Thu, 05 Jun 2008 15:57:56 -0700
6711316: Open source the Garbage-First garbage collector
Summary: First mercurial integration of the code for the Garbage-First garbage collector.
Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr
1 /*
2 * Copyright 2005-2006 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 */
25 // The following class hierarchy represents
26 // a set of operations (VM_Operation) related to GC.
27 //
28 // VM_Operation
29 // VM_GC_Operation
30 // VM_GC_HeapInspection
31 // VM_GenCollectForAllocation
32 // VM_GenCollectFull
33 // VM_GenCollectFullConcurrent
34 // VM_ParallelGCFailedAllocation
35 // VM_ParallelGCFailedPermanentAllocation
36 // VM_ParallelGCSystemGC
37 // VM_GC_Operation
38 // - implements methods common to all classes in the hierarchy:
39 // prevents multiple gc requests and manages lock on heap;
40 //
41 // VM_GC_HeapInspection
42 // - prints class histogram on SIGBREAK if PrintClassHistogram
43 // is specified; and also the attach "inspectheap" operation
44 //
45 // VM_GenCollectForAllocation
46 // VM_GenCollectForPermanentAllocation
47 // VM_ParallelGCFailedAllocation
48 // VM_ParallelGCFailedPermanentAllocation
49 // - this operation is invoked when allocation is failed;
50 // operation performs garbage collection and tries to
51 // allocate afterwards;
52 //
53 // VM_GenCollectFull
54 // VM_GenCollectFullConcurrent
55 // VM_ParallelGCSystemGC
56 // - these operations preform full collection of heaps of
57 // different kind
58 //
60 class VM_GC_Operation: public VM_Operation {
61 protected:
62 BasicLock _pending_list_basic_lock; // for refs pending list notification (PLL)
63 unsigned int _gc_count_before; // gc count before acquiring PLL
64 unsigned int _full_gc_count_before; // full gc count before acquiring PLL
65 bool _full; // whether a "full" collection
66 bool _prologue_succeeded; // whether doit_prologue succeeded
67 GCCause::Cause _gc_cause; // the putative cause for this gc op
68 bool _gc_locked; // will be set if gc was locked
70 virtual bool skip_operation() const;
72 // java.lang.ref.Reference support
73 void acquire_pending_list_lock();
74 void release_and_notify_pending_list_lock();
76 public:
77 VM_GC_Operation(unsigned int gc_count_before,
78 unsigned int full_gc_count_before = 0,
79 bool full = false) {
80 _full = full;
81 _prologue_succeeded = false;
82 _gc_count_before = gc_count_before;
84 // A subclass constructor will likely overwrite the following
85 _gc_cause = GCCause::_no_cause_specified;
87 _gc_locked = false;
89 if (full) {
90 _full_gc_count_before = full_gc_count_before;
91 }
92 }
93 ~VM_GC_Operation() {}
95 // Acquire the reference synchronization lock
96 virtual bool doit_prologue();
97 // Do notifyAll (if needed) and release held lock
98 virtual void doit_epilogue();
100 virtual bool allow_nested_vm_operations() const { return true; }
101 bool prologue_succeeded() const { return _prologue_succeeded; }
103 void set_gc_locked() { _gc_locked = true; }
104 bool gc_locked() const { return _gc_locked; }
106 static void notify_gc_begin(bool full = false);
107 static void notify_gc_end();
108 };
111 class VM_GC_HeapInspection: public VM_GC_Operation {
112 private:
113 outputStream* _out;
114 bool _full_gc;
115 public:
116 VM_GC_HeapInspection(outputStream* out, bool request_full_gc) :
117 VM_GC_Operation(0 /* total collections, dummy, ignored */,
118 0 /* total full collections, dummy, ignored */,
119 request_full_gc) {
120 _out = out;
121 _full_gc = request_full_gc;
122 }
124 ~VM_GC_HeapInspection() {}
125 virtual VMOp_Type type() const { return VMOp_GC_HeapInspection; }
126 virtual bool skip_operation() const;
127 virtual bool doit_prologue();
128 virtual void doit();
129 };
132 class VM_GenCollectForAllocation: public VM_GC_Operation {
133 private:
134 HeapWord* _res;
135 size_t _size; // size of object to be allocated.
136 bool _tlab; // alloc is of a tlab.
137 public:
138 VM_GenCollectForAllocation(size_t size,
139 bool tlab,
140 unsigned int gc_count_before)
141 : VM_GC_Operation(gc_count_before),
142 _size(size),
143 _tlab(tlab) {
144 _res = NULL;
145 }
146 ~VM_GenCollectForAllocation() {}
147 virtual VMOp_Type type() const { return VMOp_GenCollectForAllocation; }
148 virtual void doit();
149 HeapWord* result() const { return _res; }
150 };
153 // VM operation to invoke a collection of the heap as a
154 // GenCollectedHeap heap.
155 class VM_GenCollectFull: public VM_GC_Operation {
156 private:
157 int _max_level;
158 public:
159 VM_GenCollectFull(unsigned int gc_count_before,
160 unsigned int full_gc_count_before,
161 GCCause::Cause gc_cause,
162 int max_level)
163 : VM_GC_Operation(gc_count_before, full_gc_count_before, true /* full */),
164 _max_level(max_level)
165 { _gc_cause = gc_cause; }
166 ~VM_GenCollectFull() {}
167 virtual VMOp_Type type() const { return VMOp_GenCollectFull; }
168 virtual void doit();
169 };
171 class VM_GenCollectForPermanentAllocation: public VM_GC_Operation {
172 private:
173 HeapWord* _res;
174 size_t _size; // size of object to be allocated
175 public:
176 VM_GenCollectForPermanentAllocation(size_t size,
177 unsigned int gc_count_before,
178 unsigned int full_gc_count_before,
179 GCCause::Cause gc_cause)
180 : VM_GC_Operation(gc_count_before, full_gc_count_before, true),
181 _size(size) {
182 _res = NULL;
183 _gc_cause = gc_cause;
184 }
185 ~VM_GenCollectForPermanentAllocation() {}
186 virtual VMOp_Type type() const { return VMOp_GenCollectForPermanentAllocation; }
187 virtual void doit();
188 HeapWord* result() const { return _res; }
189 };