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

comparison src/share/vm/memory/genCollectedHeap.cpp @ 0:a61af66fc99e jdk7-b24

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author	duke
date	Sat, 01 Dec 2007 00:00:00 +0000
parents
children	ba764ed4b6f2

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--1:000000000000
+:a61af66fc99e
+/*
+* Copyright 2000-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+* CA 95054 USA or visit www.sun.com if you need additional information or
+* have any questions.
+*
+*/
+# include "incls/_precompiled.incl"
+# include "incls/_genCollectedHeap.cpp.incl"
+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");
+_preloading_shared_classes = false;
+}
+jint GenCollectedHeap::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 alignment = Generation::GenGrain;
+_gen_specs = gen_policy()->generations();
+PermanentGenerationSpec *perm_gen_spec =
+collector_policy()->permanent_generation();
+// Make sure the sizes are all aligned.
+for (i = 0; i < _n_gens; i++) {
+_gen_specs[i]->align(alignment);
+}
+perm_gen_spec->align(alignment);
+// If we are dumping the heap, then allocate a wasted block of address
+// space in order to push the heap to a lower address.  This extra
+// address range allows for other (or larger) libraries to be loaded
+// without them occupying the space required for the shared spaces.
+if (DumpSharedSpaces) {
+uintx reserved = 0;
+uintx block_size = 64*1024*1024;
+while (reserved < SharedDummyBlockSize) {
+char* dummy = os::reserve_memory(block_size);
+reserved += block_size;
+}
+}
+// Allocate space for the heap.
+char* heap_address;
+size_t total_reserved = 0;
+int n_covered_regions = 0;
+ReservedSpace heap_rs(0);
+heap_address = allocate(alignment, perm_gen_spec, &total_reserved,
+&n_covered_regions, &heap_rs);
+if (UseSharedSpaces) {
+if (!heap_rs.is_reserved() || heap_address != heap_rs.base()) {
+if (heap_rs.is_reserved()) {
+heap_rs.release();
+}
+FileMapInfo* mapinfo = FileMapInfo::current_info();
+mapinfo->fail_continue("Unable to reserve shared region.");
+allocate(alignment, perm_gen_spec, &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() - perm_gen_spec->misc_data_size()
+- perm_gen_spec->misc_code_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(),
+UseSharedSpaces, UseSharedSpaces);
+_gens[i] = _gen_specs[i]->init(this_rs, i, rem_set());
+heap_rs = heap_rs.last_part(_gen_specs[i]->max_size());
+}
+_perm_gen = perm_gen_spec->init(heap_rs, PermSize, rem_set());
+clear_incremental_collection_will_fail();
+clear_last_incremental_collection_failed();
+#ifndef SERIALGC
+// 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 // SERIALGC
+return JNI_OK;
+}
+char* GenCollectedHeap::allocate(size_t alignment,
+PermanentGenerationSpec* perm_gen_spec,
+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();
+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 % pageSize == 0, "Gen size");
+total_reserved += perm_gen_spec->max_size();
+assert(total_reserved % pageSize == 0, "Perm Gen size");
+if (total_reserved < perm_gen_spec->max_size()) {
+vm_exit_during_initialization(overflow_msg);
+}
+n_covered_regions += perm_gen_spec->n_covered_regions();
+// Add the size of the data area which shares the same reserved area
+// as the heap, but which is not actually part of the heap.
+size_t s = perm_gen_spec->misc_data_size() + perm_gen_spec->misc_code_size();
+total_reserved += s;
+if (total_reserved < s) {
+vm_exit_during_initialization(overflow_msg);
+}
+if (UseLargePages) {
+assert(total_reserved != 0, "total_reserved cannot be 0");
+total_reserved = round_to(total_reserved, os::large_page_size());
+if (total_reserved < os::large_page_size()) {
+vm_exit_during_initialization(overflow_msg);
+}
+}
+// Calculate the address at which the heap must reside in order for
+// the shared data to be at the required address.
+char* heap_address;
+if (UseSharedSpaces) {
+// Calculate the address of the first word beyond the heap.
+FileMapInfo* mapinfo = FileMapInfo::current_info();
+int lr = CompactingPermGenGen::n_regions - 1;
+size_t capacity = align_size_up(mapinfo->space_capacity(lr), alignment);
+heap_address = mapinfo->region_base(lr) + capacity;
+// Calculate the address of the first word of the heap.
+heap_address -= total_reserved;
+} else {
+heap_address = NULL;  // any address will do.
+}
+*_total_reserved = total_reserved;
+*_n_covered_regions = n_covered_regions;
+*heap_rs = ReservedSpace(total_reserved, alignment,
+UseLargePages, heap_address);
+return heap_address;
+}
+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,
+// and, if perm is true, for perm gen.
+void GenCollectedHeap::save_used_regions(int level, bool perm) {
+assert(level < _n_gens, "Illegal level parameter");
+for (int i = level; i >= 0; i--) {
+_gens[i]->save_used_region();
+}
+if (perm) {
+perm_gen()->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 is_large_noref,
+bool is_tlab,
+bool* gc_overhead_limit_was_exceeded) {
+return collector_policy()->mem_allocate_work(size,
+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 (cause == GCCause::_java_lang_system_gc ||
+cause == GCCause::_gc_locker) &&
+UseConcMarkSweepGC && 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 size_t perm_prev_used = perm_gen()->used();
+if (PrintHeapAtGC) {
+Universe::print_heap_before_gc();
+if (Verbose) {
+gclog_or_tty->print_cr("GC Cause: %s", GCCause::to_string(gc_cause()));
+}
+}
+{
+FlagSetting fl(_is_gc_active, true);
+bool complete = full && (max_level == (n_gens()-1));
+const char* gc_cause_str = "GC ";
+if (complete) {
+GCCause::Cause cause = gc_cause();
+if (cause == GCCause::_java_lang_system_gc) {
+gc_cause_str = "Full GC (System) ";
+} else {
+gc_cause_str = "Full GC ";
+}
+}
+gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
+TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
+TraceTime t(gc_cause_str, PrintGCDetails, false, gclog_or_tty);
+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)) {
+// Timer for individual generations. Last argument is false: no CR
+TraceTime t1(_gens[i]->short_name(), PrintGCDetails, false, gclog_or_tty);
+TraceCollectorStats tcs(_gens[i]->counters());
+TraceMemoryManagerStats tmms(_gens[i]->kind());
+size_t prev_used = _gens[i]->used();
+_gens[i]->stat_record()->invocations++;
+_gens[i]->stat_record()->accumulated_time.start();
+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;
+}
+gclog_or_tty->print(" VerifyBeforeGC:");
+Universe::verify(true);
+}
+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->verify_no_references_recorded();
+rp->enable_discovery();
+} else {
+// collect() will enable discovery as appropriate
+}
+_gens[i]->collect(full, 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
+gclog_or_tty->print(" VerifyAfterGC:");
+Universe::verify(false);
+}
+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 (PrintGCDetails) {
+print_heap_change(gch_prev_used);
+// Print perm gen info for full GC with PrintGCDetails flag.
+if (complete) {
+print_perm_heap_change(perm_prev_used);
+}
+}
+for (int j = max_level_collected; j >= 0; j -= 1) {
+// Adjust generation sizes.
+_gens[j]->compute_new_size();
+}
+if (complete) {
+// Ask the permanent generation to adjust size for full collections
+perm()->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());
+if (PrintHeapAtGC) {
+Universe::print_heap_after_gc();
+}
+if (ExitAfterGCNum > 0 && total_collections() == ExitAfterGCNum) {
+tty->print_cr("Stopping after GC #%d", ExitAfterGCNum);
+vm_exit(-1);
+}
+}
+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(int t) {
+SharedHeap::set_par_threads(t);
+_gen_process_strong_tasks->set_par_threads(t);
+}
+class AssertIsPermClosure: public OopClosure {
+public:
+void do_oop(oop* p) {
+assert((*p) == NULL || (*p)->is_perm(), "Referent should be perm.");
+}
+};
+static AssertIsPermClosure assert_is_perm_closure;
+void GenCollectedHeap::
+gen_process_strong_roots(int level,
+bool younger_gens_as_roots,
+bool collecting_perm_gen,
+SharedHeap::ScanningOption so,
+OopsInGenClosure* older_gens,
+OopsInGenClosure* not_older_gens) {
+// General strong roots.
+SharedHeap::process_strong_roots(collecting_perm_gen, so,
+not_older_gens, older_gens);
+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,
+OopClosure* non_root_closure) {
+SharedHeap::process_weak_roots(root_closure, non_root_closure);
+// "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);           \
+}                                                                     \
+perm_gen()->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 perm_gen()->no_allocs_since_save_marks();
+}
+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)) {
+#ifndef SERIALGC
+// mostly concurrent full collection
+collect_mostly_concurrent(cause);
+#else  // SERIALGC
+ShouldNotReachHere();
+#endif // SERIALGC
+} 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);
+}
+// This interface assumes that it's being called by the
+// vm thread. It collects the heap assuming that the
+// heap lock is already held and that we are executing in
+// the context of the vm thread.
+void GenCollectedHeap::collect_as_vm_thread(GCCause::Cause cause) {
+assert(Thread::current()->is_VM_thread(), "Precondition#1");
+assert(Heap_lock->is_locked(), "Precondition#2");
+GCCauseSetter gcs(this, cause);
+switch (cause) {
+case GCCause::_heap_inspection:
+case GCCause::_heap_dump: {
+HandleMark hm;
+do_full_collection(false,         // don't clear all soft refs
+n_gens() - 1);
+break;
+}
+default: // XXX FIX ME
+ShouldNotReachHere(); // Unexpected use of this function
+}
+}
+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) {
+if (_preloading_shared_classes) {
+warning("\nThe permanent generation is not large enough to preload "
+"requested classes.\nUse -XX:PermSize= to increase the initial "
+"size of the permanent generation.\n");
+vm_exit(2);
+}
+// 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);
+}
+}
+#ifndef SERIALGC
+bool GenCollectedHeap::create_cms_collector() {
+assert(((_gens[1]->kind() == Generation::ConcurrentMarkSweep) ||
+(_gens[1]->kind() == Generation::ASConcurrentMarkSweep)) &&
+_perm_gen->as_gen()->kind() == Generation::ConcurrentMarkSweep,
+"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],
+(ConcurrentMarkSweepGeneration*)_perm_gen->as_gen(),
+_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 // SERIALGC
+void GenCollectedHeap::do_full_collection(bool clear_all_soft_refs,
+int max_level) {
+int local_max_level;
+if (!incremental_collection_will_fail() &&
+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()) {
+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 */);
+}
+}
+// Returns "TRUE" iff "p" points into the allocated area of the heap.
+bool GenCollectedHeap::is_in(const void* p) const {
+#ifndef ASSERT
+guarantee(VerifyBeforeGC   ||
+VerifyDuringGC   ||
+VerifyBeforeExit ||
+VerifyAfterGC, "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;
+}
+if (_perm_gen->as_gen()->is_in(p)) return true;
+// Otherwise...
+return false;
+}
+// Returns "TRUE" iff "p" points into the allocated area of the heap.
+bool GenCollectedHeap::is_in_youngest(void* p) {
+return _gens[0]->is_in(p);
+}
+void GenCollectedHeap::oop_iterate(OopClosure* cl) {
+for (int i = 0; i < _n_gens; i++) {
+_gens[i]->oop_iterate(cl);
+}
+}
+void GenCollectedHeap::oop_iterate(MemRegion mr, OopClosure* 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);
+}
+perm_gen()->object_iterate(cl);
+}
+void GenCollectedHeap::object_iterate_since_last_GC(ObjectClosure* cl) {
+for (int i = 0; i < _n_gens; i++) {
+_gens[i]->object_iterate_since_last_GC(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;
+}
+Space* res = perm_gen()->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);
+}
+}
+if (perm_gen()->is_in_reserved(addr)) {
+assert(perm_gen()->is_in(addr),
+"addr should be in allocated part of perm gen");
+return perm_gen()->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);
+}
+}
+if (perm_gen()->is_in_reserved(addr)) {
+assert(perm_gen()->is_in(addr),
+"addr should be in allocated part of perm gen");
+return perm_gen()->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);
+}
+}
+if (perm_gen()->is_in_reserved(addr)) {
+return perm_gen()->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::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;
+HeapWord* result = mem_allocate(size   /* size */,
+false  /* is_large_noref */,
+true   /* is_tlab */,
+&gc_overhead_limit_was_exceeded);
+return result;
+}
+// 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;
+}
+size_t GenCollectedHeap::large_typearray_limit() {
+return gen_policy()->large_typearray_limit();
+}
+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);
+perm_gen()->prepare_for_verify();
+}
+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);
+}
+perm_gen()->space_iterate(cl, true);
+}
+bool GenCollectedHeap::is_maximal_no_gc() const {
+for (int i = 0; i < _n_gens; i++) {  // skip perm gen
+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();
+}
+perm_gen()->save_marks();
+}
+void GenCollectedHeap::compute_new_generation_sizes(int collectedGen) {
+for (int i = 0; i <= collectedGen; i++) {
+_gens[i]->compute_new_size();
+}
+}
+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() {
+Generation* scanning_gen = _gens[_n_gens-1];
+// Start by compacting into same gen.
+CompactPoint cp(scanning_gen, NULL, NULL);
+while (scanning_gen != NULL) {
+scanning_gen->prepare_for_compaction(&cp);
+scanning_gen = prev_gen(scanning_gen);
+}
+}
+GCStats* GenCollectedHeap::gc_stats(int level) const {
+return _gens[level]->gc_stats();
+}
+void GenCollectedHeap::verify(bool allow_dirty, bool silent) {
+if (!silent) {
+gclog_or_tty->print("permgen ");
+}
+perm_gen()->verify(allow_dirty);
+for (int i = _n_gens-1; i >= 0; i--) {
+Generation* g = _gens[i];
+if (!silent) {
+gclog_or_tty->print(g->name());
+gclog_or_tty->print(" ");
+}
+g->verify(allow_dirty);
+}
+if (!silent) {
+gclog_or_tty->print("remset ");
+}
+rem_set()->verify();
+if (!silent) {
+gclog_or_tty->print("ref_proc ");
+}
+ReferenceProcessor::verify();
+}
+void GenCollectedHeap::print() const { print_on(tty); }
+void GenCollectedHeap::print_on(outputStream* st) const {
+for (int i = 0; i < _n_gens; i++) {
+_gens[i]->print_on(st);
+}
+perm_gen()->print_on(st);
+}
+void GenCollectedHeap::gc_threads_do(ThreadClosure* tc) const {
+if (workers() != NULL) {
+workers()->threads_do(tc);
+}
+#ifndef SERIALGC
+if (UseConcMarkSweepGC) {
+ConcurrentMarkSweepThread::threads_do(tc);
+}
+#endif // SERIALGC
+}
+void GenCollectedHeap::print_gc_threads_on(outputStream* st) const {
+#ifndef SERIALGC
+if (UseParNewGC) {
+workers()->print_worker_threads_on(st);
+}
+if (UseConcMarkSweepGC) {
+ConcurrentMarkSweepThread::print_all_on(st);
+}
+#endif // SERIALGC
+}
+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);
+}
+}
+//New method to print perm gen info with PrintGCDetails flag
+void GenCollectedHeap::print_perm_heap_change(size_t perm_prev_used) const {
+gclog_or_tty->print(", [%s :", perm_gen()->short_name());
+perm_gen()->print_heap_change(perm_prev_used);
+gclog_or_tty->print("]");
+}
+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
+// Call allocation profiler
+AllocationProfiler::iterate_since_last_gc();
+// Walk generations
+GenGCPrologueClosure blk(full);
+generation_iterate(&blk, false);  // not old-to-young.
+perm_gen()->gc_prologue(full);
+};
+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) {
+// Remember if a partial collection of the heap failed, and
+// we did a complete collection.
+if (full && incremental_collection_will_fail()) {
+set_last_incremental_collection_failed();
+} else {
+clear_last_incremental_collection_failed();
+}
+// Clear the flag, if set; the generation gc_epilogues will set the
+// flag again if the condition persists despite the collection.
+clear_incremental_collection_will_fail();
+#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.
+perm_gen()->gc_epilogue(full);
+always_do_update_barrier = UseConcMarkSweepGC;
+};
+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);
+perm_gen()->ensure_parsability();
+}
+oop GenCollectedHeap::handle_failed_promotion(Generation* gen,
+oop obj,
+size_t obj_size,
+oop* ref) {
+assert(obj_size == (size_t)obj->size(), "bad obj_size passed in");
+HeapWord* result = NULL;
+// First give each higher generation a chance to allocate the promoted object.
+Generation* allocator = next_gen(gen);
+if (allocator != NULL) {
+do {
+result = allocator->allocate(obj_size, false);
+} while (result == NULL && (allocator = next_gen(allocator)) != NULL);
+}
+if (result == NULL) {
+// Then give gen and higher generations a chance to expand and allocate the
+// object.
+do {
+result = gen->expand_and_allocate(obj_size, false);
+} while (result == NULL && (gen = next_gen(gen)) != NULL);
+}
+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() {
+jlong now = os::javaTimeMillis();
+GenTimeOfLastGCClosure tolgc_cl(now);
+// iterate over generations getting the oldest
+// time that a generation was collected
+generation_iterate(&tolgc_cl, false);
+tolgc_cl.do_generation(perm_gen());
+// XXX Despite the assert above, since javaTimeMillis()
+// doesnot guarantee monotonically increasing return
+// values (note, i didn't say "strictly monotonic"),
+// we need to guard against getting back a time
+// later than now. This should be fixed by basing
+// on someting like gethrtime() which guarantees
+// monotonicity. Note that cond_wait() is susceptible
+// to a similar problem, because its interface is
+// based on absolute time in the form of the
+// system time's notion of UCT. See also 4506635
+// for yet another problem of similar nature. XXX
+jlong retVal = now - tolgc_cl.time();
+if (retVal < 0) {
+NOT_PRODUCT(warning("time warp: %d", retVal);)
+return 0;
+}
+return retVal;
+}

Mercurial > hg > truffle

comparison src/share/vm/memory/genCollectedHeap.cpp @ 0:a61af66fc99e jdk7-b24