graal-compiler: src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp comparison

comparison src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp @ 342:37f87013dfd8

6711316: Open source the Garbage-First garbage collector Summary: First mercurial integration of the code for the Garbage-First garbage collector. Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr

author	ysr
date	Thu, 05 Jun 2008 15:57:56 -0700
parents
children	e0c09f7ec5c4

comparison

equal deleted inserted replaced

-:0b27f3512f9e
+:37f87013dfd8
+/*
+* 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/_g1CollectedHeap.cpp.incl"
+// turn it on so that the contents of the young list (scan-only /
+// to-be-collected) are printed at "strategic" points before / during
+// / after the collection --- this is useful for debugging
+#define SCAN_ONLY_VERBOSE 0
+// CURRENT STATUS
+// This file is under construction.  Search for "FIXME".
+// INVARIANTS/NOTES
+//
+// All allocation activity covered by the G1CollectedHeap interface is
+//   serialized by acquiring the HeapLock.  This happens in
+//   mem_allocate_work, which all such allocation functions call.
+//   (Note that this does not apply to TLAB allocation, which is not part
+//   of this interface: it is done by clients of this interface.)
+// Local to this file.
+// Finds the first HeapRegion.
+// No longer used, but might be handy someday.
+class FindFirstRegionClosure: public HeapRegionClosure {
+HeapRegion* _a_region;
+public:
+FindFirstRegionClosure() : _a_region(NULL) {}
+bool doHeapRegion(HeapRegion* r) {
+_a_region = r;
+return true;
+}
+HeapRegion* result() { return _a_region; }
+};
+class RefineCardTableEntryClosure: public CardTableEntryClosure {
+SuspendibleThreadSet* _sts;
+G1RemSet* _g1rs;
+ConcurrentG1Refine* _cg1r;
+bool _concurrent;
+public:
+RefineCardTableEntryClosure(SuspendibleThreadSet* sts,
+G1RemSet* g1rs,
+ConcurrentG1Refine* cg1r) :
+_sts(sts), _g1rs(g1rs), _cg1r(cg1r), _concurrent(true)
+{}
+bool do_card_ptr(jbyte* card_ptr, int worker_i) {
+_g1rs->concurrentRefineOneCard(card_ptr, worker_i);
+if (_concurrent && _sts->should_yield()) {
+// Caller will actually yield.
+return false;
+}
+// Otherwise, we finished successfully; return true.
+return true;
+}
+void set_concurrent(bool b) { _concurrent = b; }
+};
+class ClearLoggedCardTableEntryClosure: public CardTableEntryClosure {
+int _calls;
+G1CollectedHeap* _g1h;
+CardTableModRefBS* _ctbs;
+int _histo[256];
+public:
+ClearLoggedCardTableEntryClosure() :
+_calls(0)
+{
+_g1h = G1CollectedHeap::heap();
+_ctbs = (CardTableModRefBS*)_g1h->barrier_set();
+for (int i = 0; i < 256; i++) _histo[i] = 0;
+}
+bool do_card_ptr(jbyte* card_ptr, int worker_i) {
+if (_g1h->is_in_reserved(_ctbs->addr_for(card_ptr))) {
+_calls++;
+unsigned char* ujb = (unsigned char*)card_ptr;
+int ind = (int)(*ujb);
+_histo[ind]++;
+*card_ptr = -1;
+}
+return true;
+}
+int calls() { return _calls; }
+void print_histo() {
+gclog_or_tty->print_cr("Card table value histogram:");
+for (int i = 0; i < 256; i++) {
+if (_histo[i] != 0) {
+gclog_or_tty->print_cr("  %d: %d", i, _histo[i]);
+}
+}
+}
+};
+class RedirtyLoggedCardTableEntryClosure: public CardTableEntryClosure {
+int _calls;
+G1CollectedHeap* _g1h;
+CardTableModRefBS* _ctbs;
+public:
+RedirtyLoggedCardTableEntryClosure() :
+_calls(0)
+{
+_g1h = G1CollectedHeap::heap();
+_ctbs = (CardTableModRefBS*)_g1h->barrier_set();
+}
+bool do_card_ptr(jbyte* card_ptr, int worker_i) {
+if (_g1h->is_in_reserved(_ctbs->addr_for(card_ptr))) {
+_calls++;
+*card_ptr = 0;
+}
+return true;
+}
+int calls() { return _calls; }
+};
+YoungList::YoungList(G1CollectedHeap* g1h)
+: _g1h(g1h), _head(NULL),
+_scan_only_head(NULL), _scan_only_tail(NULL), _curr_scan_only(NULL),
+_length(0), _scan_only_length(0),
+_last_sampled_rs_lengths(0),
+_survivor_head(NULL), _survivors_tail(NULL), _survivor_length(0)
+{
+guarantee( check_list_empty(false), "just making sure..." );
+}
+void YoungList::push_region(HeapRegion *hr) {
+assert(!hr->is_young(), "should not already be young");
+assert(hr->get_next_young_region() == NULL, "cause it should!");
+hr->set_next_young_region(_head);
+_head = hr;
+hr->set_young();
+double yg_surv_rate = _g1h->g1_policy()->predict_yg_surv_rate((int)_length);
+++_length;
+}
+void YoungList::add_survivor_region(HeapRegion* hr) {
+assert(!hr->is_survivor(), "should not already be for survived");
+assert(hr->get_next_young_region() == NULL, "cause it should!");
+hr->set_next_young_region(_survivor_head);
+if (_survivor_head == NULL) {
+_survivors_tail = hr;
+}
+_survivor_head = hr;
+hr->set_survivor();
+++_survivor_length;
+}
+HeapRegion* YoungList::pop_region() {
+while (_head != NULL) {
+assert( length() > 0, "list should not be empty" );
+HeapRegion* ret = _head;
+_head = ret->get_next_young_region();
+ret->set_next_young_region(NULL);
+--_length;
+assert(ret->is_young(), "region should be very young");
+// Replace 'Survivor' region type with 'Young'. So the region will
+// be treated as a young region and will not be 'confused' with
+// newly created survivor regions.
+if (ret->is_survivor()) {
+ret->set_young();
+}
+if (!ret->is_scan_only()) {
+return ret;
+}
+// scan-only, we'll add it to the scan-only list
+if (_scan_only_tail == NULL) {
+guarantee( _scan_only_head == NULL, "invariant" );
+_scan_only_head = ret;
+_curr_scan_only = ret;
+} else {
+guarantee( _scan_only_head != NULL, "invariant" );
+_scan_only_tail->set_next_young_region(ret);
+}
+guarantee( ret->get_next_young_region() == NULL, "invariant" );
+_scan_only_tail = ret;
+// no need to be tagged as scan-only any more
+ret->set_young();
+++_scan_only_length;
+}
+assert( length() == 0, "list should be empty" );
+return NULL;
+}
+void YoungList::empty_list(HeapRegion* list) {
+while (list != NULL) {
+HeapRegion* next = list->get_next_young_region();
+list->set_next_young_region(NULL);
+list->uninstall_surv_rate_group();
+list->set_not_young();
+list = next;
+}
+}
+void YoungList::empty_list() {
+assert(check_list_well_formed(), "young list should be well formed");
+empty_list(_head);
+_head = NULL;
+_length = 0;
+empty_list(_scan_only_head);
+_scan_only_head = NULL;
+_scan_only_tail = NULL;
+_scan_only_length = 0;
+_curr_scan_only = NULL;
+empty_list(_survivor_head);
+_survivor_head = NULL;
+_survivors_tail = NULL;
+_survivor_length = 0;
+_last_sampled_rs_lengths = 0;
+assert(check_list_empty(false), "just making sure...");
+}
+bool YoungList::check_list_well_formed() {
+bool ret = true;
+size_t length = 0;
+HeapRegion* curr = _head;
+HeapRegion* last = NULL;
+while (curr != NULL) {
+if (!curr->is_young() || curr->is_scan_only()) {
+gclog_or_tty->print_cr("### YOUNG REGION "PTR_FORMAT"-"PTR_FORMAT" "
+"incorrectly tagged (%d, %d)",
+curr->bottom(), curr->end(),
+curr->is_young(), curr->is_scan_only());
+ret = false;
+}
+++length;
+last = curr;
+curr = curr->get_next_young_region();
+}
+ret = ret && (length == _length);
+if (!ret) {
+gclog_or_tty->print_cr("### YOUNG LIST seems not well formed!");
+gclog_or_tty->print_cr("###   list has %d entries, _length is %d",
+length, _length);
+}
+bool scan_only_ret = true;
+length = 0;
+curr = _scan_only_head;
+last = NULL;
+while (curr != NULL) {
+if (!curr->is_young() || curr->is_scan_only()) {
+gclog_or_tty->print_cr("### SCAN-ONLY REGION "PTR_FORMAT"-"PTR_FORMAT" "
+"incorrectly tagged (%d, %d)",
+curr->bottom(), curr->end(),
+curr->is_young(), curr->is_scan_only());
+scan_only_ret = false;
+}
+++length;
+last = curr;
+curr = curr->get_next_young_region();
+}
+scan_only_ret = scan_only_ret && (length == _scan_only_length);
+if ( (last != _scan_only_tail) ||
+(_scan_only_head == NULL && _scan_only_tail != NULL) ||
+(_scan_only_head != NULL && _scan_only_tail == NULL) ) {
+gclog_or_tty->print_cr("## _scan_only_tail is set incorrectly");
+scan_only_ret = false;
+}
+if (_curr_scan_only != NULL && _curr_scan_only != _scan_only_head) {
+gclog_or_tty->print_cr("### _curr_scan_only is set incorrectly");
+scan_only_ret = false;
+}
+if (!scan_only_ret) {
+gclog_or_tty->print_cr("### SCAN-ONLY LIST seems not well formed!");
+gclog_or_tty->print_cr("###   list has %d entries, _scan_only_length is %d",
+length, _scan_only_length);
+}
+return ret && scan_only_ret;
+}
+bool YoungList::check_list_empty(bool ignore_scan_only_list,
+bool check_sample) {
+bool ret = true;
+if (_length != 0) {
+gclog_or_tty->print_cr("### YOUNG LIST should have 0 length, not %d",
+_length);
+ret = false;
+}
+if (check_sample && _last_sampled_rs_lengths != 0) {
+gclog_or_tty->print_cr("### YOUNG LIST has non-zero last sampled RS lengths");
+ret = false;
+}
+if (_head != NULL) {
+gclog_or_tty->print_cr("### YOUNG LIST does not have a NULL head");
+ret = false;
+}
+if (!ret) {
+gclog_or_tty->print_cr("### YOUNG LIST does not seem empty");
+}
+if (ignore_scan_only_list)
+return ret;
+bool scan_only_ret = true;
+if (_scan_only_length != 0) {
+gclog_or_tty->print_cr("### SCAN-ONLY LIST should have 0 length, not %d",
+_scan_only_length);
+scan_only_ret = false;
+}
+if (_scan_only_head != NULL) {
+gclog_or_tty->print_cr("### SCAN-ONLY LIST does not have a NULL head");
+scan_only_ret = false;
+}
+if (_scan_only_tail != NULL) {
+gclog_or_tty->print_cr("### SCAN-ONLY LIST does not have a NULL tail");
+scan_only_ret = false;
+}
+if (!scan_only_ret) {
+gclog_or_tty->print_cr("### SCAN-ONLY LIST does not seem empty");
+}
+return ret && scan_only_ret;
+}
+void
+YoungList::rs_length_sampling_init() {
+_sampled_rs_lengths = 0;
+_curr               = _head;
+}
+bool
+YoungList::rs_length_sampling_more() {
+return _curr != NULL;
+}
+void
+YoungList::rs_length_sampling_next() {
+assert( _curr != NULL, "invariant" );
+_sampled_rs_lengths += _curr->rem_set()->occupied();
+_curr = _curr->get_next_young_region();
+if (_curr == NULL) {
+_last_sampled_rs_lengths = _sampled_rs_lengths;
+// gclog_or_tty->print_cr("last sampled RS lengths = %d", _last_sampled_rs_lengths);
+}
+}
+void
+YoungList::reset_auxilary_lists() {
+// We could have just "moved" the scan-only list to the young list.
+// However, the scan-only list is ordered according to the region
+// age in descending order, so, by moving one entry at a time, we
+// ensure that it is recreated in ascending order.
+guarantee( is_empty(), "young list should be empty" );
+assert(check_list_well_formed(), "young list should be well formed");
+// Add survivor regions to SurvRateGroup.
+_g1h->g1_policy()->note_start_adding_survivor_regions();
+for (HeapRegion* curr = _survivor_head;
+curr != NULL;
+curr = curr->get_next_young_region()) {
+_g1h->g1_policy()->set_region_survivors(curr);
+}
+_g1h->g1_policy()->note_stop_adding_survivor_regions();
+if (_survivor_head != NULL) {
+_head           = _survivor_head;
+_length         = _survivor_length + _scan_only_length;
+_survivors_tail->set_next_young_region(_scan_only_head);
+} else {
+_head           = _scan_only_head;
+_length         = _scan_only_length;
+}
+for (HeapRegion* curr = _scan_only_head;
+curr != NULL;
+curr = curr->get_next_young_region()) {
+curr->recalculate_age_in_surv_rate_group();
+}
+_scan_only_head   = NULL;
+_scan_only_tail   = NULL;
+_scan_only_length = 0;
+_curr_scan_only   = NULL;
+_survivor_head    = NULL;
+_survivors_tail   = NULL;
+_survivor_length  = 0;
+_g1h->g1_policy()->finished_recalculating_age_indexes();
+assert(check_list_well_formed(), "young list should be well formed");
+}
+void YoungList::print() {
+HeapRegion* lists[] = {_head,   _scan_only_head, _survivor_head};
+const char* names[] = {"YOUNG", "SCAN-ONLY",     "SURVIVOR"};
+for (unsigned int list = 0; list < ARRAY_SIZE(lists); ++list) {
+gclog_or_tty->print_cr("%s LIST CONTENTS", names[list]);
+HeapRegion *curr = lists[list];
+if (curr == NULL)
+gclog_or_tty->print_cr("  empty");
+while (curr != NULL) {
+gclog_or_tty->print_cr("  [%08x-%08x], t: %08x, P: %08x, N: %08x, C: %08x, "
+"age: %4d, y: %d, s-o: %d, surv: %d",
+curr->bottom(), curr->end(),
+curr->top(),
+curr->prev_top_at_mark_start(),
+curr->next_top_at_mark_start(),
+curr->top_at_conc_mark_count(),
+curr->age_in_surv_rate_group_cond(),
+curr->is_young(),
+curr->is_scan_only(),
+curr->is_survivor());
+curr = curr->get_next_young_region();
+}
+}
+gclog_or_tty->print_cr("");
+}
+void G1CollectedHeap::stop_conc_gc_threads() {
+_cg1r->cg1rThread()->stop();
+_czft->stop();
+_cmThread->stop();
+}
+void G1CollectedHeap::check_ct_logs_at_safepoint() {
+DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
+CardTableModRefBS* ct_bs = (CardTableModRefBS*)barrier_set();
+// Count the dirty cards at the start.
+CountNonCleanMemRegionClosure count1(this);
+ct_bs->mod_card_iterate(&count1);
+int orig_count = count1.n();
+// First clear the logged cards.
+ClearLoggedCardTableEntryClosure clear;
+dcqs.set_closure(&clear);
+dcqs.apply_closure_to_all_completed_buffers();
+dcqs.iterate_closure_all_threads(false);
+clear.print_histo();
+// Now ensure that there's no dirty cards.
+CountNonCleanMemRegionClosure count2(this);
+ct_bs->mod_card_iterate(&count2);
+if (count2.n() != 0) {
+gclog_or_tty->print_cr("Card table has %d entries; %d originally",
+count2.n(), orig_count);
+}
+guarantee(count2.n() == 0, "Card table should be clean.");
+RedirtyLoggedCardTableEntryClosure redirty;
+JavaThread::dirty_card_queue_set().set_closure(&redirty);
+dcqs.apply_closure_to_all_completed_buffers();
+dcqs.iterate_closure_all_threads(false);
+gclog_or_tty->print_cr("Log entries = %d, dirty cards = %d.",
+clear.calls(), orig_count);
+guarantee(redirty.calls() == clear.calls(),
+"Or else mechanism is broken.");
+CountNonCleanMemRegionClosure count3(this);
+ct_bs->mod_card_iterate(&count3);
+if (count3.n() != orig_count) {
+gclog_or_tty->print_cr("Should have restored them all: orig = %d, final = %d.",
+orig_count, count3.n());
+guarantee(count3.n() >= orig_count, "Should have restored them all.");
+}
+JavaThread::dirty_card_queue_set().set_closure(_refine_cte_cl);
+}
+// Private class members.
+G1CollectedHeap* G1CollectedHeap::_g1h;
+// Private methods.
+// Finds a HeapRegion that can be used to allocate a given size of block.
+HeapRegion* G1CollectedHeap::newAllocRegion_work(size_t word_size,
+bool do_expand,
+bool zero_filled) {
+ConcurrentZFThread::note_region_alloc();
+HeapRegion* res = alloc_free_region_from_lists(zero_filled);
+if (res == NULL && do_expand) {
+expand(word_size * HeapWordSize);
+res = alloc_free_region_from_lists(zero_filled);
+assert(res == NULL ||
+(!res->isHumongous() &&
+(!zero_filled ||
+res->zero_fill_state() == HeapRegion::Allocated)),
+"Alloc Regions must be zero filled (and non-H)");
+}
+if (res != NULL && res->is_empty()) _free_regions--;
+assert(res == NULL ||
+(!res->isHumongous() &&
+(!zero_filled ||
+res->zero_fill_state() == HeapRegion::Allocated)),
+"Non-young alloc Regions must be zero filled (and non-H)");
+if (G1TraceRegions) {
+if (res != NULL) {
+gclog_or_tty->print_cr("new alloc region %d:["PTR_FORMAT", "PTR_FORMAT"], "
+"top "PTR_FORMAT,
+res->hrs_index(), res->bottom(), res->end(), res->top());
+}
+}
+return res;
+}
+HeapRegion* G1CollectedHeap::newAllocRegionWithExpansion(int purpose,
+size_t word_size,
+bool zero_filled) {
+HeapRegion* alloc_region = NULL;
+if (_gc_alloc_region_counts[purpose] < g1_policy()->max_regions(purpose)) {
+alloc_region = newAllocRegion_work(word_size, true, zero_filled);
+if (purpose == GCAllocForSurvived && alloc_region != NULL) {
+_young_list->add_survivor_region(alloc_region);
+}
+++_gc_alloc_region_counts[purpose];
+} else {
+g1_policy()->note_alloc_region_limit_reached(purpose);
+}
+return alloc_region;
+}
+// If could fit into free regions w/o expansion, try.
+// Otherwise, if can expand, do so.
+// Otherwise, if using ex regions might help, try with ex given back.
+HeapWord* G1CollectedHeap::humongousObjAllocate(size_t word_size) {
+assert(regions_accounted_for(), "Region leakage!");
+// We can't allocate H regions while cleanupComplete is running, since
+// some of the regions we find to be empty might not yet be added to the
+// unclean list.  (If we're already at a safepoint, this call is
+// unnecessary, not to mention wrong.)
+if (!SafepointSynchronize::is_at_safepoint())
+wait_for_cleanup_complete();
+size_t num_regions =
+round_to(word_size, HeapRegion::GrainWords) / HeapRegion::GrainWords;
+// Special case if < one region???
+// Remember the ft size.
+size_t x_size = expansion_regions();
+HeapWord* res = NULL;
+bool eliminated_allocated_from_lists = false;
+// Can the allocation potentially fit in the free regions?
+if (free_regions() >= num_regions) {
+res = _hrs->obj_allocate(word_size);
+}
+if (res == NULL) {
+// Try expansion.
+size_t fs = _hrs->free_suffix();
+if (fs + x_size >= num_regions) {
+expand((num_regions - fs) * HeapRegion::GrainBytes);
+res = _hrs->obj_allocate(word_size);
+assert(res != NULL, "This should have worked.");
+} else {
+// Expansion won't help.  Are there enough free regions if we get rid
+// of reservations?
+size_t avail = free_regions();
+if (avail >= num_regions) {
+res = _hrs->obj_allocate(word_size);
+if (res != NULL) {
+remove_allocated_regions_from_lists();
+eliminated_allocated_from_lists = true;
+}
+}
+}
+}
+if (res != NULL) {
+// Increment by the number of regions allocated.
+// FIXME: Assumes regions all of size GrainBytes.
+#ifndef PRODUCT
+mr_bs()->verify_clean_region(MemRegion(res, res + num_regions *
+HeapRegion::GrainWords));
+#endif
+if (!eliminated_allocated_from_lists)
+remove_allocated_regions_from_lists();
+_summary_bytes_used += word_size * HeapWordSize;
+_free_regions -= num_regions;
+_num_humongous_regions += (int) num_regions;
+}
+assert(regions_accounted_for(), "Region Leakage");
+return res;
+}
+HeapWord*
+G1CollectedHeap::attempt_allocation_slow(size_t word_size,
+bool permit_collection_pause) {
+HeapWord* res = NULL;
+HeapRegion* allocated_young_region = NULL;
+assert( SafepointSynchronize::is_at_safepoint() ||
+Heap_lock->owned_by_self(), "pre condition of the call" );
+if (isHumongous(word_size)) {
+// Allocation of a humongous object can, in a sense, complete a
+// partial region, if the previous alloc was also humongous, and
+// caused the test below to succeed.
+if (permit_collection_pause)
+do_collection_pause_if_appropriate(word_size);
+res = humongousObjAllocate(word_size);
+assert(_cur_alloc_region == NULL
+|| !_cur_alloc_region->isHumongous(),
+"Prevent a regression of this bug.");
+} else {
+// If we do a collection pause, this will be reset to a non-NULL
+// value.  If we don't, nulling here ensures that we allocate a new
+// region below.
+if (_cur_alloc_region != NULL) {
+// We're finished with the _cur_alloc_region.
+_summary_bytes_used += _cur_alloc_region->used();
+_cur_alloc_region = NULL;
+}
+assert(_cur_alloc_region == NULL, "Invariant.");
+// Completion of a heap region is perhaps a good point at which to do
+// a collection pause.
+if (permit_collection_pause)
+do_collection_pause_if_appropriate(word_size);
+// Make sure we have an allocation region available.
+if (_cur_alloc_region == NULL) {
+if (!SafepointSynchronize::is_at_safepoint())
+wait_for_cleanup_complete();
+bool next_is_young = should_set_young_locked();
+// If the next region is not young, make sure it's zero-filled.
+_cur_alloc_region = newAllocRegion(word_size, !next_is_young);
+if (_cur_alloc_region != NULL) {
+_summary_bytes_used -= _cur_alloc_region->used();
+if (next_is_young) {
+set_region_short_lived_locked(_cur_alloc_region);
+allocated_young_region = _cur_alloc_region;
+}
+}
+}
+assert(_cur_alloc_region == NULL || !_cur_alloc_region->isHumongous(),
+"Prevent a regression of this bug.");
+// Now retry the allocation.
+if (_cur_alloc_region != NULL) {
+res = _cur_alloc_region->allocate(word_size);
+}
+}
+// NOTE: fails frequently in PRT
+assert(regions_accounted_for(), "Region leakage!");
+if (res != NULL) {
+if (!SafepointSynchronize::is_at_safepoint()) {
+assert( permit_collection_pause, "invariant" );
+assert( Heap_lock->owned_by_self(), "invariant" );
+Heap_lock->unlock();
+}
+if (allocated_young_region != NULL) {
+HeapRegion* hr = allocated_young_region;
+HeapWord* bottom = hr->bottom();
+HeapWord* end = hr->end();
+MemRegion mr(bottom, end);
+((CardTableModRefBS*)_g1h->barrier_set())->dirty(mr);
+}
+}
+assert( SafepointSynchronize::is_at_safepoint() ||
+(res == NULL && Heap_lock->owned_by_self()) ||
+(res != NULL && !Heap_lock->owned_by_self()),
+"post condition of the call" );
+return res;
+}
+HeapWord*
+G1CollectedHeap::mem_allocate(size_t word_size,
+bool   is_noref,
+bool   is_tlab,
+bool* gc_overhead_limit_was_exceeded) {
+debug_only(check_for_valid_allocation_state());
+assert(no_gc_in_progress(), "Allocation during gc not allowed");
+HeapWord* result = NULL;
+// Loop until the allocation is satisified,
+// or unsatisfied after GC.
+for (int try_count = 1; /* return or throw */; try_count += 1) {
+int gc_count_before;
+{
+Heap_lock->lock();
+result = attempt_allocation(word_size);
+if (result != NULL) {
+// attempt_allocation should have unlocked the heap lock
+assert(is_in(result), "result not in heap");
+return result;
+}
+// Read the gc count while the heap lock is held.
+gc_count_before = SharedHeap::heap()->total_collections();
+Heap_lock->unlock();
+}
+// Create the garbage collection operation...
+VM_G1CollectForAllocation op(word_size,
+gc_count_before);
+// ...and get the VM thread to execute it.
+VMThread::execute(&op);
+if (op.prologue_succeeded()) {
+result = op.result();
+assert(result == NULL || is_in(result), "result not in heap");
+return result;
+}
+// Give a warning if we seem to be looping forever.
+if ((QueuedAllocationWarningCount > 0) &&
+(try_count % QueuedAllocationWarningCount == 0)) {
+warning("G1CollectedHeap::mem_allocate_work retries %d times",
+try_count);
+}
+}
+}
+void G1CollectedHeap::abandon_cur_alloc_region() {
+if (_cur_alloc_region != NULL) {
+// We're finished with the _cur_alloc_region.
+if (_cur_alloc_region->is_empty()) {
+_free_regions++;
+free_region(_cur_alloc_region);
+} else {
+_summary_bytes_used += _cur_alloc_region->used();
+}
+_cur_alloc_region = NULL;
+}
+}
+class PostMCRemSetClearClosure: public HeapRegionClosure {
+ModRefBarrierSet* _mr_bs;
+public:
+PostMCRemSetClearClosure(ModRefBarrierSet* mr_bs) : _mr_bs(mr_bs) {}
+bool doHeapRegion(HeapRegion* r) {
+r->reset_gc_time_stamp();
+if (r->continuesHumongous())
+return false;
+HeapRegionRemSet* hrrs = r->rem_set();
+if (hrrs != NULL) hrrs->clear();
+// You might think here that we could clear just the cards
+// corresponding to the used region.  But no: if we leave a dirty card
+// in a region we might allocate into, then it would prevent that card
+// from being enqueued, and cause it to be missed.
+// Re: the performance cost: we shouldn't be doing full GC anyway!
+_mr_bs->clear(MemRegion(r->bottom(), r->end()));
+return false;
+}
+};
+class PostMCRemSetInvalidateClosure: public HeapRegionClosure {
+ModRefBarrierSet* _mr_bs;
+public:
+PostMCRemSetInvalidateClosure(ModRefBarrierSet* mr_bs) : _mr_bs(mr_bs) {}
+bool doHeapRegion(HeapRegion* r) {
+if (r->continuesHumongous()) return false;
+if (r->used_region().word_size() != 0) {
+_mr_bs->invalidate(r->used_region(), true /*whole heap*/);
+}
+return false;
+}
+};
+void G1CollectedHeap::do_collection(bool full, bool clear_all_soft_refs,
+size_t word_size) {
+ResourceMark rm;
+if (full && DisableExplicitGC) {
+gclog_or_tty->print("\n\n\nDisabling Explicit GC\n\n\n");
+return;
+}
+assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
+assert(Thread::current() == VMThread::vm_thread(), "should be in vm thread");
+if (GC_locker::is_active()) {
+return; // GC is disabled (e.g. JNI GetXXXCritical operation)
+}
+{
+IsGCActiveMark x;
+// Timing
+gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
+TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
+TraceTime t(full ? "Full GC (System.gc())" : "Full GC", PrintGC, true, gclog_or_tty);
+double start = os::elapsedTime();
+GCOverheadReporter::recordSTWStart(start);
+g1_policy()->record_full_collection_start();
+gc_prologue(true);
+increment_total_collections();
+size_t g1h_prev_used = used();
+assert(used() == recalculate_used(), "Should be equal");
+if (VerifyBeforeGC && total_collections() >= VerifyGCStartAt) {
+HandleMark hm;  // Discard invalid handles created during verification
+prepare_for_verify();
+gclog_or_tty->print(" VerifyBeforeGC:");
+Universe::verify(true);
+}
+assert(regions_accounted_for(), "Region leakage!");
+COMPILER2_PRESENT(DerivedPointerTable::clear());
+// We want to discover references, but not process them yet.
+// This mode is disabled in
+// instanceRefKlass::process_discovered_references if the
+// generation does some collection work, or
+// instanceRefKlass::enqueue_discovered_references if the
+// generation returns without doing any work.
+ref_processor()->disable_discovery();
+ref_processor()->abandon_partial_discovery();
+ref_processor()->verify_no_references_recorded();
+// Abandon current iterations of concurrent marking and concurrent
+// refinement, if any are in progress.
+concurrent_mark()->abort();
+// Make sure we'll choose a new allocation region afterwards.
+abandon_cur_alloc_region();
+assert(_cur_alloc_region == NULL, "Invariant.");
+g1_rem_set()->as_HRInto_G1RemSet()->cleanupHRRS();
+tear_down_region_lists();
+set_used_regions_to_need_zero_fill();
+if (g1_policy()->in_young_gc_mode()) {
+empty_young_list();
+g1_policy()->set_full_young_gcs(true);
+}
+// Temporarily make reference _discovery_ single threaded (non-MT).
+ReferenceProcessorMTMutator rp_disc_ser(ref_processor(), false);
+// Temporarily make refs discovery atomic
+ReferenceProcessorAtomicMutator rp_disc_atomic(ref_processor(), true);
+// Temporarily clear _is_alive_non_header
+ReferenceProcessorIsAliveMutator rp_is_alive_null(ref_processor(), NULL);
+ref_processor()->enable_discovery();
+// Do collection work
+{
+HandleMark hm;  // Discard invalid handles created during gc
+G1MarkSweep::invoke_at_safepoint(ref_processor(), clear_all_soft_refs);
+}
+// Because freeing humongous regions may have added some unclean
+// regions, it is necessary to tear down again before rebuilding.
+tear_down_region_lists();
+rebuild_region_lists();
+_summary_bytes_used = recalculate_used();
+ref_processor()->enqueue_discovered_references();
+COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
+if (VerifyAfterGC && total_collections() >= VerifyGCStartAt) {
+HandleMark hm;  // Discard invalid handles created during verification
+gclog_or_tty->print(" VerifyAfterGC:");
+Universe::verify(false);
+}
+NOT_PRODUCT(ref_processor()->verify_no_references_recorded());
+reset_gc_time_stamp();
+// Since everything potentially moved, we will clear all remembered
+// sets, and clear all cards.  Later we will also cards in the used
+// portion of the heap after the resizing (which could be a shrinking.)
+// We will also reset the GC time stamps of the regions.
+PostMCRemSetClearClosure rs_clear(mr_bs());
+heap_region_iterate(&rs_clear);
+// Resize the heap if necessary.
+resize_if_necessary_after_full_collection(full ? 0 : word_size);
+// Since everything potentially moved, we will clear all remembered
+// sets, but also dirty all cards corresponding to used regions.
+PostMCRemSetInvalidateClosure rs_invalidate(mr_bs());
+heap_region_iterate(&rs_invalidate);
+if (_cg1r->use_cache()) {
+_cg1r->clear_and_record_card_counts();
+_cg1r->clear_hot_cache();
+}
+if (PrintGC) {
+print_size_transition(gclog_or_tty, g1h_prev_used, used(), capacity());
+}
+if (true) { // FIXME
+// Ask the permanent generation to adjust size for full collections
+perm()->compute_new_size();
+}
+double end = os::elapsedTime();
+GCOverheadReporter::recordSTWEnd(end);
+g1_policy()->record_full_collection_end();
+gc_epilogue(true);
+// Abandon concurrent refinement.  This must happen last: in the
+// dirty-card logging system, some cards may be dirty by weak-ref
+// processing, and may be enqueued.  But the whole card table is
+// dirtied, so this should abandon those logs, and set "do_traversal"
+// to true.
+concurrent_g1_refine()->set_pya_restart();
+assert(regions_accounted_for(), "Region leakage!");
+}
+if (g1_policy()->in_young_gc_mode()) {
+_young_list->reset_sampled_info();
+assert( check_young_list_empty(false, false),
+"young list should be empty at this point");
+}
+}
+void G1CollectedHeap::do_full_collection(bool clear_all_soft_refs) {
+do_collection(true, clear_all_soft_refs, 0);
+}
+// This code is mostly copied from TenuredGeneration.
+void
+G1CollectedHeap::
+resize_if_necessary_after_full_collection(size_t word_size) {
+assert(MinHeapFreeRatio <= MaxHeapFreeRatio, "sanity check");
+// Include the current allocation, if any, and bytes that will be
+// pre-allocated to support collections, as "used".
+const size_t used_after_gc = used();
+const size_t capacity_after_gc = capacity();
+const size_t free_after_gc = capacity_after_gc - used_after_gc;
+// We don't have floating point command-line arguments
+const double minimum_free_percentage = (double) MinHeapFreeRatio / 100;
+const double maximum_used_percentage = 1.0 - minimum_free_percentage;
+const double maximum_free_percentage = (double) MaxHeapFreeRatio / 100;
+const double minimum_used_percentage = 1.0 - maximum_free_percentage;
+size_t minimum_desired_capacity = (size_t) (used_after_gc / maximum_used_percentage);
+size_t maximum_desired_capacity = (size_t) (used_after_gc / minimum_used_percentage);
+// Don't shrink less than the initial size.
+minimum_desired_capacity =
+MAX2(minimum_desired_capacity,
+collector_policy()->initial_heap_byte_size());
+maximum_desired_capacity =
+MAX2(maximum_desired_capacity,
+collector_policy()->initial_heap_byte_size());
+// We are failing here because minimum_desired_capacity is
+assert(used_after_gc <= minimum_desired_capacity, "sanity check");
+assert(minimum_desired_capacity <= maximum_desired_capacity, "sanity check");
+if (PrintGC && Verbose) {
+const double free_percentage = ((double)free_after_gc) / capacity();
+gclog_or_tty->print_cr("Computing new size after full GC ");
+gclog_or_tty->print_cr("  "
+"  minimum_free_percentage: %6.2f",
+minimum_free_percentage);
+gclog_or_tty->print_cr("  "
+"  maximum_free_percentage: %6.2f",
+maximum_free_percentage);
+gclog_or_tty->print_cr("  "
+"  capacity: %6.1fK"
+"  minimum_desired_capacity: %6.1fK"
+"  maximum_desired_capacity: %6.1fK",
+capacity() / (double) K,
+minimum_desired_capacity / (double) K,
+maximum_desired_capacity / (double) K);
+gclog_or_tty->print_cr("  "
+"   free_after_gc   : %6.1fK"
+"   used_after_gc   : %6.1fK",
+free_after_gc / (double) K,
+used_after_gc / (double) K);
+gclog_or_tty->print_cr("  "
+"   free_percentage: %6.2f",
+free_percentage);
+}
+if (capacity() < minimum_desired_capacity) {
+// Don't expand unless it's significant
+size_t expand_bytes = minimum_desired_capacity - capacity_after_gc;
+expand(expand_bytes);
+if (PrintGC && Verbose) {
+gclog_or_tty->print_cr("    expanding:"
+"  minimum_desired_capacity: %6.1fK"
+"  expand_bytes: %6.1fK",
+minimum_desired_capacity / (double) K,
+expand_bytes / (double) K);
+}
+// No expansion, now see if we want to shrink
+} else if (capacity() > maximum_desired_capacity) {
+// Capacity too large, compute shrinking size
+size_t shrink_bytes = capacity_after_gc - maximum_desired_capacity;
+shrink(shrink_bytes);
+if (PrintGC && Verbose) {
+gclog_or_tty->print_cr("  "
+"  shrinking:"
+"  initSize: %.1fK"
+"  maximum_desired_capacity: %.1fK",
+collector_policy()->initial_heap_byte_size() / (double) K,
+maximum_desired_capacity / (double) K);
+gclog_or_tty->print_cr("  "
+"  shrink_bytes: %.1fK",
+shrink_bytes / (double) K);
+}
+}
+}
+HeapWord*
+G1CollectedHeap::satisfy_failed_allocation(size_t word_size) {
+HeapWord* result = NULL;
+// In a G1 heap, we're supposed to keep allocation from failing by
+// incremental pauses.  Therefore, at least for now, we'll favor
+// expansion over collection.  (This might change in the future if we can
+// do something smarter than full collection to satisfy a failed alloc.)
+result = expand_and_allocate(word_size);
+if (result != NULL) {
+assert(is_in(result), "result not in heap");
+return result;
+}
+// OK, I guess we have to try collection.
+do_collection(false, false, word_size);
+result = attempt_allocation(word_size, /*permit_collection_pause*/false);
+if (result != NULL) {
+assert(is_in(result), "result not in heap");
+return result;
+}
+// Try collecting soft references.
+do_collection(false, true, word_size);
+result = attempt_allocation(word_size, /*permit_collection_pause*/false);
+if (result != NULL) {
+assert(is_in(result), "result not in heap");
+return result;
+}
+// What else?  We might try synchronous finalization later.  If the total
+// space available is large enough for the allocation, then a more
+// complete compaction phase than we've tried so far might be
+// appropriate.
+return NULL;
+}
+// Attempting to expand the heap sufficiently
+// to support an allocation of the given "word_size".  If
+// successful, perform the allocation and return the address of the
+// allocated block, or else "NULL".
+HeapWord* G1CollectedHeap::expand_and_allocate(size_t word_size) {
+size_t expand_bytes = word_size * HeapWordSize;
+if (expand_bytes < MinHeapDeltaBytes) {
+expand_bytes = MinHeapDeltaBytes;
+}
+expand(expand_bytes);
+assert(regions_accounted_for(), "Region leakage!");
+HeapWord* result = attempt_allocation(word_size, false /* permit_collection_pause */);
+return result;
+}
+size_t G1CollectedHeap::free_region_if_totally_empty(HeapRegion* hr) {
+size_t pre_used = 0;
+size_t cleared_h_regions = 0;
+size_t freed_regions = 0;
+UncleanRegionList local_list;
+free_region_if_totally_empty_work(hr, pre_used, cleared_h_regions,
+freed_regions, &local_list);
+finish_free_region_work(pre_used, cleared_h_regions, freed_regions,
+&local_list);
+return pre_used;
+}
+void
+G1CollectedHeap::free_region_if_totally_empty_work(HeapRegion* hr,
+size_t& pre_used,
+size_t& cleared_h,
+size_t& freed_regions,
+UncleanRegionList* list,
+bool par) {
+assert(!hr->continuesHumongous(), "should have filtered these out");
+size_t res = 0;
+if (!hr->popular() && hr->used() > 0 && hr->garbage_bytes() == hr->used()) {
+if (!hr->is_young()) {
+if (G1PolicyVerbose > 0)
+gclog_or_tty->print_cr("Freeing empty region "PTR_FORMAT "(" SIZE_FORMAT " bytes)"
+" during cleanup", hr, hr->used());
+free_region_work(hr, pre_used, cleared_h, freed_regions, list, par);
+}
+}
+}
+// FIXME: both this and shrink could probably be more efficient by
+// doing one "VirtualSpace::expand_by" call rather than several.
+void G1CollectedHeap::expand(size_t expand_bytes) {
+size_t old_mem_size = _g1_storage.committed_size();
+// We expand by a minimum of 1K.
+expand_bytes = MAX2(expand_bytes, (size_t)K);
+size_t aligned_expand_bytes =
+ReservedSpace::page_align_size_up(expand_bytes);
+aligned_expand_bytes = align_size_up(aligned_expand_bytes,
+HeapRegion::GrainBytes);
+expand_bytes = aligned_expand_bytes;
+while (expand_bytes > 0) {
+HeapWord* base = (HeapWord*)_g1_storage.high();
+// Commit more storage.
+bool successful = _g1_storage.expand_by(HeapRegion::GrainBytes);
+if (!successful) {
+expand_bytes = 0;
+} else {
+expand_bytes -= HeapRegion::GrainBytes;
+// Expand the committed region.
+HeapWord* high = (HeapWord*) _g1_storage.high();
+_g1_committed.set_end(high);
+// Create a new HeapRegion.
+MemRegion mr(base, high);
+bool is_zeroed = !_g1_max_committed.contains(base);
+HeapRegion* hr = new HeapRegion(_bot_shared, mr, is_zeroed);
+// Now update max_committed if necessary.
+_g1_max_committed.set_end(MAX2(_g1_max_committed.end(), high));
+// Add it to the HeapRegionSeq.
+_hrs->insert(hr);
+// Set the zero-fill state, according to whether it's already
+// zeroed.
+{
+MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag);
+if (is_zeroed) {
+hr->set_zero_fill_complete();
+put_free_region_on_list_locked(hr);
+} else {
+hr->set_zero_fill_needed();
+put_region_on_unclean_list_locked(hr);
+}
+}
+_free_regions++;
+// And we used up an expansion region to create it.
+_expansion_regions--;
+// Tell the cardtable about it.
+Universe::heap()->barrier_set()->resize_covered_region(_g1_committed);
+// And the offset table as well.
+_bot_shared->resize(_g1_committed.word_size());
+}
+}
+if (Verbose && PrintGC) {
+size_t new_mem_size = _g1_storage.committed_size();
+gclog_or_tty->print_cr("Expanding garbage-first heap from %ldK by %ldK to %ldK",
+old_mem_size/K, aligned_expand_bytes/K,
+new_mem_size/K);
+}
+}
+void G1CollectedHeap::shrink_helper(size_t shrink_bytes)
+{
+size_t old_mem_size = _g1_storage.committed_size();
+size_t aligned_shrink_bytes =
+ReservedSpace::page_align_size_down(shrink_bytes);
+aligned_shrink_bytes = align_size_down(aligned_shrink_bytes,
+HeapRegion::GrainBytes);
+size_t num_regions_deleted = 0;
+MemRegion mr = _hrs->shrink_by(aligned_shrink_bytes, num_regions_deleted);
+assert(mr.end() == (HeapWord*)_g1_storage.high(), "Bad shrink!");
+if (mr.byte_size() > 0)
+_g1_storage.shrink_by(mr.byte_size());
+assert(mr.start() == (HeapWord*)_g1_storage.high(), "Bad shrink!");
+_g1_committed.set_end(mr.start());
+_free_regions -= num_regions_deleted;
+_expansion_regions += num_regions_deleted;
+// Tell the cardtable about it.
+Universe::heap()->barrier_set()->resize_covered_region(_g1_committed);
+// And the offset table as well.
+_bot_shared->resize(_g1_committed.word_size());
+HeapRegionRemSet::shrink_heap(n_regions());
+if (Verbose && PrintGC) {
+size_t new_mem_size = _g1_storage.committed_size();
+gclog_or_tty->print_cr("Shrinking garbage-first heap from %ldK by %ldK to %ldK",
+old_mem_size/K, aligned_shrink_bytes/K,
+new_mem_size/K);
+}
+}
+void G1CollectedHeap::shrink(size_t shrink_bytes) {
+release_gc_alloc_regions();
+tear_down_region_lists();  // We will rebuild them in a moment.
+shrink_helper(shrink_bytes);
+rebuild_region_lists();
+}
+// Public methods.
+#ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
+#pragma warning( disable:4355 ) // 'this' : used in base member initializer list
+#endif // _MSC_VER
+G1CollectedHeap::G1CollectedHeap(G1CollectorPolicy* policy_) :
+SharedHeap(policy_),
+_g1_policy(policy_),
+_ref_processor(NULL),
+_process_strong_tasks(new SubTasksDone(G1H_PS_NumElements)),
+_bot_shared(NULL),
+_par_alloc_during_gc_lock(Mutex::leaf, "par alloc during GC lock"),
+_objs_with_preserved_marks(NULL), _preserved_marks_of_objs(NULL),
+_evac_failure_scan_stack(NULL) ,
+_mark_in_progress(false),
+_cg1r(NULL), _czft(NULL), _summary_bytes_used(0),
+_cur_alloc_region(NULL),
+_refine_cte_cl(NULL),
+_free_region_list(NULL), _free_region_list_size(0),
+_free_regions(0),
+_popular_object_boundary(NULL),
+_cur_pop_hr_index(0),
+_popular_regions_to_be_evacuated(NULL),
+_pop_obj_rc_at_copy(),
+_full_collection(false),
+_unclean_region_list(),
+_unclean_regions_coming(false),
+_young_list(new YoungList(this)),
+_gc_time_stamp(0),
+_surviving_young_words(NULL)
+{
+_g1h = this; // To catch bugs.
+if (_process_strong_tasks == NULL || !_process_strong_tasks->valid()) {
+vm_exit_during_initialization("Failed necessary allocation.");
+}
+int n_queues = MAX2((int)ParallelGCThreads, 1);
+_task_queues = new RefToScanQueueSet(n_queues);
+int n_rem_sets = HeapRegionRemSet::num_par_rem_sets();
+assert(n_rem_sets > 0, "Invariant.");
+HeapRegionRemSetIterator** iter_arr =
+NEW_C_HEAP_ARRAY(HeapRegionRemSetIterator*, n_queues);
+for (int i = 0; i < n_queues; i++) {
+iter_arr[i] = new HeapRegionRemSetIterator();
+}
+_rem_set_iterator = iter_arr;
+for (int i = 0; i < n_queues; i++) {
+RefToScanQueue* q = new RefToScanQueue();
+q->initialize();
+_task_queues->register_queue(i, q);
+}
+for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
+_gc_alloc_regions[ap]       = NULL;
+_gc_alloc_region_counts[ap] = 0;
+}
+guarantee(_task_queues != NULL, "task_queues allocation failure.");
+}
+jint G1CollectedHeap::initialize() {
+os::enable_vtime();
+// Necessary to satisfy locking discipline assertions.
+MutexLocker x(Heap_lock);
+// 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");
+size_t init_byte_size = collector_policy()->initial_heap_byte_size();
+size_t max_byte_size = collector_policy()->max_heap_byte_size();
+// Ensure that the sizes are properly aligned.
+Universe::check_alignment(init_byte_size, HeapRegion::GrainBytes, "g1 heap");
+Universe::check_alignment(max_byte_size, HeapRegion::GrainBytes, "g1 heap");
+// We allocate this in any case, but only do no work if the command line
+// param is off.
+_cg1r = new ConcurrentG1Refine();
+// Reserve the maximum.
+PermanentGenerationSpec* pgs = collector_policy()->permanent_generation();
+// Includes the perm-gen.
+ReservedSpace heap_rs(max_byte_size + pgs->max_size(),
+HeapRegion::GrainBytes,
+false /*ism*/);
+if (!heap_rs.is_reserved()) {
+vm_exit_during_initialization("Could not reserve enough space for object heap");
+return JNI_ENOMEM;
+}
+// It is important to do this in a way such that concurrent readers can't
+// temporarily think somethings in the heap.  (I've actually seen this
+// happen in asserts: DLD.)
+_reserved.set_word_size(0);
+_reserved.set_start((HeapWord*)heap_rs.base());
+_reserved.set_end((HeapWord*)(heap_rs.base() + heap_rs.size()));
+_expansion_regions = max_byte_size/HeapRegion::GrainBytes;
+_num_humongous_regions = 0;
+// Create the gen rem set (and barrier set) for the entire reserved region.
+_rem_set = collector_policy()->create_rem_set(_reserved, 2);
+set_barrier_set(rem_set()->bs());
+if (barrier_set()->is_a(BarrierSet::ModRef)) {
+_mr_bs = (ModRefBarrierSet*)_barrier_set;
+} else {
+vm_exit_during_initialization("G1 requires a mod ref bs.");
+return JNI_ENOMEM;
+}
+// Also create a G1 rem set.
+if (G1UseHRIntoRS) {
+if (mr_bs()->is_a(BarrierSet::CardTableModRef)) {
+_g1_rem_set = new HRInto_G1RemSet(this, (CardTableModRefBS*)mr_bs());
+} else {
+vm_exit_during_initialization("G1 requires a cardtable mod ref bs.");
+return JNI_ENOMEM;
+}
+} else {
+_g1_rem_set = new StupidG1RemSet(this);
+}
+// Carve out the G1 part of the heap.
+ReservedSpace g1_rs   = heap_rs.first_part(max_byte_size);
+_g1_reserved = MemRegion((HeapWord*)g1_rs.base(),
+g1_rs.size()/HeapWordSize);
+ReservedSpace perm_gen_rs = heap_rs.last_part(max_byte_size);
+_perm_gen = pgs->init(perm_gen_rs, pgs->init_size(), rem_set());
+_g1_storage.initialize(g1_rs, 0);
+_g1_committed = MemRegion((HeapWord*)_g1_storage.low(), (size_t) 0);
+_g1_max_committed = _g1_committed;
+_hrs = new HeapRegionSeq();
+guarantee(_hrs != NULL, "Couldn't allocate HeapRegionSeq");
+guarantee(_cur_alloc_region == NULL, "from constructor");
+_bot_shared = new G1BlockOffsetSharedArray(_reserved,
+heap_word_size(init_byte_size));
+_g1h = this;
+// Create the ConcurrentMark data structure and thread.
+// (Must do this late, so that "max_regions" is defined.)
+_cm       = new ConcurrentMark(heap_rs, (int) max_regions());
+_cmThread = _cm->cmThread();
+// ...and the concurrent zero-fill thread, if necessary.
+if (G1ConcZeroFill) {
+_czft = new ConcurrentZFThread();
+}
+// Allocate the popular regions; take them off free lists.
+size_t pop_byte_size = G1NumPopularRegions * HeapRegion::GrainBytes;
+expand(pop_byte_size);
+_popular_object_boundary =
+_g1_reserved.start() + (G1NumPopularRegions * HeapRegion::GrainWords);
+for (int i = 0; i < G1NumPopularRegions; i++) {
+HeapRegion* hr = newAllocRegion(HeapRegion::GrainWords);
+//    assert(hr != NULL && hr->bottom() < _popular_object_boundary,
+//     "Should be enough, and all should be below boundary.");
+hr->set_popular(true);
+}
+assert(_cur_pop_hr_index == 0, "Start allocating at the first region.");
+// Initialize the from_card cache structure of HeapRegionRemSet.
+HeapRegionRemSet::init_heap(max_regions());
+// Now expand into the rest of the initial heap size.
+expand(init_byte_size - pop_byte_size);
+// Perform any initialization actions delegated to the policy.
+g1_policy()->init();
+g1_policy()->note_start_of_mark_thread();
+_refine_cte_cl =
+new RefineCardTableEntryClosure(ConcurrentG1RefineThread::sts(),
+g1_rem_set(),
+concurrent_g1_refine());
+JavaThread::dirty_card_queue_set().set_closure(_refine_cte_cl);
+JavaThread::satb_mark_queue_set().initialize(SATB_Q_CBL_mon,
+SATB_Q_FL_lock,
+0,
+Shared_SATB_Q_lock);
+if (G1RSBarrierUseQueue) {
+JavaThread::dirty_card_queue_set().initialize(DirtyCardQ_CBL_mon,
+DirtyCardQ_FL_lock,
+G1DirtyCardQueueMax,
+Shared_DirtyCardQ_lock);
+}
+// In case we're keeping closure specialization stats, initialize those
+// counts and that mechanism.
+SpecializationStats::clear();
+_gc_alloc_region_list = NULL;
+// Do later initialization work for concurrent refinement.
+_cg1r->init();
+const char* group_names[] = { "CR", "ZF", "CM", "CL" };
+GCOverheadReporter::initGCOverheadReporter(4, group_names);
+return JNI_OK;
+}
+void G1CollectedHeap::ref_processing_init() {
+SharedHeap::ref_processing_init();
+MemRegion mr = reserved_region();
+_ref_processor = ReferenceProcessor::create_ref_processor(
+mr,    // span
+false, // Reference discovery is not atomic
+// (though it shouldn't matter here.)
+true,  // mt_discovery
+NULL,  // is alive closure: need to fill this in for efficiency
+ParallelGCThreads,
+ParallelRefProcEnabled,
+true); // Setting next fields of discovered
+// lists requires a barrier.
+}
+size_t G1CollectedHeap::capacity() const {
+return _g1_committed.byte_size();
+}
+void G1CollectedHeap::iterate_dirty_card_closure(bool concurrent,
+int worker_i) {
+DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
+int n_completed_buffers = 0;
+while (dcqs.apply_closure_to_completed_buffer(worker_i, 0, true)) {
+n_completed_buffers++;
+}
+g1_policy()->record_update_rs_processed_buffers(worker_i,
+(double) n_completed_buffers);
+dcqs.clear_n_completed_buffers();
+// Finish up the queue...
+if (worker_i == 0) concurrent_g1_refine()->clean_up_cache(worker_i,
+g1_rem_set());
+assert(!dcqs.completed_buffers_exist_dirty(), "Completed buffers exist!");
+}
+// Computes the sum of the storage used by the various regions.
+size_t G1CollectedHeap::used() const {
+assert(Heap_lock->owner() != NULL,
+"Should be owned on this thread's behalf.");
+size_t result = _summary_bytes_used;
+if (_cur_alloc_region != NULL)
+result += _cur_alloc_region->used();
+return result;
+}
+class SumUsedClosure: public HeapRegionClosure {
+size_t _used;
+public:
+SumUsedClosure() : _used(0) {}
+bool doHeapRegion(HeapRegion* r) {
+if (!r->continuesHumongous()) {
+_used += r->used();
+}
+return false;
+}
+size_t result() { return _used; }
+};
+size_t G1CollectedHeap::recalculate_used() const {
+SumUsedClosure blk;
+_hrs->iterate(&blk);
+return blk.result();
+}
+#ifndef PRODUCT
+class SumUsedRegionsClosure: public HeapRegionClosure {
+size_t _num;
+public:
+// _num is set to 1 to account for the popular region
+SumUsedRegionsClosure() : _num(G1NumPopularRegions) {}
+bool doHeapRegion(HeapRegion* r) {
+if (r->continuesHumongous() || r->used() > 0 || r->is_gc_alloc_region()) {
+_num += 1;
+}
+return false;
+}
+size_t result() { return _num; }
+};
+size_t G1CollectedHeap::recalculate_used_regions() const {
+SumUsedRegionsClosure blk;
+_hrs->iterate(&blk);
+return blk.result();
+}
+#endif // PRODUCT
+size_t G1CollectedHeap::unsafe_max_alloc() {
+if (_free_regions > 0) return HeapRegion::GrainBytes;
+// otherwise, is there space in the current allocation region?
+// We need to store the current allocation region in a local variable
+// here. The problem is that this method doesn't take any locks and
+// there may be other threads which overwrite the current allocation
+// region field. attempt_allocation(), for example, sets it to NULL
+// and this can happen *after* the NULL check here but before the call
+// to free(), resulting in a SIGSEGV. Note that this doesn't appear
+// to be a problem in the optimized build, since the two loads of the
+// current allocation region field are optimized away.
+HeapRegion* car = _cur_alloc_region;
+// FIXME: should iterate over all regions?
+if (car == NULL) {
+return 0;
+}
+return car->free();
+}
+void G1CollectedHeap::collect(GCCause::Cause cause) {
+// 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);
+}
+void G1CollectedHeap::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
+break;
+}
+default: // XXX FIX ME
+ShouldNotReachHere(); // Unexpected use of this function
+}
+}
+void G1CollectedHeap::collect_locked(GCCause::Cause cause) {
+// Don't want to do a GC until cleanup is completed.
+wait_for_cleanup_complete();
+// Read the GC count while holding the Heap_lock
+int gc_count_before = SharedHeap::heap()->total_collections();
+{
+MutexUnlocker mu(Heap_lock);  // give up heap lock, execute gets it back
+VM_G1CollectFull op(gc_count_before, cause);
+VMThread::execute(&op);
+}
+}
+bool G1CollectedHeap::is_in(const void* p) const {
+if (_g1_committed.contains(p)) {
+HeapRegion* hr = _hrs->addr_to_region(p);
+return hr->is_in(p);
+} else {
+return _perm_gen->as_gen()->is_in(p);
+}
+}
+// Iteration functions.
+// Iterates an OopClosure over all ref-containing fields of objects
+// within a HeapRegion.
+class IterateOopClosureRegionClosure: public HeapRegionClosure {
+MemRegion _mr;
+OopClosure* _cl;
+public:
+IterateOopClosureRegionClosure(MemRegion mr, OopClosure* cl)
+: _mr(mr), _cl(cl) {}
+bool doHeapRegion(HeapRegion* r) {
+if (! r->continuesHumongous()) {
+r->oop_iterate(_cl);
+}
+return false;
+}
+};
+void G1CollectedHeap::oop_iterate(OopClosure* cl) {
+IterateOopClosureRegionClosure blk(_g1_committed, cl);
+_hrs->iterate(&blk);
+}
+void G1CollectedHeap::oop_iterate(MemRegion mr, OopClosure* cl) {
+IterateOopClosureRegionClosure blk(mr, cl);
+_hrs->iterate(&blk);
+}
+// Iterates an ObjectClosure over all objects within a HeapRegion.
+class IterateObjectClosureRegionClosure: public HeapRegionClosure {
+ObjectClosure* _cl;
+public:
+IterateObjectClosureRegionClosure(ObjectClosure* cl) : _cl(cl) {}
+bool doHeapRegion(HeapRegion* r) {
+if (! r->continuesHumongous()) {
+r->object_iterate(_cl);
+}
+return false;
+}
+};
+void G1CollectedHeap::object_iterate(ObjectClosure* cl) {
+IterateObjectClosureRegionClosure blk(cl);
+_hrs->iterate(&blk);
+}
+void G1CollectedHeap::object_iterate_since_last_GC(ObjectClosure* cl) {
+// FIXME: is this right?
+guarantee(false, "object_iterate_since_last_GC not supported by G1 heap");
+}
+// Calls a SpaceClosure on a HeapRegion.
+class SpaceClosureRegionClosure: public HeapRegionClosure {
+SpaceClosure* _cl;
+public:
+SpaceClosureRegionClosure(SpaceClosure* cl) : _cl(cl) {}
+bool doHeapRegion(HeapRegion* r) {
+_cl->do_space(r);
+return false;
+}
+};
+void G1CollectedHeap::space_iterate(SpaceClosure* cl) {
+SpaceClosureRegionClosure blk(cl);
+_hrs->iterate(&blk);
+}
+void G1CollectedHeap::heap_region_iterate(HeapRegionClosure* cl) {
+_hrs->iterate(cl);
+}
+void G1CollectedHeap::heap_region_iterate_from(HeapRegion* r,
+HeapRegionClosure* cl) {
+_hrs->iterate_from(r, cl);
+}
+void
+G1CollectedHeap::heap_region_iterate_from(int idx, HeapRegionClosure* cl) {
+_hrs->iterate_from(idx, cl);
+}
+HeapRegion* G1CollectedHeap::region_at(size_t idx) { return _hrs->at(idx); }
+const int OverpartitionFactor = 4;
+void
+G1CollectedHeap::heap_region_par_iterate_chunked(HeapRegionClosure* cl,
+int worker,
+jint claim_value) {
+// We break up the heap regions into blocks of size ParallelGCThreads (to
+// decrease iteration costs).
+const size_t nregions = n_regions();
+const size_t n_thrds = (ParallelGCThreads > 0 ? ParallelGCThreads : 1);
+const size_t partitions = n_thrds * OverpartitionFactor;
+const size_t BlkSize = MAX2(nregions/partitions, (size_t)1);
+const size_t n_blocks = (nregions + BlkSize - 1)/BlkSize;
+assert(ParallelGCThreads > 0 || worker == 0, "Precondition");
+const int init_idx = (int) (n_blocks/n_thrds * worker);
+for (size_t blk = 0; blk < n_blocks; blk++) {
+size_t idx = init_idx + blk;
+if (idx >= n_blocks) idx = idx - n_blocks;
+size_t reg_idx = idx * BlkSize;
+assert(reg_idx < nregions, "Because we rounded blk up.");
+HeapRegion* r = region_at(reg_idx);
+if (r->claimHeapRegion(claim_value)) {
+for (size_t j = 0; j < BlkSize; j++) {
+size_t reg_idx2 = reg_idx + j;
+if (reg_idx2 == nregions) break;
+HeapRegion* r2 = region_at(reg_idx2);
+if (j > 0) r2->set_claim_value(claim_value);
+bool res = cl->doHeapRegion(r2);
+guarantee(!res, "Should not abort.");
+}
+}
+}
+}
+void G1CollectedHeap::collection_set_iterate(HeapRegionClosure* cl) {
+HeapRegion* r = g1_policy()->collection_set();
+while (r != NULL) {
+HeapRegion* next = r->next_in_collection_set();
+if (cl->doHeapRegion(r)) {
+cl->incomplete();
+return;
+}
+r = next;
+}
+}
+void G1CollectedHeap::collection_set_iterate_from(HeapRegion* r,
+HeapRegionClosure *cl) {
+assert(r->in_collection_set(),
+"Start region must be a member of the collection set.");
+HeapRegion* cur = r;
+while (cur != NULL) {
+HeapRegion* next = cur->next_in_collection_set();
+if (cl->doHeapRegion(cur) && false) {
+cl->incomplete();
+return;
+}
+cur = next;
+}
+cur = g1_policy()->collection_set();
+while (cur != r) {
+HeapRegion* next = cur->next_in_collection_set();
+if (cl->doHeapRegion(cur) && false) {
+cl->incomplete();
+return;
+}
+cur = next;
+}
+}
+CompactibleSpace* G1CollectedHeap::first_compactible_space() {
+return _hrs->length() > 0 ? _hrs->at(0) : NULL;
+}
+Space* G1CollectedHeap::space_containing(const void* addr) const {
+Space* res = heap_region_containing(addr);
+if (res == NULL)
+res = perm_gen()->space_containing(addr);
+return res;
+}
+HeapWord* G1CollectedHeap::block_start(const void* addr) const {
+Space* sp = space_containing(addr);
+if (sp != NULL) {
+return sp->block_start(addr);
+}
+return NULL;
+}
+size_t G1CollectedHeap::block_size(const HeapWord* addr) const {
+Space* sp = space_containing(addr);
+assert(sp != NULL, "block_size of address outside of heap");
+return sp->block_size(addr);
+}
+bool G1CollectedHeap::block_is_obj(const HeapWord* addr) const {
+Space* sp = space_containing(addr);
+return sp->block_is_obj(addr);
+}
+bool G1CollectedHeap::supports_tlab_allocation() const {
+return true;
+}
+size_t G1CollectedHeap::tlab_capacity(Thread* ignored) const {
+return HeapRegion::GrainBytes;
+}
+size_t G1CollectedHeap::unsafe_max_tlab_alloc(Thread* ignored) const {
+// Return the remaining space in the cur alloc region, but not less than
+// the min TLAB size.
+// Also, no more than half the region size, since we can't allow tlabs to
+// grow big enough to accomodate humongous objects.
+// We need to story it locally, since it might change between when we
+// test for NULL and when we use it later.
+ContiguousSpace* cur_alloc_space = _cur_alloc_region;
+if (cur_alloc_space == NULL) {
+return HeapRegion::GrainBytes/2;
+} else {
+return MAX2(MIN2(cur_alloc_space->free(),
+(size_t)(HeapRegion::GrainBytes/2)),
+(size_t)MinTLABSize);
+}
+}
+HeapWord* G1CollectedHeap::allocate_new_tlab(size_t size) {
+bool dummy;
+return G1CollectedHeap::mem_allocate(size, false, true, &dummy);
+}
+bool G1CollectedHeap::allocs_are_zero_filled() {
+return false;
+}
+size_t G1CollectedHeap::large_typearray_limit() {
+// FIXME
+return HeapRegion::GrainBytes/HeapWordSize;
+}
+size_t G1CollectedHeap::max_capacity() const {
+return _g1_committed.byte_size();
+}
+jlong G1CollectedHeap::millis_since_last_gc() {
+// assert(false, "NYI");
+return 0;
+}
+void G1CollectedHeap::prepare_for_verify() {
+if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) {
+ensure_parsability(false);
+}
+g1_rem_set()->prepare_for_verify();
+}
+class VerifyLivenessOopClosure: public OopClosure {
+G1CollectedHeap* g1h;
+public:
+VerifyLivenessOopClosure(G1CollectedHeap* _g1h) {
+g1h = _g1h;
+}
+void do_oop(narrowOop *p) {
+guarantee(false, "NYI");
+}
+void do_oop(oop *p) {
+oop obj = *p;
+assert(obj == NULL || !g1h->is_obj_dead(obj),
+"Dead object referenced by a not dead object");
+}
+};
+class VerifyObjsInRegionClosure: public ObjectClosure {
+G1CollectedHeap* _g1h;
+size_t _live_bytes;
+HeapRegion *_hr;
+public:
+VerifyObjsInRegionClosure(HeapRegion *hr) : _live_bytes(0), _hr(hr) {
+_g1h = G1CollectedHeap::heap();
+}
+void do_object(oop o) {
+VerifyLivenessOopClosure isLive(_g1h);
+assert(o != NULL, "Huh?");
+if (!_g1h->is_obj_dead(o)) {
+o->oop_iterate(&isLive);
+if (!_hr->obj_allocated_since_prev_marking(o))
+_live_bytes += (o->size() * HeapWordSize);
+}
+}
+size_t live_bytes() { return _live_bytes; }
+};
+class PrintObjsInRegionClosure : public ObjectClosure {
+HeapRegion *_hr;
+G1CollectedHeap *_g1;
+public:
+PrintObjsInRegionClosure(HeapRegion *hr) : _hr(hr) {
+_g1 = G1CollectedHeap::heap();
+};
+void do_object(oop o) {
+if (o != NULL) {
+HeapWord *start = (HeapWord *) o;
+size_t word_sz = o->size();
+gclog_or_tty->print("\nPrinting obj "PTR_FORMAT" of size " SIZE_FORMAT
+" isMarkedPrev %d isMarkedNext %d isAllocSince %d\n",
+(void*) o, word_sz,
+_g1->isMarkedPrev(o),
+_g1->isMarkedNext(o),
+_hr->obj_allocated_since_prev_marking(o));
+HeapWord *end = start + word_sz;
+HeapWord *cur;
+int *val;
+for (cur = start; cur < end; cur++) {
+val = (int *) cur;
+gclog_or_tty->print("\t "PTR_FORMAT":"PTR_FORMAT"\n", val, *val);
+}
+}
+}
+};
+class VerifyRegionClosure: public HeapRegionClosure {
+public:
+bool _allow_dirty;
+VerifyRegionClosure(bool allow_dirty)
+: _allow_dirty(allow_dirty) {}
+bool doHeapRegion(HeapRegion* r) {
+guarantee(r->claim_value() == 0, "Should be unclaimed at verify points.");
+if (r->isHumongous()) {
+if (r->startsHumongous()) {
+// Verify the single H object.
+oop(r->bottom())->verify();
+size_t word_sz = oop(r->bottom())->size();
+guarantee(r->top() == r->bottom() + word_sz,
+"Only one object in a humongous region");
+}
+} else {
+VerifyObjsInRegionClosure not_dead_yet_cl(r);
+r->verify(_allow_dirty);
+r->object_iterate(&not_dead_yet_cl);
+guarantee(r->max_live_bytes() >= not_dead_yet_cl.live_bytes(),
+"More live objects than counted in last complete marking.");
+}
+return false;
+}
+};
+class VerifyRootsClosure: public OopsInGenClosure {
+private:
+G1CollectedHeap* _g1h;
+bool             _failures;
+public:
+VerifyRootsClosure() :
+_g1h(G1CollectedHeap::heap()), _failures(false) { }
+bool failures() { return _failures; }
+void do_oop(narrowOop* p) {
+guarantee(false, "NYI");
+}
+void do_oop(oop* p) {
+oop obj = *p;
+if (obj != NULL) {
+if (_g1h->is_obj_dead(obj)) {
+gclog_or_tty->print_cr("Root location "PTR_FORMAT" "
+"points to dead obj "PTR_FORMAT, p, (void*) obj);
+obj->print_on(gclog_or_tty);
+_failures = true;
+}
+}
+}
+};
+void G1CollectedHeap::verify(bool allow_dirty, bool silent) {
+if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) {
+if (!silent) { gclog_or_tty->print("roots "); }
+VerifyRootsClosure rootsCl;
+process_strong_roots(false,
+SharedHeap::SO_AllClasses,
+&rootsCl,
+&rootsCl);
+rem_set()->invalidate(perm_gen()->used_region(), false);
+if (!silent) { gclog_or_tty->print("heapRegions "); }
+VerifyRegionClosure blk(allow_dirty);
+_hrs->iterate(&blk);
+if (!silent) gclog_or_tty->print("remset ");
+rem_set()->verify();
+guarantee(!rootsCl.failures(), "should not have had failures");
+} else {
+if (!silent) gclog_or_tty->print("(SKIPPING roots, heapRegions, remset) ");
+}
+}
+class PrintRegionClosure: public HeapRegionClosure {
+outputStream* _st;
+public:
+PrintRegionClosure(outputStream* st) : _st(st) {}
+bool doHeapRegion(HeapRegion* r) {
+r->print_on(_st);
+return false;
+}
+};
+void G1CollectedHeap::print() const { print_on(gclog_or_tty); }
+void G1CollectedHeap::print_on(outputStream* st) const {
+PrintRegionClosure blk(st);
+_hrs->iterate(&blk);
+}
+void G1CollectedHeap::print_gc_threads_on(outputStream* st) const {
+if (ParallelGCThreads > 0) {
+workers()->print_worker_threads();
+}
+st->print("\"G1 concurrent mark GC Thread\" ");
+_cmThread->print();
+st->cr();
+st->print("\"G1 concurrent refinement GC Thread\" ");
+_cg1r->cg1rThread()->print_on(st);
+st->cr();
+st->print("\"G1 zero-fill GC Thread\" ");
+_czft->print_on(st);
+st->cr();
+}
+void G1CollectedHeap::gc_threads_do(ThreadClosure* tc) const {
+if (ParallelGCThreads > 0) {
+workers()->threads_do(tc);
+}
+tc->do_thread(_cmThread);
+tc->do_thread(_cg1r->cg1rThread());
+tc->do_thread(_czft);
+}
+void G1CollectedHeap::print_tracing_info() const {
+concurrent_g1_refine()->print_final_card_counts();
+// We'll overload this to mean "trace GC pause statistics."
+if (TraceGen0Time || TraceGen1Time) {
+// The "G1CollectorPolicy" is keeping track of these stats, so delegate
+// to that.
+g1_policy()->print_tracing_info();
+}
+if (SummarizeG1RSStats) {
+g1_rem_set()->print_summary_info();
+}
+if (SummarizeG1ConcMark) {
+concurrent_mark()->print_summary_info();
+}
+if (SummarizeG1ZFStats) {
+ConcurrentZFThread::print_summary_info();
+}
+if (G1SummarizePopularity) {
+print_popularity_summary_info();
+}
+g1_policy()->print_yg_surv_rate_info();
+GCOverheadReporter::printGCOverhead();
+SpecializationStats::print();
+}
+int G1CollectedHeap::addr_to_arena_id(void* addr) const {
+HeapRegion* hr = heap_region_containing(addr);
+if (hr == NULL) {
+return 0;
+} else {
+return 1;
+}
+}
+G1CollectedHeap* G1CollectedHeap::heap() {
+assert(_sh->kind() == CollectedHeap::G1CollectedHeap,
+"not a garbage-first heap");
+return _g1h;
+}
+void G1CollectedHeap::gc_prologue(bool full /* Ignored */) {
+if (PrintHeapAtGC){
+gclog_or_tty->print_cr(" {Heap before GC collections=%d:", total_collections());
+Universe::print();
+}
+assert(InlineCacheBuffer::is_empty(), "should have cleaned up ICBuffer");
+// Call allocation profiler
+AllocationProfiler::iterate_since_last_gc();
+// Fill TLAB's and such
+ensure_parsability(true);
+}
+void G1CollectedHeap::gc_epilogue(bool full /* Ignored */) {
+// FIXME: what is this about?
+// I'm ignoring the "fill_newgen()" call if "alloc_event_enabled"
+// is set.
+COMPILER2_PRESENT(assert(DerivedPointerTable::is_empty(),
+"derived pointer present"));
+if (PrintHeapAtGC){
+gclog_or_tty->print_cr(" Heap after GC collections=%d:", total_collections());
+Universe::print();
+gclog_or_tty->print("} ");
+}
+}
+void G1CollectedHeap::do_collection_pause() {
+// Read the GC count while holding the Heap_lock
+// we need to do this _before_ wait_for_cleanup_complete(), to
+// ensure that we do not give up the heap lock and potentially
+// pick up the wrong count
+int gc_count_before = SharedHeap::heap()->total_collections();
+// Don't want to do a GC pause while cleanup is being completed!
+wait_for_cleanup_complete();
+g1_policy()->record_stop_world_start();
+{
+MutexUnlocker mu(Heap_lock);  // give up heap lock, execute gets it back
+VM_G1IncCollectionPause op(gc_count_before);
+VMThread::execute(&op);
+}
+}
+void
+G1CollectedHeap::doConcurrentMark() {
+if (G1ConcMark) {
+MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag);
+if (!_cmThread->in_progress()) {
+_cmThread->set_started();
+CGC_lock->notify();
+}
+}
+}
+class VerifyMarkedObjsClosure: public ObjectClosure {
+G1CollectedHeap* _g1h;
+public:
+VerifyMarkedObjsClosure(G1CollectedHeap* g1h) : _g1h(g1h) {}
+void do_object(oop obj) {
+assert(obj->mark()->is_marked() ? !_g1h->is_obj_dead(obj) : true,
+"markandsweep mark should agree with concurrent deadness");
+}
+};
+void
+G1CollectedHeap::checkConcurrentMark() {
+VerifyMarkedObjsClosure verifycl(this);
+doConcurrentMark();
+//    MutexLockerEx x(getMarkBitMapLock(),
+//              Mutex::_no_safepoint_check_flag);
+object_iterate(&verifycl);
+}
+void G1CollectedHeap::do_sync_mark() {
+_cm->checkpointRootsInitial();
+_cm->markFromRoots();
+_cm->checkpointRootsFinal(false);
+}
+// <NEW PREDICTION>
+double G1CollectedHeap::predict_region_elapsed_time_ms(HeapRegion *hr,
+bool young) {
+return _g1_policy->predict_region_elapsed_time_ms(hr, young);
+}
+void G1CollectedHeap::check_if_region_is_too_expensive(double
+predicted_time_ms) {
+_g1_policy->check_if_region_is_too_expensive(predicted_time_ms);
+}
+size_t G1CollectedHeap::pending_card_num() {
+size_t extra_cards = 0;
+JavaThread *curr = Threads::first();
+while (curr != NULL) {
+DirtyCardQueue& dcq = curr->dirty_card_queue();
+extra_cards += dcq.size();
+curr = curr->next();
+}
+DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
+size_t buffer_size = dcqs.buffer_size();
+size_t buffer_num = dcqs.completed_buffers_num();
+return buffer_size * buffer_num + extra_cards;
+}
+size_t G1CollectedHeap::max_pending_card_num() {
+DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
+size_t buffer_size = dcqs.buffer_size();
+size_t buffer_num  = dcqs.completed_buffers_num();
+int thread_num  = Threads::number_of_threads();
+return (buffer_num + thread_num) * buffer_size;
+}
+size_t G1CollectedHeap::cards_scanned() {
+HRInto_G1RemSet* g1_rset = (HRInto_G1RemSet*) g1_rem_set();
+return g1_rset->cardsScanned();
+}
+void
+G1CollectedHeap::setup_surviving_young_words() {
+guarantee( _surviving_young_words == NULL, "pre-condition" );
+size_t array_length = g1_policy()->young_cset_length();
+_surviving_young_words = NEW_C_HEAP_ARRAY(size_t, array_length);
+if (_surviving_young_words == NULL) {
+vm_exit_out_of_memory(sizeof(size_t) * array_length,
+"Not enough space for young surv words summary.");
+}
+memset(_surviving_young_words, 0, array_length * sizeof(size_t));
+for (size_t i = 0;  i < array_length; ++i) {
+guarantee( _surviving_young_words[i] == 0, "invariant" );
+}
+}
+void
+G1CollectedHeap::update_surviving_young_words(size_t* surv_young_words) {
+MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag);
+size_t array_length = g1_policy()->young_cset_length();
+for (size_t i = 0; i < array_length; ++i)
+_surviving_young_words[i] += surv_young_words[i];
+}
+void
+G1CollectedHeap::cleanup_surviving_young_words() {
+guarantee( _surviving_young_words != NULL, "pre-condition" );
+FREE_C_HEAP_ARRAY(size_t, _surviving_young_words);
+_surviving_young_words = NULL;
+}
+// </NEW PREDICTION>
+void
+G1CollectedHeap::do_collection_pause_at_safepoint(HeapRegion* popular_region) {
+char verbose_str[128];
+sprintf(verbose_str, "GC pause ");
+if (popular_region != NULL)
+strcat(verbose_str, "(popular)");
+else if (g1_policy()->in_young_gc_mode()) {
+if (g1_policy()->full_young_gcs())
+strcat(verbose_str, "(young)");
+else
+strcat(verbose_str, "(partial)");
+}
+bool reset_should_initiate_conc_mark = false;
+if (popular_region != NULL && g1_policy()->should_initiate_conc_mark()) {
+// we currently do not allow an initial mark phase to be piggy-backed
+// on a popular pause
+reset_should_initiate_conc_mark = true;
+g1_policy()->unset_should_initiate_conc_mark();
+}
+if (g1_policy()->should_initiate_conc_mark())
+strcat(verbose_str, " (initial-mark)");
+GCCauseSetter x(this, (popular_region == NULL ?
+GCCause::_g1_inc_collection_pause :
+GCCause::_g1_pop_region_collection_pause));
+// if PrintGCDetails is on, we'll print long statistics information
+// in the collector policy code, so let's not print this as the output
+// is messy if we do.
+gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
+TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
+TraceTime t(verbose_str, PrintGC && !PrintGCDetails, true, gclog_or_tty);
+ResourceMark rm;
+assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
+assert(Thread::current() == VMThread::vm_thread(), "should be in vm thread");
+guarantee(!is_gc_active(), "collection is not reentrant");
+assert(regions_accounted_for(), "Region leakage!");
+++_gc_time_stamp;
+if (g1_policy()->in_young_gc_mode()) {
+assert(check_young_list_well_formed(),
+"young list should be well formed");
+}
+if (GC_locker::is_active()) {
+return; // GC is disabled (e.g. JNI GetXXXCritical operation)
+}
+bool abandoned = false;
+{ // Call to jvmpi::post_class_unload_events must occur outside of active GC
+IsGCActiveMark x;
+gc_prologue(false);
+increment_total_collections();
+#if G1_REM_SET_LOGGING
+gclog_or_tty->print_cr("\nJust chose CS, heap:");
+print();
+#endif
+if (VerifyBeforeGC && total_collections() >= VerifyGCStartAt) {
+HandleMark hm;  // Discard invalid handles created during verification
+prepare_for_verify();
+gclog_or_tty->print(" VerifyBeforeGC:");
+Universe::verify(false);
+}
+COMPILER2_PRESENT(DerivedPointerTable::clear());
+// We want to turn off ref discovere, if necessary, and turn it back on
+// on again later if we do.
+bool was_enabled = ref_processor()->discovery_enabled();
+if (was_enabled) ref_processor()->disable_discovery();
+// Forget the current alloc region (we might even choose it to be part
+// of the collection set!).
+abandon_cur_alloc_region();
+// The elapsed time induced by the start time below deliberately elides
+// the possible verification above.
+double start_time_sec = os::elapsedTime();
+GCOverheadReporter::recordSTWStart(start_time_sec);
+size_t start_used_bytes = used();
+if (!G1ConcMark) {
+do_sync_mark();
+}
+g1_policy()->record_collection_pause_start(start_time_sec,
+start_used_bytes);
+#if SCAN_ONLY_VERBOSE
+_young_list->print();
+#endif // SCAN_ONLY_VERBOSE
+if (g1_policy()->should_initiate_conc_mark()) {
+concurrent_mark()->checkpointRootsInitialPre();
+}
+save_marks();
+// We must do this before any possible evacuation that should propogate
+// marks, including evacuation of popular objects in a popular pause.
+if (mark_in_progress()) {
+double start_time_sec = os::elapsedTime();
+_cm->drainAllSATBBuffers();
+double finish_mark_ms = (os::elapsedTime() - start_time_sec) * 1000.0;
+g1_policy()->record_satb_drain_time(finish_mark_ms);
+}
+// Record the number of elements currently on the mark stack, so we
+// only iterate over these.  (Since evacuation may add to the mark
+// stack, doing more exposes race conditions.)  If no mark is in
+// progress, this will be zero.
+_cm->set_oops_do_bound();
+assert(regions_accounted_for(), "Region leakage.");
+bool abandoned = false;
+if (mark_in_progress())
+concurrent_mark()->newCSet();
+// Now choose the CS.
+if (popular_region == NULL) {
+g1_policy()->choose_collection_set();
+} else {
+// We may be evacuating a single region (for popularity).
+g1_policy()->record_popular_pause_preamble_start();
+popularity_pause_preamble(popular_region);
+g1_policy()->record_popular_pause_preamble_end();
+abandoned = (g1_policy()->collection_set() == NULL);
+// Now we allow more regions to be added (we have to collect
+// all popular regions).
+if (!abandoned) {
+g1_policy()->choose_collection_set(popular_region);
+}
+}
+// We may abandon a pause if we find no region that will fit in the MMU
+// pause.
+abandoned = (g1_policy()->collection_set() == NULL);
+// Nothing to do if we were unable to choose a collection set.
+if (!abandoned) {
+#if G1_REM_SET_LOGGING
+gclog_or_tty->print_cr("\nAfter pause, heap:");
+print();
+#endif
+setup_surviving_young_words();
+// Set up the gc allocation regions.
+get_gc_alloc_regions();
+// Actually do the work...
+evacuate_collection_set();
+free_collection_set(g1_policy()->collection_set());
+g1_policy()->clear_collection_set();
+if (popular_region != NULL) {
+// We have to wait until now, because we don't want the region to
+// be rescheduled for pop-evac during RS update.
+popular_region->set_popular_pending(false);
+}
+release_gc_alloc_regions();
+cleanup_surviving_young_words();
+if (g1_policy()->in_young_gc_mode()) {
+_young_list->reset_sampled_info();
+assert(check_young_list_empty(true),
+"young list should be empty");
+#if SCAN_ONLY_VERBOSE
+_young_list->print();
+#endif // SCAN_ONLY_VERBOSE
+_young_list->reset_auxilary_lists();
+}
+} else {
+COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
+}
+if (evacuation_failed()) {
+_summary_bytes_used = recalculate_used();
+} else {
+// The "used" of the the collection set have already been subtracted
+// when they were freed.  Add in the bytes evacuated.
+_summary_bytes_used += g1_policy()->bytes_in_to_space();
+}
+if (g1_policy()->in_young_gc_mode() &&
+g1_policy()->should_initiate_conc_mark()) {
+concurrent_mark()->checkpointRootsInitialPost();
+set_marking_started();
+doConcurrentMark();
+}
+#if SCAN_ONLY_VERBOSE
+_young_list->print();
+#endif // SCAN_ONLY_VERBOSE
+double end_time_sec = os::elapsedTime();
+g1_policy()->record_pause_time((end_time_sec - start_time_sec)*1000.0);
+GCOverheadReporter::recordSTWEnd(end_time_sec);
+g1_policy()->record_collection_pause_end(popular_region != NULL,
+abandoned);
+assert(regions_accounted_for(), "Region leakage.");
+if (VerifyAfterGC && total_collections() >= VerifyGCStartAt) {
+HandleMark hm;  // Discard invalid handles created during verification
+gclog_or_tty->print(" VerifyAfterGC:");
+Universe::verify(false);
+}
+if (was_enabled) ref_processor()->enable_discovery();
+{
+size_t expand_bytes = g1_policy()->expansion_amount();
+if (expand_bytes > 0) {
+size_t bytes_before = capacity();
+expand(expand_bytes);
+}
+}
+if (mark_in_progress())
+concurrent_mark()->update_g1_committed();
+gc_epilogue(false);
+}
+assert(verify_region_lists(), "Bad region lists.");
+if (reset_should_initiate_conc_mark)
+g1_policy()->set_should_initiate_conc_mark();
+if (ExitAfterGCNum > 0 && total_collections() == ExitAfterGCNum) {
+gclog_or_tty->print_cr("Stopping after GC #%d", ExitAfterGCNum);
+print_tracing_info();
+vm_exit(-1);
+}
+}
+void G1CollectedHeap::set_gc_alloc_region(int purpose, HeapRegion* r) {
+assert(purpose >= 0 && purpose < GCAllocPurposeCount, "invalid purpose");
+HeapWord* original_top = NULL;
+if (r != NULL)
+original_top = r->top();
+// We will want to record the used space in r as being there before gc.
+// One we install it as a GC alloc region it's eligible for allocation.
+// So record it now and use it later.
+size_t r_used = 0;
+if (r != NULL) {
+r_used = r->used();
+if (ParallelGCThreads > 0) {
+// need to take the lock to guard against two threads calling
+// get_gc_alloc_region concurrently (very unlikely but...)
+MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag);
+r->save_marks();
+}
+}
+HeapRegion* old_alloc_region = _gc_alloc_regions[purpose];
+_gc_alloc_regions[purpose] = r;
+if (old_alloc_region != NULL) {
+// Replace aliases too.
+for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
+if (_gc_alloc_regions[ap] == old_alloc_region) {
+_gc_alloc_regions[ap] = r;
+}
+}
+}
+if (r != NULL) {
+push_gc_alloc_region(r);
+if (mark_in_progress() && original_top != r->next_top_at_mark_start()) {
+// We are using a region as a GC alloc region after it has been used
+// as a mutator allocation region during the current marking cycle.
+// The mutator-allocated objects are currently implicitly marked, but
+// when we move hr->next_top_at_mark_start() forward at the the end
+// of the GC pause, they won't be.  We therefore mark all objects in
+// the "gap".  We do this object-by-object, since marking densely
+// does not currently work right with marking bitmap iteration.  This
+// means we rely on TLAB filling at the start of pauses, and no
+// "resuscitation" of filled TLAB's.  If we want to do this, we need
+// to fix the marking bitmap iteration.
+HeapWord* curhw = r->next_top_at_mark_start();
+HeapWord* t = original_top;
+while (curhw < t) {
+oop cur = (oop)curhw;
+// We'll assume parallel for generality.  This is rare code.
+concurrent_mark()->markAndGrayObjectIfNecessary(cur); // can't we just mark them?
+curhw = curhw + cur->size();
+}
+assert(curhw == t, "Should have parsed correctly.");
+}
+if (G1PolicyVerbose > 1) {
+gclog_or_tty->print("New alloc region ["PTR_FORMAT", "PTR_FORMAT", " PTR_FORMAT") "
+"for survivors:", r->bottom(), original_top, r->end());
+r->print();
+}
+g1_policy()->record_before_bytes(r_used);
+}
+}
+void G1CollectedHeap::push_gc_alloc_region(HeapRegion* hr) {
+assert(Thread::current()->is_VM_thread() ||
+par_alloc_during_gc_lock()->owned_by_self(), "Precondition");
+assert(!hr->is_gc_alloc_region() && !hr->in_collection_set(),
+"Precondition.");
+hr->set_is_gc_alloc_region(true);
+hr->set_next_gc_alloc_region(_gc_alloc_region_list);
+_gc_alloc_region_list = hr;
+}
+#ifdef G1_DEBUG
+class FindGCAllocRegion: public HeapRegionClosure {
+public:
+bool doHeapRegion(HeapRegion* r) {
+if (r->is_gc_alloc_region()) {
+gclog_or_tty->print_cr("Region %d ["PTR_FORMAT"...] is still a gc_alloc_region.",
+r->hrs_index(), r->bottom());
+}
+return false;
+}
+};
+#endif // G1_DEBUG
+void G1CollectedHeap::forget_alloc_region_list() {
+assert(Thread::current()->is_VM_thread(), "Precondition");
+while (_gc_alloc_region_list != NULL) {
+HeapRegion* r = _gc_alloc_region_list;
+assert(r->is_gc_alloc_region(), "Invariant.");
+_gc_alloc_region_list = r->next_gc_alloc_region();
+r->set_next_gc_alloc_region(NULL);
+r->set_is_gc_alloc_region(false);
+if (r->is_empty()) {
+++_free_regions;
+}
+}
+#ifdef G1_DEBUG
+FindGCAllocRegion fa;
+heap_region_iterate(&fa);
+#endif // G1_DEBUG
+}
+bool G1CollectedHeap::check_gc_alloc_regions() {
+// TODO: allocation regions check
+return true;
+}
+void G1CollectedHeap::get_gc_alloc_regions() {
+for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
+// Create new GC alloc regions.
+HeapRegion* alloc_region = _gc_alloc_regions[ap];
+// Clear this alloc region, so that in case it turns out to be
+// unacceptable, we end up with no allocation region, rather than a bad
+// one.
+_gc_alloc_regions[ap] = NULL;
+if (alloc_region == NULL || alloc_region->in_collection_set()) {
+// Can't re-use old one.  Allocate a new one.
+alloc_region = newAllocRegionWithExpansion(ap, 0);
+}
+if (alloc_region != NULL) {
+set_gc_alloc_region(ap, alloc_region);
+}
+}
+// Set alternative regions for allocation purposes that have reached
+// thier limit.
+for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
+GCAllocPurpose alt_purpose = g1_policy()->alternative_purpose(ap);
+if (_gc_alloc_regions[ap] == NULL && alt_purpose != ap) {
+_gc_alloc_regions[ap] = _gc_alloc_regions[alt_purpose];
+}
+}
+assert(check_gc_alloc_regions(), "alloc regions messed up");
+}
+void G1CollectedHeap::release_gc_alloc_regions() {
+// We keep a separate list of all regions that have been alloc regions in
+// the current collection pause.  Forget that now.
+forget_alloc_region_list();
+// The current alloc regions contain objs that have survived
+// collection. Make them no longer GC alloc regions.
+for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
+HeapRegion* r = _gc_alloc_regions[ap];
+if (r != NULL && r->is_empty()) {
+{
+MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag);
+r->set_zero_fill_complete();
+put_free_region_on_list_locked(r);
+}
+}
+// set_gc_alloc_region will also NULLify all aliases to the region
+set_gc_alloc_region(ap, NULL);
+_gc_alloc_region_counts[ap] = 0;
+}
+}
+void G1CollectedHeap::init_for_evac_failure(OopsInHeapRegionClosure* cl) {
+_drain_in_progress = false;
+set_evac_failure_closure(cl);
+_evac_failure_scan_stack = new (ResourceObj::C_HEAP) GrowableArray<oop>(40, true);
+}
+void G1CollectedHeap::finalize_for_evac_failure() {
+assert(_evac_failure_scan_stack != NULL &&
+_evac_failure_scan_stack->length() == 0,
+"Postcondition");
+assert(!_drain_in_progress, "Postcondition");
+// Don't have to delete, since the scan stack is a resource object.
+_evac_failure_scan_stack = NULL;
+}
+// *** Sequential G1 Evacuation
+HeapWord* G1CollectedHeap::allocate_during_gc(GCAllocPurpose purpose, size_t word_size) {
+HeapRegion* alloc_region = _gc_alloc_regions[purpose];
+// let the caller handle alloc failure
+if (alloc_region == NULL) return NULL;
+assert(isHumongous(word_size) || !alloc_region->isHumongous(),
+"Either the object is humongous or the region isn't");
+HeapWord* block = alloc_region->allocate(word_size);
+if (block == NULL) {
+block = allocate_during_gc_slow(purpose, alloc_region, false, word_size);
+}
+return block;
+}
+class G1IsAliveClosure: public BoolObjectClosure {
+G1CollectedHeap* _g1;
+public:
+G1IsAliveClosure(G1CollectedHeap* g1) : _g1(g1) {}
+void do_object(oop p) { assert(false, "Do not call."); }
+bool do_object_b(oop p) {
+// It is reachable if it is outside the collection set, or is inside
+// and forwarded.
+#ifdef G1_DEBUG
+gclog_or_tty->print_cr("is alive "PTR_FORMAT" in CS %d forwarded %d overall %d",
+(void*) p, _g1->obj_in_cs(p), p->is_forwarded(),
+!_g1->obj_in_cs(p) || p->is_forwarded());
+#endif // G1_DEBUG
+return !_g1->obj_in_cs(p) || p->is_forwarded();
+}
+};
+class G1KeepAliveClosure: public OopClosure {
+G1CollectedHeap* _g1;
+public:
+G1KeepAliveClosure(G1CollectedHeap* g1) : _g1(g1) {}
+void do_oop(narrowOop* p) {
+guarantee(false, "NYI");
+}
+void do_oop(oop* p) {
+oop obj = *p;
+#ifdef G1_DEBUG
+if (PrintGC && Verbose) {
+gclog_or_tty->print_cr("keep alive *"PTR_FORMAT" = "PTR_FORMAT" "PTR_FORMAT,
+p, (void*) obj, (void*) *p);
+}
+#endif // G1_DEBUG
+if (_g1->obj_in_cs(obj)) {
+assert( obj->is_forwarded(), "invariant" );
+*p = obj->forwardee();
+#ifdef G1_DEBUG
+gclog_or_tty->print_cr("     in CSet: moved "PTR_FORMAT" -> "PTR_FORMAT,
+(void*) obj, (void*) *p);
+#endif // G1_DEBUG
+}
+}
+};
+class RecreateRSetEntriesClosure: public OopClosure {
+private:
+G1CollectedHeap* _g1;
+G1RemSet* _g1_rem_set;
+HeapRegion* _from;
+public:
+RecreateRSetEntriesClosure(G1CollectedHeap* g1, HeapRegion* from) :
+_g1(g1), _g1_rem_set(g1->g1_rem_set()), _from(from)
+{}
+void do_oop(narrowOop* p) {
+guarantee(false, "NYI");
+}
+void do_oop(oop* p) {
+assert(_from->is_in_reserved(p), "paranoia");
+if (*p != NULL) {
+_g1_rem_set->write_ref(_from, p);
+}
+}
+};
+class RemoveSelfPointerClosure: public ObjectClosure {
+private:
+G1CollectedHeap* _g1;
+ConcurrentMark* _cm;
+HeapRegion* _hr;
+HeapWord* _last_self_forwarded_end;
+size_t _prev_marked_bytes;
+size_t _next_marked_bytes;
+public:
+RemoveSelfPointerClosure(G1CollectedHeap* g1, HeapRegion* hr) :
+_g1(g1), _cm(_g1->concurrent_mark()), _hr(hr),
+_last_self_forwarded_end(_hr->bottom()),
+_prev_marked_bytes(0), _next_marked_bytes(0)
+{}
+size_t prev_marked_bytes() { return _prev_marked_bytes; }
+size_t next_marked_bytes() { return _next_marked_bytes; }
+void fill_remainder() {
+HeapWord* limit = _hr->top();
+MemRegion mr(_last_self_forwarded_end, limit);
+if (!mr.is_empty()) {
+SharedHeap::fill_region_with_object(mr);
+_cm->clearRangeBothMaps(mr);
+_hr->declare_filled_region_to_BOT(mr);
+}
+}
+void do_object(oop obj) {
+if (obj->is_forwarded()) {
+if (obj->forwardee() == obj) {
+assert(!_g1->is_obj_dead(obj), "We should not be preserving dead objs.");
+_cm->markPrev(obj);
+assert(_cm->isPrevMarked(obj), "Should be marked!");
+_prev_marked_bytes += (obj->size() * HeapWordSize);
+if (_g1->mark_in_progress() && !_g1->is_obj_ill(obj)) {
+_cm->markAndGrayObjectIfNecessary(obj);
+}
+HeapWord* obj_start = (HeapWord*)obj;
+if (obj_start > _last_self_forwarded_end) {
+MemRegion mr(_last_self_forwarded_end, obj_start);
+SharedHeap::fill_region_with_object(mr);
+assert(_cm->isPrevMarked(obj), "Should be marked!");
+_cm->clearRangeBothMaps(mr);
+assert(_cm->isPrevMarked(obj), "Should be marked!");
+_hr->declare_filled_region_to_BOT(mr);
+}
+_last_self_forwarded_end = obj_start + obj->size();
+obj->set_mark(markOopDesc::prototype());
+// While we were processing RSet buffers during the
+// collection, we actually didn't scan any cards on the
+// collection set, since we didn't want to update remebered
+// sets with entries that point into the collection set, given
+// that live objects fromthe collection set are about to move
+// and such entries will be stale very soon. This change also
+// dealt with a reliability issue which involved scanning a
+// card in the collection set and coming across an array that
+// was being chunked and looking malformed. The problem is
+// that, if evacuation fails, we might have remembered set
+// entries missing given that we skipped cards on the
+// collection set. So, we'll recreate such entries now.
+RecreateRSetEntriesClosure cl(_g1, _hr);
+obj->oop_iterate(&cl);
+assert(_cm->isPrevMarked(obj), "Should be marked!");
+}
+}
+}
+};
+void G1CollectedHeap::remove_self_forwarding_pointers() {
+HeapRegion* cur = g1_policy()->collection_set();
+while (cur != NULL) {
+assert(g1_policy()->assertMarkedBytesDataOK(), "Should be!");
+if (cur->evacuation_failed()) {
+RemoveSelfPointerClosure rspc(_g1h, cur);
+assert(cur->in_collection_set(), "bad CS");
+cur->object_iterate(&rspc);
+rspc.fill_remainder();
+// A number of manipulations to make the TAMS be the current top,
+// and the marked bytes be the ones observed in the iteration.
+if (_g1h->concurrent_mark()->at_least_one_mark_complete()) {
+// The comments below are the postconditions achieved by the
+// calls.  Note especially the last such condition, which says that
+// the count of marked bytes has been properly restored.
+cur->note_start_of_marking(false);
+// _next_top_at_mark_start == top, _next_marked_bytes == 0
+cur->add_to_marked_bytes(rspc.prev_marked_bytes());
+// _next_marked_bytes == prev_marked_bytes.
+cur->note_end_of_marking();
+// _prev_top_at_mark_start == top(),
+// _prev_marked_bytes == prev_marked_bytes
+}
+// If there is no mark in progress, we modified the _next variables
+// above needlessly, but harmlessly.
+if (_g1h->mark_in_progress()) {
+cur->note_start_of_marking(false);
+// _next_top_at_mark_start == top, _next_marked_bytes == 0
+// _next_marked_bytes == next_marked_bytes.
+}
+// Now make sure the region has the right index in the sorted array.
+g1_policy()->note_change_in_marked_bytes(cur);
+}
+cur = cur->next_in_collection_set();
+}
+assert(g1_policy()->assertMarkedBytesDataOK(), "Should be!");
+// Now restore saved marks, if any.
+if (_objs_with_preserved_marks != NULL) {
+assert(_preserved_marks_of_objs != NULL, "Both or none.");
+assert(_objs_with_preserved_marks->length() ==
+_preserved_marks_of_objs->length(), "Both or none.");
+guarantee(_objs_with_preserved_marks->length() ==
+_preserved_marks_of_objs->length(), "Both or none.");
+for (int i = 0; i < _objs_with_preserved_marks->length(); i++) {
+oop obj   = _objs_with_preserved_marks->at(i);
+markOop m = _preserved_marks_of_objs->at(i);
+obj->set_mark(m);
+}
+// Delete the preserved marks growable arrays (allocated on the C heap).
+delete _objs_with_preserved_marks;
+delete _preserved_marks_of_objs;
+_objs_with_preserved_marks = NULL;
+_preserved_marks_of_objs = NULL;
+}
+}
+void G1CollectedHeap::push_on_evac_failure_scan_stack(oop obj) {
+_evac_failure_scan_stack->push(obj);
+}
+void G1CollectedHeap::drain_evac_failure_scan_stack() {
+assert(_evac_failure_scan_stack != NULL, "precondition");
+while (_evac_failure_scan_stack->length() > 0) {
+oop obj = _evac_failure_scan_stack->pop();
+_evac_failure_closure->set_region(heap_region_containing(obj));
+obj->oop_iterate_backwards(_evac_failure_closure);
+}
+}
+void G1CollectedHeap::handle_evacuation_failure(oop old) {
+markOop m = old->mark();
+// forward to self
+assert(!old->is_forwarded(), "precondition");
+old->forward_to(old);
+handle_evacuation_failure_common(old, m);
+}
+oop
+G1CollectedHeap::handle_evacuation_failure_par(OopsInHeapRegionClosure* cl,
+oop old) {
+markOop m = old->mark();
+oop forward_ptr = old->forward_to_atomic(old);
+if (forward_ptr == NULL) {
+// Forward-to-self succeeded.
+if (_evac_failure_closure != cl) {
+MutexLockerEx x(EvacFailureStack_lock, Mutex::_no_safepoint_check_flag);
+assert(!_drain_in_progress,
+"Should only be true while someone holds the lock.");
+// Set the global evac-failure closure to the current thread's.
+assert(_evac_failure_closure == NULL, "Or locking has failed.");
+set_evac_failure_closure(cl);
+// Now do the common part.
+handle_evacuation_failure_common(old, m);
+// Reset to NULL.
+set_evac_failure_closure(NULL);
+} else {
+// The lock is already held, and this is recursive.
+assert(_drain_in_progress, "This should only be the recursive case.");
+handle_evacuation_failure_common(old, m);
+}
+return old;
+} else {
+// Someone else had a place to copy it.
+return forward_ptr;
+}
+}
+void G1CollectedHeap::handle_evacuation_failure_common(oop old, markOop m) {
+set_evacuation_failed(true);
+preserve_mark_if_necessary(old, m);
+HeapRegion* r = heap_region_containing(old);
+if (!r->evacuation_failed()) {
+r->set_evacuation_failed(true);
+if (G1TraceRegions) {
+gclog_or_tty->print("evacuation failed in heap region "PTR_FORMAT" "
+"["PTR_FORMAT","PTR_FORMAT")\n",
+r, r->bottom(), r->end());
+}
+}
+push_on_evac_failure_scan_stack(old);
+if (!_drain_in_progress) {
+// prevent recursion in copy_to_survivor_space()
+_drain_in_progress = true;
+drain_evac_failure_scan_stack();
+_drain_in_progress = false;
+}
+}
+void G1CollectedHeap::preserve_mark_if_necessary(oop obj, markOop m) {
+if (m != markOopDesc::prototype()) {
+if (_objs_with_preserved_marks == NULL) {
+assert(_preserved_marks_of_objs == NULL, "Both or none.");
+_objs_with_preserved_marks =
+new (ResourceObj::C_HEAP) GrowableArray<oop>(40, true);
+_preserved_marks_of_objs =
+new (ResourceObj::C_HEAP) GrowableArray<markOop>(40, true);
+}
+_objs_with_preserved_marks->push(obj);
+_preserved_marks_of_objs->push(m);
+}
+}
+// *** Parallel G1 Evacuation
+HeapWord* G1CollectedHeap::par_allocate_during_gc(GCAllocPurpose purpose,
+size_t word_size) {
+HeapRegion* alloc_region = _gc_alloc_regions[purpose];
+// let the caller handle alloc failure
+if (alloc_region == NULL) return NULL;
+HeapWord* block = alloc_region->par_allocate(word_size);
+if (block == NULL) {
+MutexLockerEx x(par_alloc_during_gc_lock(),
+Mutex::_no_safepoint_check_flag);
+block = allocate_during_gc_slow(purpose, alloc_region, true, word_size);
+}
+return block;
+}
+HeapWord*
+G1CollectedHeap::allocate_during_gc_slow(GCAllocPurpose purpose,
+HeapRegion*    alloc_region,
+bool           par,
+size_t         word_size) {
+HeapWord* block = NULL;
+// In the parallel case, a previous thread to obtain the lock may have
+// already assigned a new gc_alloc_region.
+if (alloc_region != _gc_alloc_regions[purpose]) {
+assert(par, "But should only happen in parallel case.");
+alloc_region = _gc_alloc_regions[purpose];
+if (alloc_region == NULL) return NULL;
+block = alloc_region->par_allocate(word_size);
+if (block != NULL) return block;
+// Otherwise, continue; this new region is empty, too.
+}
+assert(alloc_region != NULL, "We better have an allocation region");
+// Another thread might have obtained alloc_region for the given
+// purpose, and might be attempting to allocate in it, and might
+// succeed.  Therefore, we can't do the "finalization" stuff on the
+// region below until we're sure the last allocation has happened.
+// We ensure this by allocating the remaining space with a garbage
+// object.
+if (par) par_allocate_remaining_space(alloc_region);
+// Now we can do the post-GC stuff on the region.
+alloc_region->note_end_of_copying();
+g1_policy()->record_after_bytes(alloc_region->used());
+if (_gc_alloc_region_counts[purpose] >= g1_policy()->max_regions(purpose)) {
+// Cannot allocate more regions for the given purpose.
+GCAllocPurpose alt_purpose = g1_policy()->alternative_purpose(purpose);
+// Is there an alternative?
+if (purpose != alt_purpose) {
+HeapRegion* alt_region = _gc_alloc_regions[alt_purpose];
+// Has not the alternative region been aliased?
+if (alloc_region != alt_region) {
+// Try to allocate in the alternative region.
+if (par) {
+block = alt_region->par_allocate(word_size);
+} else {
+block = alt_region->allocate(word_size);
+}
+// Make an alias.
+_gc_alloc_regions[purpose] = _gc_alloc_regions[alt_purpose];
+}
+if (block != NULL) {
+return block;
+}
+// Both the allocation region and the alternative one are full
+// and aliased, replace them with a new allocation region.
+purpose = alt_purpose;
+} else {
+set_gc_alloc_region(purpose, NULL);
+return NULL;
+}
+}
+// Now allocate a new region for allocation.
+alloc_region = newAllocRegionWithExpansion(purpose, word_size, false /*zero_filled*/);
+// let the caller handle alloc failure
+if (alloc_region != NULL) {
+assert(check_gc_alloc_regions(), "alloc regions messed up");
+assert(alloc_region->saved_mark_at_top(),
+"Mark should have been saved already.");
+// We used to assert that the region was zero-filled here, but no
+// longer.
+// This must be done last: once it's installed, other regions may
+// allocate in it (without holding the lock.)
+set_gc_alloc_region(purpose, alloc_region);
+if (par) {
+block = alloc_region->par_allocate(word_size);
+} else {
+block = alloc_region->allocate(word_size);
+}
+// Caller handles alloc failure.
+} else {
+// This sets other apis using the same old alloc region to NULL, also.
+set_gc_alloc_region(purpose, NULL);
+}
+return block;  // May be NULL.
+}
+void G1CollectedHeap::par_allocate_remaining_space(HeapRegion* r) {
+HeapWord* block = NULL;
+size_t free_words;
+do {
+free_words = r->free()/HeapWordSize;
+// If there's too little space, no one can allocate, so we're done.
+if (free_words < (size_t)oopDesc::header_size()) return;
+// Otherwise, try to claim it.
+block = r->par_allocate(free_words);
+} while (block == NULL);
+SharedHeap::fill_region_with_object(MemRegion(block, free_words));
+}
+#define use_local_bitmaps         1
+#define verify_local_bitmaps      0
+#ifndef PRODUCT
+class GCLabBitMap;
+class GCLabBitMapClosure: public BitMapClosure {
+private:
+ConcurrentMark* _cm;
+GCLabBitMap*    _bitmap;
+public:
+GCLabBitMapClosure(ConcurrentMark* cm,
+GCLabBitMap* bitmap) {
+_cm     = cm;
+_bitmap = bitmap;
+}
+virtual bool do_bit(size_t offset);
+};
+#endif // PRODUCT
+#define oop_buffer_length 256
+class GCLabBitMap: public BitMap {
+private:
+ConcurrentMark* _cm;
+int       _shifter;
+size_t    _bitmap_word_covers_words;
+// beginning of the heap
+HeapWord* _heap_start;
+// this is the actual start of the GCLab
+HeapWord* _real_start_word;
+// this is the actual end of the GCLab
+HeapWord* _real_end_word;
+// this is the first word, possibly located before the actual start
+// of the GCLab, that corresponds to the first bit of the bitmap
+HeapWord* _start_word;
+// size of a GCLab in words
+size_t _gclab_word_size;
+static int shifter() {
+return MinObjAlignment - 1;
+}
+// how many heap words does a single bitmap word corresponds to?
+static size_t bitmap_word_covers_words() {
+return BitsPerWord << shifter();
+}
+static size_t gclab_word_size() {
+return ParallelGCG1AllocBufferSize / HeapWordSize;
+}
+static size_t bitmap_size_in_bits() {
+size_t bits_in_bitmap = gclab_word_size() >> shifter();
+// We are going to ensure that the beginning of a word in this
+// bitmap also corresponds to the beginning of a word in the
+// global marking bitmap. To handle the case where a GCLab
+// starts from the middle of the bitmap, we need to add enough
+// space (i.e. up to a bitmap word) to ensure that we have
+// enough bits in the bitmap.
+return bits_in_bitmap + BitsPerWord - 1;
+}
+public:
+GCLabBitMap(HeapWord* heap_start)
+: BitMap(bitmap_size_in_bits()),
+_cm(G1CollectedHeap::heap()->concurrent_mark()),
+_shifter(shifter()),
+_bitmap_word_covers_words(bitmap_word_covers_words()),
+_heap_start(heap_start),
+_gclab_word_size(gclab_word_size()),
+_real_start_word(NULL),
+_real_end_word(NULL),
+_start_word(NULL)
+{
+guarantee( size_in_words() >= bitmap_size_in_words(),
+"just making sure");
+}
+inline unsigned heapWordToOffset(HeapWord* addr) {
+unsigned offset = (unsigned) pointer_delta(addr, _start_word) >> _shifter;
+assert(offset < size(), "offset should be within bounds");
+return offset;
+}
+inline HeapWord* offsetToHeapWord(size_t offset) {
+HeapWord* addr =  _start_word + (offset << _shifter);
+assert(_real_start_word <= addr && addr < _real_end_word, "invariant");
+return addr;
+}
+bool fields_well_formed() {
+bool ret1 = (_real_start_word == NULL) &&
+(_real_end_word == NULL) &&
+(_start_word == NULL);
+if (ret1)
+return true;
+bool ret2 = _real_start_word >= _start_word &&
+_start_word < _real_end_word &&
+(_real_start_word + _gclab_word_size) == _real_end_word &&
+(_start_word + _gclab_word_size + _bitmap_word_covers_words)
+> _real_end_word;
+return ret2;
+}
+inline bool mark(HeapWord* addr) {
+guarantee(use_local_bitmaps, "invariant");
+assert(fields_well_formed(), "invariant");
+if (addr >= _real_start_word && addr < _real_end_word) {
+assert(!isMarked(addr), "should not have already been marked");
+// first mark it on the bitmap
+at_put(heapWordToOffset(addr), true);
+return true;
+} else {
+return false;
+}
+}
+inline bool isMarked(HeapWord* addr) {
+guarantee(use_local_bitmaps, "invariant");
+assert(fields_well_formed(), "invariant");
+return at(heapWordToOffset(addr));
+}
+void set_buffer(HeapWord* start) {
+guarantee(use_local_bitmaps, "invariant");
+clear();
+assert(start != NULL, "invariant");
+_real_start_word = start;
+_real_end_word   = start + _gclab_word_size;
+size_t diff =
+pointer_delta(start, _heap_start) % _bitmap_word_covers_words;
+_start_word = start - diff;
+assert(fields_well_formed(), "invariant");
+}
+#ifndef PRODUCT
+void verify() {
+// verify that the marks have been propagated
+GCLabBitMapClosure cl(_cm, this);
+iterate(&cl);
+}
+#endif // PRODUCT
+void retire() {
+guarantee(use_local_bitmaps, "invariant");
+assert(fields_well_formed(), "invariant");
+if (_start_word != NULL) {
+CMBitMap*       mark_bitmap = _cm->nextMarkBitMap();
+// this means that the bitmap was set up for the GCLab
+assert(_real_start_word != NULL && _real_end_word != NULL, "invariant");
+mark_bitmap->mostly_disjoint_range_union(this,
+0, // always start from the start of the bitmap
+_start_word,
+size_in_words());
+_cm->grayRegionIfNecessary(MemRegion(_real_start_word, _real_end_word));
+#ifndef PRODUCT
+if (use_local_bitmaps && verify_local_bitmaps)
+verify();
+#endif // PRODUCT
+} else {
+assert(_real_start_word == NULL && _real_end_word == NULL, "invariant");
+}
+}
+static size_t bitmap_size_in_words() {
+return (bitmap_size_in_bits() + BitsPerWord - 1) / BitsPerWord;
+}
+};
+#ifndef PRODUCT
+bool GCLabBitMapClosure::do_bit(size_t offset) {
+HeapWord* addr = _bitmap->offsetToHeapWord(offset);
+guarantee(_cm->isMarked(oop(addr)), "it should be!");
+return true;
+}
+#endif // PRODUCT
+class G1ParGCAllocBuffer: public ParGCAllocBuffer {
+private:
+bool        _retired;
+bool        _during_marking;
+GCLabBitMap _bitmap;
+public:
+G1ParGCAllocBuffer() :
+ParGCAllocBuffer(ParallelGCG1AllocBufferSize / HeapWordSize),
+_during_marking(G1CollectedHeap::heap()->mark_in_progress()),
+_bitmap(G1CollectedHeap::heap()->reserved_region().start()),
+_retired(false)
+{ }
+inline bool mark(HeapWord* addr) {
+guarantee(use_local_bitmaps, "invariant");
+assert(_during_marking, "invariant");
+return _bitmap.mark(addr);
+}
+inline void set_buf(HeapWord* buf) {
+if (use_local_bitmaps && _during_marking)
+_bitmap.set_buffer(buf);
+ParGCAllocBuffer::set_buf(buf);
+_retired = false;
+}
+inline void retire(bool end_of_gc, bool retain) {
+if (_retired)
+return;
+if (use_local_bitmaps && _during_marking) {
+_bitmap.retire();
+}
+ParGCAllocBuffer::retire(end_of_gc, retain);
+_retired = true;
+}
+};
+class G1ParScanThreadState : public StackObj {
+protected:
+G1CollectedHeap* _g1h;
+RefToScanQueue*  _refs;
+typedef GrowableArray<oop*> OverflowQueue;
+OverflowQueue* _overflowed_refs;
+G1ParGCAllocBuffer _alloc_buffers[GCAllocPurposeCount];
+size_t           _alloc_buffer_waste;
+size_t           _undo_waste;
+OopsInHeapRegionClosure*      _evac_failure_cl;
+G1ParScanHeapEvacClosure*     _evac_cl;
+G1ParScanPartialArrayClosure* _partial_scan_cl;
+int _hash_seed;
+int _queue_num;
+int _term_attempts;
+#if G1_DETAILED_STATS
+int _pushes, _pops, _steals, _steal_attempts;
+int _overflow_pushes;
+#endif
+double _start;
+double _start_strong_roots;
+double _strong_roots_time;
+double _start_term;
+double _term_time;
+// Map from young-age-index (0 == not young, 1 is youngest) to
+// surviving words. base is what we get back from the malloc call
+size_t* _surviving_young_words_base;
+// this points into the array, as we use the first few entries for padding
+size_t* _surviving_young_words;
+#define PADDING_ELEM_NUM (64 / sizeof(size_t))
+void   add_to_alloc_buffer_waste(size_t waste) { _alloc_buffer_waste += waste; }
+void   add_to_undo_waste(size_t waste)         { _undo_waste += waste; }
+public:
+G1ParScanThreadState(G1CollectedHeap* g1h, int queue_num)
+: _g1h(g1h),
+_refs(g1h->task_queue(queue_num)),
+_hash_seed(17), _queue_num(queue_num),
+_term_attempts(0),
+#if G1_DETAILED_STATS
+_pushes(0), _pops(0), _steals(0),
+_steal_attempts(0),  _overflow_pushes(0),
+#endif
+_strong_roots_time(0), _term_time(0),
+_alloc_buffer_waste(0), _undo_waste(0)
+{
+// we allocate G1YoungSurvRateNumRegions plus one entries, since
+// we "sacrifice" entry 0 to keep track of surviving bytes for
+// non-young regions (where the age is -1)
+// We also add a few elements at the beginning and at the end in
+// an attempt to eliminate cache contention
+size_t real_length = 1 + _g1h->g1_policy()->young_cset_length();
+size_t array_length = PADDING_ELEM_NUM +
+real_length +
+PADDING_ELEM_NUM;
+_surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length);
+if (_surviving_young_words_base == NULL)
+vm_exit_out_of_memory(array_length * sizeof(size_t),
+"Not enough space for young surv histo.");
+_surviving_young_words = _surviving_young_words_base + PADDING_ELEM_NUM;
+memset(_surviving_young_words, 0, real_length * sizeof(size_t));
+_overflowed_refs = new OverflowQueue(10);
+_start = os::elapsedTime();
+}
+~G1ParScanThreadState() {
+FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base);
+}
+RefToScanQueue*   refs()            { return _refs;             }
+OverflowQueue*    overflowed_refs() { return _overflowed_refs;  }
+inline G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose) {
+return &_alloc_buffers[purpose];
+}
+size_t alloc_buffer_waste()                    { return _alloc_buffer_waste; }
+size_t undo_waste()                            { return _undo_waste; }
+void push_on_queue(oop* ref) {
+if (!refs()->push(ref)) {
+overflowed_refs()->push(ref);
+IF_G1_DETAILED_STATS(note_overflow_push());
+} else {
+IF_G1_DETAILED_STATS(note_push());
+}
+}
+void pop_from_queue(oop*& ref) {
+if (!refs()->pop_local(ref)) {
+ref = NULL;
+} else {
+IF_G1_DETAILED_STATS(note_pop());
+}
+}
+void pop_from_overflow_queue(oop*& ref) {
+ref = overflowed_refs()->pop();
+}
+int refs_to_scan()                             { return refs()->size();                 }
+int overflowed_refs_to_scan()                  { return overflowed_refs()->length();    }
+HeapWord* allocate_slow(GCAllocPurpose purpose, size_t word_sz) {
+HeapWord* obj = NULL;
+if (word_sz * 100 <
+(size_t)(ParallelGCG1AllocBufferSize / HeapWordSize) *
+ParallelGCBufferWastePct) {
+G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose);
+add_to_alloc_buffer_waste(alloc_buf->words_remaining());
+alloc_buf->retire(false, false);
+HeapWord* buf =
+_g1h->par_allocate_during_gc(purpose, ParallelGCG1AllocBufferSize / HeapWordSize);
+if (buf == NULL) return NULL; // Let caller handle allocation failure.
+// Otherwise.
+alloc_buf->set_buf(buf);
+obj = alloc_buf->allocate(word_sz);
+assert(obj != NULL, "buffer was definitely big enough...");
+}
+else {
+obj = _g1h->par_allocate_during_gc(purpose, word_sz);
+}
+return obj;
+}
+HeapWord* allocate(GCAllocPurpose purpose, size_t word_sz) {
+HeapWord* obj = alloc_buffer(purpose)->allocate(word_sz);
+if (obj != NULL) return obj;
+return allocate_slow(purpose, word_sz);
+}
+void undo_allocation(GCAllocPurpose purpose, HeapWord* obj, size_t word_sz) {
+if (alloc_buffer(purpose)->contains(obj)) {
+guarantee(alloc_buffer(purpose)->contains(obj + word_sz - 1),
+"should contain whole object");
+alloc_buffer(purpose)->undo_allocation(obj, word_sz);
+}
+else {
+SharedHeap::fill_region_with_object(MemRegion(obj, word_sz));
+add_to_undo_waste(word_sz);
+}
+}
+void set_evac_failure_closure(OopsInHeapRegionClosure* evac_failure_cl) {
+_evac_failure_cl = evac_failure_cl;
+}
+OopsInHeapRegionClosure* evac_failure_closure() {
+return _evac_failure_cl;
+}
+void set_evac_closure(G1ParScanHeapEvacClosure* evac_cl) {
+_evac_cl = evac_cl;
+}
+void set_partial_scan_closure(G1ParScanPartialArrayClosure* partial_scan_cl) {
+_partial_scan_cl = partial_scan_cl;
+}
+int* hash_seed() { return &_hash_seed; }
+int  queue_num() { return _queue_num; }
+int term_attempts()   { return _term_attempts; }
+void note_term_attempt()  { _term_attempts++; }
+#if G1_DETAILED_STATS
+int pushes()          { return _pushes; }
+int pops()            { return _pops; }
+int steals()          { return _steals; }
+int steal_attempts()  { return _steal_attempts; }
+int overflow_pushes() { return _overflow_pushes; }
+void note_push()          { _pushes++; }
+void note_pop()           { _pops++; }
+void note_steal()         { _steals++; }
+void note_steal_attempt() { _steal_attempts++; }
+void note_overflow_push() { _overflow_pushes++; }
+#endif
+void start_strong_roots() {
+_start_strong_roots = os::elapsedTime();
+}
+void end_strong_roots() {
+_strong_roots_time += (os::elapsedTime() - _start_strong_roots);
+}
+double strong_roots_time() { return _strong_roots_time; }
+void start_term_time() {
+note_term_attempt();
+_start_term = os::elapsedTime();
+}
+void end_term_time() {
+_term_time += (os::elapsedTime() - _start_term);
+}
+double term_time() { return _term_time; }
+double elapsed() {
+return os::elapsedTime() - _start;
+}
+size_t* surviving_young_words() {
+// We add on to hide entry 0 which accumulates surviving words for
+// age -1 regions (i.e. non-young ones)
+return _surviving_young_words;
+}
+void retire_alloc_buffers() {
+for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
+size_t waste = _alloc_buffers[ap].words_remaining();
+add_to_alloc_buffer_waste(waste);
+_alloc_buffers[ap].retire(true, false);
+}
+}
+void trim_queue() {
+while (refs_to_scan() > 0 || overflowed_refs_to_scan() > 0) {
+oop *ref_to_scan = NULL;
+if (overflowed_refs_to_scan() == 0) {
+pop_from_queue(ref_to_scan);
+} else {
+pop_from_overflow_queue(ref_to_scan);
+}
+if (ref_to_scan != NULL) {
+if ((intptr_t)ref_to_scan & G1_PARTIAL_ARRAY_MASK) {
+_partial_scan_cl->do_oop_nv(ref_to_scan);
+} else {
+// Note: we can use "raw" versions of "region_containing" because
+// "obj_to_scan" is definitely in the heap, and is not in a
+// humongous region.
+HeapRegion* r = _g1h->heap_region_containing_raw(ref_to_scan);
+_evac_cl->set_region(r);
+_evac_cl->do_oop_nv(ref_to_scan);
+}
+}
+}
+}
+};
+G1ParClosureSuper::G1ParClosureSuper(G1CollectedHeap* g1, G1ParScanThreadState* par_scan_state) :
+_g1(g1), _g1_rem(_g1->g1_rem_set()), _cm(_g1->concurrent_mark()),
+_par_scan_state(par_scan_state) { }
+// This closure is applied to the fields of the objects that have just been copied.
+// Should probably be made inline and moved in g1OopClosures.inline.hpp.
+void G1ParScanClosure::do_oop_nv(oop* p) {
+oop obj = *p;
+if (obj != NULL) {
+if (_g1->obj_in_cs(obj)) {
+if (obj->is_forwarded()) {
+*p = obj->forwardee();
+} else {
+_par_scan_state->push_on_queue(p);
+return;
+}
+}
+_g1_rem->par_write_ref(_from, p, _par_scan_state->queue_num());
+}
+}
+void G1ParCopyHelper::mark_forwardee(oop* p) {
+// This is called _after_ do_oop_work has been called, hence after
+// the object has been relocated to its new location and *p points
+// to its new location.
+oop thisOop = *p;
+if (thisOop != NULL) {
+assert((_g1->evacuation_failed()) || (!_g1->obj_in_cs(thisOop)),
+"shouldn't still be in the CSet if evacuation didn't fail.");
+HeapWord* addr = (HeapWord*)thisOop;
+if (_g1->is_in_g1_reserved(addr))
+_cm->grayRoot(oop(addr));
+}
+}
+oop G1ParCopyHelper::copy_to_survivor_space(oop old) {
+size_t    word_sz = old->size();
+HeapRegion* from_region = _g1->heap_region_containing_raw(old);
+// +1 to make the -1 indexes valid...
+int       young_index = from_region->young_index_in_cset()+1;
+assert( (from_region->is_young() && young_index > 0) ||
+(!from_region->is_young() && young_index == 0), "invariant" );
+G1CollectorPolicy* g1p = _g1->g1_policy();
+markOop m = old->mark();
+GCAllocPurpose alloc_purpose = g1p->evacuation_destination(from_region, m->age(),
+word_sz);
+HeapWord* obj_ptr = _par_scan_state->allocate(alloc_purpose, word_sz);
+oop       obj     = oop(obj_ptr);
+if (obj_ptr == NULL) {
+// This will either forward-to-self, or detect that someone else has
+// installed a forwarding pointer.
+OopsInHeapRegionClosure* cl = _par_scan_state->evac_failure_closure();
+return _g1->handle_evacuation_failure_par(cl, old);
+}
+oop forward_ptr = old->forward_to_atomic(obj);
+if (forward_ptr == NULL) {
+Copy::aligned_disjoint_words((HeapWord*) old, obj_ptr, word_sz);
+obj->set_mark(m);
+if (g1p->track_object_age(alloc_purpose)) {
+obj->incr_age();
+}
+// preserve "next" mark bit
+if (_g1->mark_in_progress() && !_g1->is_obj_ill(old)) {
+if (!use_local_bitmaps ||
+!_par_scan_state->alloc_buffer(alloc_purpose)->mark(obj_ptr)) {
+// if we couldn't mark it on the local bitmap (this happens when
+// the object was not allocated in the GCLab), we have to bite
+// the bullet and do the standard parallel mark
+_cm->markAndGrayObjectIfNecessary(obj);
+}
+#if 1
+if (_g1->isMarkedNext(old)) {
+_cm->nextMarkBitMap()->parClear((HeapWord*)old);
+}
+#endif
+}
+size_t* surv_young_words = _par_scan_state->surviving_young_words();
+surv_young_words[young_index] += word_sz;
+if (obj->is_objArray() && arrayOop(obj)->length() >= ParGCArrayScanChunk) {
+arrayOop(old)->set_length(0);
+_par_scan_state->push_on_queue((oop*) ((intptr_t)old | G1_PARTIAL_ARRAY_MASK));
+} else {
+_scanner->set_region(_g1->heap_region_containing(obj));
+obj->oop_iterate_backwards(_scanner);
+}
+} else {
+_par_scan_state->undo_allocation(alloc_purpose, obj_ptr, word_sz);
+obj = forward_ptr;
+}
+return obj;
+}
+template<bool do_gen_barrier, G1Barrier barrier, bool do_mark_forwardee>
+void G1ParCopyClosure<do_gen_barrier, barrier, do_mark_forwardee>::do_oop_work(oop* p) {
+oop obj = *p;
+assert(barrier != G1BarrierRS || obj != NULL,
+"Precondition: G1BarrierRS implies obj is nonNull");
+if (obj != NULL) {
+if (_g1->obj_in_cs(obj)) {
+#if G1_REM_SET_LOGGING
+gclog_or_tty->print_cr("Loc "PTR_FORMAT" contains pointer "PTR_FORMAT" into CS.",
+p, (void*) obj);
+#endif
+if (obj->is_forwarded()) {
+*p = obj->forwardee();
+} else {
+*p = copy_to_survivor_space(obj);
+}
+// When scanning the RS, we only care about objs in CS.
+if (barrier == G1BarrierRS) {
+_g1_rem->par_write_ref(_from, p, _par_scan_state->queue_num());
+}
+}
+// When scanning moved objs, must look at all oops.
+if (barrier == G1BarrierEvac) {
+_g1_rem->par_write_ref(_from, p, _par_scan_state->queue_num());
+}
+if (do_gen_barrier) {
+par_do_barrier(p);
+}
+}
+}
+template void G1ParCopyClosure<false, G1BarrierEvac, false>::do_oop_work(oop* p);
+template <class T> void G1ParScanPartialArrayClosure::process_array_chunk(
+oop obj, int start, int end) {
+// process our set of indices (include header in first chunk)
+assert(start < end, "invariant");
+T* const base      = (T*)objArrayOop(obj)->base();
+T* const start_addr = base + start;
+T* const end_addr   = base + end;
+MemRegion mr((HeapWord*)start_addr, (HeapWord*)end_addr);
+_scanner.set_region(_g1->heap_region_containing(obj));
+obj->oop_iterate(&_scanner, mr);
+}
+void G1ParScanPartialArrayClosure::do_oop_nv(oop* p) {
+assert(!UseCompressedOops, "Needs to be fixed to work with compressed oops");
+oop old = oop((intptr_t)p & ~G1_PARTIAL_ARRAY_MASK);
+assert(old->is_objArray(), "must be obj array");
+assert(old->is_forwarded(), "must be forwarded");
+assert(Universe::heap()->is_in_reserved(old), "must be in heap.");
+objArrayOop obj = objArrayOop(old->forwardee());
+assert((void*)old != (void*)old->forwardee(), "self forwarding here?");
+// Process ParGCArrayScanChunk elements now
+// and push the remainder back onto queue
+int start     = arrayOop(old)->length();
+int end       = obj->length();
+int remainder = end - start;
+assert(start <= end, "just checking");
+if (remainder > 2 * ParGCArrayScanChunk) {
+// Test above combines last partial chunk with a full chunk
+end = start + ParGCArrayScanChunk;
+arrayOop(old)->set_length(end);
+// Push remainder.
+_par_scan_state->push_on_queue((oop*) ((intptr_t) old | G1_PARTIAL_ARRAY_MASK));
+} else {
+// Restore length so that the heap remains parsable in
+// case of evacuation failure.
+arrayOop(old)->set_length(end);
+}
+// process our set of indices (include header in first chunk)
+process_array_chunk<oop>(obj, start, end);
+oop* start_addr = start == 0 ? (oop*)obj : obj->obj_at_addr<oop>(start);
+oop* end_addr   = (oop*)(obj->base()) + end; // obj_at_addr(end) asserts end < length
+MemRegion mr((HeapWord*)start_addr, (HeapWord*)end_addr);
+_scanner.set_region(_g1->heap_region_containing(obj));
+obj->oop_iterate(&_scanner, mr);
+}
+int G1ScanAndBalanceClosure::_nq = 0;
+class G1ParEvacuateFollowersClosure : public VoidClosure {
+protected:
+G1CollectedHeap*              _g1h;
+G1ParScanThreadState*         _par_scan_state;
+RefToScanQueueSet*            _queues;
+ParallelTaskTerminator*       _terminator;
+G1ParScanThreadState*   par_scan_state() { return _par_scan_state; }
+RefToScanQueueSet*      queues()         { return _queues; }
+ParallelTaskTerminator* terminator()     { return _terminator; }
+public:
+G1ParEvacuateFollowersClosure(G1CollectedHeap* g1h,
+G1ParScanThreadState* par_scan_state,
+RefToScanQueueSet* queues,
+ParallelTaskTerminator* terminator)
+: _g1h(g1h), _par_scan_state(par_scan_state),
+_queues(queues), _terminator(terminator) {}
+void do_void() {
+G1ParScanThreadState* pss = par_scan_state();
+while (true) {
+oop* ref_to_scan;
+pss->trim_queue();
+IF_G1_DETAILED_STATS(pss->note_steal_attempt());
+if (queues()->steal(pss->queue_num(),
+pss->hash_seed(),
+ref_to_scan)) {
+IF_G1_DETAILED_STATS(pss->note_steal());
+pss->push_on_queue(ref_to_scan);
+continue;
+}
+pss->start_term_time();
+if (terminator()->offer_termination()) break;
+pss->end_term_time();
+}
+pss->end_term_time();
+pss->retire_alloc_buffers();
+}
+};
+class G1ParTask : public AbstractGangTask {
+protected:
+G1CollectedHeap*       _g1h;
+RefToScanQueueSet      *_queues;
+ParallelTaskTerminator _terminator;
+Mutex _stats_lock;
+Mutex* stats_lock() { return &_stats_lock; }
+size_t getNCards() {
+return (_g1h->capacity() + G1BlockOffsetSharedArray::N_bytes - 1)
+/ G1BlockOffsetSharedArray::N_bytes;
+}
+public:
+G1ParTask(G1CollectedHeap* g1h, int workers, RefToScanQueueSet *task_queues)
+: AbstractGangTask("G1 collection"),
+_g1h(g1h),
+_queues(task_queues),
+_terminator(workers, _queues),
+_stats_lock(Mutex::leaf, "parallel G1 stats lock", true)
+{}
+RefToScanQueueSet* queues() { return _queues; }
+RefToScanQueue *work_queue(int i) {
+return queues()->queue(i);
+}
+void work(int i) {
+ResourceMark rm;
+HandleMark   hm;
+G1ParScanThreadState pss(_g1h, i);
+G1ParScanHeapEvacClosure     scan_evac_cl(_g1h, &pss);
+G1ParScanHeapEvacClosure     evac_failure_cl(_g1h, &pss);
+G1ParScanPartialArrayClosure partial_scan_cl(_g1h, &pss);
+pss.set_evac_closure(&scan_evac_cl);
+pss.set_evac_failure_closure(&evac_failure_cl);
+pss.set_partial_scan_closure(&partial_scan_cl);
+G1ParScanExtRootClosure         only_scan_root_cl(_g1h, &pss);
+G1ParScanPermClosure            only_scan_perm_cl(_g1h, &pss);
+G1ParScanHeapRSClosure          only_scan_heap_rs_cl(_g1h, &pss);
+G1ParScanAndMarkExtRootClosure  scan_mark_root_cl(_g1h, &pss);
+G1ParScanAndMarkPermClosure     scan_mark_perm_cl(_g1h, &pss);
+G1ParScanAndMarkHeapRSClosure   scan_mark_heap_rs_cl(_g1h, &pss);
+OopsInHeapRegionClosure        *scan_root_cl;
+OopsInHeapRegionClosure        *scan_perm_cl;
+OopsInHeapRegionClosure        *scan_so_cl;
+if (_g1h->g1_policy()->should_initiate_conc_mark()) {
+scan_root_cl = &scan_mark_root_cl;
+scan_perm_cl = &scan_mark_perm_cl;
+scan_so_cl   = &scan_mark_heap_rs_cl;
+} else {
+scan_root_cl = &only_scan_root_cl;
+scan_perm_cl = &only_scan_perm_cl;
+scan_so_cl   = &only_scan_heap_rs_cl;
+}
+pss.start_strong_roots();
+_g1h->g1_process_strong_roots(/* not collecting perm */ false,
+SharedHeap::SO_AllClasses,
+scan_root_cl,
+&only_scan_heap_rs_cl,
+scan_so_cl,
+scan_perm_cl,
+i);
+pss.end_strong_roots();
+{
+double start = os::elapsedTime();
+G1ParEvacuateFollowersClosure evac(_g1h, &pss, _queues, &_terminator);
+evac.do_void();
+double elapsed_ms = (os::elapsedTime()-start)*1000.0;
+double term_ms = pss.term_time()*1000.0;
+_g1h->g1_policy()->record_obj_copy_time(i, elapsed_ms-term_ms);
+_g1h->g1_policy()->record_termination_time(i, term_ms);
+}
+_g1h->update_surviving_young_words(pss.surviving_young_words()+1);
+// Clean up any par-expanded rem sets.
+HeapRegionRemSet::par_cleanup();
+MutexLocker x(stats_lock());
+if (ParallelGCVerbose) {
+gclog_or_tty->print("Thread %d complete:\n", i);
+#if G1_DETAILED_STATS
+gclog_or_tty->print("  Pushes: %7d    Pops: %7d   Overflows: %7d   Steals %7d (in %d attempts)\n",
+pss.pushes(),
+pss.pops(),
+pss.overflow_pushes(),
+pss.steals(),
+pss.steal_attempts());
+#endif
+double elapsed      = pss.elapsed();
+double strong_roots = pss.strong_roots_time();
+double term         = pss.term_time();
+gclog_or_tty->print("  Elapsed: %7.2f ms.\n"
+"    Strong roots: %7.2f ms (%6.2f%%)\n"
+"    Termination:  %7.2f ms (%6.2f%%) (in %d entries)\n",
+elapsed * 1000.0,
+strong_roots * 1000.0, (strong_roots*100.0/elapsed),
+term * 1000.0, (term*100.0/elapsed),
+pss.term_attempts());
+size_t total_waste = pss.alloc_buffer_waste() + pss.undo_waste();
+gclog_or_tty->print("  Waste: %8dK\n"
+"    Alloc Buffer: %8dK\n"
+"    Undo: %8dK\n",
+(total_waste * HeapWordSize) / K,
+(pss.alloc_buffer_waste() * HeapWordSize) / K,
+(pss.undo_waste() * HeapWordSize) / K);
+}
+assert(pss.refs_to_scan() == 0, "Task queue should be empty");
+assert(pss.overflowed_refs_to_scan() == 0, "Overflow queue should be empty");
+}
+};
+// *** Common G1 Evacuation Stuff
+class G1CountClosure: public OopsInHeapRegionClosure {
+public:
+int n;
+G1CountClosure() : n(0) {}
+void do_oop(narrowOop* p) {
+guarantee(false, "NYI");
+}
+void do_oop(oop* p) {
+oop obj = *p;
+assert(obj != NULL && G1CollectedHeap::heap()->obj_in_cs(obj),
+"Rem set closure called on non-rem-set pointer.");
+n++;
+}
+};
+static G1CountClosure count_closure;
+void
+G1CollectedHeap::
+g1_process_strong_roots(bool collecting_perm_gen,
+SharedHeap::ScanningOption so,
+OopClosure* scan_non_heap_roots,
+OopsInHeapRegionClosure* scan_rs,
+OopsInHeapRegionClosure* scan_so,
+OopsInGenClosure* scan_perm,
+int worker_i) {
+// First scan the strong roots, including the perm gen.
+double ext_roots_start = os::elapsedTime();
+double closure_app_time_sec = 0.0;
+BufferingOopClosure buf_scan_non_heap_roots(scan_non_heap_roots);
+BufferingOopsInGenClosure buf_scan_perm(scan_perm);
+buf_scan_perm.set_generation(perm_gen());
+process_strong_roots(collecting_perm_gen, so,
+&buf_scan_non_heap_roots,
+&buf_scan_perm);
+// Finish up any enqueued closure apps.
+buf_scan_non_heap_roots.done();
+buf_scan_perm.done();
+double ext_roots_end = os::elapsedTime();
+g1_policy()->reset_obj_copy_time(worker_i);
+double obj_copy_time_sec =
+buf_scan_non_heap_roots.closure_app_seconds() +
+buf_scan_perm.closure_app_seconds();
+g1_policy()->record_obj_copy_time(worker_i, obj_copy_time_sec * 1000.0);
+double ext_root_time_ms =
+((ext_roots_end - ext_roots_start) - obj_copy_time_sec) * 1000.0;
+g1_policy()->record_ext_root_scan_time(worker_i, ext_root_time_ms);
+// Scan strong roots in mark stack.
+if (!_process_strong_tasks->is_task_claimed(G1H_PS_mark_stack_oops_do)) {
+concurrent_mark()->oops_do(scan_non_heap_roots);
+}
+double mark_stack_scan_ms = (os::elapsedTime() - ext_roots_end) * 1000.0;
+g1_policy()->record_mark_stack_scan_time(worker_i, mark_stack_scan_ms);
+// XXX What should this be doing in the parallel case?
+g1_policy()->record_collection_pause_end_CH_strong_roots();
+if (G1VerifyRemSet) {
+// :::: FIXME ::::
+// The stupid remembered set doesn't know how to filter out dead
+// objects, which the smart one does, and so when it is created
+// and then compared the number of entries in each differs and
+// the verification code fails.
+guarantee(false, "verification code is broken, see note");
+// Let's make sure that the current rem set agrees with the stupidest
+// one possible!
+bool refs_enabled = ref_processor()->discovery_enabled();
+if (refs_enabled) ref_processor()->disable_discovery();
+StupidG1RemSet stupid(this);
+count_closure.n = 0;
+stupid.oops_into_collection_set_do(&count_closure, worker_i);
+int stupid_n = count_closure.n;
+count_closure.n = 0;
+g1_rem_set()->oops_into_collection_set_do(&count_closure, worker_i);
+guarantee(count_closure.n == stupid_n, "Old and new rem sets differ.");
+gclog_or_tty->print_cr("\nFound %d pointers in heap RS.", count_closure.n);
+if (refs_enabled) ref_processor()->enable_discovery();
+}
+if (scan_so != NULL) {
+scan_scan_only_set(scan_so, worker_i);
+}
+// Now scan the complement of the collection set.
+if (scan_rs != NULL) {
+g1_rem_set()->oops_into_collection_set_do(scan_rs, worker_i);
+}
+// Finish with the ref_processor roots.
+if (!_process_strong_tasks->is_task_claimed(G1H_PS_refProcessor_oops_do)) {
+ref_processor()->oops_do(scan_non_heap_roots);
+}
+g1_policy()->record_collection_pause_end_G1_strong_roots();
+_process_strong_tasks->all_tasks_completed();
+}
+void
+G1CollectedHeap::scan_scan_only_region(HeapRegion* r,
+OopsInHeapRegionClosure* oc,
+int worker_i) {
+HeapWord* startAddr = r->bottom();
+HeapWord* endAddr = r->used_region().end();
+oc->set_region(r);
+HeapWord* p = r->bottom();
+HeapWord* t = r->top();
+guarantee( p == r->next_top_at_mark_start(), "invariant" );
+while (p < t) {
+oop obj = oop(p);
+p += obj->oop_iterate(oc);
+}
+}
+void
+G1CollectedHeap::scan_scan_only_set(OopsInHeapRegionClosure* oc,
+int worker_i) {
+double start = os::elapsedTime();
+BufferingOopsInHeapRegionClosure boc(oc);
+FilterInHeapRegionAndIntoCSClosure scan_only(this, &boc);
+FilterAndMarkInHeapRegionAndIntoCSClosure scan_and_mark(this, &boc, concurrent_mark());
+OopsInHeapRegionClosure *foc;
+if (g1_policy()->should_initiate_conc_mark())
+foc = &scan_and_mark;
+else
+foc = &scan_only;
+HeapRegion* hr;
+int n = 0;
+while ((hr = _young_list->par_get_next_scan_only_region()) != NULL) {
+scan_scan_only_region(hr, foc, worker_i);
+++n;
+}
+boc.done();
+double closure_app_s = boc.closure_app_seconds();
+g1_policy()->record_obj_copy_time(worker_i, closure_app_s * 1000.0);
+double ms = (os::elapsedTime() - start - closure_app_s)*1000.0;
+g1_policy()->record_scan_only_time(worker_i, ms, n);
+}
+void
+G1CollectedHeap::g1_process_weak_roots(OopClosure* root_closure,
+OopClosure* non_root_closure) {
+SharedHeap::process_weak_roots(root_closure, non_root_closure);
+}
+class SaveMarksClosure: public HeapRegionClosure {
+public:
+bool doHeapRegion(HeapRegion* r) {
+r->save_marks();
+return false;
+}
+};
+void G1CollectedHeap::save_marks() {
+if (ParallelGCThreads == 0) {
+SaveMarksClosure sm;
+heap_region_iterate(&sm);
+}
+// We do this even in the parallel case
+perm_gen()->save_marks();
+}
+void G1CollectedHeap::evacuate_collection_set() {
+set_evacuation_failed(false);
+g1_rem_set()->prepare_for_oops_into_collection_set_do();
+concurrent_g1_refine()->set_use_cache(false);
+int n_workers = (ParallelGCThreads > 0 ? workers()->total_workers() : 1);
+set_par_threads(n_workers);
+G1ParTask g1_par_task(this, n_workers, _task_queues);
+init_for_evac_failure(NULL);
+change_strong_roots_parity();  // In preparation for parallel strong roots.
+rem_set()->prepare_for_younger_refs_iterate(true);
+double start_par = os::elapsedTime();
+if (ParallelGCThreads > 0) {
+// The individual threads will set their evac-failure closures.
+workers()->run_task(&g1_par_task);
+} else {
+g1_par_task.work(0);
+}
+double par_time = (os::elapsedTime() - start_par) * 1000.0;
+g1_policy()->record_par_time(par_time);
+set_par_threads(0);
+// Is this the right thing to do here?  We don't save marks
+// on individual heap regions when we allocate from
+// them in parallel, so this seems like the correct place for this.
+all_alloc_regions_note_end_of_copying();
+{
+G1IsAliveClosure is_alive(this);
+G1KeepAliveClosure keep_alive(this);
+JNIHandles::weak_oops_do(&is_alive, &keep_alive);
+}
+g1_rem_set()->cleanup_after_oops_into_collection_set_do();
+concurrent_g1_refine()->set_use_cache(true);
+finalize_for_evac_failure();
+// Must do this before removing self-forwarding pointers, which clears
+// the per-region evac-failure flags.
+concurrent_mark()->complete_marking_in_collection_set();
+if (evacuation_failed()) {
+remove_self_forwarding_pointers();
+if (PrintGCDetails) {
+gclog_or_tty->print(" (evacuation failed)");
+} else if (PrintGC) {
+gclog_or_tty->print("--");
+}
+}
+COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
+}
+void G1CollectedHeap::free_region(HeapRegion* hr) {
+size_t pre_used = 0;
+size_t cleared_h_regions = 0;
+size_t freed_regions = 0;
+UncleanRegionList local_list;
+HeapWord* start = hr->bottom();
+HeapWord* end   = hr->prev_top_at_mark_start();
+size_t used_bytes = hr->used();
+size_t live_bytes = hr->max_live_bytes();
+if (used_bytes > 0) {
+guarantee( live_bytes <= used_bytes, "invariant" );
+} else {
+guarantee( live_bytes == 0, "invariant" );
+}
+size_t garbage_bytes = used_bytes - live_bytes;
+if (garbage_bytes > 0)
+g1_policy()->decrease_known_garbage_bytes(garbage_bytes);
+free_region_work(hr, pre_used, cleared_h_regions, freed_regions,
+&local_list);
+finish_free_region_work(pre_used, cleared_h_regions, freed_regions,
+&local_list);
+}
+void
+G1CollectedHeap::free_region_work(HeapRegion* hr,
+size_t& pre_used,
+size_t& cleared_h_regions,
+size_t& freed_regions,
+UncleanRegionList* list,
+bool par) {
+assert(!hr->popular(), "should not free popular regions");
+pre_used += hr->used();
+if (hr->isHumongous()) {
+assert(hr->startsHumongous(),
+"Only the start of a humongous region should be freed.");
+int ind = _hrs->find(hr);
+assert(ind != -1, "Should have an index.");
+// Clear the start region.
+hr->hr_clear(par, true /*clear_space*/);
+list->insert_before_head(hr);
+cleared_h_regions++;
+freed_regions++;
+// Clear any continued regions.
+ind++;
+while ((size_t)ind < n_regions()) {
+HeapRegion* hrc = _hrs->at(ind);
+if (!hrc->continuesHumongous()) break;
+// Otherwise, does continue the H region.
+assert(hrc->humongous_start_region() == hr, "Huh?");
+hrc->hr_clear(par, true /*clear_space*/);
+cleared_h_regions++;
+freed_regions++;
+list->insert_before_head(hrc);
+ind++;
+}
+} else {
+hr->hr_clear(par, true /*clear_space*/);
+list->insert_before_head(hr);
+freed_regions++;
+// If we're using clear2, this should not be enabled.
+// assert(!hr->in_cohort(), "Can't be both free and in a cohort.");
+}
+}
+void G1CollectedHeap::finish_free_region_work(size_t pre_used,
+size_t cleared_h_regions,
+size_t freed_regions,
+UncleanRegionList* list) {
+if (list != NULL && list->sz() > 0) {
+prepend_region_list_on_unclean_list(list);
+}
+// Acquire a lock, if we're parallel, to update possibly-shared
+// variables.
+Mutex* lock = (n_par_threads() > 0) ? ParGCRareEvent_lock : NULL;
+{
+MutexLockerEx x(lock, Mutex::_no_safepoint_check_flag);
+_summary_bytes_used -= pre_used;
+_num_humongous_regions -= (int) cleared_h_regions;
+_free_regions += freed_regions;
+}
+}
+void G1CollectedHeap::dirtyCardsForYoungRegions(CardTableModRefBS* ct_bs, HeapRegion* list) {
+while (list != NULL) {
+guarantee( list->is_young(), "invariant" );
+HeapWord* bottom = list->bottom();
+HeapWord* end = list->end();
+MemRegion mr(bottom, end);
+ct_bs->dirty(mr);
+list = list->get_next_young_region();
+}
+}
+void G1CollectedHeap::cleanUpCardTable() {
+CardTableModRefBS* ct_bs = (CardTableModRefBS*) (barrier_set());
+double start = os::elapsedTime();
+ct_bs->clear(_g1_committed);
+// now, redirty the cards of the scan-only and survivor regions
+// (it seemed faster to do it this way, instead of iterating over
+// all regions and then clearing / dirtying as approprite)
+dirtyCardsForYoungRegions(ct_bs, _young_list->first_scan_only_region());
+dirtyCardsForYoungRegions(ct_bs, _young_list->first_survivor_region());
+double elapsed = os::elapsedTime() - start;
+g1_policy()->record_clear_ct_time( elapsed * 1000.0);
+}
+void G1CollectedHeap::do_collection_pause_if_appropriate(size_t word_size) {
+// First do any popular regions.
+HeapRegion* hr;
+while ((hr = popular_region_to_evac()) != NULL) {
+evac_popular_region(hr);
+}
+// Now do heuristic pauses.
+if (g1_policy()->should_do_collection_pause(word_size)) {
+do_collection_pause();
+}
+}
+void G1CollectedHeap::free_collection_set(HeapRegion* cs_head) {
+double young_time_ms     = 0.0;
+double non_young_time_ms = 0.0;
+G1CollectorPolicy* policy = g1_policy();
+double start_sec = os::elapsedTime();
+bool non_young = true;
+HeapRegion* cur = cs_head;
+int age_bound = -1;
+size_t rs_lengths = 0;
+while (cur != NULL) {
+if (non_young) {
+if (cur->is_young()) {
+double end_sec = os::elapsedTime();
+double elapsed_ms = (end_sec - start_sec) * 1000.0;
+non_young_time_ms += elapsed_ms;
+start_sec = os::elapsedTime();
+non_young = false;
+}
+} else {
+if (!cur->is_on_free_list()) {
+double end_sec = os::elapsedTime();
+double elapsed_ms = (end_sec - start_sec) * 1000.0;
+young_time_ms += elapsed_ms;
+start_sec = os::elapsedTime();
+non_young = true;
+}
+}
+rs_lengths += cur->rem_set()->occupied();
+HeapRegion* next = cur->next_in_collection_set();
+assert(cur->in_collection_set(), "bad CS");
+cur->set_next_in_collection_set(NULL);
+cur->set_in_collection_set(false);
+if (cur->is_young()) {
+int index = cur->young_index_in_cset();
+guarantee( index != -1, "invariant" );
+guarantee( (size_t)index < policy->young_cset_length(), "invariant" );
+size_t words_survived = _surviving_young_words[index];
+cur->record_surv_words_in_group(words_survived);
+} else {
+int index = cur->young_index_in_cset();
+guarantee( index == -1, "invariant" );
+}
+assert( (cur->is_young() && cur->young_index_in_cset() > -1) ||
+(!cur->is_young() && cur->young_index_in_cset() == -1),
+"invariant" );
+if (!cur->evacuation_failed()) {
+// And the region is empty.
+assert(!cur->is_empty(),
+"Should not have empty regions in a CS.");
+free_region(cur);
+} else {
+guarantee( !cur->is_scan_only(), "should not be scan only" );
+cur->uninstall_surv_rate_group();
+if (cur->is_young())
+cur->set_young_index_in_cset(-1);
+cur->set_not_young();
+cur->set_evacuation_failed(false);
+}
+cur = next;
+}
+policy->record_max_rs_lengths(rs_lengths);
+policy->cset_regions_freed();
+double end_sec = os::elapsedTime();
+double elapsed_ms = (end_sec - start_sec) * 1000.0;
+if (non_young)
+non_young_time_ms += elapsed_ms;
+else
+young_time_ms += elapsed_ms;
+policy->record_young_free_cset_time_ms(young_time_ms);
+policy->record_non_young_free_cset_time_ms(non_young_time_ms);
+}
+HeapRegion*
+G1CollectedHeap::alloc_region_from_unclean_list_locked(bool zero_filled) {
+assert(ZF_mon->owned_by_self(), "Precondition");
+HeapRegion* res = pop_unclean_region_list_locked();
+if (res != NULL) {
+assert(!res->continuesHumongous() &&
+res->zero_fill_state() != HeapRegion::Allocated,
+"Only free regions on unclean list.");
+if (zero_filled) {
+res->ensure_zero_filled_locked();
+res->set_zero_fill_allocated();
+}
+}
+return res;
+}
+HeapRegion* G1CollectedHeap::alloc_region_from_unclean_list(bool zero_filled) {
+MutexLockerEx zx(ZF_mon, Mutex::_no_safepoint_check_flag);
+return alloc_region_from_unclean_list_locked(zero_filled);
+}
+void G1CollectedHeap::put_region_on_unclean_list(HeapRegion* r) {
+MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag);
+put_region_on_unclean_list_locked(r);
+if (should_zf()) ZF_mon->notify_all(); // Wake up ZF thread.
+}
+void G1CollectedHeap::set_unclean_regions_coming(bool b) {
+MutexLockerEx x(Cleanup_mon);
+set_unclean_regions_coming_locked(b);
+}
+void G1CollectedHeap::set_unclean_regions_coming_locked(bool b) {
+assert(Cleanup_mon->owned_by_self(), "Precondition");
+_unclean_regions_coming = b;
+// Wake up mutator threads that might be waiting for completeCleanup to
+// finish.
+if (!b) Cleanup_mon->notify_all();
+}
+void G1CollectedHeap::wait_for_cleanup_complete() {
+MutexLockerEx x(Cleanup_mon);
+wait_for_cleanup_complete_locked();
+}
+void G1CollectedHeap::wait_for_cleanup_complete_locked() {
+assert(Cleanup_mon->owned_by_self(), "precondition");
+while (_unclean_regions_coming) {
+Cleanup_mon->wait();
+}
+}
+void
+G1CollectedHeap::put_region_on_unclean_list_locked(HeapRegion* r) {
+assert(ZF_mon->owned_by_self(), "precondition.");
+_unclean_region_list.insert_before_head(r);
+}
+void
+G1CollectedHeap::prepend_region_list_on_unclean_list(UncleanRegionList* list) {
+MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag);
+prepend_region_list_on_unclean_list_locked(list);
+if (should_zf()) ZF_mon->notify_all(); // Wake up ZF thread.
+}
+void
+G1CollectedHeap::
+prepend_region_list_on_unclean_list_locked(UncleanRegionList* list) {
+assert(ZF_mon->owned_by_self(), "precondition.");
+_unclean_region_list.prepend_list(list);
+}
+HeapRegion* G1CollectedHeap::pop_unclean_region_list_locked() {
+assert(ZF_mon->owned_by_self(), "precondition.");
+HeapRegion* res = _unclean_region_list.pop();
+if (res != NULL) {
+// Inform ZF thread that there's a new unclean head.
+if (_unclean_region_list.hd() != NULL && should_zf())
+ZF_mon->notify_all();
+}
+return res;
+}
+HeapRegion* G1CollectedHeap::peek_unclean_region_list_locked() {
+assert(ZF_mon->owned_by_self(), "precondition.");
+return _unclean_region_list.hd();
+}
+bool G1CollectedHeap::move_cleaned_region_to_free_list_locked() {
+assert(ZF_mon->owned_by_self(), "Precondition");
+HeapRegion* r = peek_unclean_region_list_locked();
+if (r != NULL && r->zero_fill_state() == HeapRegion::ZeroFilled) {
+// Result of below must be equal to "r", since we hold the lock.
+(void)pop_unclean_region_list_locked();
+put_free_region_on_list_locked(r);
+return true;
+} else {
+return false;
+}
+}
+bool G1CollectedHeap::move_cleaned_region_to_free_list() {
+MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag);
+return move_cleaned_region_to_free_list_locked();
+}
+void G1CollectedHeap::put_free_region_on_list_locked(HeapRegion* r) {
+assert(ZF_mon->owned_by_self(), "precondition.");
+assert(_free_region_list_size == free_region_list_length(), "Inv");
+assert(r->zero_fill_state() == HeapRegion::ZeroFilled,
+"Regions on free list must be zero filled");
+assert(!r->isHumongous(), "Must not be humongous.");
+assert(r->is_empty(), "Better be empty");
+assert(!r->is_on_free_list(),
+"Better not already be on free list");
+assert(!r->is_on_unclean_list(),
+"Better not already be on unclean list");
+r->set_on_free_list(true);
+r->set_next_on_free_list(_free_region_list);
+_free_region_list = r;
+_free_region_list_size++;
+assert(_free_region_list_size == free_region_list_length(), "Inv");
+}
+void G1CollectedHeap::put_free_region_on_list(HeapRegion* r) {
+MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag);
+put_free_region_on_list_locked(r);
+}
+HeapRegion* G1CollectedHeap::pop_free_region_list_locked() {
+assert(ZF_mon->owned_by_self(), "precondition.");
+assert(_free_region_list_size == free_region_list_length(), "Inv");
+HeapRegion* res = _free_region_list;
+if (res != NULL) {
+_free_region_list = res->next_from_free_list();
+_free_region_list_size--;
+res->set_on_free_list(false);
+res->set_next_on_free_list(NULL);
+assert(_free_region_list_size == free_region_list_length(), "Inv");
+}
+return res;
+}
+HeapRegion* G1CollectedHeap::alloc_free_region_from_lists(bool zero_filled) {
+// By self, or on behalf of self.
+assert(Heap_lock->is_locked(), "Precondition");
+HeapRegion* res = NULL;
+bool first = true;
+while (res == NULL) {
+if (zero_filled || !first) {
+MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag);
+res = pop_free_region_list_locked();
+if (res != NULL) {
+assert(!res->zero_fill_is_allocated(),
+"No allocated regions on free list.");
+res->set_zero_fill_allocated();
+} else if (!first) {
+break;  // We tried both, time to return NULL.
+}
+}
+if (res == NULL) {
+res = alloc_region_from_unclean_list(zero_filled);
+}
+assert(res == NULL ||
+!zero_filled ||
+res->zero_fill_is_allocated(),
+"We must have allocated the region we're returning");
+first = false;
+}
+return res;
+}
+void G1CollectedHeap::remove_allocated_regions_from_lists() {
+MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag);
+{
+HeapRegion* prev = NULL;
+HeapRegion* cur = _unclean_region_list.hd();
+while (cur != NULL) {
+HeapRegion* next = cur->next_from_unclean_list();
+if (cur->zero_fill_is_allocated()) {
+// Remove from the list.
+if (prev == NULL) {
+(void)_unclean_region_list.pop();
+} else {
+_unclean_region_list.delete_after(prev);
+}
+cur->set_on_unclean_list(false);
+cur->set_next_on_unclean_list(NULL);
+} else {
+prev = cur;
+}
+cur = next;
+}
+assert(_unclean_region_list.sz() == unclean_region_list_length(),
+"Inv");
+}
+{
+HeapRegion* prev = NULL;
+HeapRegion* cur = _free_region_list;
+while (cur != NULL) {
+HeapRegion* next = cur->next_from_free_list();
+if (cur->zero_fill_is_allocated()) {
+// Remove from the list.
+if (prev == NULL) {
+_free_region_list = cur->next_from_free_list();
+} else {
+prev->set_next_on_free_list(cur->next_from_free_list());
+}
+cur->set_on_free_list(false);
+cur->set_next_on_free_list(NULL);
+_free_region_list_size--;
+} else {
+prev = cur;
+}
+cur = next;
+}
+assert(_free_region_list_size == free_region_list_length(), "Inv");
+}
+}
+bool G1CollectedHeap::verify_region_lists() {
+MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag);
+return verify_region_lists_locked();
+}
+bool G1CollectedHeap::verify_region_lists_locked() {
+HeapRegion* unclean = _unclean_region_list.hd();
+while (unclean != NULL) {
+guarantee(unclean->is_on_unclean_list(), "Well, it is!");
+guarantee(!unclean->is_on_free_list(), "Well, it shouldn't be!");
+guarantee(unclean->zero_fill_state() != HeapRegion::Allocated,
+"Everything else is possible.");
+unclean = unclean->next_from_unclean_list();
+}
+guarantee(_unclean_region_list.sz() == unclean_region_list_length(), "Inv");
+HeapRegion* free_r = _free_region_list;
+while (free_r != NULL) {
+assert(free_r->is_on_free_list(), "Well, it is!");
+assert(!free_r->is_on_unclean_list(), "Well, it shouldn't be!");
+switch (free_r->zero_fill_state()) {
+case HeapRegion::NotZeroFilled:
+case HeapRegion::ZeroFilling:
+guarantee(false, "Should not be on free list.");
+break;
+default:
+// Everything else is possible.
+break;
+}
+free_r = free_r->next_from_free_list();
+}
+guarantee(_free_region_list_size == free_region_list_length(), "Inv");
+// If we didn't do an assertion...
+return true;
+}
+size_t G1CollectedHeap::free_region_list_length() {
+assert(ZF_mon->owned_by_self(), "precondition.");
+size_t len = 0;
+HeapRegion* cur = _free_region_list;
+while (cur != NULL) {
+len++;
+cur = cur->next_from_free_list();
+}
+return len;
+}
+size_t G1CollectedHeap::unclean_region_list_length() {
+assert(ZF_mon->owned_by_self(), "precondition.");
+return _unclean_region_list.length();
+}
+size_t G1CollectedHeap::n_regions() {
+return _hrs->length();
+}
+size_t G1CollectedHeap::max_regions() {
+return
+(size_t)align_size_up(g1_reserved_obj_bytes(), HeapRegion::GrainBytes) /
+HeapRegion::GrainBytes;
+}
+size_t G1CollectedHeap::free_regions() {
+/* Possibly-expensive assert.
+assert(_free_regions == count_free_regions(),
+"_free_regions is off.");
+*/
+return _free_regions;
+}
+bool G1CollectedHeap::should_zf() {
+return _free_region_list_size < (size_t) G1ConcZFMaxRegions;
+}
+class RegionCounter: public HeapRegionClosure {
+size_t _n;
+public:
+RegionCounter() : _n(0) {}
+bool doHeapRegion(HeapRegion* r) {
+if (r->is_empty() && !r->popular()) {
+assert(!r->isHumongous(), "H regions should not be empty.");
+_n++;
+}
+return false;
+}
+int res() { return (int) _n; }
+};
+size_t G1CollectedHeap::count_free_regions() {
+RegionCounter rc;
+heap_region_iterate(&rc);
+size_t n = rc.res();
+if (_cur_alloc_region != NULL && _cur_alloc_region->is_empty())
+n--;
+return n;
+}
+size_t G1CollectedHeap::count_free_regions_list() {
+size_t n = 0;
+size_t o = 0;
+ZF_mon->lock_without_safepoint_check();
+HeapRegion* cur = _free_region_list;
+while (cur != NULL) {
+cur = cur->next_from_free_list();
+n++;
+}
+size_t m = unclean_region_list_length();
+ZF_mon->unlock();
+return n + m;
+}
+bool G1CollectedHeap::should_set_young_locked() {
+assert(heap_lock_held_for_gc(),
+"the heap lock should already be held by or for this thread");
+return  (g1_policy()->in_young_gc_mode() &&
+g1_policy()->should_add_next_region_to_young_list());
+}
+void G1CollectedHeap::set_region_short_lived_locked(HeapRegion* hr) {
+assert(heap_lock_held_for_gc(),
+"the heap lock should already be held by or for this thread");
+_young_list->push_region(hr);
+g1_policy()->set_region_short_lived(hr);
+}
+class NoYoungRegionsClosure: public HeapRegionClosure {
+private:
+bool _success;
+public:
+NoYoungRegionsClosure() : _success(true) { }
+bool doHeapRegion(HeapRegion* r) {
+if (r->is_young()) {
+gclog_or_tty->print_cr("Region ["PTR_FORMAT", "PTR_FORMAT") tagged as young",
+r->bottom(), r->end());
+_success = false;
+}
+return false;
+}
+bool success() { return _success; }
+};
+bool G1CollectedHeap::check_young_list_empty(bool ignore_scan_only_list,
+bool check_sample) {
+bool ret = true;
+ret = _young_list->check_list_empty(ignore_scan_only_list, check_sample);
+if (!ignore_scan_only_list) {
+NoYoungRegionsClosure closure;
+heap_region_iterate(&closure);
+ret = ret && closure.success();
+}
+return ret;
+}
+void G1CollectedHeap::empty_young_list() {
+assert(heap_lock_held_for_gc(),
+"the heap lock should already be held by or for this thread");
+assert(g1_policy()->in_young_gc_mode(), "should be in young GC mode");
+_young_list->empty_list();
+}
+bool G1CollectedHeap::all_alloc_regions_no_allocs_since_save_marks() {
+bool no_allocs = true;
+for (int ap = 0; ap < GCAllocPurposeCount && no_allocs; ++ap) {
+HeapRegion* r = _gc_alloc_regions[ap];
+no_allocs = r == NULL || r->saved_mark_at_top();
+}
+return no_allocs;
+}
+void G1CollectedHeap::all_alloc_regions_note_end_of_copying() {
+for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
+HeapRegion* r = _gc_alloc_regions[ap];
+if (r != NULL) {
+// Check for aliases.
+bool has_processed_alias = false;
+for (int i = 0; i < ap; ++i) {
+if (_gc_alloc_regions[i] == r) {
+has_processed_alias = true;
+break;
+}
+}
+if (!has_processed_alias) {
+r->note_end_of_copying();
+g1_policy()->record_after_bytes(r->used());
+}
+}
+}
+}
+// Done at the start of full GC.
+void G1CollectedHeap::tear_down_region_lists() {
+MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag);
+while (pop_unclean_region_list_locked() != NULL) ;
+assert(_unclean_region_list.hd() == NULL && _unclean_region_list.sz() == 0,
+"Postconditions of loop.")
+while (pop_free_region_list_locked() != NULL) ;
+assert(_free_region_list == NULL, "Postcondition of loop.");
+if (_free_region_list_size != 0) {
+gclog_or_tty->print_cr("Size is %d.", _free_region_list_size);
+print();
+}
+assert(_free_region_list_size == 0, "Postconditions of loop.");
+}
+class RegionResetter: public HeapRegionClosure {
+G1CollectedHeap* _g1;
+int _n;
+public:
+RegionResetter() : _g1(G1CollectedHeap::heap()), _n(0) {}
+bool doHeapRegion(HeapRegion* r) {
+if (r->continuesHumongous()) return false;
+if (r->top() > r->bottom()) {
+if (r->top() < r->end()) {
+Copy::fill_to_words(r->top(),
+pointer_delta(r->end(), r->top()));
+}
+r->set_zero_fill_allocated();
+} else {
+assert(r->is_empty(), "tautology");
+if (r->popular()) {
+if (r->zero_fill_state() != HeapRegion::Allocated) {
+r->ensure_zero_filled_locked();
+r->set_zero_fill_allocated();
+}
+} else {
+_n++;
+switch (r->zero_fill_state()) {
+case HeapRegion::NotZeroFilled:
+case HeapRegion::ZeroFilling:
+_g1->put_region_on_unclean_list_locked(r);
+break;
+case HeapRegion::Allocated:
+r->set_zero_fill_complete();
+// no break; go on to put on free list.
+case HeapRegion::ZeroFilled:
+_g1->put_free_region_on_list_locked(r);
+break;
+}
+}
+}
+return false;
+}
+int getFreeRegionCount() {return _n;}
+};
+// Done at the end of full GC.
+void G1CollectedHeap::rebuild_region_lists() {
+MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag);
+// This needs to go at the end of the full GC.
+RegionResetter rs;
+heap_region_iterate(&rs);
+_free_regions = rs.getFreeRegionCount();
+// Tell the ZF thread it may have work to do.
+if (should_zf()) ZF_mon->notify_all();
+}
+class UsedRegionsNeedZeroFillSetter: public HeapRegionClosure {
+G1CollectedHeap* _g1;
+int _n;
+public:
+UsedRegionsNeedZeroFillSetter() : _g1(G1CollectedHeap::heap()), _n(0) {}
+bool doHeapRegion(HeapRegion* r) {
+if (r->continuesHumongous()) return false;
+if (r->top() > r->bottom()) {
+// There are assertions in "set_zero_fill_needed()" below that
+// require top() == bottom(), so this is technically illegal.
+// We'll skirt the law here, by making that true temporarily.
+DEBUG_ONLY(HeapWord* save_top = r->top();
+r->set_top(r->bottom()));
+r->set_zero_fill_needed();
+DEBUG_ONLY(r->set_top(save_top));
+}
+return false;
+}
+};
+// Done at the start of full GC.
+void G1CollectedHeap::set_used_regions_to_need_zero_fill() {
+MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag);
+// This needs to go at the end of the full GC.
+UsedRegionsNeedZeroFillSetter rs;
+heap_region_iterate(&rs);
+}
+class CountObjClosure: public ObjectClosure {
+size_t _n;
+public:
+CountObjClosure() : _n(0) {}
+void do_object(oop obj) { _n++; }
+size_t n() { return _n; }
+};
+size_t G1CollectedHeap::pop_object_used_objs() {
+size_t sum_objs = 0;
+for (int i = 0; i < G1NumPopularRegions; i++) {
+CountObjClosure cl;
+_hrs->at(i)->object_iterate(&cl);
+sum_objs += cl.n();
+}
+return sum_objs;
+}
+size_t G1CollectedHeap::pop_object_used_bytes() {
+size_t sum_bytes = 0;
+for (int i = 0; i < G1NumPopularRegions; i++) {
+sum_bytes += _hrs->at(i)->used();
+}
+return sum_bytes;
+}
+static int nq = 0;
+HeapWord* G1CollectedHeap::allocate_popular_object(size_t word_size) {
+while (_cur_pop_hr_index < G1NumPopularRegions) {
+HeapRegion* cur_pop_region = _hrs->at(_cur_pop_hr_index);
+HeapWord* res = cur_pop_region->allocate(word_size);
+if (res != NULL) {
+// We account for popular objs directly in the used summary:
+_summary_bytes_used += (word_size * HeapWordSize);
+return res;
+}
+// Otherwise, try the next region (first making sure that we remember
+// the last "top" value as the "next_top_at_mark_start", so that
+// objects made popular during markings aren't automatically considered
+// live).
+cur_pop_region->note_end_of_copying();
+// Otherwise, try the next region.
+_cur_pop_hr_index++;
+}
+// XXX: For now !!!
+vm_exit_out_of_memory(word_size,
+"Not enough pop obj space (To Be Fixed)");
+return NULL;
+}
+class HeapRegionList: public CHeapObj {
+public:
+HeapRegion* hr;
+HeapRegionList* next;
+};
+void G1CollectedHeap::schedule_popular_region_evac(HeapRegion* r) {
+// This might happen during parallel GC, so protect by this lock.
+MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag);
+// We don't schedule regions whose evacuations are already pending, or
+// are already being evacuated.
+if (!r->popular_pending() && !r->in_collection_set()) {
+r->set_popular_pending(true);
+if (G1TracePopularity) {
+gclog_or_tty->print_cr("Scheduling region "PTR_FORMAT" "
+"["PTR_FORMAT", "PTR_FORMAT") for pop-object evacuation.",
+r, r->bottom(), r->end());
+}
+HeapRegionList* hrl = new HeapRegionList;
+hrl->hr = r;
+hrl->next = _popular_regions_to_be_evacuated;
+_popular_regions_to_be_evacuated = hrl;
+}
+}
+HeapRegion* G1CollectedHeap::popular_region_to_evac() {
+MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag);
+HeapRegion* res = NULL;
+while (_popular_regions_to_be_evacuated != NULL && res == NULL) {
+HeapRegionList* hrl = _popular_regions_to_be_evacuated;
+_popular_regions_to_be_evacuated = hrl->next;
+res = hrl->hr;
+// The G1RSPopLimit may have increased, so recheck here...
+if (res->rem_set()->occupied() < (size_t) G1RSPopLimit) {
+// Hah: don't need to schedule.
+if (G1TracePopularity) {
+gclog_or_tty->print_cr("Unscheduling region "PTR_FORMAT" "
+"["PTR_FORMAT", "PTR_FORMAT") "
+"for pop-object evacuation (size %d < limit %d)",
+res, res->bottom(), res->end(),
+res->rem_set()->occupied(), G1RSPopLimit);
+}
+res->set_popular_pending(false);
+res = NULL;
+}
+// We do not reset res->popular() here; if we did so, it would allow
+// the region to be "rescheduled" for popularity evacuation.  Instead,
+// this is done in the collection pause, with the world stopped.
+// So the invariant is that the regions in the list have the popularity
+// boolean set, but having the boolean set does not imply membership
+// on the list (though there can at most one such pop-pending region
+// not on the list at any time).
+delete hrl;
+}
+return res;
+}
+void G1CollectedHeap::evac_popular_region(HeapRegion* hr) {
+while (true) {
+// Don't want to do a GC pause while cleanup is being completed!
+wait_for_cleanup_complete();
+// Read the GC count while holding the Heap_lock
+int gc_count_before = SharedHeap::heap()->total_collections();
+g1_policy()->record_stop_world_start();
+{
+MutexUnlocker mu(Heap_lock);  // give up heap lock, execute gets it back
+VM_G1PopRegionCollectionPause op(gc_count_before, hr);
+VMThread::execute(&op);
+// If the prolog succeeded, we didn't do a GC for this.
+if (op.prologue_succeeded()) break;
+}
+// Otherwise we didn't.  We should recheck the size, though, since
+// the limit may have increased...
+if (hr->rem_set()->occupied() < (size_t) G1RSPopLimit) {
+hr->set_popular_pending(false);
+break;
+}
+}
+}
+void G1CollectedHeap::atomic_inc_obj_rc(oop obj) {
+Atomic::inc(obj_rc_addr(obj));
+}
+class CountRCClosure: public OopsInHeapRegionClosure {
+G1CollectedHeap* _g1h;
+bool _parallel;
+public:
+CountRCClosure(G1CollectedHeap* g1h) :
+_g1h(g1h), _parallel(ParallelGCThreads > 0)
+{}
+void do_oop(narrowOop* p) {
+guarantee(false, "NYI");
+}
+void do_oop(oop* p) {
+oop obj = *p;
+assert(obj != NULL, "Precondition.");
+if (_parallel) {
+// We go sticky at the limit to avoid excess contention.
+// If we want to track the actual RC's further, we'll need to keep a
+// per-thread hash table or something for the popular objects.
+if (_g1h->obj_rc(obj) < G1ObjPopLimit) {
+_g1h->atomic_inc_obj_rc(obj);
+}
+} else {
+_g1h->inc_obj_rc(obj);
+}
+}
+};
+class EvacPopObjClosure: public ObjectClosure {
+G1CollectedHeap* _g1h;
+size_t _pop_objs;
+size_t _max_rc;
+public:
+EvacPopObjClosure(G1CollectedHeap* g1h) :
+_g1h(g1h), _pop_objs(0), _max_rc(0) {}
+void do_object(oop obj) {
+size_t rc = _g1h->obj_rc(obj);
+_max_rc = MAX2(rc, _max_rc);
+if (rc >= (size_t) G1ObjPopLimit) {
+_g1h->_pop_obj_rc_at_copy.add((double)rc);
+size_t word_sz = obj->size();
+HeapWord* new_pop_loc = _g1h->allocate_popular_object(word_sz);
+oop new_pop_obj = (oop)new_pop_loc;
+Copy::aligned_disjoint_words((HeapWord*)obj, new_pop_loc, word_sz);
+obj->forward_to(new_pop_obj);
+G1ScanAndBalanceClosure scan_and_balance(_g1h);
+new_pop_obj->oop_iterate_backwards(&scan_and_balance);
+// preserve "next" mark bit if marking is in progress.
+if (_g1h->mark_in_progress() && !_g1h->is_obj_ill(obj)) {
+_g1h->concurrent_mark()->markAndGrayObjectIfNecessary(new_pop_obj);
+}
+if (G1TracePopularity) {
+gclog_or_tty->print_cr("Found obj " PTR_FORMAT " of word size " SIZE_FORMAT
+" pop (%d), move to " PTR_FORMAT,
+(void*) obj, word_sz,
+_g1h->obj_rc(obj), (void*) new_pop_obj);
+}
+_pop_objs++;
+}
+}
+size_t pop_objs() { return _pop_objs; }
+size_t max_rc() { return _max_rc; }
+};
+class G1ParCountRCTask : public AbstractGangTask {
+G1CollectedHeap* _g1h;
+BitMap _bm;
+size_t getNCards() {
+return (_g1h->capacity() + G1BlockOffsetSharedArray::N_bytes - 1)
+/ G1BlockOffsetSharedArray::N_bytes;
+}
+CountRCClosure _count_rc_closure;
+public:
+G1ParCountRCTask(G1CollectedHeap* g1h) :
+AbstractGangTask("G1 Par RC Count task"),
+_g1h(g1h), _bm(getNCards()), _count_rc_closure(g1h)
+{}
+void work(int i) {
+ResourceMark rm;
+HandleMark   hm;
+_g1h->g1_rem_set()->oops_into_collection_set_do(&_count_rc_closure, i);
+}
+};
+void G1CollectedHeap::popularity_pause_preamble(HeapRegion* popular_region) {
+// We're evacuating a single region (for popularity).
+if (G1TracePopularity) {
+gclog_or_tty->print_cr("Doing pop region pause for ["PTR_FORMAT", "PTR_FORMAT")",
+popular_region->bottom(), popular_region->end());
+}
+g1_policy()->set_single_region_collection_set(popular_region);
+size_t max_rc;
+if (!compute_reference_counts_and_evac_popular(popular_region,
+&max_rc)) {
+// We didn't evacuate any popular objects.
+// We increase the RS popularity limit, to prevent this from
+// happening in the future.
+if (G1RSPopLimit < (1 << 30)) {
+G1RSPopLimit *= 2;
+}
+// For now, interesting enough for a message:
+#if 1
+gclog_or_tty->print_cr("In pop region pause for ["PTR_FORMAT", "PTR_FORMAT"), "
+"failed to find a pop object (max = %d).",
+popular_region->bottom(), popular_region->end(),
+max_rc);
+gclog_or_tty->print_cr("Increased G1RSPopLimit to %d.", G1RSPopLimit);
+#endif // 0
+// Also, we reset the collection set to NULL, to make the rest of
+// the collection do nothing.
+assert(popular_region->next_in_collection_set() == NULL,
+"should be single-region.");
+popular_region->set_in_collection_set(false);
+popular_region->set_popular_pending(false);
+g1_policy()->clear_collection_set();
+}
+}
+bool G1CollectedHeap::
+compute_reference_counts_and_evac_popular(HeapRegion* popular_region,
+size_t* max_rc) {
+HeapWord* rc_region_bot;
+HeapWord* rc_region_end;
+// Set up the reference count region.
+HeapRegion* rc_region = newAllocRegion(HeapRegion::GrainWords);
+if (rc_region != NULL) {
+rc_region_bot = rc_region->bottom();
+rc_region_end = rc_region->end();
+} else {
+rc_region_bot = NEW_C_HEAP_ARRAY(HeapWord, HeapRegion::GrainWords);
+if (rc_region_bot == NULL) {
+vm_exit_out_of_memory(HeapRegion::GrainWords,
+"No space for RC region.");
+}
+rc_region_end = rc_region_bot + HeapRegion::GrainWords;
+}
+if (G1TracePopularity)
+gclog_or_tty->print_cr("RC region is ["PTR_FORMAT", "PTR_FORMAT")",
+rc_region_bot, rc_region_end);
+if (rc_region_bot > popular_region->bottom()) {
+_rc_region_above = true;
+_rc_region_diff =
+pointer_delta(rc_region_bot, popular_region->bottom(), 1);
+} else {
+assert(rc_region_bot < popular_region->bottom(), "Can't be equal.");
+_rc_region_above = false;
+_rc_region_diff =
+pointer_delta(popular_region->bottom(), rc_region_bot, 1);
+}
+g1_policy()->record_pop_compute_rc_start();
+// Count external references.
+g1_rem_set()->prepare_for_oops_into_collection_set_do();
+if (ParallelGCThreads > 0) {
+set_par_threads(workers()->total_workers());
+G1ParCountRCTask par_count_rc_task(this);
+workers()->run_task(&par_count_rc_task);
+set_par_threads(0);
+} else {
+CountRCClosure count_rc_closure(this);
+g1_rem_set()->oops_into_collection_set_do(&count_rc_closure, 0);
+}
+g1_rem_set()->cleanup_after_oops_into_collection_set_do();
+g1_policy()->record_pop_compute_rc_end();
+// Now evacuate popular objects.
+g1_policy()->record_pop_evac_start();
+EvacPopObjClosure evac_pop_obj_cl(this);
+popular_region->object_iterate(&evac_pop_obj_cl);
+*max_rc = evac_pop_obj_cl.max_rc();
+// Make sure the last "top" value of the current popular region is copied
+// as the "next_top_at_mark_start", so that objects made popular during
+// markings aren't automatically considered live.
+HeapRegion* cur_pop_region = _hrs->at(_cur_pop_hr_index);
+cur_pop_region->note_end_of_copying();
+if (rc_region != NULL) {
+free_region(rc_region);
+} else {
+FREE_C_HEAP_ARRAY(HeapWord, rc_region_bot);
+}
+g1_policy()->record_pop_evac_end();
+return evac_pop_obj_cl.pop_objs() > 0;
+}
+class CountPopObjInfoClosure: public HeapRegionClosure {
+size_t _objs;
+size_t _bytes;
+class CountObjClosure: public ObjectClosure {
+int _n;
+public:
+CountObjClosure() : _n(0) {}
+void do_object(oop obj) { _n++; }
+size_t n() { return _n; }
+};
+public:
+CountPopObjInfoClosure() : _objs(0), _bytes(0) {}
+bool doHeapRegion(HeapRegion* r) {
+_bytes += r->used();
+CountObjClosure blk;
+r->object_iterate(&blk);
+_objs += blk.n();
+return false;
+}
+size_t objs() { return _objs; }
+size_t bytes() { return _bytes; }
+};
+void G1CollectedHeap::print_popularity_summary_info() const {
+CountPopObjInfoClosure blk;
+for (int i = 0; i <= _cur_pop_hr_index; i++) {
+blk.doHeapRegion(_hrs->at(i));
+}
+gclog_or_tty->print_cr("\nPopular objects: %d objs, %d bytes.",
+blk.objs(), blk.bytes());
+gclog_or_tty->print_cr("   RC at copy = [avg = %5.2f, max = %5.2f, sd = %5.2f].",
+_pop_obj_rc_at_copy.avg(),
+_pop_obj_rc_at_copy.maximum(),
+_pop_obj_rc_at_copy.sd());
+}
+void G1CollectedHeap::set_refine_cte_cl_concurrency(bool concurrent) {
+_refine_cte_cl->set_concurrent(concurrent);
+}
+#ifndef PRODUCT
+class PrintHeapRegionClosure: public HeapRegionClosure {
+public:
+bool doHeapRegion(HeapRegion *r) {
+gclog_or_tty->print("Region: "PTR_FORMAT":", r);
+if (r != NULL) {
+if (r->is_on_free_list())
+gclog_or_tty->print("Free ");
+if (r->is_young())
+gclog_or_tty->print("Young ");
+if (r->isHumongous())
+gclog_or_tty->print("Is Humongous ");
+r->print();
+}
+return false;
+}
+};
+class SortHeapRegionClosure : public HeapRegionClosure {
+size_t young_regions,free_regions, unclean_regions;
+size_t hum_regions, count;
+size_t unaccounted, cur_unclean, cur_alloc;
+size_t total_free;
+HeapRegion* cur;
+public:
+SortHeapRegionClosure(HeapRegion *_cur) : cur(_cur), young_regions(0),
+free_regions(0), unclean_regions(0),
+hum_regions(0),
+count(0), unaccounted(0),
+cur_alloc(0), total_free(0)
+{}
+bool doHeapRegion(HeapRegion *r) {
+count++;
+if (r->is_on_free_list()) free_regions++;
+else if (r->is_on_unclean_list()) unclean_regions++;
+else if (r->isHumongous())  hum_regions++;
+else if (r->is_young()) young_regions++;
+else if (r == cur) cur_alloc++;
+else unaccounted++;
+return false;
+}
+void print() {
+total_free = free_regions + unclean_regions;
+gclog_or_tty->print("%d regions\n", count);
+gclog_or_tty->print("%d free: free_list = %d unclean = %d\n",
+total_free, free_regions, unclean_regions);
+gclog_or_tty->print("%d humongous %d young\n",
+hum_regions, young_regions);
+gclog_or_tty->print("%d cur_alloc\n", cur_alloc);
+gclog_or_tty->print("UHOH unaccounted = %d\n", unaccounted);
+}
+};
+void G1CollectedHeap::print_region_counts() {
+SortHeapRegionClosure sc(_cur_alloc_region);
+PrintHeapRegionClosure cl;
+heap_region_iterate(&cl);
+heap_region_iterate(&sc);
+sc.print();
+print_region_accounting_info();
+};
+bool G1CollectedHeap::regions_accounted_for() {
+// TODO: regions accounting for young/survivor/tenured
+return true;
+}
+bool G1CollectedHeap::print_region_accounting_info() {
+gclog_or_tty->print_cr("P regions: %d.", G1NumPopularRegions);
+gclog_or_tty->print_cr("Free regions: %d (count: %d count list %d) (clean: %d unclean: %d).",
+free_regions(),
+count_free_regions(), count_free_regions_list(),
+_free_region_list_size, _unclean_region_list.sz());
+gclog_or_tty->print_cr("cur_alloc: %d.",
+(_cur_alloc_region == NULL ? 0 : 1));
+gclog_or_tty->print_cr("H regions: %d.", _num_humongous_regions);
+// TODO: check regions accounting for young/survivor/tenured
+return true;
+}
+bool G1CollectedHeap::is_in_closed_subset(const void* p) const {
+HeapRegion* hr = heap_region_containing(p);
+if (hr == NULL) {
+return is_in_permanent(p);
+} else {
+return hr->is_in(p);
+}
+}
+#endif // PRODUCT
+void G1CollectedHeap::g1_unimplemented() {
+// Unimplemented();
+}
+// Local Variables: ***
+// c-indentation-style: gnu ***
+// End: ***

Mercurial > hg > graal-compiler

comparison src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp @ 342:37f87013dfd8