Mon, 26 Jan 2009 12:47:21 -0800
6786503: Overflow list performance can be improved
Summary: Avoid overflow list walk in CMS & ParNew when it is unnecessary. Fix a couple of correctness issues, including a C-heap leak, in ParNew at the intersection of promotion failure, work queue overflow and object array chunking. Add stress testing option and related assertion checking.
Reviewed-by: jmasa
1 /*
2 * Copyright 2000-2008 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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25 // referencePolicy is used to determine when soft reference objects
26 // should be cleared.
29 class ReferencePolicy : public CHeapObj {
30 public:
31 virtual bool should_clear_reference(oop p) { ShouldNotReachHere(); return true; }
32 // Capture state (of-the-VM) information needed to evaluate the policy
33 virtual void setup() { /* do nothing */ }
34 };
36 class NeverClearPolicy : public ReferencePolicy {
37 public:
38 bool should_clear_reference(oop p) { return false; }
39 };
41 class AlwaysClearPolicy : public ReferencePolicy {
42 public:
43 bool should_clear_reference(oop p) { return true; }
44 };
46 class LRUCurrentHeapPolicy : public ReferencePolicy {
47 private:
48 jlong _max_interval;
50 public:
51 LRUCurrentHeapPolicy();
53 // Capture state (of-the-VM) information needed to evaluate the policy
54 void setup();
55 bool should_clear_reference(oop p);
56 };
58 class LRUMaxHeapPolicy : public ReferencePolicy {
59 private:
60 jlong _max_interval;
62 public:
63 LRUMaxHeapPolicy();
65 // Capture state (of-the-VM) information needed to evaluate the policy
66 void setup();
67 bool should_clear_reference(oop p);
68 };