1 /* 2 * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "gc_implementation/concurrentMarkSweep/freeChunk.hpp" 27 #include "memory/freeBlockDictionary.hpp" 28 #include "utilities/copy.hpp" 29 30 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 31 32 #ifndef PRODUCT 33 34 #define baadbabeHeapWord badHeapWordVal 35 #define deadbeefHeapWord 0xdeadbeef 36 37 size_t const FreeChunk::header_size() { 38 return sizeof(FreeChunk)/HeapWordSize; 39 } 40 41 void FreeChunk::mangleAllocated(size_t size) { 42 // mangle all but the header of a just-allocated block 43 // of storage 44 assert(size >= MinChunkSize, "smallest size of object"); 45 // we can't assert that _size == size because this may be an 46 // allocation out of a linear allocation block 47 assert(sizeof(FreeChunk) % HeapWordSize == 0, 48 "shouldn't write beyond chunk"); 49 HeapWord* addr = (HeapWord*)this; 50 size_t hdr = header_size(); 51 Copy::fill_to_words(addr + hdr, size - hdr, baadbabeHeapWord); 52 } 53 54 void FreeChunk::mangleFreed(size_t sz) { 55 assert(baadbabeHeapWord != deadbeefHeapWord, "Need distinct patterns"); 56 // mangle all but the header of a just-freed block of storage 57 // just prior to passing it to the storage dictionary 58 assert(sz >= MinChunkSize, "smallest size of object"); 59 assert(sz == size(), "just checking"); 60 HeapWord* addr = (HeapWord*)this; 61 size_t hdr = header_size(); 62 Copy::fill_to_words(addr + hdr, sz - hdr, deadbeefHeapWord); 63 } 64 65 void FreeChunk::verifyList() const { 66 FreeChunk* nextFC = next(); 67 if (nextFC != NULL) { 68 assert(this == nextFC->prev(), "broken chain"); 69 assert(size() == nextFC->size(), "wrong size"); 70 nextFC->verifyList(); 71 } 72 } 73 #endif 74 75 void FreeChunk::print_on(outputStream* st) { 76 st->print_cr("Next: " PTR_FORMAT " Prev: " PTR_FORMAT " %s", 77 next(), prev(), cantCoalesce() ? "[can't coalesce]" : ""); 78 }