1 /*
2 * Copyright (c) 2001, 2003, 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 package sun.jvm.hotspot.utilities;
26
27 import sun.jvm.hotspot.debugger.*;
28 import sun.jvm.hotspot.gc_interface.*;
29 import sun.jvm.hotspot.memory.*;
30 import sun.jvm.hotspot.oops.*;
31 import sun.jvm.hotspot.runtime.*;
32
33 /** Helper class which covers the reserved area of the heap with an
34 (object-external) set of mark bits, used for GC-like scans through
35 the heap like liveness analysis. */
36
37 public class MarkBits {
38 public MarkBits(CollectedHeap heap) {
39 MemRegion reserved = heap.reservedRegion();
40 // Must cover "reserved" with one bit for each OopHandle
41 start = reserved.start();
42 end = reserved.end();
43 long numOopHandles = end.minus(start) / VM.getVM().getOopSize();
44 // FIXME: will have trouble with larger heap sizes
45 bits = new BitMap((int) numOopHandles);
46 }
47
48 public void clear() {
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1 /*
2 * Copyright (c) 2001, 2015, 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 package sun.jvm.hotspot.utilities;
26
27 import sun.jvm.hotspot.debugger.*;
28 import sun.jvm.hotspot.gc.shared.*;
29 import sun.jvm.hotspot.memory.*;
30 import sun.jvm.hotspot.oops.*;
31 import sun.jvm.hotspot.runtime.*;
32
33 /** Helper class which covers the reserved area of the heap with an
34 (object-external) set of mark bits, used for GC-like scans through
35 the heap like liveness analysis. */
36
37 public class MarkBits {
38 public MarkBits(CollectedHeap heap) {
39 MemRegion reserved = heap.reservedRegion();
40 // Must cover "reserved" with one bit for each OopHandle
41 start = reserved.start();
42 end = reserved.end();
43 long numOopHandles = end.minus(start) / VM.getVM().getOopSize();
44 // FIXME: will have trouble with larger heap sizes
45 bits = new BitMap((int) numOopHandles);
46 }
47
48 public void clear() {
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