--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,670 @@
+/*
+ * Copyright 2001-2007 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/_psMarkSweep.cpp.incl"
+
+elapsedTimer PSMarkSweep::_accumulated_time;
+unsigned int PSMarkSweep::_total_invocations = 0;
+jlong PSMarkSweep::_time_of_last_gc = 0;
+CollectorCounters* PSMarkSweep::_counters = NULL;
+
+void PSMarkSweep::initialize() {
+ MemRegion mr = Universe::heap()->reserved_region();
+ _ref_processor = new ReferenceProcessor(mr,
+ true, // atomic_discovery
+ false); // mt_discovery
+ if (!UseParallelOldGC || !VerifyParallelOldWithMarkSweep) {
+ _counters = new CollectorCounters("PSMarkSweep", 1);
+ }
+}
+
+// This method contains all heap specific policy for invoking mark sweep.
+// PSMarkSweep::invoke_no_policy() will only attempt to mark-sweep-compact
+// the heap. It will do nothing further. If we need to bail out for policy
+// reasons, scavenge before full gc, or any other specialized behavior, it
+// needs to be added here.
+//
+// Note that this method should only be called from the vm_thread while
+// at a safepoint!
+void PSMarkSweep::invoke(bool maximum_heap_compaction) {
+ assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
+ assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
+ assert(!Universe::heap()->is_gc_active(), "not reentrant");
+
+ ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+ GCCause::Cause gc_cause = heap->gc_cause();
+ PSAdaptiveSizePolicy* policy = heap->size_policy();
+
+ // Before each allocation/collection attempt, find out from the
+ // policy object if GCs are, on the whole, taking too long. If so,
+ // bail out without attempting a collection. The exceptions are
+ // for explicitly requested GC's.
+ if (!policy->gc_time_limit_exceeded() ||
+ GCCause::is_user_requested_gc(gc_cause) ||
+ GCCause::is_serviceability_requested_gc(gc_cause)) {
+ IsGCActiveMark mark;
+
+ if (ScavengeBeforeFullGC) {
+ PSScavenge::invoke_no_policy();
+ }
+
+ int count = (maximum_heap_compaction)?1:MarkSweepAlwaysCompactCount;
+ IntFlagSetting flag_setting(MarkSweepAlwaysCompactCount, count);
+ PSMarkSweep::invoke_no_policy(maximum_heap_compaction);
+ }
+}
+
+// This method contains no policy. You should probably
+// be calling invoke() instead.
+void PSMarkSweep::invoke_no_policy(bool clear_all_softrefs) {
+ assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
+ assert(ref_processor() != NULL, "Sanity");
+
+ if (GC_locker::check_active_before_gc()) {
+ return;
+ }
+
+ ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+ GCCause::Cause gc_cause = heap->gc_cause();
+ assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
+ PSAdaptiveSizePolicy* size_policy = heap->size_policy();
+
+ PSYoungGen* young_gen = heap->young_gen();
+ PSOldGen* old_gen = heap->old_gen();
+ PSPermGen* perm_gen = heap->perm_gen();
+
+ // Increment the invocation count
+ heap->increment_total_collections(true /* full */);
+
+ // We need to track unique mark sweep invocations as well.
+ _total_invocations++;
+
+ AdaptiveSizePolicyOutput(size_policy, heap->total_collections());
+
+ if (PrintHeapAtGC) {
+ Universe::print_heap_before_gc();
+ }
+
+ // Fill in TLABs
+ heap->accumulate_statistics_all_tlabs();
+ heap->ensure_parsability(true); // retire TLABs
+
+ if (VerifyBeforeGC && heap->total_collections() >= VerifyGCStartAt) {
+ HandleMark hm; // Discard invalid handles created during verification
+ gclog_or_tty->print(" VerifyBeforeGC:");
+ Universe::verify(true);
+ }
+
+ // Verify object start arrays
+ if (VerifyObjectStartArray &&
+ VerifyBeforeGC) {
+ old_gen->verify_object_start_array();
+ perm_gen->verify_object_start_array();
+ }
+
+ // Filled in below to track the state of the young gen after the collection.
+ bool eden_empty;
+ bool survivors_empty;
+ bool young_gen_empty;
+
+ {
+ HandleMark hm;
+ const bool is_system_gc = gc_cause == GCCause::_java_lang_system_gc;
+ // This is useful for debugging but don't change the output the
+ // the customer sees.
+ const char* gc_cause_str = "Full GC";
+ if (is_system_gc && PrintGCDetails) {
+ gc_cause_str = "Full GC (System)";
+ }
+ gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
+ TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
+ TraceTime t1(gc_cause_str, PrintGC, !PrintGCDetails, gclog_or_tty);
+ TraceCollectorStats tcs(counters());
+ TraceMemoryManagerStats tms(true /* Full GC */);
+
+ if (TraceGen1Time) accumulated_time()->start();
+
+ // Let the size policy know we're starting
+ size_policy->major_collection_begin();
+
+ // When collecting the permanent generation methodOops may be moving,
+ // so we either have to flush all bcp data or convert it into bci.
+ CodeCache::gc_prologue();
+ Threads::gc_prologue();
+ BiasedLocking::preserve_marks();
+
+ // Capture heap size before collection for printing.
+ size_t prev_used = heap->used();
+
+ // Capture perm gen size before collection for sizing.
+ size_t perm_gen_prev_used = perm_gen->used_in_bytes();
+
+ // For PrintGCDetails
+ size_t old_gen_prev_used = old_gen->used_in_bytes();
+ size_t young_gen_prev_used = young_gen->used_in_bytes();
+
+ allocate_stacks();
+
+ NOT_PRODUCT(ref_processor()->verify_no_references_recorded());
+ COMPILER2_PRESENT(DerivedPointerTable::clear());
+
+ ref_processor()->enable_discovery();
+
+ mark_sweep_phase1(clear_all_softrefs);
+
+ mark_sweep_phase2();
+
+ // Don't add any more derived pointers during phase3
+ COMPILER2_PRESENT(assert(DerivedPointerTable::is_active(), "Sanity"));
+ COMPILER2_PRESENT(DerivedPointerTable::set_active(false));
+
+ mark_sweep_phase3();
+
+ mark_sweep_phase4();
+
+ restore_marks();
+
+ deallocate_stacks();
+
+ eden_empty = young_gen->eden_space()->is_empty();
+ if (!eden_empty) {
+ eden_empty = absorb_live_data_from_eden(size_policy, young_gen, old_gen);
+ }
+
+ // Update heap occupancy information which is used as
+ // input to soft ref clearing policy at the next gc.
+ Universe::update_heap_info_at_gc();
+
+ survivors_empty = young_gen->from_space()->is_empty() &&
+ young_gen->to_space()->is_empty();
+ young_gen_empty = eden_empty && survivors_empty;
+
+ BarrierSet* bs = heap->barrier_set();
+ if (bs->is_a(BarrierSet::ModRef)) {
+ ModRefBarrierSet* modBS = (ModRefBarrierSet*)bs;
+ MemRegion old_mr = heap->old_gen()->reserved();
+ MemRegion perm_mr = heap->perm_gen()->reserved();
+ assert(perm_mr.end() <= old_mr.start(), "Generations out of order");
+
+ if (young_gen_empty) {
+ modBS->clear(MemRegion(perm_mr.start(), old_mr.end()));
+ } else {
+ modBS->invalidate(MemRegion(perm_mr.start(), old_mr.end()));
+ }
+ }
+
+ BiasedLocking::restore_marks();
+ Threads::gc_epilogue();
+ CodeCache::gc_epilogue();
+
+ COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
+
+ ref_processor()->enqueue_discovered_references(NULL);
+
+ // Update time of last GC
+ reset_millis_since_last_gc();
+
+ // Let the size policy know we're done
+ size_policy->major_collection_end(old_gen->used_in_bytes(), gc_cause);
+
+ if (UseAdaptiveSizePolicy) {
+
+ if (PrintAdaptiveSizePolicy) {
+ gclog_or_tty->print("AdaptiveSizeStart: ");
+ gclog_or_tty->stamp();
+ gclog_or_tty->print_cr(" collection: %d ",
+ heap->total_collections());
+ if (Verbose) {
+ gclog_or_tty->print("old_gen_capacity: %d young_gen_capacity: %d"
+ " perm_gen_capacity: %d ",
+ old_gen->capacity_in_bytes(), young_gen->capacity_in_bytes(),
+ perm_gen->capacity_in_bytes());
+ }
+ }
+
+ // Don't check if the size_policy is ready here. Let
+ // the size_policy check that internally.
+ if (UseAdaptiveGenerationSizePolicyAtMajorCollection &&
+ ((gc_cause != GCCause::_java_lang_system_gc) ||
+ UseAdaptiveSizePolicyWithSystemGC)) {
+ // Calculate optimal free space amounts
+ assert(young_gen->max_size() >
+ young_gen->from_space()->capacity_in_bytes() +
+ young_gen->to_space()->capacity_in_bytes(),
+ "Sizes of space in young gen are out-of-bounds");
+ size_t max_eden_size = young_gen->max_size() -
+ young_gen->from_space()->capacity_in_bytes() -
+ young_gen->to_space()->capacity_in_bytes();
+ size_policy->compute_generation_free_space(young_gen->used_in_bytes(),
+ young_gen->eden_space()->used_in_bytes(),
+ old_gen->used_in_bytes(),
+ perm_gen->used_in_bytes(),
+ young_gen->eden_space()->capacity_in_bytes(),
+ old_gen->max_gen_size(),
+ max_eden_size,
+ true /* full gc*/,
+ gc_cause);
+
+ heap->resize_old_gen(size_policy->calculated_old_free_size_in_bytes());
+
+ // Don't resize the young generation at an major collection. A
+ // desired young generation size may have been calculated but
+ // resizing the young generation complicates the code because the
+ // resizing of the old generation may have moved the boundary
+ // between the young generation and the old generation. Let the
+ // young generation resizing happen at the minor collections.
+ }
+ if (PrintAdaptiveSizePolicy) {
+ gclog_or_tty->print_cr("AdaptiveSizeStop: collection: %d ",
+ heap->total_collections());
+ }
+ }
+
+ if (UsePerfData) {
+ heap->gc_policy_counters()->update_counters();
+ heap->gc_policy_counters()->update_old_capacity(
+ old_gen->capacity_in_bytes());
+ heap->gc_policy_counters()->update_young_capacity(
+ young_gen->capacity_in_bytes());
+ }
+
+ heap->resize_all_tlabs();
+
+ // We collected the perm gen, so we'll resize it here.
+ perm_gen->compute_new_size(perm_gen_prev_used);
+
+ if (TraceGen1Time) accumulated_time()->stop();
+
+ if (PrintGC) {
+ if (PrintGCDetails) {
+ // Don't print a GC timestamp here. This is after the GC so
+ // would be confusing.
+ young_gen->print_used_change(young_gen_prev_used);
+ old_gen->print_used_change(old_gen_prev_used);
+ }
+ heap->print_heap_change(prev_used);
+ // Do perm gen after heap becase prev_used does
+ // not include the perm gen (done this way in the other
+ // collectors).
+ if (PrintGCDetails) {
+ perm_gen->print_used_change(perm_gen_prev_used);
+ }
+ }
+
+ // Track memory usage and detect low memory
+ MemoryService::track_memory_usage();
+ heap->update_counters();
+
+ if (PrintGCDetails) {
+ if (size_policy->print_gc_time_limit_would_be_exceeded()) {
+ if (size_policy->gc_time_limit_exceeded()) {
+ gclog_or_tty->print_cr(" GC time is exceeding GCTimeLimit "
+ "of %d%%", GCTimeLimit);
+ } else {
+ gclog_or_tty->print_cr(" GC time would exceed GCTimeLimit "
+ "of %d%%", GCTimeLimit);
+ }
+ }
+ size_policy->set_print_gc_time_limit_would_be_exceeded(false);
+ }
+ }
+
+ if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) {
+ HandleMark hm; // Discard invalid handles created during verification
+ gclog_or_tty->print(" VerifyAfterGC:");
+ Universe::verify(false);
+ }
+
+ // Re-verify object start arrays
+ if (VerifyObjectStartArray &&
+ VerifyAfterGC) {
+ old_gen->verify_object_start_array();
+ perm_gen->verify_object_start_array();
+ }
+
+ NOT_PRODUCT(ref_processor()->verify_no_references_recorded());
+
+ if (PrintHeapAtGC) {
+ Universe::print_heap_after_gc();
+ }
+}
+
+bool PSMarkSweep::absorb_live_data_from_eden(PSAdaptiveSizePolicy* size_policy,
+ PSYoungGen* young_gen,
+ PSOldGen* old_gen) {
+ MutableSpace* const eden_space = young_gen->eden_space();
+ assert(!eden_space->is_empty(), "eden must be non-empty");
+ assert(young_gen->virtual_space()->alignment() ==
+ old_gen->virtual_space()->alignment(), "alignments do not match");
+
+ if (!(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary)) {
+ return false;
+ }
+
+ // Both generations must be completely committed.
+ if (young_gen->virtual_space()->uncommitted_size() != 0) {
+ return false;
+ }
+ if (old_gen->virtual_space()->uncommitted_size() != 0) {
+ return false;
+ }
+
+ // Figure out how much to take from eden. Include the average amount promoted
+ // in the total; otherwise the next young gen GC will simply bail out to a
+ // full GC.
+ const size_t alignment = old_gen->virtual_space()->alignment();
+ const size_t eden_used = eden_space->used_in_bytes();
+ const size_t promoted = (size_t)(size_policy->avg_promoted()->padded_average());
+ const size_t absorb_size = align_size_up(eden_used + promoted, alignment);
+ const size_t eden_capacity = eden_space->capacity_in_bytes();
+
+ if (absorb_size >= eden_capacity) {
+ return false; // Must leave some space in eden.
+ }
+
+ const size_t new_young_size = young_gen->capacity_in_bytes() - absorb_size;
+ if (new_young_size < young_gen->min_gen_size()) {
+ return false; // Respect young gen minimum size.
+ }
+
+ if (TraceAdaptiveGCBoundary && Verbose) {
+ gclog_or_tty->print(" absorbing " SIZE_FORMAT "K: "
+ "eden " SIZE_FORMAT "K->" SIZE_FORMAT "K "
+ "from " SIZE_FORMAT "K, to " SIZE_FORMAT "K "
+ "young_gen " SIZE_FORMAT "K->" SIZE_FORMAT "K ",
+ absorb_size / K,
+ eden_capacity / K, (eden_capacity - absorb_size) / K,
+ young_gen->from_space()->used_in_bytes() / K,
+ young_gen->to_space()->used_in_bytes() / K,
+ young_gen->capacity_in_bytes() / K, new_young_size / K);
+ }
+
+ // Fill the unused part of the old gen.
+ MutableSpace* const old_space = old_gen->object_space();
+ MemRegion old_gen_unused(old_space->top(), old_space->end());
+
+ // If the unused part of the old gen cannot be filled, skip
+ // absorbing eden.
+ if (old_gen_unused.word_size() < SharedHeap::min_fill_size()) {
+ return false;
+ }
+
+ if (!old_gen_unused.is_empty()) {
+ SharedHeap::fill_region_with_object(old_gen_unused);
+ }
+
+ // Take the live data from eden and set both top and end in the old gen to
+ // eden top. (Need to set end because reset_after_change() mangles the region
+ // from end to virtual_space->high() in debug builds).
+ HeapWord* const new_top = eden_space->top();
+ old_gen->virtual_space()->expand_into(young_gen->virtual_space(),
+ absorb_size);
+ young_gen->reset_after_change();
+ old_space->set_top(new_top);
+ old_space->set_end(new_top);
+ old_gen->reset_after_change();
+
+ // Update the object start array for the filler object and the data from eden.
+ ObjectStartArray* const start_array = old_gen->start_array();
+ HeapWord* const start = old_gen_unused.start();
+ for (HeapWord* addr = start; addr < new_top; addr += oop(addr)->size()) {
+ start_array->allocate_block(addr);
+ }
+
+ // Could update the promoted average here, but it is not typically updated at
+ // full GCs and the value to use is unclear. Something like
+ //
+ // cur_promoted_avg + absorb_size / number_of_scavenges_since_last_full_gc.
+
+ size_policy->set_bytes_absorbed_from_eden(absorb_size);
+ return true;
+}
+
+void PSMarkSweep::allocate_stacks() {
+ ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+ assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
+
+ PSYoungGen* young_gen = heap->young_gen();
+
+ MutableSpace* to_space = young_gen->to_space();
+ _preserved_marks = (PreservedMark*)to_space->top();
+ _preserved_count = 0;
+
+ // We want to calculate the size in bytes first.
+ _preserved_count_max = pointer_delta(to_space->end(), to_space->top(), sizeof(jbyte));
+ // Now divide by the size of a PreservedMark
+ _preserved_count_max /= sizeof(PreservedMark);
+
+ _preserved_mark_stack = NULL;
+ _preserved_oop_stack = NULL;
+
+ _marking_stack = new (ResourceObj::C_HEAP) GrowableArray<oop>(4000, true);
+
+ int size = SystemDictionary::number_of_classes() * 2;
+ _revisit_klass_stack = new (ResourceObj::C_HEAP) GrowableArray<Klass*>(size, true);
+}
+
+
+void PSMarkSweep::deallocate_stacks() {
+ if (_preserved_oop_stack) {
+ delete _preserved_mark_stack;
+ _preserved_mark_stack = NULL;
+ delete _preserved_oop_stack;
+ _preserved_oop_stack = NULL;
+ }
+
+ delete _marking_stack;
+ delete _revisit_klass_stack;
+}
+
+void PSMarkSweep::mark_sweep_phase1(bool clear_all_softrefs) {
+ // Recursively traverse all live objects and mark them
+ EventMark m("1 mark object");
+ TraceTime tm("phase 1", PrintGCDetails && Verbose, true, gclog_or_tty);
+ trace(" 1");
+
+ ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+ assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
+
+ // General strong roots.
+ Universe::oops_do(mark_and_push_closure());
+ ReferenceProcessor::oops_do(mark_and_push_closure());
+ JNIHandles::oops_do(mark_and_push_closure()); // Global (strong) JNI handles
+ Threads::oops_do(mark_and_push_closure());
+ ObjectSynchronizer::oops_do(mark_and_push_closure());
+ FlatProfiler::oops_do(mark_and_push_closure());
+ Management::oops_do(mark_and_push_closure());
+ JvmtiExport::oops_do(mark_and_push_closure());
+ SystemDictionary::always_strong_oops_do(mark_and_push_closure());
+ vmSymbols::oops_do(mark_and_push_closure());
+
+ // Flush marking stack.
+ follow_stack();
+
+ // Process reference objects found during marking
+
+ // Skipping the reference processing for VerifyParallelOldWithMarkSweep
+ // affects the marking (makes it different).
+ {
+ ReferencePolicy *soft_ref_policy;
+ if (clear_all_softrefs) {
+ soft_ref_policy = new AlwaysClearPolicy();
+ } else {
+#ifdef COMPILER2
+ soft_ref_policy = new LRUMaxHeapPolicy();
+#else
+ soft_ref_policy = new LRUCurrentHeapPolicy();
+#endif // COMPILER2
+ }
+ assert(soft_ref_policy != NULL,"No soft reference policy");
+ ref_processor()->process_discovered_references(
+ soft_ref_policy, is_alive_closure(), mark_and_push_closure(),
+ follow_stack_closure(), NULL);
+ }
+
+ // Follow system dictionary roots and unload classes
+ bool purged_class = SystemDictionary::do_unloading(is_alive_closure());
+
+ // Follow code cache roots
+ CodeCache::do_unloading(is_alive_closure(), mark_and_push_closure(),
+ purged_class);
+ follow_stack(); // Flush marking stack
+
+ // Update subklass/sibling/implementor links of live klasses
+ follow_weak_klass_links();
+ assert(_marking_stack->is_empty(), "just drained");
+
+ // Visit symbol and interned string tables and delete unmarked oops
+ SymbolTable::unlink(is_alive_closure());
+ StringTable::unlink(is_alive_closure());
+
+ assert(_marking_stack->is_empty(), "stack should be empty by now");
+}
+
+
+void PSMarkSweep::mark_sweep_phase2() {
+ EventMark m("2 compute new addresses");
+ TraceTime tm("phase 2", PrintGCDetails && Verbose, true, gclog_or_tty);
+ trace("2");
+
+ // Now all live objects are marked, compute the new object addresses.
+
+ // It is imperative that we traverse perm_gen LAST. If dead space is
+ // allowed a range of dead object may get overwritten by a dead int
+ // array. If perm_gen is not traversed last a klassOop may get
+ // overwritten. This is fine since it is dead, but if the class has dead
+ // instances we have to skip them, and in order to find their size we
+ // need the klassOop!
+ //
+ // It is not required that we traverse spaces in the same order in
+ // phase2, phase3 and phase4, but the ValidateMarkSweep live oops
+ // tracking expects us to do so. See comment under phase4.
+
+ ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+ assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
+
+ PSOldGen* old_gen = heap->old_gen();
+ PSPermGen* perm_gen = heap->perm_gen();
+
+ // Begin compacting into the old gen
+ PSMarkSweepDecorator::set_destination_decorator_tenured();
+
+ // This will also compact the young gen spaces.
+ old_gen->precompact();
+
+ // Compact the perm gen into the perm gen
+ PSMarkSweepDecorator::set_destination_decorator_perm_gen();
+
+ perm_gen->precompact();
+}
+
+// This should be moved to the shared markSweep code!
+class PSAlwaysTrueClosure: public BoolObjectClosure {
+public:
+ void do_object(oop p) { ShouldNotReachHere(); }
+ bool do_object_b(oop p) { return true; }
+};
+static PSAlwaysTrueClosure always_true;
+
+void PSMarkSweep::mark_sweep_phase3() {
+ // Adjust the pointers to reflect the new locations
+ EventMark m("3 adjust pointers");
+ TraceTime tm("phase 3", PrintGCDetails && Verbose, true, gclog_or_tty);
+ trace("3");
+
+ ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+ assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
+
+ PSYoungGen* young_gen = heap->young_gen();
+ PSOldGen* old_gen = heap->old_gen();
+ PSPermGen* perm_gen = heap->perm_gen();
+
+ // General strong roots.
+ Universe::oops_do(adjust_root_pointer_closure());
+ ReferenceProcessor::oops_do(adjust_root_pointer_closure());
+ JNIHandles::oops_do(adjust_root_pointer_closure()); // Global (strong) JNI handles
+ Threads::oops_do(adjust_root_pointer_closure());
+ ObjectSynchronizer::oops_do(adjust_root_pointer_closure());
+ FlatProfiler::oops_do(adjust_root_pointer_closure());
+ Management::oops_do(adjust_root_pointer_closure());
+ JvmtiExport::oops_do(adjust_root_pointer_closure());
+ // SO_AllClasses
+ SystemDictionary::oops_do(adjust_root_pointer_closure());
+ vmSymbols::oops_do(adjust_root_pointer_closure());
+
+ // Now adjust pointers in remaining weak roots. (All of which should
+ // have been cleared if they pointed to non-surviving objects.)
+ // Global (weak) JNI handles
+ JNIHandles::weak_oops_do(&always_true, adjust_root_pointer_closure());
+
+ CodeCache::oops_do(adjust_pointer_closure());
+ SymbolTable::oops_do(adjust_root_pointer_closure());
+ StringTable::oops_do(adjust_root_pointer_closure());
+ ref_processor()->weak_oops_do(adjust_root_pointer_closure());
+ PSScavenge::reference_processor()->weak_oops_do(adjust_root_pointer_closure());
+
+ adjust_marks();
+
+ young_gen->adjust_pointers();
+ old_gen->adjust_pointers();
+ perm_gen->adjust_pointers();
+}
+
+void PSMarkSweep::mark_sweep_phase4() {
+ EventMark m("4 compact heap");
+ TraceTime tm("phase 4", PrintGCDetails && Verbose, true, gclog_or_tty);
+ trace("4");
+
+ // All pointers are now adjusted, move objects accordingly
+
+ // It is imperative that we traverse perm_gen first in phase4. All
+ // classes must be allocated earlier than their instances, and traversing
+ // perm_gen first makes sure that all klassOops have moved to their new
+ // location before any instance does a dispatch through it's klass!
+ ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
+ assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
+
+ PSYoungGen* young_gen = heap->young_gen();
+ PSOldGen* old_gen = heap->old_gen();
+ PSPermGen* perm_gen = heap->perm_gen();
+
+ perm_gen->compact();
+ old_gen->compact();
+ young_gen->compact();
+}
+
+jlong PSMarkSweep::millis_since_last_gc() {
+ jlong ret_val = os::javaTimeMillis() - _time_of_last_gc;
+ // XXX See note in genCollectedHeap::millis_since_last_gc().
+ if (ret_val < 0) {
+ NOT_PRODUCT(warning("time warp: %d", ret_val);)
+ return 0;
+ }
+ return ret_val;
+}
+
+void PSMarkSweep::reset_millis_since_last_gc() {
+ _time_of_last_gc = os::javaTimeMillis();
+}