hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/freeChunk.cpp
author duke
Sat, 01 Dec 2007 00:00:00 +0000
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/*
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 * Copyright 2001-2006 Sun Microsystems, Inc.  All Rights Reserved.
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * This code is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 only, as
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 * published by the Free Software Foundation.
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 *
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * accompanied this code).
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 *
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 * You should have received a copy of the GNU General Public License version
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 *
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 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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 * CA 95054 USA or visit www.sun.com if you need additional information or
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 * have any questions.
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 *
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 */
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# include "incls/_precompiled.incl"
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# include "incls/_freeChunk.cpp.incl"
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#ifndef PRODUCT
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#define baadbabeHeapWord badHeapWordVal
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#define deadbeefHeapWord 0xdeadbeef
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size_t const FreeChunk::header_size() {
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  return sizeof(FreeChunk)/HeapWordSize;
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}
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void FreeChunk::mangleAllocated(size_t size) {
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  // mangle all but the header of a just-allocated block
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  // of storage
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  assert(size >= MinChunkSize, "smallest size of object");
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  // we can't assert that _size == size because this may be an
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  // allocation out of a linear allocation block
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  assert(sizeof(FreeChunk) % HeapWordSize == 0,
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         "shouldn't write beyond chunk");
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  HeapWord* addr = (HeapWord*)this;
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  size_t hdr = header_size();
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  Copy::fill_to_words(addr + hdr, size - hdr, baadbabeHeapWord);
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}
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void FreeChunk::mangleFreed(size_t size) {
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  assert(baadbabeHeapWord != deadbeefHeapWord, "Need distinct patterns");
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  // mangle all but the header of a just-freed block of storage
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  // just prior to passing it to the storage dictionary
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  assert(size >= MinChunkSize, "smallest size of object");
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  assert(size == _size, "just checking");
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  HeapWord* addr = (HeapWord*)this;
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  size_t hdr = header_size();
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  Copy::fill_to_words(addr + hdr, size - hdr, deadbeefHeapWord);
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}
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void FreeChunk::verifyList() const {
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  FreeChunk* nextFC = next();
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  if (nextFC != NULL) {
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    assert(this == nextFC->prev(), "broken chain");
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    assert(size() == nextFC->size(), "wrong size");
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    nextFC->verifyList();
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  }
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}
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#endif