src/share/vm/gc_implementation/g1/g1Allocator.cpp

Thu, 23 Oct 2014 12:02:08 -0700

author
asaha
date
Thu, 23 Oct 2014 12:02:08 -0700
changeset 7476
c2844108a708
parent 7118
227a9e5e4b4a
child 7647
80ac3ee51955
permissions
-rw-r--r--

Merge

sjohanss@7118 1 /*
sjohanss@7118 2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
sjohanss@7118 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
sjohanss@7118 4 *
sjohanss@7118 5 * This code is free software; you can redistribute it and/or modify it
sjohanss@7118 6 * under the terms of the GNU General Public License version 2 only, as
sjohanss@7118 7 * published by the Free Software Foundation.
sjohanss@7118 8 *
sjohanss@7118 9 * This code is distributed in the hope that it will be useful, but WITHOUT
sjohanss@7118 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
sjohanss@7118 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
sjohanss@7118 12 * version 2 for more details (a copy is included in the LICENSE file that
sjohanss@7118 13 * accompanied this code).
sjohanss@7118 14 *
sjohanss@7118 15 * You should have received a copy of the GNU General Public License version
sjohanss@7118 16 * 2 along with this work; if not, write to the Free Software Foundation,
sjohanss@7118 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
sjohanss@7118 18 *
sjohanss@7118 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
sjohanss@7118 20 * or visit www.oracle.com if you need additional information or have any
sjohanss@7118 21 * questions.
sjohanss@7118 22 *
sjohanss@7118 23 */
sjohanss@7118 24
sjohanss@7118 25 #include "precompiled.hpp"
sjohanss@7118 26 #include "gc_implementation/g1/g1Allocator.hpp"
sjohanss@7118 27 #include "gc_implementation/g1/g1CollectedHeap.hpp"
sjohanss@7118 28 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
sjohanss@7118 29 #include "gc_implementation/g1/heapRegion.inline.hpp"
sjohanss@7118 30 #include "gc_implementation/g1/heapRegionSet.inline.hpp"
sjohanss@7118 31
sjohanss@7118 32 void G1DefaultAllocator::init_mutator_alloc_region() {
sjohanss@7118 33 assert(_mutator_alloc_region.get() == NULL, "pre-condition");
sjohanss@7118 34 _mutator_alloc_region.init();
sjohanss@7118 35 }
sjohanss@7118 36
sjohanss@7118 37 void G1DefaultAllocator::release_mutator_alloc_region() {
sjohanss@7118 38 _mutator_alloc_region.release();
sjohanss@7118 39 assert(_mutator_alloc_region.get() == NULL, "post-condition");
sjohanss@7118 40 }
sjohanss@7118 41
sjohanss@7118 42 void G1Allocator::reuse_retained_old_region(EvacuationInfo& evacuation_info,
sjohanss@7118 43 OldGCAllocRegion* old,
sjohanss@7118 44 HeapRegion** retained_old) {
sjohanss@7118 45 HeapRegion* retained_region = *retained_old;
sjohanss@7118 46 *retained_old = NULL;
sjohanss@7118 47
sjohanss@7118 48 // We will discard the current GC alloc region if:
sjohanss@7118 49 // a) it's in the collection set (it can happen!),
sjohanss@7118 50 // b) it's already full (no point in using it),
sjohanss@7118 51 // c) it's empty (this means that it was emptied during
sjohanss@7118 52 // a cleanup and it should be on the free list now), or
sjohanss@7118 53 // d) it's humongous (this means that it was emptied
sjohanss@7118 54 // during a cleanup and was added to the free list, but
sjohanss@7118 55 // has been subsequently used to allocate a humongous
sjohanss@7118 56 // object that may be less than the region size).
sjohanss@7118 57 if (retained_region != NULL &&
sjohanss@7118 58 !retained_region->in_collection_set() &&
sjohanss@7118 59 !(retained_region->top() == retained_region->end()) &&
sjohanss@7118 60 !retained_region->is_empty() &&
sjohanss@7118 61 !retained_region->isHumongous()) {
sjohanss@7118 62 retained_region->record_top_and_timestamp();
sjohanss@7118 63 // The retained region was added to the old region set when it was
sjohanss@7118 64 // retired. We have to remove it now, since we don't allow regions
sjohanss@7118 65 // we allocate to in the region sets. We'll re-add it later, when
sjohanss@7118 66 // it's retired again.
sjohanss@7118 67 _g1h->_old_set.remove(retained_region);
sjohanss@7118 68 bool during_im = _g1h->g1_policy()->during_initial_mark_pause();
sjohanss@7118 69 retained_region->note_start_of_copying(during_im);
sjohanss@7118 70 old->set(retained_region);
sjohanss@7118 71 _g1h->_hr_printer.reuse(retained_region);
sjohanss@7118 72 evacuation_info.set_alloc_regions_used_before(retained_region->used());
sjohanss@7118 73 }
sjohanss@7118 74 }
sjohanss@7118 75
sjohanss@7118 76 void G1DefaultAllocator::init_gc_alloc_regions(EvacuationInfo& evacuation_info) {
sjohanss@7118 77 assert_at_safepoint(true /* should_be_vm_thread */);
sjohanss@7118 78
sjohanss@7118 79 _survivor_gc_alloc_region.init();
sjohanss@7118 80 _old_gc_alloc_region.init();
sjohanss@7118 81 reuse_retained_old_region(evacuation_info,
sjohanss@7118 82 &_old_gc_alloc_region,
sjohanss@7118 83 &_retained_old_gc_alloc_region);
sjohanss@7118 84 }
sjohanss@7118 85
sjohanss@7118 86 void G1DefaultAllocator::release_gc_alloc_regions(uint no_of_gc_workers, EvacuationInfo& evacuation_info) {
sjohanss@7118 87 AllocationContext_t context = AllocationContext::current();
sjohanss@7118 88 evacuation_info.set_allocation_regions(survivor_gc_alloc_region(context)->count() +
sjohanss@7118 89 old_gc_alloc_region(context)->count());
sjohanss@7118 90 survivor_gc_alloc_region(context)->release();
sjohanss@7118 91 // If we have an old GC alloc region to release, we'll save it in
sjohanss@7118 92 // _retained_old_gc_alloc_region. If we don't
sjohanss@7118 93 // _retained_old_gc_alloc_region will become NULL. This is what we
sjohanss@7118 94 // want either way so no reason to check explicitly for either
sjohanss@7118 95 // condition.
sjohanss@7118 96 _retained_old_gc_alloc_region = old_gc_alloc_region(context)->release();
sjohanss@7118 97
sjohanss@7118 98 if (ResizePLAB) {
sjohanss@7118 99 _g1h->_survivor_plab_stats.adjust_desired_plab_sz(no_of_gc_workers);
sjohanss@7118 100 _g1h->_old_plab_stats.adjust_desired_plab_sz(no_of_gc_workers);
sjohanss@7118 101 }
sjohanss@7118 102 }
sjohanss@7118 103
sjohanss@7118 104 void G1DefaultAllocator::abandon_gc_alloc_regions() {
sjohanss@7118 105 assert(survivor_gc_alloc_region(AllocationContext::current())->get() == NULL, "pre-condition");
sjohanss@7118 106 assert(old_gc_alloc_region(AllocationContext::current())->get() == NULL, "pre-condition");
sjohanss@7118 107 _retained_old_gc_alloc_region = NULL;
sjohanss@7118 108 }
sjohanss@7118 109
sjohanss@7118 110 G1ParGCAllocBuffer::G1ParGCAllocBuffer(size_t gclab_word_size) :
sjohanss@7118 111 ParGCAllocBuffer(gclab_word_size), _retired(true) { }
sjohanss@7118 112
sjohanss@7118 113 HeapWord* G1ParGCAllocator::allocate_slow(GCAllocPurpose purpose, size_t word_sz, AllocationContext_t context) {
sjohanss@7118 114 HeapWord* obj = NULL;
sjohanss@7118 115 size_t gclab_word_size = _g1h->desired_plab_sz(purpose);
sjohanss@7118 116 if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) {
sjohanss@7118 117 G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose, context);
sjohanss@7118 118 add_to_alloc_buffer_waste(alloc_buf->words_remaining());
sjohanss@7118 119 alloc_buf->retire(false /* end_of_gc */, false /* retain */);
sjohanss@7118 120
sjohanss@7118 121 HeapWord* buf = _g1h->par_allocate_during_gc(purpose, gclab_word_size, context);
sjohanss@7118 122 if (buf == NULL) {
sjohanss@7118 123 return NULL; // Let caller handle allocation failure.
sjohanss@7118 124 }
sjohanss@7118 125 // Otherwise.
sjohanss@7118 126 alloc_buf->set_word_size(gclab_word_size);
sjohanss@7118 127 alloc_buf->set_buf(buf);
sjohanss@7118 128
sjohanss@7118 129 obj = alloc_buf->allocate(word_sz);
sjohanss@7118 130 assert(obj != NULL, "buffer was definitely big enough...");
sjohanss@7118 131 } else {
sjohanss@7118 132 obj = _g1h->par_allocate_during_gc(purpose, word_sz, context);
sjohanss@7118 133 }
sjohanss@7118 134 return obj;
sjohanss@7118 135 }
sjohanss@7118 136
sjohanss@7118 137 G1DefaultParGCAllocator::G1DefaultParGCAllocator(G1CollectedHeap* g1h) :
sjohanss@7118 138 G1ParGCAllocator(g1h),
sjohanss@7118 139 _surviving_alloc_buffer(g1h->desired_plab_sz(GCAllocForSurvived)),
sjohanss@7118 140 _tenured_alloc_buffer(g1h->desired_plab_sz(GCAllocForTenured)) {
sjohanss@7118 141
sjohanss@7118 142 _alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer;
sjohanss@7118 143 _alloc_buffers[GCAllocForTenured] = &_tenured_alloc_buffer;
sjohanss@7118 144
sjohanss@7118 145 }
sjohanss@7118 146
sjohanss@7118 147 void G1DefaultParGCAllocator::retire_alloc_buffers() {
sjohanss@7118 148 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
sjohanss@7118 149 size_t waste = _alloc_buffers[ap]->words_remaining();
sjohanss@7118 150 add_to_alloc_buffer_waste(waste);
sjohanss@7118 151 _alloc_buffers[ap]->flush_stats_and_retire(_g1h->stats_for_purpose((GCAllocPurpose)ap),
sjohanss@7118 152 true /* end_of_gc */,
sjohanss@7118 153 false /* retain */);
sjohanss@7118 154 }
sjohanss@7118 155 }

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