1 /*
2 * Copyright (c) 2001, 2014, 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
header_size()37 size_t const FreeChunk::header_size() {
38 return sizeof(FreeChunk)/HeapWordSize;
39 }
40
mangleAllocated(size_t size)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
mangleFreed(size_t sz)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
verifyList() const65 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
print_on(outputStream * st)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 }
79