1 #ifdef USE_PRAGMA_IDENT_HDR
2 #pragma ident "@(#)vmGCOperations.hpp 1.14 07/05/29 09:44:12 JVM"
3 #endif
4 /*
5 * Copyright 2005-2006 Sun Microsystems, Inc. All Rights Reserved.
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
7 *
8 * This code is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License version 2 only, as
10 * published by the Free Software Foundation.
11 *
12 * This code is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * version 2 for more details (a copy is included in the LICENSE file that
16 * accompanied this code).
17 *
18 * You should have received a copy of the GNU General Public License version
19 * 2 along with this work; if not, write to the Free Software Foundation,
20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21 *
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
24 * have any questions.
25 *
26 */
27
28 // The following class hierarchy represents
29 // a set of operations (VM_Operation) related to GC.
30 //
31 // VM_Operation
32 // VM_GC_Operation
33 // VM_GC_HeapInspection
34 // VM_GenCollectForAllocation
35 // VM_GenCollectFull
36 // VM_GenCollectFullConcurrent
37 // VM_ParallelGCFailedAllocation
38 // VM_ParallelGCFailedPermanentAllocation
39 // VM_ParallelGCSystemGC
40 // VM_GC_Operation
41 // - implements methods common to all classes in the hierarchy:
42 // prevents multiple gc requests and manages lock on heap;
43 //
44 // VM_GC_HeapInspection
45 // - prints class histogram on SIGBREAK if PrintClassHistogram
46 // is specified; and also the attach "inspectheap" operation
47 //
48 // VM_GenCollectForAllocation
49 // VM_ParallelGCFailedAllocation
50 // VM_ParallelGCFailedPermanentAllocation
51 // - this operation is invoked when allocation is failed;
52 // operation performs garbage collection and tries to
53 // allocate afterwards;
54 //
55 // VM_GenCollectFull
56 // VM_GenCollectFullConcurrent
57 // VM_ParallelGCSystemGC
58 // - these operations preform full collection of heaps of
59 // different kind
60 //
61
62 class VM_GC_Operation: public VM_Operation {
63 protected:
64 BasicLock _pending_list_basic_lock; // for refs pending list notification (PLL)
65 unsigned int _gc_count_before; // gc count before acquiring PLL
66 unsigned int _full_gc_count_before; // full gc count before acquiring PLL
67 bool _full; // whether a "full" collection
68 bool _prologue_succeeded; // whether doit_prologue succeeded
69 GCCause::Cause _gc_cause; // the putative cause for this gc op
70 bool _gc_locked; // will be set if gc was locked
71
72 virtual bool skip_operation() const;
73
74 // java.lang.ref.Reference support
75 void acquire_pending_list_lock();
76 void release_and_notify_pending_list_lock();
77
78 public:
79 VM_GC_Operation(unsigned int gc_count_before,
80 unsigned int full_gc_count_before = 0,
81 bool full = false) {
82 _full = full;
83 _prologue_succeeded = false;
84 _gc_count_before = gc_count_before;
85
86 // A subclass constructor will likely overwrite the following
87 _gc_cause = GCCause::_no_cause_specified;
88
89 _gc_locked = false;
90
91 if (full) {
92 _full_gc_count_before = full_gc_count_before;
93 }
94 }
95 ~VM_GC_Operation() {}
96
97 // Acquire the reference synchronization lock
98 virtual bool doit_prologue();
99 // Do notifyAll (if needed) and release held lock
100 virtual void doit_epilogue();
101
102 virtual bool allow_nested_vm_operations() const { return true; }
103 bool prologue_succeeded() const { return _prologue_succeeded; }
104
105 void set_gc_locked() { _gc_locked = true; }
106 bool gc_locked() const { return _gc_locked; }
107
108 static void notify_gc_begin(bool full = false);
109 static void notify_gc_end();
110 };
111
112
113 class VM_GC_HeapInspection: public VM_GC_Operation {
114 private:
115 outputStream* _out;
116 bool _full_gc;
117 public:
118 VM_GC_HeapInspection(outputStream* out, bool request_full_gc) :
119 VM_GC_Operation(0 /* total collections, dummy, ignored */,
120 0 /* total full collections, dummy, ignored */,
121 request_full_gc) {
122 _out = out;
123 _full_gc = request_full_gc;
124 }
125
126 ~VM_GC_HeapInspection() {}
127 virtual VMOp_Type type() const { return VMOp_GC_HeapInspection; }
128 virtual bool skip_operation() const;
129 virtual bool doit_prologue();
130 virtual void doit();
131 };
132
133
134 class VM_GenCollectForAllocation: public VM_GC_Operation {
135 private:
136 HeapWord* _res;
137 size_t _size; // size of object to be allocated.
138 bool _tlab; // alloc is of a tlab.
139 public:
140 VM_GenCollectForAllocation(size_t size,
141 bool tlab,
142 unsigned int gc_count_before)
143 : VM_GC_Operation(gc_count_before),
144 _size(size),
145 _tlab(tlab) {
146 _res = NULL;
147 }
148 ~VM_GenCollectForAllocation() {}
149 virtual VMOp_Type type() const { return VMOp_GenCollectForAllocation; }
150 virtual void doit();
151 HeapWord* result() const { return _res; }
152 };
153
154
155 // VM operation to invoke a collection of the heap as a
156 // GenCollectedHeap heap.
157 class VM_GenCollectFull: public VM_GC_Operation {
158 private:
159 int _max_level;
160 public:
161 VM_GenCollectFull(unsigned int gc_count_before,
162 unsigned int full_gc_count_before,
163 GCCause::Cause gc_cause,
164 int max_level)
165 : VM_GC_Operation(gc_count_before, full_gc_count_before, true /* full */),
166 _max_level(max_level)
167 { _gc_cause = gc_cause; }
168 ~VM_GenCollectFull() {}
169 virtual VMOp_Type type() const { return VMOp_GenCollectFull; }
170 virtual void doit();
171 };