1 /*
2 * Copyright (c) 2005, 2016, 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 #ifndef SHARE_VM_GC_CMS_VMCMSOPERATIONS_HPP
26 #define SHARE_VM_GC_CMS_VMCMSOPERATIONS_HPP
27
28 #include "gc/cms/concurrentMarkSweepGeneration.hpp"
29 #include "gc/shared/gcCause.hpp"
30 #include "gc/shared/gcId.hpp"
31 #include "gc/shared/referencePendingListLocker.hpp"
32 #include "gc/shared/vmGCOperations.hpp"
33 #include "runtime/vm_operations.hpp"
34
35 // The VM_CMS_Operation is slightly different from
36 // a VM_GC_Operation -- and would not have subclassed easily
37 // to VM_GC_Operation without several changes to VM_GC_Operation.
38 // To minimize the changes, we have replicated some of the VM_GC_Operation
39 // functionality here. We will consolidate that back by doing subclassing
40 // as appropriate in Dolphin.
41 //
42 // VM_Operation
43 // VM_CMS_Operation
44 // - implements the common portion of work done in support
45 // of CMS' stop-world phases (initial mark and remark).
46 //
47 // VM_CMS_Initial_Mark
48 // VM_CMS_Final_Mark
49 //
50
51 // Forward decl.
52 class CMSCollector;
53
54 class VM_CMS_Operation: public VM_Operation {
55 private:
56 ReferencePendingListLocker _pending_list_locker;
57
58 protected:
59 CMSCollector* _collector; // associated collector
60 bool _prologue_succeeded; // whether doit_prologue succeeded
61 uint _gc_id;
62
63 bool lost_race() const;
64
65 // java.lang.ref.Reference support
66 void acquire_pending_list_lock();
67 void release_and_notify_pending_list_lock();
68
69 public:
70 VM_CMS_Operation(CMSCollector* collector):
71 _collector(collector),
72 _prologue_succeeded(false),
73 _gc_id(GCId::current()) {}
74 ~VM_CMS_Operation() {}
75
76 // The legal collector state for executing this CMS op.
77 virtual const CMSCollector::CollectorState legal_state() const = 0;
78
79 // Whether the pending list lock needs to be held
80 virtual const bool needs_pll() const = 0;
81
82 // Execute operations in the context of the caller,
83 // prior to execution of the vm operation itself.
84 virtual bool doit_prologue();
85 // Execute operations in the context of the caller,
86 // following completion of the vm operation.
87 virtual void doit_epilogue();
88
89 virtual bool evaluate_at_safepoint() const { return true; }
90 virtual bool is_cheap_allocated() const { return false; }
91 virtual bool allow_nested_vm_operations() const { return false; }
92 bool prologue_succeeded() const { return _prologue_succeeded; }
93
94 void verify_before_gc();
95 void verify_after_gc();
96 };
97
98
99 // VM_CMS_Operation for the initial marking phase of CMS.
100 class VM_CMS_Initial_Mark: public VM_CMS_Operation {
101 public:
102 VM_CMS_Initial_Mark(CMSCollector* _collector) :
103 VM_CMS_Operation(_collector) {}
104
105 virtual VMOp_Type type() const { return VMOp_CMS_Initial_Mark; }
106 virtual void doit();
107
108 virtual const CMSCollector::CollectorState legal_state() const {
109 return CMSCollector::InitialMarking;
110 }
111
112 virtual const bool needs_pll() const {
113 return false;
114 }
115 };
116
117 // VM_CMS_Operation for the final remark phase of CMS.
118 class VM_CMS_Final_Remark: public VM_CMS_Operation {
119 public:
120 VM_CMS_Final_Remark(CMSCollector* _collector) :
121 VM_CMS_Operation(_collector) {}
122 virtual VMOp_Type type() const { return VMOp_CMS_Final_Remark; }
123 virtual void doit();
124
125 virtual const CMSCollector::CollectorState legal_state() const {
126 return CMSCollector::FinalMarking;
127 }
128
129 virtual const bool needs_pll() const {
130 return true;
131 }
132 };
133
134
135 // VM operation to invoke a concurrent collection of the heap as a
136 // GenCollectedHeap heap.
137 class VM_GenCollectFullConcurrent: public VM_GC_Operation {
138 public:
139 VM_GenCollectFullConcurrent(uint gc_count_before,
140 uint full_gc_count_before,
141 GCCause::Cause gc_cause)
142 : VM_GC_Operation(gc_count_before, gc_cause, full_gc_count_before, true /* full */)
143 {
144 assert(FullGCCount_lock != NULL, "Error");
145 }
146 ~VM_GenCollectFullConcurrent() {}
147 virtual VMOp_Type type() const { return VMOp_GenCollectFullConcurrent; }
148 virtual void doit();
149 virtual void doit_epilogue();
150 virtual bool is_cheap_allocated() const { return false; }
151 virtual bool evaluate_at_safepoint() const;
152 };
153
154 #endif // SHARE_VM_GC_CMS_VMCMSOPERATIONS_HPP