1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/g1/g1Allocator.cpp Fri Sep 05 09:49:19 2014 +0200
1.3 @@ -0,0 +1,155 @@
1.4 +/*
1.5 + * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#include "precompiled.hpp"
1.29 +#include "gc_implementation/g1/g1Allocator.hpp"
1.30 +#include "gc_implementation/g1/g1CollectedHeap.hpp"
1.31 +#include "gc_implementation/g1/g1CollectorPolicy.hpp"
1.32 +#include "gc_implementation/g1/heapRegion.inline.hpp"
1.33 +#include "gc_implementation/g1/heapRegionSet.inline.hpp"
1.34 +
1.35 +void G1DefaultAllocator::init_mutator_alloc_region() {
1.36 + assert(_mutator_alloc_region.get() == NULL, "pre-condition");
1.37 + _mutator_alloc_region.init();
1.38 +}
1.39 +
1.40 +void G1DefaultAllocator::release_mutator_alloc_region() {
1.41 + _mutator_alloc_region.release();
1.42 + assert(_mutator_alloc_region.get() == NULL, "post-condition");
1.43 +}
1.44 +
1.45 +void G1Allocator::reuse_retained_old_region(EvacuationInfo& evacuation_info,
1.46 + OldGCAllocRegion* old,
1.47 + HeapRegion** retained_old) {
1.48 + HeapRegion* retained_region = *retained_old;
1.49 + *retained_old = NULL;
1.50 +
1.51 + // We will discard the current GC alloc region if:
1.52 + // a) it's in the collection set (it can happen!),
1.53 + // b) it's already full (no point in using it),
1.54 + // c) it's empty (this means that it was emptied during
1.55 + // a cleanup and it should be on the free list now), or
1.56 + // d) it's humongous (this means that it was emptied
1.57 + // during a cleanup and was added to the free list, but
1.58 + // has been subsequently used to allocate a humongous
1.59 + // object that may be less than the region size).
1.60 + if (retained_region != NULL &&
1.61 + !retained_region->in_collection_set() &&
1.62 + !(retained_region->top() == retained_region->end()) &&
1.63 + !retained_region->is_empty() &&
1.64 + !retained_region->isHumongous()) {
1.65 + retained_region->record_top_and_timestamp();
1.66 + // The retained region was added to the old region set when it was
1.67 + // retired. We have to remove it now, since we don't allow regions
1.68 + // we allocate to in the region sets. We'll re-add it later, when
1.69 + // it's retired again.
1.70 + _g1h->_old_set.remove(retained_region);
1.71 + bool during_im = _g1h->g1_policy()->during_initial_mark_pause();
1.72 + retained_region->note_start_of_copying(during_im);
1.73 + old->set(retained_region);
1.74 + _g1h->_hr_printer.reuse(retained_region);
1.75 + evacuation_info.set_alloc_regions_used_before(retained_region->used());
1.76 + }
1.77 +}
1.78 +
1.79 +void G1DefaultAllocator::init_gc_alloc_regions(EvacuationInfo& evacuation_info) {
1.80 + assert_at_safepoint(true /* should_be_vm_thread */);
1.81 +
1.82 + _survivor_gc_alloc_region.init();
1.83 + _old_gc_alloc_region.init();
1.84 + reuse_retained_old_region(evacuation_info,
1.85 + &_old_gc_alloc_region,
1.86 + &_retained_old_gc_alloc_region);
1.87 +}
1.88 +
1.89 +void G1DefaultAllocator::release_gc_alloc_regions(uint no_of_gc_workers, EvacuationInfo& evacuation_info) {
1.90 + AllocationContext_t context = AllocationContext::current();
1.91 + evacuation_info.set_allocation_regions(survivor_gc_alloc_region(context)->count() +
1.92 + old_gc_alloc_region(context)->count());
1.93 + survivor_gc_alloc_region(context)->release();
1.94 + // If we have an old GC alloc region to release, we'll save it in
1.95 + // _retained_old_gc_alloc_region. If we don't
1.96 + // _retained_old_gc_alloc_region will become NULL. This is what we
1.97 + // want either way so no reason to check explicitly for either
1.98 + // condition.
1.99 + _retained_old_gc_alloc_region = old_gc_alloc_region(context)->release();
1.100 +
1.101 + if (ResizePLAB) {
1.102 + _g1h->_survivor_plab_stats.adjust_desired_plab_sz(no_of_gc_workers);
1.103 + _g1h->_old_plab_stats.adjust_desired_plab_sz(no_of_gc_workers);
1.104 + }
1.105 +}
1.106 +
1.107 +void G1DefaultAllocator::abandon_gc_alloc_regions() {
1.108 + assert(survivor_gc_alloc_region(AllocationContext::current())->get() == NULL, "pre-condition");
1.109 + assert(old_gc_alloc_region(AllocationContext::current())->get() == NULL, "pre-condition");
1.110 + _retained_old_gc_alloc_region = NULL;
1.111 +}
1.112 +
1.113 +G1ParGCAllocBuffer::G1ParGCAllocBuffer(size_t gclab_word_size) :
1.114 + ParGCAllocBuffer(gclab_word_size), _retired(true) { }
1.115 +
1.116 +HeapWord* G1ParGCAllocator::allocate_slow(GCAllocPurpose purpose, size_t word_sz, AllocationContext_t context) {
1.117 + HeapWord* obj = NULL;
1.118 + size_t gclab_word_size = _g1h->desired_plab_sz(purpose);
1.119 + if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) {
1.120 + G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose, context);
1.121 + add_to_alloc_buffer_waste(alloc_buf->words_remaining());
1.122 + alloc_buf->retire(false /* end_of_gc */, false /* retain */);
1.123 +
1.124 + HeapWord* buf = _g1h->par_allocate_during_gc(purpose, gclab_word_size, context);
1.125 + if (buf == NULL) {
1.126 + return NULL; // Let caller handle allocation failure.
1.127 + }
1.128 + // Otherwise.
1.129 + alloc_buf->set_word_size(gclab_word_size);
1.130 + alloc_buf->set_buf(buf);
1.131 +
1.132 + obj = alloc_buf->allocate(word_sz);
1.133 + assert(obj != NULL, "buffer was definitely big enough...");
1.134 + } else {
1.135 + obj = _g1h->par_allocate_during_gc(purpose, word_sz, context);
1.136 + }
1.137 + return obj;
1.138 +}
1.139 +
1.140 +G1DefaultParGCAllocator::G1DefaultParGCAllocator(G1CollectedHeap* g1h) :
1.141 + G1ParGCAllocator(g1h),
1.142 + _surviving_alloc_buffer(g1h->desired_plab_sz(GCAllocForSurvived)),
1.143 + _tenured_alloc_buffer(g1h->desired_plab_sz(GCAllocForTenured)) {
1.144 +
1.145 + _alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer;
1.146 + _alloc_buffers[GCAllocForTenured] = &_tenured_alloc_buffer;
1.147 +
1.148 +}
1.149 +
1.150 +void G1DefaultParGCAllocator::retire_alloc_buffers() {
1.151 + for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
1.152 + size_t waste = _alloc_buffers[ap]->words_remaining();
1.153 + add_to_alloc_buffer_waste(waste);
1.154 + _alloc_buffers[ap]->flush_stats_and_retire(_g1h->stats_for_purpose((GCAllocPurpose)ap),
1.155 + true /* end_of_gc */,
1.156 + false /* retain */);
1.157 + }
1.158 +}
