1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/parallelScavenge/psPromotionLAB.cpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,167 @@
1.4 +/*
1.5 + * Copyright (c) 2002, 2010, 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/parallelScavenge/parallelScavengeHeap.hpp"
1.30 +#include "gc_implementation/parallelScavenge/psPromotionLAB.hpp"
1.31 +#include "gc_implementation/shared/mutableSpace.hpp"
1.32 +#include "oops/oop.inline.hpp"
1.33 +
1.34 +size_t PSPromotionLAB::filler_header_size;
1.35 +
1.36 +// This is the shared initialization code. It sets up the basic pointers,
1.37 +// and allows enough extra space for a filler object. We call a virtual
1.38 +// method, "lab_is_valid()" to handle the different asserts the old/young
1.39 +// labs require.
1.40 +void PSPromotionLAB::initialize(MemRegion lab) {
1.41 + assert(lab_is_valid(lab), "Sanity");
1.42 +
1.43 + HeapWord* bottom = lab.start();
1.44 + HeapWord* end = lab.end();
1.45 +
1.46 + set_bottom(bottom);
1.47 + set_end(end);
1.48 + set_top(bottom);
1.49 +
1.50 + // Initialize after VM starts up because header_size depends on compressed
1.51 + // oops.
1.52 + filler_header_size = align_object_size(typeArrayOopDesc::header_size(T_INT));
1.53 +
1.54 + // We can be initialized to a zero size!
1.55 + if (free() > 0) {
1.56 + if (ZapUnusedHeapArea) {
1.57 + debug_only(Copy::fill_to_words(top(), free()/HeapWordSize, badHeapWord));
1.58 + }
1.59 +
1.60 + // NOTE! We need to allow space for a filler object.
1.61 + assert(lab.word_size() >= filler_header_size, "lab is too small");
1.62 + end = end - filler_header_size;
1.63 + set_end(end);
1.64 +
1.65 + _state = needs_flush;
1.66 + } else {
1.67 + _state = zero_size;
1.68 + }
1.69 +
1.70 + assert(this->top() <= this->end(), "pointers out of order");
1.71 +}
1.72 +
1.73 +// Fill all remaining lab space with an unreachable object.
1.74 +// The goal is to leave a contiguous parseable span of objects.
1.75 +void PSPromotionLAB::flush() {
1.76 + assert(_state != flushed, "Attempt to flush PLAB twice");
1.77 + assert(top() <= end(), "pointers out of order");
1.78 +
1.79 + // If we were initialized to a zero sized lab, there is
1.80 + // nothing to flush
1.81 + if (_state == zero_size)
1.82 + return;
1.83 +
1.84 + // PLAB's never allocate the last aligned_header_size
1.85 + // so they can always fill with an array.
1.86 + HeapWord* tlab_end = end() + filler_header_size;
1.87 + typeArrayOop filler_oop = (typeArrayOop) top();
1.88 + filler_oop->set_mark(markOopDesc::prototype());
1.89 + filler_oop->set_klass(Universe::intArrayKlassObj());
1.90 + const size_t array_length =
1.91 + pointer_delta(tlab_end, top()) - typeArrayOopDesc::header_size(T_INT);
1.92 + assert( (array_length * (HeapWordSize/sizeof(jint))) < (size_t)max_jint, "array too big in PSPromotionLAB");
1.93 + filler_oop->set_length((int)(array_length * (HeapWordSize/sizeof(jint))));
1.94 +
1.95 +#ifdef ASSERT
1.96 + // Note that we actually DO NOT want to use the aligned header size!
1.97 + HeapWord* elt_words = ((HeapWord*)filler_oop) + typeArrayOopDesc::header_size(T_INT);
1.98 + Copy::fill_to_words(elt_words, array_length, 0xDEAABABE);
1.99 +#endif
1.100 +
1.101 + set_bottom(NULL);
1.102 + set_end(NULL);
1.103 + set_top(NULL);
1.104 +
1.105 + _state = flushed;
1.106 +}
1.107 +
1.108 +bool PSPromotionLAB::unallocate_object(HeapWord* obj, size_t obj_size) {
1.109 + assert(Universe::heap()->is_in(obj), "Object outside heap");
1.110 +
1.111 + if (contains(obj)) {
1.112 + HeapWord* object_end = obj + obj_size;
1.113 + assert(object_end == top(), "Not matching last allocation");
1.114 +
1.115 + set_top(obj);
1.116 + return true;
1.117 + }
1.118 +
1.119 + return false;
1.120 +}
1.121 +
1.122 +// Fill all remaining lab space with an unreachable object.
1.123 +// The goal is to leave a contiguous parseable span of objects.
1.124 +void PSOldPromotionLAB::flush() {
1.125 + assert(_state != flushed, "Attempt to flush PLAB twice");
1.126 + assert(top() <= end(), "pointers out of order");
1.127 +
1.128 + if (_state == zero_size)
1.129 + return;
1.130 +
1.131 + HeapWord* obj = top();
1.132 +
1.133 + PSPromotionLAB::flush();
1.134 +
1.135 + assert(_start_array != NULL, "Sanity");
1.136 +
1.137 + _start_array->allocate_block(obj);
1.138 +}
1.139 +
1.140 +#ifdef ASSERT
1.141 +
1.142 +bool PSYoungPromotionLAB::lab_is_valid(MemRegion lab) {
1.143 + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
1.144 + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
1.145 +
1.146 + MutableSpace* to_space = heap->young_gen()->to_space();
1.147 + MemRegion used = to_space->used_region();
1.148 + if (used.contains(lab)) {
1.149 + return true;
1.150 + }
1.151 +
1.152 + return false;
1.153 +}
1.154 +
1.155 +bool PSOldPromotionLAB::lab_is_valid(MemRegion lab) {
1.156 + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
1.157 + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
1.158 + assert(_start_array->covered_region().contains(lab), "Sanity");
1.159 +
1.160 + PSOldGen* old_gen = heap->old_gen();
1.161 + MemRegion used = old_gen->object_space()->used_region();
1.162 +
1.163 + if (used.contains(lab)) {
1.164 + return true;
1.165 + }
1.166 +
1.167 + return false;
1.168 +}
1.169 +
1.170 +#endif /* ASSERT */
