Wed, 23 Jan 2013 13:02:39 -0500
8005915: Unify SERIALGC and INCLUDE_ALTERNATE_GCS
Summary: Rename INCLUDE_ALTERNATE_GCS to INCLUDE_ALL_GCS and replace SERIALGC with INCLUDE_ALL_GCS.
Reviewed-by: coleenp, stefank
1 /*
2 * Copyright (c) 2005, 2010, 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_UTILITIES_YIELDINGWORKGROUP_HPP
26 #define SHARE_VM_UTILITIES_YIELDINGWORKGROUP_HPP
28 #include "utilities/macros.hpp"
29 #if INCLUDE_ALL_GCS
30 #include "utilities/workgroup.hpp"
31 #endif // INCLUDE_ALL_GCS
34 // Forward declarations
35 class YieldingFlexibleWorkGang;
37 // Status of tasks
38 enum Status {
39 INACTIVE,
40 ACTIVE,
41 YIELDING,
42 YIELDED,
43 ABORTING,
44 ABORTED,
45 COMPLETING,
46 COMPLETED
47 };
49 // Class YieldingFlexibleGangWorker:
50 // Several instances of this class run in parallel as workers for a gang.
51 class YieldingFlexibleGangWorker: public GangWorker {
52 public:
53 // Ctor
54 YieldingFlexibleGangWorker(AbstractWorkGang* gang, int id) :
55 GangWorker(gang, id) { }
57 public:
58 YieldingFlexibleWorkGang* yf_gang() const
59 { return (YieldingFlexibleWorkGang*)gang(); }
61 protected: // Override from parent class
62 virtual void loop();
63 };
65 class FlexibleGangTask: public AbstractGangTask {
66 int _actual_size; // size of gang obtained
67 protected:
68 int _requested_size; // size of gang requested
69 public:
70 FlexibleGangTask(const char* name): AbstractGangTask(name),
71 _requested_size(0) {}
73 // The abstract work method.
74 // The argument tells you which member of the gang you are.
75 virtual void work(uint worker_id) = 0;
77 int requested_size() const { return _requested_size; }
78 int actual_size() const { return _actual_size; }
80 void set_requested_size(int sz) { _requested_size = sz; }
81 void set_actual_size(int sz) { _actual_size = sz; }
82 };
84 // An abstract task to be worked on by a flexible work gang,
85 // and where the workers will periodically yield, usually
86 // in response to some condition that is signalled by means
87 // that are specific to the task at hand.
88 // You subclass this to supply your own work() method.
89 // A second feature of this kind of work gang is that
90 // it allows for the signalling of certain exceptional
91 // conditions that may be encountered during the performance
92 // of the task and that may require the task at hand to be
93 // `aborted' forthwith. Finally, these gangs are `flexible'
94 // in that they can operate at partial capacity with some
95 // gang workers waiting on the bench; in other words, the
96 // size of the active worker pool can flex (up to an apriori
97 // maximum) in response to task requests at certain points.
98 // The last part (the flexible part) has not yet been fully
99 // fleshed out and is a work in progress.
100 class YieldingFlexibleGangTask: public FlexibleGangTask {
101 Status _status;
102 YieldingFlexibleWorkGang* _gang;
104 protected:
105 // Constructor and desctructor: only construct subclasses.
106 YieldingFlexibleGangTask(const char* name): FlexibleGangTask(name),
107 _status(INACTIVE),
108 _gang(NULL) { }
110 ~YieldingFlexibleGangTask() { }
112 friend class YieldingFlexibleWorkGang;
113 friend class YieldingFlexibleGangWorker;
114 NOT_PRODUCT(virtual bool is_YieldingFlexibleGang_task() const {
115 return true;
116 })
118 void set_status(Status s) {
119 _status = s;
120 }
121 YieldingFlexibleWorkGang* gang() {
122 return _gang;
123 }
124 void set_gang(YieldingFlexibleWorkGang* gang) {
125 assert(_gang == NULL || gang == NULL, "Clobber without intermediate reset?");
126 _gang = gang;
127 }
129 public:
130 // The abstract work method.
131 // The argument tells you which member of the gang you are.
132 virtual void work(uint worker_id) = 0;
134 // Subclasses should call the parent's yield() method
135 // after having done any work specific to the subclass.
136 virtual void yield();
138 // An abstract method supplied by
139 // a concrete sub-class which is used by the coordinator
140 // to do any "central yielding" work.
141 virtual void coordinator_yield() = 0;
143 // Subclasses should call the parent's abort() method
144 // after having done any work specific to the sunbclass.
145 virtual void abort();
147 Status status() const { return _status; }
148 bool yielding() const { return _status == YIELDING; }
149 bool yielded() const { return _status == YIELDED; }
150 bool completed() const { return _status == COMPLETED; }
151 bool aborted() const { return _status == ABORTED; }
152 bool active() const { return _status == ACTIVE; }
153 };
154 // Class YieldingWorkGang: A subclass of WorkGang.
155 // In particular, a YieldingWorkGang is made up of
156 // YieldingGangWorkers, and provides infrastructure
157 // supporting yielding to the "GangOverseer",
158 // being the thread that orchestrates the WorkGang via run_task().
159 class YieldingFlexibleWorkGang: public FlexibleWorkGang {
160 // Here's the public interface to this class.
161 public:
162 // Constructor and destructor.
163 YieldingFlexibleWorkGang(const char* name, uint workers,
164 bool are_GC_task_threads);
166 YieldingFlexibleGangTask* yielding_task() const {
167 assert(task() == NULL || task()->is_YieldingFlexibleGang_task(),
168 "Incorrect cast");
169 return (YieldingFlexibleGangTask*)task();
170 }
171 // Allocate a worker and return a pointer to it.
172 GangWorker* allocate_worker(uint which);
174 // Run a task; returns when the task is done, or the workers yield,
175 // or the task is aborted, or the work gang is terminated via stop().
176 // A task that has been yielded can be continued via this same interface
177 // by using the same task repeatedly as the argument to the call.
178 // It is expected that the YieldingFlexibleGangTask carries the appropriate
179 // continuation information used by workers to continue the task
180 // from its last yield point. Thus, a completed task will return
181 // immediately with no actual work having been done by the workers.
182 void run_task(AbstractGangTask* task) {
183 guarantee(false, "Use start_task instead");
184 }
185 void start_task(YieldingFlexibleGangTask* new_task);
186 void continue_task(YieldingFlexibleGangTask* gang_task);
188 // Abort a currently running task, if any; returns when all the workers
189 // have stopped working on the current task and have returned to their
190 // waiting stations.
191 void abort_task();
193 // Yield: workers wait at their current working stations
194 // until signalled to proceed by the overseer.
195 void yield();
197 // Abort: workers are expected to return to their waiting
198 // stations, whence they are ready for the next task dispatched
199 // by the overseer.
200 void abort();
202 private:
203 uint _yielded_workers;
204 void wait_for_gang();
206 public:
207 // Accessors for fields
208 uint yielded_workers() const {
209 return _yielded_workers;
210 }
212 private:
213 friend class YieldingFlexibleGangWorker;
214 void reset(); // NYI
215 };
217 #endif // SHARE_VM_UTILITIES_YIELDINGWORKGROUP_HPP