1 /*
2 * Copyright (c) 2000, 2014, 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 *
86 // to a value > 1 before a task that you would like executed in parallel
87 // and then to set it to 0 after that task has completed. A value of
88 // 0 is a "special" value in set_n_threads() which translates to
89 // setting _n_threads to 1.
90 //
91 // Some code uses _n_termination to decide if work should be done in
92 // parallel. The notorious possibly_parallel_oops_do() in threads.cpp
93 // is an example of such code. Look for variable "is_par" for other
94 // examples.
95 //
96 // The active_workers is not reset to 0 after a parallel phase. It's
97 // value may be used in later phases and in one instance at least
98 // (the parallel remark) it has to be used (the parallel remark depends
99 // on the partitioning done in the previous parallel scavenge).
100
101 class SharedHeap : public CollectedHeap {
102 friend class VMStructs;
103
104 friend class VM_GC_Operation;
105 friend class VM_CGC_Operation;
106
107 private:
108 // For claiming strong_roots tasks.
109 SubTasksDone* _process_strong_tasks;
110
111 protected:
112 // There should be only a single instance of "SharedHeap" in a program.
113 // This is enforced with the protected constructor below, which will also
114 // set the static pointer "_sh" to that instance.
115 static SharedHeap* _sh;
116
117 // A gc policy, controls global gc resource issues
118 CollectorPolicy *_collector_policy;
119
120 // See the discussion below, in the specification of the reader function
121 // for this variable.
122 int _strong_roots_parity;
123
124 // If we're doing parallel GC, use this gang of threads.
125 FlexibleWorkGang* _workers;
126
223 public:
224 enum ScanningOption {
225 SO_None = 0x0,
226 SO_AllCodeCache = 0x8,
227 SO_ScavengeCodeCache = 0x10
228 };
229
230 FlexibleWorkGang* workers() const { return _workers; }
231
232 // Invoke the "do_oop" method the closure "roots" on all root locations.
233 // The "so" argument determines which roots the closure is applied to:
234 // "SO_None" does none;
235 // "SO_AllCodeCache" applies the closure to all elements of the CodeCache.
236 // "SO_ScavengeCodeCache" applies the closure to elements on the scavenge root list in the CodeCache.
237 void process_roots(bool activate_scope,
238 ScanningOption so,
239 OopClosure* strong_roots,
240 OopClosure* weak_roots,
241 CLDClosure* strong_cld_closure,
242 CLDClosure* weak_cld_closure,
243 CodeBlobClosure* code_roots);
244 void process_all_roots(bool activate_scope,
245 ScanningOption so,
246 OopClosure* roots,
247 CLDClosure* cld_closure,
248 CodeBlobClosure* code_roots);
249 void process_strong_roots(bool activate_scope,
250 ScanningOption so,
251 OopClosure* roots,
252 CLDClosure* cld_closure,
253 CodeBlobClosure* code_roots);
254
255
256 // Apply "root_closure" to the JNI weak roots..
257 void process_weak_roots(OopClosure* root_closure);
258
259 // The functions below are helper functions that a subclass of
260 // "SharedHeap" can use in the implementation of its virtual
261 // functions.
262
263 public:
264
265 // Do anything common to GC's.
266 virtual void gc_prologue(bool full) = 0;
267 virtual void gc_epilogue(bool full) = 0;
268
269 // Sets the number of parallel threads that will be doing tasks
270 // (such as process roots) subsequently.
271 virtual void set_par_threads(uint t);
272
273 int n_termination();
|
1 /*
2 * Copyright (c) 2000, 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 *
86 // to a value > 1 before a task that you would like executed in parallel
87 // and then to set it to 0 after that task has completed. A value of
88 // 0 is a "special" value in set_n_threads() which translates to
89 // setting _n_threads to 1.
90 //
91 // Some code uses _n_termination to decide if work should be done in
92 // parallel. The notorious possibly_parallel_oops_do() in threads.cpp
93 // is an example of such code. Look for variable "is_par" for other
94 // examples.
95 //
96 // The active_workers is not reset to 0 after a parallel phase. It's
97 // value may be used in later phases and in one instance at least
98 // (the parallel remark) it has to be used (the parallel remark depends
99 // on the partitioning done in the previous parallel scavenge).
100
101 class SharedHeap : public CollectedHeap {
102 friend class VMStructs;
103
104 friend class VM_GC_Operation;
105 friend class VM_CGC_Operation;
106 public:
107 // The set of potentially parallel tasks in root scanning.
108 enum SH_process_roots_tasks {
109 SH_PS_Threads_oops_do,
110 SH_PS_StringTable_oops_do,
111 SH_PS_Universe_oops_do,
112 SH_PS_JNIHandles_oops_do,
113 SH_PS_ObjectSynchronizer_oops_do,
114 SH_PS_FlatProfiler_oops_do,
115 SH_PS_Management_oops_do,
116 SH_PS_SystemDictionary_oops_do,
117 SH_PS_ClassLoaderDataGraph_oops_do,
118 SH_PS_jvmti_oops_do,
119 SH_PS_CodeCache_oops_do,
120 // Leave this one last.
121 SH_PS_NumElements
122 };
123
124 static const char* ext_roots_task_str(uint task);
125 private:
126 // For claiming strong_roots tasks.
127 SubTasksDone* _process_strong_tasks;
128
129 protected:
130 // There should be only a single instance of "SharedHeap" in a program.
131 // This is enforced with the protected constructor below, which will also
132 // set the static pointer "_sh" to that instance.
133 static SharedHeap* _sh;
134
135 // A gc policy, controls global gc resource issues
136 CollectorPolicy *_collector_policy;
137
138 // See the discussion below, in the specification of the reader function
139 // for this variable.
140 int _strong_roots_parity;
141
142 // If we're doing parallel GC, use this gang of threads.
143 FlexibleWorkGang* _workers;
144
241 public:
242 enum ScanningOption {
243 SO_None = 0x0,
244 SO_AllCodeCache = 0x8,
245 SO_ScavengeCodeCache = 0x10
246 };
247
248 FlexibleWorkGang* workers() const { return _workers; }
249
250 // Invoke the "do_oop" method the closure "roots" on all root locations.
251 // The "so" argument determines which roots the closure is applied to:
252 // "SO_None" does none;
253 // "SO_AllCodeCache" applies the closure to all elements of the CodeCache.
254 // "SO_ScavengeCodeCache" applies the closure to elements on the scavenge root list in the CodeCache.
255 void process_roots(bool activate_scope,
256 ScanningOption so,
257 OopClosure* strong_roots,
258 OopClosure* weak_roots,
259 CLDClosure* strong_cld_closure,
260 CLDClosure* weak_cld_closure,
261 CodeBlobClosure* code_roots,
262 PhaseTimeData* phase_durations = NULL);
263 void process_all_roots(bool activate_scope,
264 ScanningOption so,
265 OopClosure* roots,
266 CLDClosure* cld_closure,
267 CodeBlobClosure* code_roots,
268 PhaseTimeData* phase_durations = NULL);
269 void process_strong_roots(bool activate_scope,
270 ScanningOption so,
271 OopClosure* roots,
272 CLDClosure* cld_closure,
273 CodeBlobClosure* code_roots,
274 PhaseTimeData* phase_durations = NULL);
275
276
277 // Apply "root_closure" to the JNI weak roots..
278 void process_weak_roots(OopClosure* root_closure);
279
280 // The functions below are helper functions that a subclass of
281 // "SharedHeap" can use in the implementation of its virtual
282 // functions.
283
284 public:
285
286 // Do anything common to GC's.
287 virtual void gc_prologue(bool full) = 0;
288 virtual void gc_epilogue(bool full) = 0;
289
290 // Sets the number of parallel threads that will be doing tasks
291 // (such as process roots) subsequently.
292 virtual void set_par_threads(uint t);
293
294 int n_termination();
|