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 2005-2008 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_GenCollectForPermanentAllocation
50 // VM_ParallelGCFailedAllocation
51 // VM_ParallelGCFailedPermanentAllocation
52 // - this operation is invoked when allocation is failed;
53 // operation performs garbage collection and tries to
54 // allocate afterwards;
55 //
56 // VM_GenCollectFull
57 // VM_GenCollectFullConcurrent
58 // VM_ParallelGCSystemGC
59 // - these operations preform full collection of heaps of
60 // different kind
61 //
62
63 class VM_GC_Operation: public VM_Operation {
64 protected:
65 BasicLock _pending_list_basic_lock; // for refs pending list notification (PLL)
66 unsigned int _gc_count_before; // gc count before acquiring PLL
67 unsigned int _full_gc_count_before; // full gc count before acquiring PLL
68 bool _full; // whether a "full" collection
69 bool _prologue_succeeded; // whether doit_prologue succeeded
70 GCCause::Cause _gc_cause; // the putative cause for this gc op
71 bool _gc_locked; // will be set if gc was locked
72
73 virtual bool skip_operation() const;
74
75 // java.lang.ref.Reference support
76 void acquire_pending_list_lock();
77 void release_and_notify_pending_list_lock();
78
79 public:
80 VM_GC_Operation(unsigned int gc_count_before,
81 unsigned int full_gc_count_before = 0,
82 bool full = false) {
83 _full = full;
84 _prologue_succeeded = false;
85 _gc_count_before = gc_count_before;
86
87 // A subclass constructor will likely overwrite the following
88 _gc_cause = GCCause::_no_cause_specified;
89
90 _gc_locked = false;
91
92 if (full) {
93 _full_gc_count_before = full_gc_count_before;
94 }
95 }
96 ~VM_GC_Operation() {}
97
98 // Acquire the reference synchronization lock
99 virtual bool doit_prologue();
100 // Do notifyAll (if needed) and release held lock
101 virtual void doit_epilogue();
102
103 virtual bool allow_nested_vm_operations() const { return true; }
104 bool prologue_succeeded() const { return _prologue_succeeded; }
105
106 void set_gc_locked() { _gc_locked = true; }
107 bool gc_locked() const { return _gc_locked; }
108
109 static void notify_gc_begin(bool full = false);
110 static void notify_gc_end();
111 };
112
113
114 class VM_GC_HeapInspection: public VM_GC_Operation {
115 private:
116 outputStream* _out;
117 bool _full_gc;
118 public:
119 VM_GC_HeapInspection(outputStream* out, bool request_full_gc) :
120 VM_GC_Operation(0 /* total collections, dummy, ignored */,
121 0 /* total full collections, dummy, ignored */,
122 request_full_gc) {
123 _out = out;
124 _full_gc = request_full_gc;
125 }
126
127 ~VM_GC_HeapInspection() {}
128 virtual VMOp_Type type() const { return VMOp_GC_HeapInspection; }
129 virtual bool skip_operation() const;
130 virtual bool doit_prologue();
131 virtual void doit();
132 };
133
134
135 class VM_GenCollectForAllocation: public VM_GC_Operation {
136 private:
137 HeapWord* _res;
138 size_t _size; // size of object to be allocated.
139 bool _tlab; // alloc is of a tlab.
140 public:
141 VM_GenCollectForAllocation(size_t size,
142 bool tlab,
143 unsigned int gc_count_before)
144 : VM_GC_Operation(gc_count_before),
145 _size(size),
146 _tlab(tlab) {
147 _res = NULL;
148 }
149 ~VM_GenCollectForAllocation() {}
150 virtual VMOp_Type type() const { return VMOp_GenCollectForAllocation; }
151 virtual void doit();
152 HeapWord* result() const { return _res; }
153 };
154
155
156 // VM operation to invoke a collection of the heap as a
157 // GenCollectedHeap heap.
158 class VM_GenCollectFull: public VM_GC_Operation {
159 private:
160 int _max_level;
161 public:
162 VM_GenCollectFull(unsigned int gc_count_before,
163 unsigned int full_gc_count_before,
164 GCCause::Cause gc_cause,
165 int max_level)
166 : VM_GC_Operation(gc_count_before, full_gc_count_before, true /* full */),
167 _max_level(max_level)
168 { _gc_cause = gc_cause; }
169 ~VM_GenCollectFull() {}
170 virtual VMOp_Type type() const { return VMOp_GenCollectFull; }
171 virtual void doit();
172 };
173
174 class VM_GenCollectForPermanentAllocation: public VM_GC_Operation {
175 private:
176 HeapWord* _res;
177 size_t _size; // size of object to be allocated
178 public:
179 VM_GenCollectForPermanentAllocation(size_t size,
180 unsigned int gc_count_before,
181 unsigned int full_gc_count_before,
182 GCCause::Cause gc_cause)
183 : VM_GC_Operation(gc_count_before, full_gc_count_before, true),
184 _size(size) {
185 _res = NULL;
186 _gc_cause = gc_cause;
187 }
188 ~VM_GenCollectForPermanentAllocation() {}
189 virtual VMOp_Type type() const { return VMOp_GenCollectForPermanentAllocation; }
190 virtual void doit();
191 HeapWord* result() const { return _res; }
192 };