1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/parallelScavenge/psPromotionLAB.cpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,162 @@
1.4 +/*
1.5 + * Copyright 2002-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#include "incls/_precompiled.incl"
1.29 +#include "incls/_psPromotionLAB.cpp.incl"
1.30 +
1.31 +const size_t PSPromotionLAB::filler_header_size = align_object_size(typeArrayOopDesc::header_size(T_INT));
1.32 +
1.33 +// This is the shared initialization code. It sets up the basic pointers,
1.34 +// and allows enough extra space for a filler object. We call a virtual
1.35 +// method, "lab_is_valid()" to handle the different asserts the old/young
1.36 +// labs require.
1.37 +void PSPromotionLAB::initialize(MemRegion lab) {
1.38 + assert(lab_is_valid(lab), "Sanity");
1.39 +
1.40 + HeapWord* bottom = lab.start();
1.41 + HeapWord* end = lab.end();
1.42 +
1.43 + set_bottom(bottom);
1.44 + set_end(end);
1.45 + set_top(bottom);
1.46 +
1.47 + // We can be initialized to a zero size!
1.48 + if (free() > 0) {
1.49 + if (ZapUnusedHeapArea) {
1.50 + debug_only(Copy::fill_to_words(top(), free()/HeapWordSize, badHeapWord));
1.51 + }
1.52 +
1.53 + // NOTE! We need to allow space for a filler object.
1.54 + assert(lab.word_size() >= filler_header_size, "lab is too small");
1.55 + end = end - filler_header_size;
1.56 + set_end(end);
1.57 +
1.58 + _state = needs_flush;
1.59 + } else {
1.60 + _state = zero_size;
1.61 + }
1.62 +
1.63 + assert(this->top() <= this->end(), "pointers out of order");
1.64 +}
1.65 +
1.66 +// Fill all remaining lab space with an unreachable object.
1.67 +// The goal is to leave a contiguous parseable span of objects.
1.68 +void PSPromotionLAB::flush() {
1.69 + assert(_state != flushed, "Attempt to flush PLAB twice");
1.70 + assert(top() <= end(), "pointers out of order");
1.71 +
1.72 + // If we were initialized to a zero sized lab, there is
1.73 + // nothing to flush
1.74 + if (_state == zero_size)
1.75 + return;
1.76 +
1.77 + // PLAB's never allocate the last aligned_header_size
1.78 + // so they can always fill with an array.
1.79 + HeapWord* tlab_end = end() + filler_header_size;
1.80 + typeArrayOop filler_oop = (typeArrayOop) top();
1.81 + filler_oop->set_mark(markOopDesc::prototype());
1.82 + filler_oop->set_klass(Universe::intArrayKlassObj());
1.83 + const size_t array_length =
1.84 + pointer_delta(tlab_end, top()) - typeArrayOopDesc::header_size(T_INT);
1.85 + assert( (array_length * (HeapWordSize/sizeof(jint))) < (size_t)max_jint, "array too big in PSPromotionLAB");
1.86 + filler_oop->set_length((int)(array_length * (HeapWordSize/sizeof(jint))));
1.87 +
1.88 +#ifdef ASSERT
1.89 + // Note that we actually DO NOT want to use the aligned header size!
1.90 + HeapWord* elt_words = ((HeapWord*)filler_oop) + typeArrayOopDesc::header_size(T_INT);
1.91 + Copy::fill_to_words(elt_words, array_length, 0xDEAABABE);
1.92 +#endif
1.93 +
1.94 + set_bottom(NULL);
1.95 + set_end(NULL);
1.96 + set_top(NULL);
1.97 +
1.98 + _state = flushed;
1.99 +}
1.100 +
1.101 +bool PSPromotionLAB::unallocate_object(oop obj) {
1.102 + assert(Universe::heap()->is_in(obj), "Object outside heap");
1.103 +
1.104 + if (contains(obj)) {
1.105 + HeapWord* object_end = (HeapWord*)obj + obj->size();
1.106 + assert(object_end <= top(), "Object crosses promotion LAB boundary");
1.107 +
1.108 + if (object_end == top()) {
1.109 + set_top((HeapWord*)obj);
1.110 + return true;
1.111 + }
1.112 + }
1.113 +
1.114 + return false;
1.115 +}
1.116 +
1.117 +// Fill all remaining lab space with an unreachable object.
1.118 +// The goal is to leave a contiguous parseable span of objects.
1.119 +void PSOldPromotionLAB::flush() {
1.120 + assert(_state != flushed, "Attempt to flush PLAB twice");
1.121 + assert(top() <= end(), "pointers out of order");
1.122 +
1.123 + if (_state == zero_size)
1.124 + return;
1.125 +
1.126 + HeapWord* obj = top();
1.127 +
1.128 + PSPromotionLAB::flush();
1.129 +
1.130 + assert(_start_array != NULL, "Sanity");
1.131 +
1.132 + _start_array->allocate_block(obj);
1.133 +}
1.134 +
1.135 +#ifdef ASSERT
1.136 +
1.137 +bool PSYoungPromotionLAB::lab_is_valid(MemRegion lab) {
1.138 + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
1.139 + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
1.140 +
1.141 + MutableSpace* to_space = heap->young_gen()->to_space();
1.142 + MemRegion used = to_space->used_region();
1.143 + if (used.contains(lab)) {
1.144 + return true;
1.145 + }
1.146 +
1.147 + return false;
1.148 +}
1.149 +
1.150 +bool PSOldPromotionLAB::lab_is_valid(MemRegion lab) {
1.151 + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
1.152 + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
1.153 + assert(_start_array->covered_region().contains(lab), "Sanity");
1.154 +
1.155 + PSOldGen* old_gen = heap->old_gen();
1.156 + MemRegion used = old_gen->object_space()->used_region();
1.157 +
1.158 + if (used.contains(lab)) {
1.159 + return true;
1.160 + }
1.161 +
1.162 + return false;
1.163 +}
1.164 +
1.165 +#endif /* ASSERT */
