return NULL;
394 }
396 HeapWord* GenCollectedHeap::mem_allocate(size_t size,
397 bool is_large_noref,
398 bool is_tlab,
399 bool* gc_overhead_limit_was_exceeded) {
400 return collector_policy()->mem_allocate_work(size,
401 is_tlab,
402 gc_overhead_limit_was_exceeded);
403 }
405 bool GenCollectedHeap::must_clear_all_soft_refs() {
406 return _gc_cause == GCCause::_last_ditch_collection;
407 }
409 bool GenCollectedHeap::should_do_concurrent_full_gc(GCCause::Cause cause) {
410 return (cause == GCCause::_java_lang_system_gc ||
411 cause == GCCause::_gc_locker) &&
412 UseConcMarkSweepGC && ExplicitGCInvokesConcurrent;
413 }
415 void GenCollectedHeap::do_collection(bool full,
416 bool clear_all_soft_refs,
417 size_t size,
418 bool is_tlab,
419 int max_level) {
420 bool prepared_for_verification = false;
421 ResourceMark rm;
422 DEBUG_ONLY(Thread* my_thread = Thread::current();)
424 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
425 assert(my_thread->is_VM_thread() ||
426 my_thread->is_ConcurrentGC_thread(),
427 "incorrect thread type capability");
428 assert(Heap_lock->is_locked(), "the requesting thread should have the Heap_lock");
429 guarantee(!is_gc_active(), "collection is not reentrant");
430 assert(max_level < n_gens(), "sanity check");
432 if (GC_locker::check_active_before_gc()) {
433 return; // GC is disabled (e.g. JNI GetXXXCritical operation)
434 }
436 const size_t perm_prev_used = perm_gen()->used();
438 if (PrintHeapAtGC) {
439 Universe::print_heap_before_gc();
440 if (Verbose) {
441 gclog_or_tty->print_cr("GC Cause: %s", GCCause::to_string(gc_cause()));
442 }
443 }
445 {
446 FlagSetting fl(_is_gc_active, true);
448 bool complete = full && (max_level == (n_gens()-1));
449 const char* gc_cause_str = "GC ";
450 if (complete) {
451 GCCause::Cause cause = gc_cause();
452 if (cause == GCCause::_java_lang_system_gc) {
453 gc_cause_str = "Full GC (System) ";
454 } else {
455 gc_cause_str = "Full GC ";
456 }
457 }
458 gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
459 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
460 TraceTime t(gc_cause_str, PrintGCDetails, false, gclog_or_tty);
462 gc_prologue(complete);
463 increment_total_collections(complete);
465 size_t gch_prev_used = used();
467 int starting_level = 0;
468 if (full) {
469 // Search for the oldest generation which will collect all younger
470 // generations, and start collection loop there.
471 for (int i = max_level; i >= 0; i--) {
472 if (_gens[i]->full_collects_younger_generations()) {
473 starting_level = i;
474 break;
475 }
476 }
477 }
479 bool must_restore_marks_for_biased_locking = false;
481 int max_level_collected = starting_level;
482 for (int i = starting_level; i <= max_level; i++) {
483 if (_gens[i]->should_collect(full, size, is_tlab)) {
484 if (i == n_gens() - 1) { // a major collection is to happen
485 if (!complete) {
486 // The full_collections increment was missed above.
487 increment_total_full_collections();
488 }
489 pre_full_gc_dump(); // do any pre full gc dumps
490 }
491 // Timer for individual generations. Last argument is false: no CR
492 TraceTime t1(_gens[i]->short_name(), PrintGCDetails, false, gclog_or_tty);
493 TraceCollectorStats tcs(_gens[i]->counters());
494 TraceMemoryManagerStats tmms(_gens[i]->kind());
496 size_t prev_used = _gens[i]->used();
497 _gens[i]->stat_record()->invocations++;
498 _gens[i]->stat_record()->accumulated_time.start();
500 // Must be done anew before each collection because
501 // a previous collection will do mangling and will
502 // change top of some spaces.
503 record_gen_tops_before_GC();
505 if (PrintGC && Verbose) {
506 gclog_or_tty->print("level=%d invoke=%d size=" SIZE_FORMAT,
507 i,
508 _gens[i]->stat_record()->invocations,
509 size*HeapWordSize);
510 }
512 if (VerifyBeforeGC && i >= VerifyGCLevel &&
513 total_collections() >= VerifyGCStartAt) {
514 HandleMark hm; // Discard invalid handles created during verification
515 if (!prepared_for_verification) {
516 prepare_for_verify();
517 prepared_for_verification = true;
518 }
519 gclog_or_tty->print(" VerifyBeforeGC:");
520 Universe::verify(true);
521 }
522 COMPILER2_PRESENT(DerivedPointerTable::clear());
524 if (!must_restore_marks_for_biased_locking &&
525 _gens[i]->performs_in_place_marking()) {
526 // We perform this mark word preservation work lazily
527 // because it's only at this point that we know whether we
528 // absolutely have to do it; we want to avoid doing it for
529 // scavenge-only collections where it's unnecessary
530 must_restore_marks_for_biased_locking = true;
531 BiasedLocking::preserve_marks();
532 }
534 // Do collection work
535 {
536 // Note on ref discovery: For what appear to be historical reasons,
537 // GCH enables and disabled (by enqueing) refs discovery.
538 // In the future this should be moved into the generation's
539 // collect method so that ref discovery and enqueueing concerns
540 // are local to a generation. The collect method could return
541 // an appropriate indication in the case that notification on
542 // the ref lock was needed. This will make the treatment of
543 // weak refs more uniform (and indeed remove such concerns
544 // from GCH). XXX
546 HandleMark hm; // Discard invalid handles created during gc
547 save_marks(); // save marks for all gens
548 // We want to discover references, but not process them yet.
549 // This mode is disabled in process_discovered_references if the
550 // generation does some collection work, or in
551 // enqueue_discovered_references if the generation returns
552 // without doing any work.
553 ReferenceProcessor* rp = _gens[i]->ref_processor();
554 // If the discovery of ("weak") refs in this generation is
555 // atomic wrt other collectors in this configuration, we
556 // are guaranteed to have empty discovered ref lists.
557 if (rp->discovery_is_atomic()) {
558 rp->verify_no_references_recorded();
559 rp->enable_discovery();
560 rp->setup_policy(clear_all_soft_refs);
561 } else {
562 // collect() below will enable discovery as appropriate
563 }
564 _gens[i]->collect(full, clear_all_soft_refs, size, is_tlab);
565 if (!rp->enqueuing_is_done()) {
566 rp->enqueue_discovered_references();
567 } else {
568 rp->set_enqueuing_is_done(false);
569 }
570 rp->verify_no_references_recorded();
571 }
572 max_level_collected = i;
574 // Determine if allocation request was met.
575 if (size > 0) {
576 if (!is_tlab || _gens[i]->supports_tlab_allocation()) {
577 if (size*HeapWordSize <= _gens[i]->unsafe_max_alloc_nogc()) {
578 size = 0;
579 }
580 }
581 }
583 COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
585 _gens[i]->stat_record()->accumulated_time.stop();
587 update_gc_stats(i, full);
589 if (VerifyAfterGC && i >= VerifyGCLevel &&
590 total_collections() >= VerifyGCStartAt) {
591 HandleMark hm; // Discard invalid handles created during verification
592 gclog_or_tty->print(" VerifyAfterGC:");
593 Universe::verify(false);
594 }
596 if (PrintGCDetails) {
597 gclog_or_tty->print(":");
598 _gens[i]->print_heap_change(prev_used);
599 }
600 }
601 }
603 // Update "complete" boolean wrt what actually transpired --
604 // for instance, a promotion failure could have led to
605 // a whole heap collection.
606 complete = complete || (max_level_collected == n_gens() - 1);
608 if (complete) { // We did a "major" collection
609 post_full_gc_dump(); // do any post full gc dumps
610 }
612 if (PrintGCDetails) {
613 print_heap_change(gch_prev_used);
615 // Print perm gen info for full GC with PrintGCDetails flag.
616 if (complete) {
617 print_perm_heap_change(perm_prev_used);
618 }
619 }
621 for (int j = max_level_collected; j >= 0; j -= 1) {
622 // Adjust generation sizes.
623 _gens[j]->compute_new_size();
624 }
626 if (complete) {
627 // Ask the permanent generation to adjust size for full collections
628 perm()->compute_new_size();
629 update_full_collections_completed();
630 }
632 // Track memory usage and detect low memory after GC finishes
633 MemoryService::track_memory_usage();
635 gc_epilogue(complete);
637 if (must_restore_marks_for_biased_locking) {
638 BiasedLocking::restore_marks();
639 }
640 }
642 AdaptiveSizePolicy* sp = gen_policy()->size_policy();
643 AdaptiveSizePolicyOutput(sp, total_collections());
645 if (PrintHeapAtGC) {
646 Universe::print_heap_after_gc();
647 }
649 #ifdef TRACESPINNING
650 ParallelTaskTerminator::print_termination_counts();
651 #endif
653 if (ExitAfterGCNum > 0 && total_collections() == ExitAfterGCNum) {
654 tty->print_cr("Stopping after GC #%d", ExitAfterGCNum);
655 vm_exit(-1);
656 }
657 }
659 HeapWord* GenCollectedHeap::satisfy_failed_allocation(size_t size, bool is_tlab) {
660 return collector_policy()->satisfy_failed_allocation(size, is_tlab);
661 }
663 void GenCollectedHeap::set_par_threads(int t) {
664 SharedHeap::set_par_threads(t);
665 _gen_process_strong_tasks->set_par_threads(t);
666 }
668 class AssertIsPermClosure: public OopClosure {
669 public:
670 void do_oop(oop* p) {
671 assert((*p) == NULL || (*p)->is_perm(), "Referent should be perm.");
672 }
673 void do_oop(narrowOop* p) { ShouldNotReachHere(); }
674 };
675 static AssertIsPermClosure assert_is_perm_closure;
677 void GenCollectedHeap::
678 gen_process_strong_roots(int level,
679 bool younger_gens_as_roots,
680 bool activate_scope,
681 bool collecting_perm_gen,
682 SharedHeap::ScanningOption so,
683 OopsInGenClosure* not_older_gens,
684 bool do_code_roots,
685 OopsInGenClosure* older_gens) {
686 // General strong roots.
688 if (!do_code_roots) {
689 SharedHeap::process_strong_roots(activate_scope, collecting_perm_gen, so,
690 not_older_gens, NULL, older_gens);
691 } else {
692 bool do_code_marking = (activate_scope || nmethod::oops_do_marking_is_active());
693 CodeBlobToOopClosure code_roots(not_older_gens, /*do_marking=*/ do_code_marking);
694 SharedHeap::process_strong_roots(activate_scope, collecting_perm_gen, so,
695 not_older_gens, &code_roots, older_gens);
696 }
698 if (younger_gens_as_roots) {
699 if (!_gen_process_strong_tasks->is_task_claimed(GCH_PS_younger_gens)) {
700 for (int i = 0; i < level; i++) {
701 not_older_gens->set_generation(_gens[i]);
702 _gens[i]->oop_iterate(not_older_gens);
703 }
704 not_older_gens->reset_generation();
705 }
706 }
707 // When collection is parallel, all threads get to cooperate to do
708 // older-gen scanning.
709 for (int i = level+1; i < _n_gens; i++) {
710 older_gens->set_generation(_gens[i]);
711 rem_set()->younger_refs_iterate(_gens[i], older_gens);
712 older_gens->reset_generation();
713 }
715 _gen_process_strong_tasks->all_tasks_completed();
716 }
718 void GenCollectedHeap::gen_process_weak_roots(OopClosure* root_closure,
719 CodeBlobClosure* code_roots,
720 OopClosure* non_root_closure) {
721 SharedHeap::process_weak_roots(root_closure, code_roots, non_root_closure);
722 // "Local" "weak" refs
723 for (int i = 0; i < _n_gens; i++) {
724 _gens[i]->ref_processor()->weak_oops_do(root_closure);
725 }
726 }
728 #define GCH_SINCE_SAVE_MARKS_ITERATE_DEFN(OopClosureType, nv_suffix) \
729 void GenCollectedHeap:: \
730 oop_since_save_marks_iterate(int level, \
731 OopClosureType* cur, \
732 OopClosureType* older) { \
733 _gens[level]->oop_since_save_marks_iterate##nv_suffix(cur); \
734 for (int i = level+1; i < n_gens(); i++) { \
735 _gens[i]->oop_since_save_marks_iterate##nv_suffix(older); \
736 } \
737 perm_gen()->oop_since_save_marks_iterate##nv_suffix(older); \
738 }
740 ALL_SINCE_SAVE_MARKS_CLOSURES(GCH_SINCE_SAVE_MARKS_ITERATE_DEFN)
742 #undef GCH_SINCE_SAVE_MARKS_ITERATE_DEFN
744 bool GenCollectedHeap::no_allocs_since_save_marks(int level) {
745 for (int i = level; i < _n_gens; i++) {
746 if (!_gens[i]->no_allocs_since_save_marks()) return false;
747 }
748 return perm_gen()->no_allocs_since_save_marks();
749 }
751 bool GenCollectedHeap::supports_inline_contig_alloc() const {
752 return _gens[0]->supports_inline_contig_alloc();
753 }
755 HeapWord** GenCollectedHeap::top_addr() const {
756 return _gens[0]->top_addr();
757 }
759 HeapWord** GenCollectedHeap::end_addr() const {
760 return _gens[0]->end_addr();
761 }
763 size_t GenCollectedHeap::unsafe_max_alloc() {
764 return _gens[0]->unsafe_max_alloc_nogc();
765 }
767 // public collection interfaces
769 void GenCollectedHeap::collect(GCCause::Cause cause) {
770 if (should_do_concurrent_full_gc(cause)) {
771 #ifndef SERIALGC
772 // mostly concurrent full collection
773 collect_mostly_concurrent(cause);
774 #else // SERIALGC
775 ShouldNotReachHere();
776 #endif // SERIALGC
777 } else {
778 #ifdef ASSERT
779 if (cause == GCCause::_scavenge_alot) {
780 // minor collection only
781 collect(cause, 0);
782 } else {
783 // Stop-the-world full collection
784 collect(cause, n_gens() - 1);
785 }
786 #else
787 // Stop-the-world full collection
788 collect(cause, n_gens() - 1);
789 #endif
790 }
791 }
793 void GenCollectedHeap::collect(GCCause::Cause cause, int max_level) {
794 // The caller doesn't have the Heap_lock
795 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
796 MutexLocker ml(Heap_lock);
797 collect_locked(cause, max_level);
798 }
800 // This interface assumes that it's being called by the
801 // vm thread. It collects the heap assuming that the
802 // heap lock is already held and that we are executing in
803 // the context of the vm thread.
804 void GenCollectedHeap::collect_as_vm_thread(GCCause::Cause cause) {
805 assert(Thread::current()->is_VM_thread(), "Precondition#1");
806 assert(Heap_lock->is_locked(), "Precondition#2");
807 GCCauseSetter gcs(this, cause);
808 switch (cause) {
809 case GCCause::_heap_inspection:
810 case GCCause::_heap_dump: {
811 HandleMark hm;
812 do_full_collection(false, // don't clear all soft refs
813 n_gens() - 1);
814 break;
815 }
816 default: // XXX FIX ME
817 ShouldNotReachHere(); // Unexpected use of this function
818 }
819 }
821 void GenCollectedHeap::collect_locked(GCCause::Cause cause) {
822 // The caller has the Heap_lock
823 assert(Heap_lock->owned_by_self(), "this thread should own the Heap_lock");
824 collect_locked(cause, n_gens() - 1);
825 }
827 // this is the private collection interface
828 // The Heap_lock is expected to be held on entry.
830 void GenCollectedHeap::collect_locked(GCCause::Cause cause, int max_level) {
831 if (_preloading_shared_classes) {
832 warning("\nThe permanent generation is not large enough to preload "
833 "requested classes.\nUse -XX:PermSize= to increase the initial "
834 "size of the permanent generation.\n");
835 vm_exit(2);
836 }
837 // Read the GC count while holding the Heap_lock
838 unsigned int gc_count_before = total_collections();
839 unsigned int full_gc_count_before = total_full_collections();
840 {
841 MutexUnlocker mu(Heap_lock); // give up heap lock, execute gets it back
842 VM_GenCollectFull op(gc_count_before, full_gc_count_before,
843 cause, max_level);
844 VMThread::execute(&op);
845 }
846 }
848 #ifndef SERIALGC
849 bool GenCollectedHeap::create_cms_collector() {
851 assert(((_gens[1]->kind() == Generation::ConcurrentMarkSweep) ||
852 (_gens[1]->kind() == Generation::ASConcurrentMarkSweep)) &&
853 _perm_gen->as_gen()->kind() == Generation::ConcurrentMarkSweep,
854 "Unexpected generation kinds");
855 // Skip two header words in the block content verification
856 NOT_PRODUCT(_skip_header_HeapWords = CMSCollector::skip_header_HeapWords();)
857 CMSCollector* collector = new CMSCollector(
858 (ConcurrentMarkSweepGeneration*)_gens[1],
859 (ConcurrentMarkSweepGeneration*)_perm_gen->as_gen(),
860 _rem_set->as_CardTableRS(),
861 (ConcurrentMarkSweepPolicy*) collector_policy());
863 if (collector == NULL || !collector->completed_initialization()) {
864 if (collector) {
865 delete collector; // Be nice in embedded situation
866 }
867 vm_shutdown_during_initialization("Could not create CMS collector");
868 return false;
869 }
870 return true; // success
871 }
873 void GenCollectedHeap::collect_mostly_concurrent(GCCause::Cause cause) {
874 assert(!Heap_lock->owned_by_self(), "Should not own Heap_lock");
876 MutexLocker ml(Heap_lock);
877 // Read the GC counts while holding the Heap_lock
878 unsigned int full_gc_count_before = total_full_collections();
879 unsigned int gc_count_before = total_collections();
880 {
881 MutexUnlocker mu(Heap_lock);
882 VM_GenCollectFullConcurrent op(gc_count_before, full_gc_count_before, cause);
883 VMThread::execute(&op);
884 }
885 }
886 #endif // SERIALGC
889 void GenCollectedHeap::do_full_collection(bool clear_all_soft_refs,
890 int max_level) {
891 int local_max_level;
892 if (!incremental_collection_will_fail() &&
893 gc_cause() == GCCause::_gc_locker) {
894 local_max_level = 0;
895 } else {
896 local_max_level = max_level;
897 }
899 do_collection(true /* full */,
900 clear_all_soft_refs /* clear_all_soft_refs */,
901 0 /* size */,
902 false /* is_tlab */,
903 local_max_level /* max_level */);
904 // Hack XXX FIX ME !!!
905 // A scavenge may not have been attempted, or may have
906 // been attempted and failed, because the old gen was too full
907 if (local_max_level == 0 && gc_cause() == GCCause::_gc_locker &&
908 incremental_collection_will_fail()) {
909 if (PrintGCDetails) {
910 gclog_or_tty->print_cr("GC locker: Trying a full collection "
911 "because scavenge failed");
912 }
913 // This time allow the old gen to be collected as well
914 do_collection(true /* full */,
915 clear_all_soft_refs /* clear_all_soft_refs */,
916 0 /* size */,
917 false /* is_tlab */,
918 n_gens() - 1 /* max_level */);
919 }
920 }
922 // Returns "TRUE" iff "p" points into the allocated area of the heap.
923 bool GenCollectedHeap::is_in(const void* p) const {
924 #ifndef ASSERT
925 guarantee(VerifyBeforeGC ||
926 VerifyDuringGC ||
927 VerifyBeforeExit ||
928 VerifyAfterGC, "too expensive");
929 #endif
930 // This might be sped up with a cache of the last generation that
931 // answered yes.
932 for (int i = 0; i < _n_gens; i++) {
933 if (_gens[i]->is_in(p)) return true;
934 }
935 if (_perm_gen->as_gen()->is_in(p)) return true;
936 // Otherwise...
937 return false;
938 }
940 // Returns "TRUE" iff "p" points into the allocated area of the heap.
941 bool GenCollectedHeap::is_in_youngest(void* p) {
942 return _gens[0]->is_in(p);
943 }
945 void GenCollectedHeap::oop_iterate(OopClosure* cl) {
946 for (int i = 0; i < _n_gens; i++) {
947 _gens[i]->oop_iterate(cl);
948 }
949 }
951 void GenCollectedHeap::oop_iterate(MemRegion mr, OopClosure* cl) {
952 for (int i = 0; i < _n_gens; i++) {
953 _gens[i]->oop_iterate(mr, cl);
954 }
955 }
957 void GenCollectedHeap::object_iterate(ObjectClosure* cl) {
958 for (int i = 0; i < _n_gens; i++) {
959 _gens[i]->object_iterate(cl);
960 }
961 perm_gen()->object_iterate(cl);
962 }
964 void GenCollectedHeap::safe_object_iterate(ObjectClosure* cl) {
965 for (int i = 0; i < _n_gens; i++) {
966 _gens[i]->safe_object_iterate(cl);
967 }
968 perm_gen()->safe_object_iterate(cl);
969 }
971 void GenCollectedHeap::object_iterate_since_last_GC(ObjectClosure* cl) {
972 for (int i = 0; i < _n_gens; i++) {
973 _gens[i]->object_iterate_since_last_GC(cl);
974 }
975 }
977 Space* GenCollectedHeap::space_containing(const void* addr) const {
978 for (int i = 0; i < _n_gens; i++) {
979 Space* res = _gens[i]->space_containing(addr);
980 if (res != NULL) return res;
981 }
982 Space* res = perm_gen()->space_containing(addr);
983 if (res != NULL) return res;
984 // Otherwise...
985 assert(false, "Could not find containing space");
986 return NULL;
987 }
990 HeapWord* GenCollectedHeap::block_start(const void* addr) const {
991 assert(is_in_reserved(addr), "block_start of address outside of heap");
992 for (int i = 0; i < _n_gens; i++) {
993 if (_gens[i]->is_in_reserved(addr)) {
994 assert(_gens[i]->is_in(addr),
995 "addr should be in allocated part of generation");
996 return _gens[i]->block_start(addr);
997 }
998 }
999 if (perm_gen()->is_in_reserved(addr)) {
1000 assert(perm_gen()->is_in(addr),
1001 "addr should be in allocated part of perm gen");
1002 return perm_gen()->block_start(addr);
1003 }
1004 assert(false, "Some generation should contain the address");
1005 return NULL;
1006 }
1008 size_t GenCollectedHeap::block_size(const HeapWord* addr) const {
1009 assert(is_in_reserved(addr), "block_size of address outside of heap");
1010 for (int i = 0; i < _n_gens; i++) {
1011 if (_gens[i]->is_in_reserved(addr)) {
1012 assert(_gens[i]->is_in(addr),
1013 "addr should be in allocated part of generation");
1014 return _gens[i]->block_size(addr);
1015 }
1016 }
1017 if (perm_gen()->is_in_reserved(addr)) {
1018 assert(perm_gen()->is_in(addr),
1019 "addr should be in allocated part of perm gen");
1020 return perm_gen()->block_size(addr);
1021 }
1022 assert(false, "Some generation should contain the address");
1023 return 0;
1024 }
1026 bool GenCollectedHeap::block_is_obj(const HeapWord* addr) const {
1027 assert(is_in_reserved(addr), "block_is_obj of address outside of heap");
1028 assert(block_start(addr) == addr, "addr must be a block start");
1029 for (int i = 0; i < _n_gens; i++) {
1030 if (_gens[i]->is_in_reserved(addr)) {
1031 return _gens[i]->block_is_obj(addr);
1032 }
1033 }
1034 if (perm_gen()->is_in_reserved(addr)) {
1035 return perm_gen()->block_is_obj(addr);
1036 }
1037 assert(false, "Some generation should contain the address");
1038 return false;
1039 }
1041 bool GenCollectedHeap::supports_tlab_allocation() const {
1042 for (int i = 0; i < _n_gens; i += 1) {
1043 if (_gens[i]->supports_tlab_allocation()) {
1044 return true;
1045 }
1046 }
1047 return false;
1048 }
1050 size_t GenCollectedHeap::tlab_capacity(Thread* thr) const {
1051 size_t result = 0;
1052 for (int i = 0; i < _n_gens; i += 1) {
1053 if (_gens[i]->supports_tlab_allocation()) {
1054 result += _gens[i]->tlab_capacity();
1055 }
1056 }
1057 return result;
1058 }
1060 size_t GenCollectedHeap::unsafe_max_tlab_alloc(Thread* thr) const {
1061 size_t result = 0;
1062 for (int i = 0; i < _n_gens; i += 1) {
1063 if (_gens[i]->supports_tlab_allocation()) {
1064 result += _gens[i]->unsafe_max_tlab_alloc();
1065 }
1066 }
1067 return result;
1068 }
1070 HeapWord* GenCollectedHeap::allocate_new_tlab(size_t size) {
1071 bool gc_overhead_limit_was_exceeded;
1072 HeapWord* result = mem_allocate(size /* size */,
1073 false /* is_large_noref */,
1074 true /* is_tlab */,
1075 &gc_overhead_limit_was_exceeded);
1076 return result;
1077 }
1079 // Requires "*prev_ptr" to be non-NULL. Deletes and a block of minimal size
1080 // from the list headed by "*prev_ptr".
1081 static ScratchBlock *removeSmallestScratch(ScratchBlock **prev_ptr) {
1082 bool first = true;
1083 size_t min_size = 0; // "first" makes this conceptually infinite.
1084 ScratchBlock **smallest_ptr, *smallest;
1085 ScratchBlock *cur = *prev_ptr;
1086 while (cur) {
1087 assert(*prev_ptr == cur, "just checking");
1088 if (first || cur->num_words < min_size) {
1089 smallest_ptr = prev_ptr;
1090 smallest = cur;
1091 min_size = smallest->num_words;
1092 first = false;
1093 }
1094 prev_ptr = &cur->next;
1095 cur = cur->next;
1096 }
1097 smallest = *smallest_ptr;
1098 *smallest_ptr = smallest->next;
1099 return smallest;
1100 }
1102 // Sort the scratch block list headed by res into decreasing size order,
1103 // and set "res" to the result.
1104 static void sort_scratch_list(ScratchBlock*& list) {
1105 ScratchBlock* sorted = NULL;
1106 ScratchBlock* unsorted = list;
1107 while (unsorted) {
1108 ScratchBlock *smallest = removeSmallestScratch(&unsorted);
1109 smallest->next = sorted;
1110 sorted = smallest;
1111 }
1112 list = sorted;
1113 }
1115 ScratchBlock* GenCollectedHeap::gather_scratch(Generation* requestor,
1116 size_t max_alloc_words) {
1117 ScratchBlock* res = NULL;
1118 for (int i = 0; i < _n_gens; i++) {
1119 _gens[i]->contribute_scratch(res, requestor, max_alloc_words);
1120 }
1121 sort_scratch_list(res);
1122 return res;
1123 }
1125 void GenCollectedHeap::release_scratch() {
1126 for (int i = 0; i < _n_gens; i++) {
1127 _gens[i]->reset_scratch();
1128 }
1129 }
1131 size_t GenCollectedHeap::large_typearray_limit() {
1132 return gen_policy()->large_typearray_limit();
1133 }
1135 class GenPrepareForVerifyClosure: public GenCollectedHeap::GenClosure {
1136 void do_generation(Generation* gen) {
1137 gen->prepare_for_verify();
1138 }
1139 };
1141 void GenCollectedHeap::prepare_for_verify() {
1142 ensure_parsability(false); // no need to retire TLABs
1143 GenPrepareForVerifyClosure blk;
1144 generation_iterate(&blk, false);
1145 perm_gen()->prepare_for_verify();
1146 }
1149 void GenCollectedHeap::generation_iterate(GenClosure* cl,
1150 bool old_to_young) {
1151 if (old_to_young) {
1152 for (int i = _n_gens-1; i >= 0; i--) {
1153 cl->do_generation(_gens[i]);
1154 }
1155 } else {
1156 for (int i = 0; i < _n_gens; i++) {
1157 cl->do_generation(_gens[i]);
1158 }
1159 }
1160 }
1162 void GenCollectedHeap::space_iterate(SpaceClosure* cl) {
1163 for (int i = 0; i < _n_gens; i++) {
1164 _gens[i]->space_iterate(cl, true);
1165 }
1166 perm_gen()->space_iterate(cl, true);
1167 }
1169 bool GenCollectedHeap::is_maximal_no_gc() const {
1170 for (int i = 0; i < _n_gens; i++) { // skip perm gen
1171 if (!_gens[i]->is_maximal_no_gc()) {
1172 return false;
1173 }
1174 }
1175 return true;
1176 }
1178 void GenCollectedHeap::save_marks() {
1179 for (int i = 0; i < _n_gens; i++) {
1180 _gens[i]->save_marks();
1181 }
1182 perm_gen()->save_marks();
1183 }
1185 void GenCollectedHeap::compute_new_generation_sizes(int collectedGen) {
1186 for (int i = 0; i <= collectedGen; i++) {
1187 _gens[i]->compute_new_size();
1188 }
1189 }
1191 GenCollectedHeap* GenCollectedHeap::heap() {
1192 assert(_gch != NULL, "Uninitialized access to GenCollectedHeap::heap()");
1193 assert(_gch->kind() == CollectedHeap::GenCollectedHeap, "not a generational heap");
1194 return _gch;
1195 }
1198 void GenCollectedHeap::prepare_for_compaction() {
1199 Generation* scanning_gen = _gens[_n_gens-1];
1200 // Start by compacting into same gen.
1201 CompactPoint cp(scanning_gen, NULL, NULL);
1202 while (scanning_gen != NULL) {
1203 scanning_gen->prepare_for_compaction(&cp);
1204 scanning_gen = prev_gen(scanning_gen);
1205 }
1206 }
1208 GCStats* GenCollectedHeap::gc_stats(int level) const {
1209 return _gens[level]->gc_stats();
1210 }
1212 void GenCollectedHeap::verify(bool allow_dirty, bool silent, bool option /* ignored */) {
1213 if (!silent) {
1214 gclog_or_tty->print("permgen ");
1215 }
1216 perm_gen()->verify(allow_dirty);
1217 for (int i = _n_gens-1; i >= 0; i--) {
1218 Generation* g = _gens[i];
1219 if (!silent) {
1220 gclog_or_tty->print(g->name());
1221 gclog_or_tty->print(" ");
1222 }
1223 g->verify(allow_dirty);
1224 }
1225 if (!silent) {
1226 gclog_or_tty->print("remset ");
1227 }
1228 rem_set()->verify();
1229 if (!silent) {
1230 gclog_or_tty->print("ref_proc ");
1231 }
1232 ReferenceProcessor::verify();
1233 }
1235 void GenCollectedHeap::print() const { print_on(tty); }
1236 void GenCollectedHeap::print_on(outputStream* st) const {
1237 for (int i = 0; i < _n_gens; i++) {
1238 _gens[i]->print_on(st);
1239 }
1240 perm_gen()->print_on(st);
1241 }
1243 void GenCollectedHeap::gc_threads_do(ThreadClosure* tc) const {
1244 if (workers() != NULL) {
1245 workers()->threads_do(tc);
1246 }
1247 #ifndef SERIALGC
1248 if (UseConcMarkSweepGC) {
1249 ConcurrentMarkSweepThread::threads_do(tc);
1250 }
1251 #endif // SERIALGC
1252 }
1254 void GenCollectedHeap::print_gc_threads_on(outputStream* st) const {
1255 #ifndef SERIALGC
1256 if (UseParNewGC) {
1257 workers()->print_worker_threads_on(st);
1258 }
1259 if (UseConcMarkSweepGC) {
1260 ConcurrentMarkSweepThread::print_all_on(st);
1261 }
1262 #endif // SERIALGC
1263 }
1265 void GenCollectedHeap::print_tracing_info() const {
1266 if (TraceGen0Time) {
1267 get_gen(0)->print_summary_info();
1268 }
1269 if (TraceGen1Time) {
1270 get_gen(1)->print_summary_info();
1271 }
1272 }
1274 void GenCollectedHeap::print_heap_change(size_t prev_used) const {
1275 if (PrintGCDetails && Verbose) {
1276 gclog_or_tty->print(" " SIZE_FORMAT
1277 "->" SIZE_FORMAT
1278 "(" SIZE_FORMAT ")",
1279 prev_used, used(), capacity());
1280 } else {
1281 gclog_or_tty->print(" " SIZE_FORMAT "K"
1282 "->" SIZE_FORMAT "K"
1283 "(" SIZE_FORMAT "K)",
1284 prev_used / K, used() / K, capacity() / K);
1285 }
1286 }
1288 //New method to print perm gen info with PrintGCDetails flag
1289 void GenCollectedHeap::print_perm_heap_change(size_t perm_prev_used) const {
1290 gclog_or_tty->print(", [%s :", perm_gen()->short_name());
1291 perm_gen()->print_heap_change(perm_prev_used);
1292 gclog_or_tty->print("]");
1293 }
1295 class GenGCPrologueClosure: public GenCollectedHeap::GenClosure {
1296 private:
1297 bool _full;
1298 public:
1299 void do_generation(Generation* gen) {
1300 gen->gc_prologue(_full);
1301 }
1302 GenGCPrologueClosure(bool full) : _full(full) {};
1303 };
1305 void GenCollectedHeap::gc_prologue(bool full) {
1306 assert(InlineCacheBuffer::is_empty(), "should have cleaned up ICBuffer");
1308 always_do_update_barrier = false;
1309 // Fill TLAB's and such
1310 CollectedHeap::accumulate_statistics_all_tlabs();
1311 ensure_parsability(true); // retire TLABs
1313 // Call allocation profiler
1314 AllocationProfiler::iterate_since_last_gc();
1315 // Walk generations
1316 GenGCPrologueClosure blk(full);
1317 generation_iterate(&blk, false); // not old-to-young.
1318 perm_gen()->gc_prologue(full);
1319 };
1321 class GenGCEpilogueClosure: public GenCollectedHeap::GenClosure {
1322 private:
1323 bool _full;
1324 public:
1325 void do_generation(Generation* gen) {
1326 gen->gc_epilogue(_full);
1327 }
1328 GenGCEpilogueClosure(bool full) : _full(full) {};
1329 };
1331 void GenCollectedHeap::gc_epilogue(bool full) {
1332 // Remember if a partial collection of the heap failed, and
1333 // we did a complete collection.
1334 if (full && incremental_collection_will_fail()) {
1335 set_last_incremental_collection_failed();
1336 } else {
1337 clear_last_incremental_collection_failed();
1338 }
1339 // Clear the flag, if set; the generation gc_epilogues will set the
1340 // flag again if the condition persists despite the collection.
1341 clear_incremental_collection_will_fail();
1343 #ifdef COMPILER2
1344 assert(DerivedPointerTable::is_empty(), "derived pointer present");
1345 size_t actual_gap = pointer_delta((HeapWord*) (max_uintx-3), *(end_addr()));
1346 guarantee(actual_gap > (size_t)FastAllocateSizeLimit, "inline allocation wraps");
1347 #endif /* COMPILER2 */
1349 resize_all_tlabs();
1351 GenGCEpilogueClosure blk(full);
1352 generation_iterate(&blk, false); // not old-to-young.
1353 perm_gen()->gc_epilogue(full);
1355 always_do_update_barrier = UseConcMarkSweepGC;
1356 };
1358 #ifndef PRODUCT
1359 class GenGCSaveTopsBeforeGCClosure: public GenCollectedHeap::GenClosure {
1360 private:
1361 public:
1362 void do_generation(Generation* gen) {
1363 gen->record_spaces_top();
1364 }
1365 };
1367 void GenCollectedHeap::record_gen_tops_before_GC() {
1368 if (ZapUnusedHeapArea) {
1369 GenGCSaveTopsBeforeGCClosure blk;
1370 generation_iterate(&blk, false); // not old-to-young.
1371 perm_gen()->record_spaces_top();
1372 }
1373 }
1374 #endif // not PRODUCT
1376 class GenEnsureParsabilityClosure: public GenCollectedHeap::GenClosure {
1377 public:
1378 void do_generation(Generation* gen) {
1379 gen->ensure_parsability();
1380 }
1381 };
1383 void GenCollectedHeap::ensure_parsability(bool retire_tlabs) {
1384 CollectedHeap::ensure_parsability(retire_tlabs);
1385 GenEnsureParsabilityClosure ep_cl;
1386 generation_iterate(&ep_cl, false);
1387 perm_gen()->ensure_parsability();
1388 }
1390 oop GenCollectedHeap::handle_failed_promotion(Generation* gen,
1391 oop obj,
1392 size_t obj_size) {
1393 assert(obj_size == (size_t)obj->size(), "bad obj_size passed in");
1394 HeapWord* result = NULL;
1396 // First give each higher generation a chance to allocate the promoted object.
1397 Generation* allocator = next_gen(gen);
1398 if (allocator != NULL) {
1399 do {
1400 result = allocator->allocate(obj_size, false);
1401 } while (result == NULL && (allocator = next_gen(allocator)) != NULL);
1402 }
1404 if (result == NULL) {
1405 // Then give gen and higher generations a chance to expand and allocate the
1406 // object.
1407 do {
1408 result = gen->expand_and_allocate(obj_size, false);
1409 } while (result == NULL && (gen = next_gen(gen)) != NULL);
1410 }
1412 if (result != NULL) {
1413 Copy::aligned_disjoint_words((HeapWord*)obj, result, obj_size);
1414 }
1415 return oop(result);
1416 }
1418 class GenTimeOfLastGCClosure: public GenCollectedHeap::GenClosure {
1419 jlong _time; // in ms
1420 jlong _now; // in ms
1422 public:
1423 GenTimeOfLastGCClosure(jlong now) : _time(now), _now(now) { }
1425 jlong time() { return _time; }
1427 void do_generation(Generation* gen) {
1428 _time = MIN2(_time, gen->time_of_last_gc(_now));
1429 }
1430 };
1432 jlong GenCollectedHeap::millis_since_last_gc() {
1433 jlong now = os::javaTimeMillis();
1434 GenTimeOfLastGCClosure tolgc_cl(now);
1435 // iterate over generations getting the oldest
1436 // time that a generation was collected
1437 generation_iterate(&tolgc_cl, false);
1438 tolgc_cl.do_generation(perm_gen());
1439 // XXX Despite the assert above, since javaTimeMillis()
1440 // doesnot guarantee monotonically increasing return
1441 // values (note, i didn't say "strictly monotonic"),
1442 // we need to guard against getting back a time
1443 // later than now. This should be fixed by basing
1444 // on someting like gethrtime() which guarantees
1445 // monotonicity. Note that cond_wait() is susceptible
1446 // to a similar problem, because its interface is
1447 // based on absolute time in the form of the
1448 // system time's notion of UCT. See also 4506635
1449 // for yet another problem of similar nature. XXX
1450 jlong retVal = now - tolgc_cl.time();
1451 if (retVal < 0) {
1452 NOT_PRODUCT(warning("time warp: %d", retVal);)
1453 return 0;
1454 }
1455 return retVal;
1456 }