Tue, 17 Oct 2017 12:58:25 +0800
merge
1 /*
2 * Copyright (c) 2005, 2015, 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 */
25 #ifndef SHARE_VM_GC_IMPLEMENTATION_SHARED_VMGCOPERATIONS_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_SHARED_VMGCOPERATIONS_HPP
28 #include "gc_implementation/shared/gcId.hpp"
29 #include "memory/heapInspection.hpp"
30 #include "runtime/handles.hpp"
31 #include "runtime/jniHandles.hpp"
32 #include "runtime/synchronizer.hpp"
33 #include "runtime/vm_operations.hpp"
34 #include "prims/jvmtiExport.hpp"
36 // The following class hierarchy represents
37 // a set of operations (VM_Operation) related to GC.
38 //
39 // VM_Operation
40 // VM_GC_Operation
41 // VM_GC_HeapInspection
42 // VM_GenCollectFull
43 // VM_GenCollectFullConcurrent
44 // VM_ParallelGCSystemGC
45 // VM_CollectForAllocation
46 // VM_GenCollectForAllocation
47 // VM_ParallelGCFailedAllocation
48 // VM_GC_Operation
49 // - implements methods common to all classes in the hierarchy:
50 // prevents multiple gc requests and manages lock on heap;
51 //
52 // VM_GC_HeapInspection
53 // - prints class histogram on SIGBREAK if PrintClassHistogram
54 // is specified; and also the attach "inspectheap" operation
55 //
56 // VM_CollectForAllocation
57 // VM_GenCollectForAllocation
58 // VM_ParallelGCFailedAllocation
59 // - this operation is invoked when allocation is failed;
60 // operation performs garbage collection and tries to
61 // allocate afterwards;
62 //
63 // VM_GenCollectFull
64 // VM_GenCollectFullConcurrent
65 // VM_ParallelGCSystemGC
66 // - these operations preform full collection of heaps of
67 // different kind
68 //
70 class VM_GC_Operation: public VM_Operation {
71 protected:
72 BasicLock _pending_list_basic_lock; // for refs pending list notification (PLL)
73 uint _gc_count_before; // gc count before acquiring PLL
74 uint _full_gc_count_before; // full gc count before acquiring PLL
75 bool _full; // whether a "full" collection
76 bool _prologue_succeeded; // whether doit_prologue succeeded
77 GCCause::Cause _gc_cause; // the putative cause for this gc op
78 bool _gc_locked; // will be set if gc was locked
80 virtual bool skip_operation() const;
82 // java.lang.ref.Reference support
83 void acquire_pending_list_lock();
84 void release_and_notify_pending_list_lock();
86 public:
87 VM_GC_Operation(uint gc_count_before,
88 GCCause::Cause _cause,
89 uint full_gc_count_before = 0,
90 bool full = false) {
91 _full = full;
92 _prologue_succeeded = false;
93 _gc_count_before = gc_count_before;
95 // A subclass constructor will likely overwrite the following
96 _gc_cause = _cause;
98 _gc_locked = false;
100 _full_gc_count_before = full_gc_count_before;
101 // In ParallelScavengeHeap::mem_allocate() collections can be
102 // executed within a loop and _all_soft_refs_clear can be set
103 // true after they have been cleared by a collection and another
104 // collection started so that _all_soft_refs_clear can be true
105 // when this collection is started. Don't assert that
106 // _all_soft_refs_clear have to be false here even though
107 // mutators have run. Soft refs will be cleared again in this
108 // collection.
109 }
110 ~VM_GC_Operation() {
111 CollectedHeap* ch = Universe::heap();
112 ch->collector_policy()->set_all_soft_refs_clear(false);
113 }
115 // Acquire the reference synchronization lock
116 virtual bool doit_prologue();
117 // Do notifyAll (if needed) and release held lock
118 virtual void doit_epilogue();
120 virtual bool allow_nested_vm_operations() const { return true; }
121 bool prologue_succeeded() const { return _prologue_succeeded; }
123 void set_gc_locked() { _gc_locked = true; }
124 bool gc_locked() const { return _gc_locked; }
126 static void notify_gc_begin(bool full = false);
127 static void notify_gc_end();
128 };
131 class VM_GC_HeapInspection: public VM_GC_Operation {
132 private:
133 outputStream* _out;
134 bool _full_gc;
135 bool _csv_format; // "comma separated values" format for spreadsheet.
136 bool _print_help;
137 bool _print_class_stats;
138 const char* _columns;
139 public:
140 VM_GC_HeapInspection(outputStream* out, bool request_full_gc) :
141 VM_GC_Operation(0 /* total collections, dummy, ignored */,
142 GCCause::_heap_inspection /* GC Cause */,
143 0 /* total full collections, dummy, ignored */,
144 request_full_gc) {
145 _out = out;
146 _full_gc = request_full_gc;
147 _csv_format = false;
148 _print_help = false;
149 _print_class_stats = false;
150 _columns = NULL;
151 }
153 ~VM_GC_HeapInspection() {}
154 virtual VMOp_Type type() const { return VMOp_GC_HeapInspection; }
155 virtual bool skip_operation() const;
156 virtual bool doit_prologue();
157 virtual void doit();
158 void set_csv_format(bool value) {_csv_format = value;}
159 void set_print_help(bool value) {_print_help = value;}
160 void set_print_class_stats(bool value) {_print_class_stats = value;}
161 void set_columns(const char* value) {_columns = value;}
162 protected:
163 bool collect();
164 };
166 class VM_CollectForAllocation : public VM_GC_Operation {
167 protected:
168 size_t _word_size; // Size of object to be allocated (in number of words)
169 HeapWord* _result; // Allocation result (NULL if allocation failed)
171 public:
172 VM_CollectForAllocation(size_t word_size, uint gc_count_before, GCCause::Cause cause);
174 HeapWord* result() const {
175 return _result;
176 }
177 };
179 class VM_GenCollectForAllocation : public VM_CollectForAllocation {
180 private:
181 bool _tlab; // alloc is of a tlab.
182 public:
183 VM_GenCollectForAllocation(size_t word_size,
184 bool tlab,
185 uint gc_count_before)
186 : VM_CollectForAllocation(word_size, gc_count_before, GCCause::_allocation_failure),
187 _tlab(tlab) {
188 assert(word_size != 0, "An allocation should always be requested with this operation.");
189 }
190 ~VM_GenCollectForAllocation() {}
191 virtual VMOp_Type type() const { return VMOp_GenCollectForAllocation; }
192 virtual void doit();
193 };
195 // VM operation to invoke a collection of the heap as a
196 // GenCollectedHeap heap.
197 class VM_GenCollectFull: public VM_GC_Operation {
198 private:
199 int _max_level;
200 public:
201 VM_GenCollectFull(uint gc_count_before,
202 uint full_gc_count_before,
203 GCCause::Cause gc_cause,
204 int max_level)
205 : VM_GC_Operation(gc_count_before, gc_cause, full_gc_count_before, true /* full */),
206 _max_level(max_level) { }
207 ~VM_GenCollectFull() {}
208 virtual VMOp_Type type() const { return VMOp_GenCollectFull; }
209 virtual void doit();
210 };
212 class VM_CollectForMetadataAllocation: public VM_GC_Operation {
213 private:
214 MetaWord* _result;
215 size_t _size; // size of object to be allocated
216 Metaspace::MetadataType _mdtype;
217 ClassLoaderData* _loader_data;
218 public:
219 VM_CollectForMetadataAllocation(ClassLoaderData* loader_data,
220 size_t size, Metaspace::MetadataType mdtype,
221 uint gc_count_before,
222 uint full_gc_count_before,
223 GCCause::Cause gc_cause);
224 virtual VMOp_Type type() const { return VMOp_CollectForMetadataAllocation; }
225 virtual void doit();
226 MetaWord* result() const { return _result; }
228 bool initiate_concurrent_GC();
229 };
231 class SvcGCMarker : public StackObj {
232 private:
233 JvmtiGCMarker _jgcm;
234 public:
235 typedef enum { MINOR, FULL, OTHER } reason_type;
237 SvcGCMarker(reason_type reason ) {
238 VM_GC_Operation::notify_gc_begin(reason == FULL);
239 }
241 ~SvcGCMarker() {
242 VM_GC_Operation::notify_gc_end();
243 }
244 };
246 #endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_VMGCOPERATIONS_HPP