jdk8-mips64-public/hotspot: comparison src/share/vm/memory/genCollectedHeap.cpp

--1:000000000000
+:f90c822e73f8
+/*
+* Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.
+* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+*
+* This code is free software; you can redistribute it and/or modify it
+* under the terms of the GNU General Public License version 2 only, as
+* published by the Free Software Foundation.
+*
+* This code is distributed in the hope that it will be useful, but WITHOUT
+* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+* version 2 for more details (a copy is included in the LICENSE file that
+* accompanied this code).
+*
+* You should have received a copy of the GNU General Public License version
+* 2 along with this work; if not, write to the Free Software Foundation,
+* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+*
+* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+* or visit www.oracle.com if you need additional information or have any
+* questions.
+*
+*/
+#include "precompiled.hpp"
+#include "classfile/symbolTable.hpp"
+#include "classfile/systemDictionary.hpp"
+#include "classfile/vmSymbols.hpp"
+#include "code/icBuffer.hpp"
+#include "gc_implementation/shared/collectorCounters.hpp"
+#include "gc_implementation/shared/gcTraceTime.hpp"
+#include "gc_implementation/shared/vmGCOperations.hpp"
+#include "gc_interface/collectedHeap.inline.hpp"
+#include "memory/filemap.hpp"
+#include "memory/gcLocker.inline.hpp"
+#include "memory/genCollectedHeap.hpp"
+#include "memory/genOopClosures.inline.hpp"
+#include "memory/generation.inline.hpp"
+#include "memory/generationSpec.hpp"
+#include "memory/resourceArea.hpp"
+#include "memory/sharedHeap.hpp"
+#include "memory/space.hpp"
+#include "oops/oop.inline.hpp"
+#include "oops/oop.inline2.hpp"
+#include "runtime/biasedLocking.hpp"
+#include "runtime/fprofiler.hpp"
+#include "runtime/handles.hpp"
+#include "runtime/handles.inline.hpp"
+#include "runtime/java.hpp"
+#include "runtime/vmThread.hpp"
+#include "services/memoryService.hpp"
+#include "utilities/vmError.hpp"
+#include "utilities/workgroup.hpp"
+#include "utilities/macros.hpp"
+#if INCLUDE_ALL_GCS
+#include "gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp"
+#include "gc_implementation/concurrentMarkSweep/vmCMSOperations.hpp"
+#endif // INCLUDE_ALL_GCS
+GenCollectedHeap* GenCollectedHeap::_gch;
+NOT_PRODUCT(size_t GenCollectedHeap::_skip_header_HeapWords = 0;)
+// The set of potentially parallel tasks in strong root scanning.
+enum GCH_process_strong_roots_tasks {
+// We probably want to parallelize both of these internally, but for now...
+GCH_PS_younger_gens,
+// Leave this one last.
+GCH_PS_NumElements
+};
+GenCollectedHeap::GenCollectedHeap(GenCollectorPolicy *policy) :
+SharedHeap(policy),
+_gen_policy(policy),
+_gen_process_strong_tasks(new SubTasksDone(GCH_PS_NumElements)),
+_full_collections_completed(0)
+{
+if (_gen_process_strong_tasks == NULL ||
+!_gen_process_strong_tasks->valid()) {
+vm_exit_during_initialization("Failed necessary allocation.");
+}
+assert(policy != NULL, "Sanity check");
+}
+jint GenCollectedHeap::initialize() {
+CollectedHeap::pre_initialize();
+int i;
+_n_gens = gen_policy()->number_of_generations();
+// While there are no constraints in the GC code that HeapWordSize
+// be any particular value, there are multiple other areas in the
+// system which believe this to be true (e.g. oop->object_size in some
+// cases incorrectly returns the size in wordSize units rather than
+// HeapWordSize).
+guarantee(HeapWordSize == wordSize, "HeapWordSize must equal wordSize");
+// The heap must be at least as aligned as generations.
+size_t gen_alignment = Generation::GenGrain;
+_gen_specs = gen_policy()->generations();
+// Make sure the sizes are all aligned.
+for (i = 0; i < _n_gens; i++) {
+_gen_specs[i]->align(gen_alignment);
+}
+// Allocate space for the heap.
+char* heap_address;
+size_t total_reserved = 0;
+int n_covered_regions = 0;
+ReservedSpace heap_rs;
+size_t heap_alignment = collector_policy()->heap_alignment();
+heap_address = allocate(heap_alignment, &total_reserved,
+&n_covered_regions, &heap_rs);
+if (!heap_rs.is_reserved()) {
+vm_shutdown_during_initialization(
+"Could not reserve enough space for object heap");
+return JNI_ENOMEM;
+}
+_reserved = MemRegion((HeapWord*)heap_rs.base(),
+(HeapWord*)(heap_rs.base() + heap_rs.size()));
+// It is important to do this in a way such that concurrent readers can't
+// temporarily think somethings in the heap.  (Seen this happen in asserts.)
+_reserved.set_word_size(0);
+_reserved.set_start((HeapWord*)heap_rs.base());
+size_t actual_heap_size = heap_rs.size();
+_reserved.set_end((HeapWord*)(heap_rs.base() + actual_heap_size));
+_rem_set = collector_policy()->create_rem_set(_reserved, n_covered_regions);
+set_barrier_set(rem_set()->bs());
+_gch = this;
+for (i = 0; i < _n_gens; i++) {
+ReservedSpace this_rs = heap_rs.first_part(_gen_specs[i]->max_size(), false, false);
+_gens[i] = _gen_specs[i]->init(this_rs, i, rem_set());
+heap_rs = heap_rs.last_part(_gen_specs[i]->max_size());
+}
+clear_incremental_collection_failed();
+#if INCLUDE_ALL_GCS
+// If we are running CMS, create the collector responsible
+// for collecting the CMS generations.
+if (collector_policy()->is_concurrent_mark_sweep_policy()) {
+bool success = create_cms_collector();
+if (!success) return JNI_ENOMEM;
+}
+#endif // INCLUDE_ALL_GCS
+return JNI_OK;
+}
+char* GenCollectedHeap::allocate(size_t alignment,
+size_t* _total_reserved,
+int* _n_covered_regions,
+ReservedSpace* heap_rs){
+const char overflow_msg[] = "The size of the object heap + VM data exceeds "
+"the maximum representable size";
+// Now figure out the total size.
+size_t total_reserved = 0;
+int n_covered_regions = 0;
+const size_t pageSize = UseLargePages ?
+os::large_page_size() : os::vm_page_size();
+assert(alignment % pageSize == 0, "Must be");
+for (int i = 0; i < _n_gens; i++) {
+total_reserved += _gen_specs[i]->max_size();
+if (total_reserved < _gen_specs[i]->max_size()) {
+vm_exit_during_initialization(overflow_msg);
+}
+n_covered_regions += _gen_specs[i]->n_covered_regions();
+}
+assert(total_reserved % alignment == 0,
+err_msg("Gen size; total_reserved=" SIZE_FORMAT ", alignment="
+SIZE_FORMAT, total_reserved, alignment));
+// Needed until the cardtable is fixed to have the right number
+// of covered regions.
+n_covered_regions += 2;
+*_total_reserved = total_reserved;
+*_n_covered_regions = n_covered_regions;
+*heap_rs = Universe::reserve_heap(total_reserved, alignment);
+return heap_rs->base();
+}
+void GenCollectedHeap::post_initialize() {
+SharedHeap::post_initialize();
+TwoGenerationCollectorPolicy *policy =
+(TwoGenerationCollectorPolicy *)collector_policy();
+guarantee(policy->is_two_generation_policy(), "Illegal policy type");
+DefNewGeneration* def_new_gen = (DefNewGeneration*) get_gen(0);
+assert(def_new_gen->kind() == Generation::DefNew ||
+def_new_gen->kind() == Generation::ParNew ||
+def_new_gen->kind() == Generation::ASParNew,
+"Wrong generation kind");
+Generation* old_gen = get_gen(1);
+assert(old_gen->kind() == Generation::ConcurrentMarkSweep ||
+old_gen->kind() == Generation::ASConcurrentMarkSweep ||
+old_gen->kind() == Generation::MarkSweepCompact,
+"Wrong generation kind");
+policy->initialize_size_policy(def_new_gen->eden()->capacity(),
+old_gen->capacity(),
+def_new_gen->from()->capacity());
+policy->initialize_gc_policy_counters();
+}
+void GenCollectedHeap::ref_processing_init() {
+SharedHeap::ref_processing_init();
+for (int i = 0; i < _n_gens; i++) {
+_gens[i]->ref_processor_init();
+}
+}
+size_t GenCollectedHeap::capacity() const {
+size_t res = 0;
+for (int i = 0; i < _n_gens; i++) {
+res += _gens[i]->capacity();
+}
+return res;
+}
+size_t GenCollectedHeap::used() const {
+size_t res = 0;
+for (int i = 0; i < _n_gens; i++) {
+res += _gens[i]->used();
+}
+return res;
+}
+// Save the "used_region" for generations level and lower.
+void GenCollectedHeap::save_used_regions(int level) {
+assert(level < _n_gens, "Illegal level parameter");
+for (int i = level; i >= 0; i--) {
+_gens[i]->save_used_region();
+}
+}
+size_t GenCollectedHeap::max_capacity() const {
+size_t res = 0;
+for (int i = 0; i < _n_gens; i++) {
+res += _gens[i]->max_capacity();
+}
+return res;
+}
+// Update the _full_collections_completed counter
+// at the end of a stop-world full GC.
+unsigned int GenCollectedHeap::update_full_collections_completed() {
+MonitorLockerEx ml(FullGCCount_lock, Mutex::_no_safepoint_check_flag);
+assert(_full_collections_completed <= _total_full_collections,
+"Can't complete more collections than were started");
+_full_collections_completed = _total_full_collections;
+ml.notify_all();
+return _full_collections_completed;
+}
+// Update the _full_collections_completed counter, as appropriate,
+// at the end of a concurrent GC cycle. Note the conditional update
+// below to allow this method to be called by a concurrent collector
+// without synchronizing in any manner with the VM thread (which
+// may already have initiated a STW full collection "concurrently").
+unsigned int GenCollectedHeap::update_full_collections_completed(unsigned int count) {
+MonitorLockerEx ml(FullGCCount_lock, Mutex::_no_safepoint_check_flag);
+assert((_full_collections_completed <= _total_full_collections) &&
+(count <= _total_full_collections),
+"Can't complete more collections than were started");
+if (count > _full_collections_completed) {
+_full_collections_completed = count;
+ml.notify_all();
+}
+return _full_collections_completed;
+}
+#ifndef PRODUCT
+// Override of memory state checking method in CollectedHeap:
+// Some collectors (CMS for example) can't have badHeapWordVal written
+// in the first two words of an object. (For instance , in the case of
+// CMS these words hold state used to synchronize between certain
+// (concurrent) GC steps and direct allocating mutators.)
+// The skip_header_HeapWords() method below, allows us to skip
+// over the requisite number of HeapWord's. Note that (for
+// generational collectors) this means that those many words are
+// skipped in each object, irrespective of the generation in which
+// that object lives. The resultant loss of precision seems to be
+// harmless and the pain of avoiding that imprecision appears somewhat
+// higher than we are prepared to pay for such rudimentary debugging
+// support.
+void GenCollectedHeap::check_for_non_bad_heap_word_value(HeapWord* addr,
+size_t size) {
+if (CheckMemoryInitialization && ZapUnusedHeapArea) {
+// We are asked to check a size in HeapWords,
+// but the memory is mangled in juint words.
+juint* start = (juint*) (addr + skip_header_HeapWords());
+juint* end   = (juint*) (addr + size);
+for (juint* slot = start; slot < end; slot += 1) {
+assert(*slot == badHeapWordVal,
+"Found non badHeapWordValue in pre-allocation check");
+}
+}
+}
+#endif
+HeapWord* GenCollectedHeap::attempt_allocation(size_t size,
+bool is_tlab,
+bool first_only) {
+HeapWord* res;
+for (int i = 0; i < _n_gens; i++) {
+if (_gens[i]->should_allocate(size, is_tlab)) {
+res = _gens[i]->allocate(size, is_tlab);
+if (res != NULL) return res;
+else if (first_only) break;
+}
+}
+// Otherwise...
+return NULL;
+}
+HeapWord* GenCollectedHeap::mem_allocate(size_t size,
+bool* gc_overhead_limit_was_exceeded) {
+return collector_policy()->mem_allocate_work(size,
+false /* is_tlab */,
+gc_overhead_limit_was_exceeded);
+}
+bool GenCollectedHeap::must_clear_all_soft_refs() {
+return _gc_cause == GCCause::_last_ditch_collection;
+}
+bool GenCollectedHeap::should_do_concurrent_full_gc(GCCause::Cause cause) {
+return UseConcMarkSweepGC &&
+((cause == GCCause::_gc_locker && GCLockerInvokesConcurrent) ||
+(cause == GCCause::_java_lang_system_gc && ExplicitGCInvokesConcurrent));
+}
+void GenCollectedHeap::do_collection(bool  full,
+bool   clear_all_soft_refs,
+size_t size,
+bool   is_tlab,
+int    max_level) {
+bool prepared_for_verification = false;
+ResourceMark rm;
+DEBUG_ONLY(Thread* my_thread = Thread::current();)
+assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
+assert(my_thread->is_VM_thread() ||
+my_thread->is_ConcurrentGC_thread(),
+"incorrect thread type capability");
+assert(Heap_lock->is_locked(),
+"the requesting thread should have the Heap_lock");
+guarantee(!is_gc_active(), "collection is not reentrant");
+assert(max_level < n_gens(), "sanity check");
+if (GC_locker::check_active_before_gc()) {
+return; // GC is disabled (e.g. JNI GetXXXCritical operation)
+}
+const bool do_clear_all_soft_refs = clear_all_soft_refs ||
+collector_policy()->should_clear_all_soft_refs();
+ClearedAllSoftRefs casr(do_clear_all_soft_refs, collector_policy());
+const size_t metadata_prev_used = MetaspaceAux::used_bytes();
+print_heap_before_gc();
+{
+FlagSetting fl(_is_gc_active, true);
+bool complete = full && (max_level == (n_gens()-1));
+const char* gc_cause_prefix = complete ? "Full GC" : "GC";
+gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
+TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
+GCTraceTime t(GCCauseString(gc_cause_prefix, gc_cause()), PrintGCDetails, false, NULL);
+gc_prologue(complete);
+increment_total_collections(complete);
+size_t gch_prev_used = used();
+int starting_level = 0;
+if (full) {
+// Search for the oldest generation which will collect all younger
+// generations, and start collection loop there.
+for (int i = max_level; i >= 0; i--) {
+if (_gens[i]->full_collects_younger_generations()) {
+starting_level = i;
+break;
+}
+}
+}
+bool must_restore_marks_for_biased_locking = false;
+int max_level_collected = starting_level;
+for (int i = starting_level; i <= max_level; i++) {
+if (_gens[i]->should_collect(full, size, is_tlab)) {
+if (i == n_gens() - 1) {  // a major collection is to happen
+if (!complete) {
+// The full_collections increment was missed above.
+increment_total_full_collections();
+}
+pre_full_gc_dump(NULL);    // do any pre full gc dumps
+}
+// Timer for individual generations. Last argument is false: no CR
+// FIXME: We should try to start the timing earlier to cover more of the GC pause
+GCTraceTime t1(_gens[i]->short_name(), PrintGCDetails, false, NULL);
+TraceCollectorStats tcs(_gens[i]->counters());
+TraceMemoryManagerStats tmms(_gens[i]->kind(),gc_cause());
+size_t prev_used = _gens[i]->used();
+_gens[i]->stat_record()->invocations++;
+_gens[i]->stat_record()->accumulated_time.start();
+// Must be done anew before each collection because
+// a previous collection will do mangling and will
+// change top of some spaces.
+record_gen_tops_before_GC();
+if (PrintGC && Verbose) {
+gclog_or_tty->print("level=%d invoke=%d size=" SIZE_FORMAT,
+i,
+_gens[i]->stat_record()->invocations,
+size*HeapWordSize);
+}
+if (VerifyBeforeGC && i >= VerifyGCLevel &&
+total_collections() >= VerifyGCStartAt) {
+HandleMark hm;  // Discard invalid handles created during verification
+if (!prepared_for_verification) {
+prepare_for_verify();
+prepared_for_verification = true;
+}
+Universe::verify(" VerifyBeforeGC:");
+}
+COMPILER2_PRESENT(DerivedPointerTable::clear());
+if (!must_restore_marks_for_biased_locking &&
+_gens[i]->performs_in_place_marking()) {
+// We perform this mark word preservation work lazily
+// because it's only at this point that we know whether we
+// absolutely have to do it; we want to avoid doing it for
+// scavenge-only collections where it's unnecessary
+must_restore_marks_for_biased_locking = true;
+BiasedLocking::preserve_marks();
+}
+// Do collection work
+{
+// Note on ref discovery: For what appear to be historical reasons,
+// GCH enables and disabled (by enqueing) refs discovery.
+// In the future this should be moved into the generation's
+// collect method so that ref discovery and enqueueing concerns
+// are local to a generation. The collect method could return
+// an appropriate indication in the case that notification on
+// the ref lock was needed. This will make the treatment of
+// weak refs more uniform (and indeed remove such concerns
+// from GCH). XXX
+HandleMark hm;  // Discard invalid handles created during gc
+save_marks();   // save marks for all gens
+// We want to discover references, but not process them yet.
+// This mode is disabled in process_discovered_references if the
+// generation does some collection work, or in
+// enqueue_discovered_references if the generation returns
+// without doing any work.
+ReferenceProcessor* rp = _gens[i]->ref_processor();
+// If the discovery of ("weak") refs in this generation is
+// atomic wrt other collectors in this configuration, we
+// are guaranteed to have empty discovered ref lists.
+if (rp->discovery_is_atomic()) {
+rp->enable_discovery(true /*verify_disabled*/, true /*verify_no_refs*/);
+rp->setup_policy(do_clear_all_soft_refs);
+} else {
+// collect() below will enable discovery as appropriate
+}
+_gens[i]->collect(full, do_clear_all_soft_refs, size, is_tlab);
+if (!rp->enqueuing_is_done()) {
+rp->enqueue_discovered_references();
+} else {
+rp->set_enqueuing_is_done(false);
+}
+rp->verify_no_references_recorded();
+}
+max_level_collected = i;
+// Determine if allocation request was met.
+if (size > 0) {
+if (!is_tlab || _gens[i]->supports_tlab_allocation()) {
+if (size*HeapWordSize <= _gens[i]->unsafe_max_alloc_nogc()) {
+size = 0;
+}
+}
+}
+COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
+_gens[i]->stat_record()->accumulated_time.stop();
+update_gc_stats(i, full);
+if (VerifyAfterGC && i >= VerifyGCLevel &&
+total_collections() >= VerifyGCStartAt) {
+HandleMark hm;  // Discard invalid handles created during verification
+Universe::verify(" VerifyAfterGC:");
+}
+if (PrintGCDetails) {
+gclog_or_tty->print(":");
+_gens[i]->print_heap_change(prev_used);
+}
+}
+}
+// Update "complete" boolean wrt what actually transpired --
+// for instance, a promotion failure could have led to
+// a whole heap collection.
+complete = complete || (max_level_collected == n_gens() - 1);
+if (complete) { // We did a "major" collection
+// FIXME: See comment at pre_full_gc_dump call
+post_full_gc_dump(NULL);   // do any post full gc dumps
+}
+if (PrintGCDetails) {
+print_heap_change(gch_prev_used);
+// Print metaspace info for full GC with PrintGCDetails flag.
+if (complete) {
+MetaspaceAux::print_metaspace_change(metadata_prev_used);
+}
+}
+for (int j = max_level_collected; j >= 0; j -= 1) {
+// Adjust generation sizes.
+_gens[j]->compute_new_size();
+}
+if (complete) {
+// Delete metaspaces for unloaded class loaders and clean up loader_data graph
+ClassLoaderDataGraph::purge();
+MetaspaceAux::verify_metrics();
+// Resize the metaspace capacity after full collections
+MetaspaceGC::compute_new_size();
+update_full_collections_completed();
+}
+// Track memory usage and detect low memory after GC finishes
+MemoryService::track_memory_usage();
+gc_epilogue(complete);
+if (must_restore_marks_for_biased_locking) {
+BiasedLocking::restore_marks();
+}
+}
+AdaptiveSizePolicy* sp = gen_policy()->size_policy();
+AdaptiveSizePolicyOutput(sp, total_collections());
+print_heap_after_gc();
+#ifdef TRACESPINNING
+ParallelTaskTerminator::print_termination_counts();
+#endif
+}
+HeapWord* GenCollectedHeap::satisfy_failed_allocation(size_t size, bool is_tlab) {
+return collector_policy()->satisfy_failed_allocation(size, is_tlab);
+}
+void GenCollectedHeap::set_par_threads(uint t) {
+SharedHeap::set_par_threads(t);
+_gen_process_strong_tasks->set_n_threads(t);
+}
+void GenCollectedHeap::
+gen_process_strong_roots(int level,
+bool younger_gens_as_roots,
+bool activate_scope,
+bool is_scavenging,
+SharedHeap::ScanningOption so,
+OopsInGenClosure* not_older_gens,
+bool do_code_roots,
+OopsInGenClosure* older_gens,
+KlassClosure* klass_closure) {
+// General strong roots.
+if (!do_code_roots) {
+SharedHeap::process_strong_roots(activate_scope, is_scavenging, so,
+not_older_gens, NULL, klass_closure);
+} else {
+bool do_code_marking = (activate_scope || nmethod::oops_do_marking_is_active());
+CodeBlobToOopClosure code_roots(not_older_gens, /*do_marking=*/ do_code_marking);
+SharedHeap::process_strong_roots(activate_scope, is_scavenging, so,
+not_older_gens, &code_roots, klass_closure);
+}
+if (younger_gens_as_roots) {
+if (!_gen_process_strong_tasks->is_task_claimed(GCH_PS_younger_gens)) {
+for (int i = 0; i < level; i++) {
+not_older_gens->set_generation(_gens[i]);
+_gens[i]->oop_iterate(not_older_gens);
+}
+not_older_gens->reset_generation();
+}
+}
+// When collection is parallel, all threads get to cooperate to do
+// older-gen scanning.
+for (int i = level+1; i < _n_gens; i++) {
+older_gens->set_generation(_gens[i]);
+rem_set()->younger_refs_iterate(_gens[i], older_gens);
+older_gens->reset_generation();
+}
+_gen_process_strong_tasks->all_tasks_completed();
+}
+void GenCollectedHeap::gen_process_weak_roots(OopClosure* root_closure,
+CodeBlobClosure* code_roots) {
+SharedHeap::process_weak_roots(root_closure, code_roots);
+// "Local" "weak" refs
+for (int i = 0; i < _n_gens; i++) {
+_gens[i]->ref_processor()->weak_oops_do(root_closure);
+}
+}
+#define GCH_SINCE_SAVE_MARKS_ITERATE_DEFN(OopClosureType, nv_suffix)    \
+void GenCollectedHeap::                                                 \
+oop_since_save_marks_iterate(int level,                                 \
+OopClosureType* cur,                       \
+OopClosureType* older) {                   \
+_gens[level]->oop_since_save_marks_iterate##nv_suffix(cur);           \
+for (int i = level+1; i < n_gens(); i++) {                            \
+_gens[i]->oop_since_save_marks_iterate##nv_suffix(older);           \
+}                                                                     \
+}
+ALL_SINCE_SAVE_MARKS_CLOSURES(GCH_SINCE_SAVE_MARKS_ITERATE_DEFN)
+#undef GCH_SINCE_SAVE_MARKS_ITERATE_DEFN
+bool GenCollectedHeap::no_allocs_since_save_marks(int level) {
+for (int i = level; i < _n_gens; i++) {
+if (!_gens[i]->no_allocs_since_save_marks()) return false;
+}
+return true;
+}
+bool GenCollectedHeap::supports_inline_contig_alloc() const {
+return _gens[0]->supports_inline_contig_alloc();
+}
+HeapWord** GenCollectedHeap::top_addr() const {
+return _gens[0]->top_addr();
+}
+HeapWord** GenCollectedHeap::end_addr() const {
+return _gens[0]->end_addr();
+}
+size_t GenCollectedHeap::unsafe_max_alloc() {
+return _gens[0]->unsafe_max_alloc_nogc();
+}
+// public collection interfaces
+void GenCollectedHeap::collect(GCCause::Cause cause) {
+if (should_do_concurrent_full_gc(cause)) {
+#if INCLUDE_ALL_GCS
+// mostly concurrent full collection
+collect_mostly_concurrent(cause);
+#else  // INCLUDE_ALL_GCS
+ShouldNotReachHere();
+#endif // INCLUDE_ALL_GCS
+} else {
+#ifdef ASSERT
+if (cause == GCCause::_scavenge_alot) {
+// minor collection only
+collect(cause, 0);
+} else {
+// Stop-the-world full collection
+collect(cause, n_gens() - 1);
+}
+#else
+// Stop-the-world full collection
+collect(cause, n_gens() - 1);
+#endif
+}
+}
+void GenCollectedHeap::collect(GCCause::Cause cause, int max_level) {
+// The caller doesn't have the Heap_lock
+assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
+MutexLocker ml(Heap_lock);
+collect_locked(cause, max_level);
+}
+void GenCollectedHeap::collect_locked(GCCause::Cause cause) {
+// The caller has the Heap_lock
+assert(Heap_lock->owned_by_self(), "this thread should own the Heap_lock");
+collect_locked(cause, n_gens() - 1);
+}
+// this is the private collection interface
+// The Heap_lock is expected to be held on entry.
+void GenCollectedHeap::collect_locked(GCCause::Cause cause, int max_level) {
+// Read the GC count while holding the Heap_lock
+unsigned int gc_count_before      = total_collections();
+unsigned int full_gc_count_before = total_full_collections();
+{
+MutexUnlocker mu(Heap_lock);  // give up heap lock, execute gets it back
+VM_GenCollectFull op(gc_count_before, full_gc_count_before,
+cause, max_level);
+VMThread::execute(&op);
+}
+}
+#if INCLUDE_ALL_GCS
+bool GenCollectedHeap::create_cms_collector() {
+assert(((_gens[1]->kind() == Generation::ConcurrentMarkSweep) ||
+(_gens[1]->kind() == Generation::ASConcurrentMarkSweep)),
+"Unexpected generation kinds");
+// Skip two header words in the block content verification
+NOT_PRODUCT(_skip_header_HeapWords = CMSCollector::skip_header_HeapWords();)
+CMSCollector* collector = new CMSCollector(
+(ConcurrentMarkSweepGeneration*)_gens[1],
+_rem_set->as_CardTableRS(),
+(ConcurrentMarkSweepPolicy*) collector_policy());
+if (collector == NULL || !collector->completed_initialization()) {
+if (collector) {
+delete collector;  // Be nice in embedded situation
+}
+vm_shutdown_during_initialization("Could not create CMS collector");
+return false;
+}
+return true;  // success
+}
+void GenCollectedHeap::collect_mostly_concurrent(GCCause::Cause cause) {
+assert(!Heap_lock->owned_by_self(), "Should not own Heap_lock");
+MutexLocker ml(Heap_lock);
+// Read the GC counts while holding the Heap_lock
+unsigned int full_gc_count_before = total_full_collections();
+unsigned int gc_count_before      = total_collections();
+{
+MutexUnlocker mu(Heap_lock);
+VM_GenCollectFullConcurrent op(gc_count_before, full_gc_count_before, cause);
+VMThread::execute(&op);
+}
+}
+#endif // INCLUDE_ALL_GCS
+void GenCollectedHeap::do_full_collection(bool clear_all_soft_refs) {
+do_full_collection(clear_all_soft_refs, _n_gens - 1);
+}
+void GenCollectedHeap::do_full_collection(bool clear_all_soft_refs,
+int max_level) {
+int local_max_level;
+if (!incremental_collection_will_fail(false /* don't consult_young */) &&
+gc_cause() == GCCause::_gc_locker) {
+local_max_level = 0;
+} else {
+local_max_level = max_level;
+}
+do_collection(true                 /* full */,
+clear_all_soft_refs  /* clear_all_soft_refs */,
+0                    /* size */,
+false                /* is_tlab */,
+local_max_level      /* max_level */);
+// Hack XXX FIX ME !!!
+// A scavenge may not have been attempted, or may have
+// been attempted and failed, because the old gen was too full
+if (local_max_level == 0 && gc_cause() == GCCause::_gc_locker &&
+incremental_collection_will_fail(false /* don't consult_young */)) {
+if (PrintGCDetails) {
+gclog_or_tty->print_cr("GC locker: Trying a full collection "
+"because scavenge failed");
+}
+// This time allow the old gen to be collected as well
+do_collection(true                 /* full */,
+clear_all_soft_refs  /* clear_all_soft_refs */,
+0                    /* size */,
+false                /* is_tlab */,
+n_gens() - 1         /* max_level */);
+}
+}
+bool GenCollectedHeap::is_in_young(oop p) {
+bool result = ((HeapWord*)p) < _gens[_n_gens - 1]->reserved().start();
+assert(result == _gens[0]->is_in_reserved(p),
+err_msg("incorrect test - result=%d, p=" PTR_FORMAT, result, p2i((void*)p)));
+return result;
+}
+// Returns "TRUE" iff "p" points into the committed areas of the heap.
+bool GenCollectedHeap::is_in(const void* p) const {
+#ifndef ASSERT
+guarantee(VerifyBeforeGC      ||
+VerifyDuringGC      ||
+VerifyBeforeExit    ||
+VerifyDuringStartup ||
+PrintAssembly       ||
+tty->count() != 0   ||   // already printing
+VerifyAfterGC       ||
+VMError::fatal_error_in_progress(), "too expensive");
+#endif
+// This might be sped up with a cache of the last generation that
+// answered yes.
+for (int i = 0; i < _n_gens; i++) {
+if (_gens[i]->is_in(p)) return true;
+}
+// Otherwise...
+return false;
+}
+#ifdef ASSERT
+// Don't implement this by using is_in_young().  This method is used
+// in some cases to check that is_in_young() is correct.
+bool GenCollectedHeap::is_in_partial_collection(const void* p) {
+assert(is_in_reserved(p) || p == NULL,
+"Does not work if address is non-null and outside of the heap");
+return p < _gens[_n_gens - 2]->reserved().end() && p != NULL;
+}
+#endif
+void GenCollectedHeap::oop_iterate(ExtendedOopClosure* cl) {
+for (int i = 0; i < _n_gens; i++) {
+_gens[i]->oop_iterate(cl);
+}
+}
+void GenCollectedHeap::oop_iterate(MemRegion mr, ExtendedOopClosure* cl) {
+for (int i = 0; i < _n_gens; i++) {
+_gens[i]->oop_iterate(mr, cl);
+}
+}
+void GenCollectedHeap::object_iterate(ObjectClosure* cl) {
+for (int i = 0; i < _n_gens; i++) {
+_gens[i]->object_iterate(cl);
+}
+}
+void GenCollectedHeap::safe_object_iterate(ObjectClosure* cl) {
+for (int i = 0; i < _n_gens; i++) {
+_gens[i]->safe_object_iterate(cl);
+}
+}
+Space* GenCollectedHeap::space_containing(const void* addr) const {
+for (int i = 0; i < _n_gens; i++) {
+Space* res = _gens[i]->space_containing(addr);
+if (res != NULL) return res;
+}
+// Otherwise...
+assert(false, "Could not find containing space");
+return NULL;
+}
+HeapWord* GenCollectedHeap::block_start(const void* addr) const {
+assert(is_in_reserved(addr), "block_start of address outside of heap");
+for (int i = 0; i < _n_gens; i++) {
+if (_gens[i]->is_in_reserved(addr)) {
+assert(_gens[i]->is_in(addr),
+"addr should be in allocated part of generation");
+return _gens[i]->block_start(addr);
+}
+}
+assert(false, "Some generation should contain the address");
+return NULL;
+}
+size_t GenCollectedHeap::block_size(const HeapWord* addr) const {
+assert(is_in_reserved(addr), "block_size of address outside of heap");
+for (int i = 0; i < _n_gens; i++) {
+if (_gens[i]->is_in_reserved(addr)) {
+assert(_gens[i]->is_in(addr),
+"addr should be in allocated part of generation");
+return _gens[i]->block_size(addr);
+}
+}
+assert(false, "Some generation should contain the address");
+return 0;
+}
+bool GenCollectedHeap::block_is_obj(const HeapWord* addr) const {
+assert(is_in_reserved(addr), "block_is_obj of address outside of heap");
+assert(block_start(addr) == addr, "addr must be a block start");
+for (int i = 0; i < _n_gens; i++) {
+if (_gens[i]->is_in_reserved(addr)) {
+return _gens[i]->block_is_obj(addr);
+}
+}
+assert(false, "Some generation should contain the address");
+return false;
+}
+bool GenCollectedHeap::supports_tlab_allocation() const {
+for (int i = 0; i < _n_gens; i += 1) {
+if (_gens[i]->supports_tlab_allocation()) {
+return true;
+}
+}
+return false;
+}
+size_t GenCollectedHeap::tlab_capacity(Thread* thr) const {
+size_t result = 0;
+for (int i = 0; i < _n_gens; i += 1) {
+if (_gens[i]->supports_tlab_allocation()) {
+result += _gens[i]->tlab_capacity();
+}
+}
+return result;
+}
+size_t GenCollectedHeap::tlab_used(Thread* thr) const {
+size_t result = 0;
+for (int i = 0; i < _n_gens; i += 1) {
+if (_gens[i]->supports_tlab_allocation()) {
+result += _gens[i]->tlab_used();
+}
+}
+return result;
+}
+size_t GenCollectedHeap::unsafe_max_tlab_alloc(Thread* thr) const {
+size_t result = 0;
+for (int i = 0; i < _n_gens; i += 1) {
+if (_gens[i]->supports_tlab_allocation()) {
+result += _gens[i]->unsafe_max_tlab_alloc();
+}
+}
+return result;
+}
+HeapWord* GenCollectedHeap::allocate_new_tlab(size_t size) {
+bool gc_overhead_limit_was_exceeded;
+return collector_policy()->mem_allocate_work(size /* size */,
+true /* is_tlab */,
+&gc_overhead_limit_was_exceeded);
+}
+// Requires "*prev_ptr" to be non-NULL.  Deletes and a block of minimal size
+// from the list headed by "*prev_ptr".
+static ScratchBlock *removeSmallestScratch(ScratchBlock **prev_ptr) {
+bool first = true;
+size_t min_size = 0;   // "first" makes this conceptually infinite.
+ScratchBlock **smallest_ptr, *smallest;
+ScratchBlock  *cur = *prev_ptr;
+while (cur) {
+assert(*prev_ptr == cur, "just checking");
+if (first || cur->num_words < min_size) {
+smallest_ptr = prev_ptr;
+smallest     = cur;
+min_size     = smallest->num_words;
+first        = false;
+}
+prev_ptr = &cur->next;
+cur     =  cur->next;
+}
+smallest      = *smallest_ptr;
+*smallest_ptr = smallest->next;
+return smallest;
+}
+// Sort the scratch block list headed by res into decreasing size order,
+// and set "res" to the result.
+static void sort_scratch_list(ScratchBlock*& list) {
+ScratchBlock* sorted = NULL;
+ScratchBlock* unsorted = list;
+while (unsorted) {
+ScratchBlock *smallest = removeSmallestScratch(&unsorted);
+smallest->next  = sorted;
+sorted          = smallest;
+}
+list = sorted;
+}
+ScratchBlock* GenCollectedHeap::gather_scratch(Generation* requestor,
+size_t max_alloc_words) {
+ScratchBlock* res = NULL;
+for (int i = 0; i < _n_gens; i++) {
+_gens[i]->contribute_scratch(res, requestor, max_alloc_words);
+}
+sort_scratch_list(res);
+return res;
+}
+void GenCollectedHeap::release_scratch() {
+for (int i = 0; i < _n_gens; i++) {
+_gens[i]->reset_scratch();
+}
+}
+class GenPrepareForVerifyClosure: public GenCollectedHeap::GenClosure {
+void do_generation(Generation* gen) {
+gen->prepare_for_verify();
+}
+};
+void GenCollectedHeap::prepare_for_verify() {
+ensure_parsability(false);        // no need to retire TLABs
+GenPrepareForVerifyClosure blk;
+generation_iterate(&blk, false);
+}
+void GenCollectedHeap::generation_iterate(GenClosure* cl,
+bool old_to_young) {
+if (old_to_young) {
+for (int i = _n_gens-1; i >= 0; i--) {
+cl->do_generation(_gens[i]);
+}
+} else {
+for (int i = 0; i < _n_gens; i++) {
+cl->do_generation(_gens[i]);
+}
+}
+}
+void GenCollectedHeap::space_iterate(SpaceClosure* cl) {
+for (int i = 0; i < _n_gens; i++) {
+_gens[i]->space_iterate(cl, true);
+}
+}
+bool GenCollectedHeap::is_maximal_no_gc() const {
+for (int i = 0; i < _n_gens; i++) {
+if (!_gens[i]->is_maximal_no_gc()) {
+return false;
+}
+}
+return true;
+}
+void GenCollectedHeap::save_marks() {
+for (int i = 0; i < _n_gens; i++) {
+_gens[i]->save_marks();
+}
+}
+GenCollectedHeap* GenCollectedHeap::heap() {
+assert(_gch != NULL, "Uninitialized access to GenCollectedHeap::heap()");
+assert(_gch->kind() == CollectedHeap::GenCollectedHeap, "not a generational heap");
+return _gch;
+}
+void GenCollectedHeap::prepare_for_compaction() {
+guarantee(_n_gens = 2, "Wrong number of generations");
+Generation* old_gen = _gens[1];
+// Start by compacting into same gen.
+CompactPoint cp(old_gen, NULL, NULL);
+old_gen->prepare_for_compaction(&cp);
+Generation* young_gen = _gens[0];
+young_gen->prepare_for_compaction(&cp);
+}
+GCStats* GenCollectedHeap::gc_stats(int level) const {
+return _gens[level]->gc_stats();
+}
+void GenCollectedHeap::verify(bool silent, VerifyOption option /* ignored */) {
+for (int i = _n_gens-1; i >= 0; i--) {
+Generation* g = _gens[i];
+if (!silent) {
+gclog_or_tty->print("%s", g->name());
+gclog_or_tty->print(" ");
+}
+g->verify();
+}
+if (!silent) {
+gclog_or_tty->print("remset ");
+}
+rem_set()->verify();
+}
+void GenCollectedHeap::print_on(outputStream* st) const {
+for (int i = 0; i < _n_gens; i++) {
+_gens[i]->print_on(st);
+}
+MetaspaceAux::print_on(st);
+}
+void GenCollectedHeap::gc_threads_do(ThreadClosure* tc) const {
+if (workers() != NULL) {
+workers()->threads_do(tc);
+}
+#if INCLUDE_ALL_GCS
+if (UseConcMarkSweepGC) {
+ConcurrentMarkSweepThread::threads_do(tc);
+}
+#endif // INCLUDE_ALL_GCS
+}
+void GenCollectedHeap::print_gc_threads_on(outputStream* st) const {
+#if INCLUDE_ALL_GCS
+if (UseParNewGC) {
+workers()->print_worker_threads_on(st);
+}
+if (UseConcMarkSweepGC) {
+ConcurrentMarkSweepThread::print_all_on(st);
+}
+#endif // INCLUDE_ALL_GCS
+}
+void GenCollectedHeap::print_on_error(outputStream* st) const {
+this->CollectedHeap::print_on_error(st);
+#if INCLUDE_ALL_GCS
+if (UseConcMarkSweepGC) {
+st->cr();
+CMSCollector::print_on_error(st);
+}
+#endif // INCLUDE_ALL_GCS
+}
+void GenCollectedHeap::print_tracing_info() const {
+if (TraceGen0Time) {
+get_gen(0)->print_summary_info();
+}
+if (TraceGen1Time) {
+get_gen(1)->print_summary_info();
+}
+}
+void GenCollectedHeap::print_heap_change(size_t prev_used) const {
+if (PrintGCDetails && Verbose) {
+gclog_or_tty->print(" "  SIZE_FORMAT
+"->" SIZE_FORMAT
+"("  SIZE_FORMAT ")",
+prev_used, used(), capacity());
+} else {
+gclog_or_tty->print(" "  SIZE_FORMAT "K"
+"->" SIZE_FORMAT "K"
+"("  SIZE_FORMAT "K)",
+prev_used / K, used() / K, capacity() / K);
+}
+}
+class GenGCPrologueClosure: public GenCollectedHeap::GenClosure {
+private:
+bool _full;
+public:
+void do_generation(Generation* gen) {
+gen->gc_prologue(_full);
+}
+GenGCPrologueClosure(bool full) : _full(full) {};
+};
+void GenCollectedHeap::gc_prologue(bool full) {
+assert(InlineCacheBuffer::is_empty(), "should have cleaned up ICBuffer");
+always_do_update_barrier = false;
+// Fill TLAB's and such
+CollectedHeap::accumulate_statistics_all_tlabs();
+ensure_parsability(true);   // retire TLABs
+// Walk generations
+GenGCPrologueClosure blk(full);
+generation_iterate(&blk, false);  // not old-to-young.
+};
+class GenGCEpilogueClosure: public GenCollectedHeap::GenClosure {
+private:
+bool _full;
+public:
+void do_generation(Generation* gen) {
+gen->gc_epilogue(_full);
+}
+GenGCEpilogueClosure(bool full) : _full(full) {};
+};
+void GenCollectedHeap::gc_epilogue(bool full) {
+#ifdef COMPILER2
+assert(DerivedPointerTable::is_empty(), "derived pointer present");
+size_t actual_gap = pointer_delta((HeapWord*) (max_uintx-3), *(end_addr()));
+guarantee(actual_gap > (size_t)FastAllocateSizeLimit, "inline allocation wraps");
+#endif /* COMPILER2 */
+resize_all_tlabs();
+GenGCEpilogueClosure blk(full);
+generation_iterate(&blk, false);  // not old-to-young.
+if (!CleanChunkPoolAsync) {
+Chunk::clean_chunk_pool();
+}
+MetaspaceCounters::update_performance_counters();
+CompressedClassSpaceCounters::update_performance_counters();
+always_do_update_barrier = UseConcMarkSweepGC;
+};
+#ifndef PRODUCT
+class GenGCSaveTopsBeforeGCClosure: public GenCollectedHeap::GenClosure {
+private:
+public:
+void do_generation(Generation* gen) {
+gen->record_spaces_top();
+}
+};
+void GenCollectedHeap::record_gen_tops_before_GC() {
+if (ZapUnusedHeapArea) {
+GenGCSaveTopsBeforeGCClosure blk;
+generation_iterate(&blk, false);  // not old-to-young.
+}
+}
+#endif  // not PRODUCT
+class GenEnsureParsabilityClosure: public GenCollectedHeap::GenClosure {
+public:
+void do_generation(Generation* gen) {
+gen->ensure_parsability();
+}
+};
+void GenCollectedHeap::ensure_parsability(bool retire_tlabs) {
+CollectedHeap::ensure_parsability(retire_tlabs);
+GenEnsureParsabilityClosure ep_cl;
+generation_iterate(&ep_cl, false);
+}
+oop GenCollectedHeap::handle_failed_promotion(Generation* old_gen,
+oop obj,
+size_t obj_size) {
+guarantee(old_gen->level() == 1, "We only get here with an old generation");
+assert(obj_size == (size_t)obj->size(), "bad obj_size passed in");
+HeapWord* result = NULL;
+result = old_gen->expand_and_allocate(obj_size, false);
+if (result != NULL) {
+Copy::aligned_disjoint_words((HeapWord*)obj, result, obj_size);
+}
+return oop(result);
+}
+class GenTimeOfLastGCClosure: public GenCollectedHeap::GenClosure {
+jlong _time;   // in ms
+jlong _now;    // in ms
+public:
+GenTimeOfLastGCClosure(jlong now) : _time(now), _now(now) { }
+jlong time() { return _time; }
+void do_generation(Generation* gen) {
+_time = MIN2(_time, gen->time_of_last_gc(_now));
+}
+};
+jlong GenCollectedHeap::millis_since_last_gc() {
+// We need a monotonically non-deccreasing time in ms but
+// os::javaTimeMillis() does not guarantee monotonicity.
+jlong now = os::javaTimeNanos() / NANOSECS_PER_MILLISEC;
+GenTimeOfLastGCClosure tolgc_cl(now);
+// iterate over generations getting the oldest
+// time that a generation was collected
+generation_iterate(&tolgc_cl, false);
+// javaTimeNanos() is guaranteed to be monotonically non-decreasing
+// provided the underlying platform provides such a time source
+// (and it is bug free). So we still have to guard against getting
+// back a time later than 'now'.
+jlong retVal = now - tolgc_cl.time();
+if (retVal < 0) {
+NOT_PRODUCT(warning("time warp: "INT64_FORMAT, (int64_t) retVal);)
+return 0;
+}
+return retVal;
+}

Mercurial > jdk8-mips64-public > hotspot / file comparison

comparison: src/share/vm/memory/genCollectedHeap.cpp

src/share/vm/memory/genCollectedHeap.cpp