Mercurial > hg > truffle

comparison src/share/vm/gc_implementation/parallelScavenge/prefetchQueue.hpp @ 0:a61af66fc99e jdk7-b24

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Initial load
author duke
date Sat, 01 Dec 2007 00:00:00 +0000
parents
children ba764ed4b6f2
comparison
equal deleted inserted replaced
-1:000000000000 0:a61af66fc99e
1 /*
2 * Copyright 2002-2003 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 //
26 // PrefetchQueue is a FIFO queue of variable length (currently 8).
27 //
28 // We need to examine the performance penalty of variable lengths.
29 // We may also want to split this into cpu dependant bits.
30 //
31
32 const int PREFETCH_QUEUE_SIZE = 8;
33
34 class PrefetchQueue : public CHeapObj {
35 private:
36 oop* _prefetch_queue[PREFETCH_QUEUE_SIZE];
37 unsigned int _prefetch_index;
38
39 public:
40 int length() { return PREFETCH_QUEUE_SIZE; }
41
42 inline void clear() {
43 for(int i=0; i<PREFETCH_QUEUE_SIZE; i++) {
44 _prefetch_queue[i] = NULL;
45 }
46 _prefetch_index = 0;
47 }
48
49 inline oop* push_and_pop(oop* p) {
50 Prefetch::write((*p)->mark_addr(), 0);
51 // This prefetch is intended to make sure the size field of array
52 // oops is in cache. It assumes the the object layout is
53 // mark -> klass -> size, and that mark and klass are heapword
54 // sized. If this should change, this prefetch will need updating!
55 Prefetch::write((*p)->mark_addr() + (HeapWordSize*2), 0);
56 _prefetch_queue[_prefetch_index++] = p;
57 _prefetch_index &= (PREFETCH_QUEUE_SIZE-1);
58 return _prefetch_queue[_prefetch_index];
59 }
60
61 // Stores a NULL pointer in the pop'd location.
62 inline oop* pop() {
63 _prefetch_queue[_prefetch_index++] = NULL;
64 _prefetch_index &= (PREFETCH_QUEUE_SIZE-1);
65 return _prefetch_queue[_prefetch_index];
66 }
67 };