src/share/vm/utilities/workgroup.hpp

Wed, 09 Apr 2008 15:10:22 -0700

author
rasbold
date
Wed, 09 Apr 2008 15:10:22 -0700
changeset 544
9f4457a14b58
parent 435
a61af66fc99e
child 777
37f87013dfd8
permissions
-rw-r--r--

Merge

duke@435 1 /*
duke@435 2 * Copyright 2002-2007 Sun Microsystems, Inc. All Rights Reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
duke@435 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435 20 * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435 21 * have any questions.
duke@435 22 *
duke@435 23 */
duke@435 24
duke@435 25 // Forward declarations of classes defined here
duke@435 26
duke@435 27 class WorkGang;
duke@435 28 class GangWorker;
duke@435 29 class YieldingFlexibleGangWorker;
duke@435 30 class YieldingFlexibleGangTask;
duke@435 31 class WorkData;
duke@435 32
duke@435 33 // An abstract task to be worked on by a gang.
duke@435 34 // You subclass this to supply your own work() method
duke@435 35 class AbstractGangTask: public CHeapObj {
duke@435 36 public:
duke@435 37 // The abstract work method.
duke@435 38 // The argument tells you which member of the gang you are.
duke@435 39 virtual void work(int i) = 0;
duke@435 40
duke@435 41 // Debugging accessor for the name.
duke@435 42 const char* name() const PRODUCT_RETURN_(return NULL;);
duke@435 43 int counter() { return _counter; }
duke@435 44 void set_counter(int value) { _counter = value; }
duke@435 45 int *address_of_counter() { return &_counter; }
duke@435 46
duke@435 47 // RTTI
duke@435 48 NOT_PRODUCT(virtual bool is_YieldingFlexibleGang_task() const {
duke@435 49 return false;
duke@435 50 })
duke@435 51
duke@435 52 private:
duke@435 53 NOT_PRODUCT(const char* _name;)
duke@435 54 // ??? Should a task have a priority associated with it?
duke@435 55 // ??? Or can the run method adjust priority as needed?
duke@435 56 int _counter;
duke@435 57
duke@435 58 protected:
duke@435 59 // Constructor and desctructor: only construct subclasses.
duke@435 60 AbstractGangTask(const char* name) {
duke@435 61 NOT_PRODUCT(_name = name);
duke@435 62 _counter = 0;
duke@435 63 }
duke@435 64 virtual ~AbstractGangTask() { }
duke@435 65 };
duke@435 66
duke@435 67
duke@435 68 // Class AbstractWorkGang:
duke@435 69 // An abstract class representing a gang of workers.
duke@435 70 // You subclass this to supply an implementation of run_task().
duke@435 71 class AbstractWorkGang: public CHeapObj {
duke@435 72 // Here's the public interface to this class.
duke@435 73 public:
duke@435 74 // Constructor and destructor.
duke@435 75 AbstractWorkGang(const char* name, bool are_GC_threads);
duke@435 76 ~AbstractWorkGang();
duke@435 77 // Run a task, returns when the task is done (or terminated).
duke@435 78 virtual void run_task(AbstractGangTask* task) = 0;
duke@435 79 // Stop and terminate all workers.
duke@435 80 virtual void stop();
duke@435 81 public:
duke@435 82 // Debugging.
duke@435 83 const char* name() const;
duke@435 84 protected:
duke@435 85 // Initialize only instance data.
duke@435 86 const bool _are_GC_threads;
duke@435 87 // Printing support.
duke@435 88 const char* _name;
duke@435 89 // The monitor which protects these data,
duke@435 90 // and notifies of changes in it.
duke@435 91 Monitor* _monitor;
duke@435 92 // The count of the number of workers in the gang.
duke@435 93 int _total_workers;
duke@435 94 // Whether the workers should terminate.
duke@435 95 bool _terminate;
duke@435 96 // The array of worker threads for this gang.
duke@435 97 // This is only needed for cleaning up.
duke@435 98 GangWorker** _gang_workers;
duke@435 99 // The task for this gang.
duke@435 100 AbstractGangTask* _task;
duke@435 101 // A sequence number for the current task.
duke@435 102 int _sequence_number;
duke@435 103 // The number of started workers.
duke@435 104 int _started_workers;
duke@435 105 // The number of finished workers.
duke@435 106 int _finished_workers;
duke@435 107 public:
duke@435 108 // Accessors for fields
duke@435 109 Monitor* monitor() const {
duke@435 110 return _monitor;
duke@435 111 }
duke@435 112 int total_workers() const {
duke@435 113 return _total_workers;
duke@435 114 }
duke@435 115 bool terminate() const {
duke@435 116 return _terminate;
duke@435 117 }
duke@435 118 GangWorker** gang_workers() const {
duke@435 119 return _gang_workers;
duke@435 120 }
duke@435 121 AbstractGangTask* task() const {
duke@435 122 return _task;
duke@435 123 }
duke@435 124 int sequence_number() const {
duke@435 125 return _sequence_number;
duke@435 126 }
duke@435 127 int started_workers() const {
duke@435 128 return _started_workers;
duke@435 129 }
duke@435 130 int finished_workers() const {
duke@435 131 return _finished_workers;
duke@435 132 }
duke@435 133 bool are_GC_threads() const {
duke@435 134 return _are_GC_threads;
duke@435 135 }
duke@435 136 // Predicates.
duke@435 137 bool is_idle() const {
duke@435 138 return (task() == NULL);
duke@435 139 }
duke@435 140 // Return the Ith gang worker.
duke@435 141 GangWorker* gang_worker(int i) const;
duke@435 142
duke@435 143 void threads_do(ThreadClosure* tc) const;
duke@435 144
duke@435 145 // Printing
duke@435 146 void print_worker_threads_on(outputStream *st) const;
duke@435 147 void print_worker_threads() const {
duke@435 148 print_worker_threads_on(tty);
duke@435 149 }
duke@435 150
duke@435 151 protected:
duke@435 152 friend class GangWorker;
duke@435 153 friend class YieldingFlexibleGangWorker;
duke@435 154 // Note activation and deactivation of workers.
duke@435 155 // These methods should only be called with the mutex held.
duke@435 156 void internal_worker_poll(WorkData* data) const;
duke@435 157 void internal_note_start();
duke@435 158 void internal_note_finish();
duke@435 159 };
duke@435 160
duke@435 161 class WorkData: public StackObj {
duke@435 162 // This would be a struct, but I want accessor methods.
duke@435 163 private:
duke@435 164 bool _terminate;
duke@435 165 AbstractGangTask* _task;
duke@435 166 int _sequence_number;
duke@435 167 public:
duke@435 168 // Constructor and destructor
duke@435 169 WorkData() {
duke@435 170 _terminate = false;
duke@435 171 _task = NULL;
duke@435 172 _sequence_number = 0;
duke@435 173 }
duke@435 174 ~WorkData() {
duke@435 175 }
duke@435 176 // Accessors and modifiers
duke@435 177 bool terminate() const { return _terminate; }
duke@435 178 void set_terminate(bool value) { _terminate = value; }
duke@435 179 AbstractGangTask* task() const { return _task; }
duke@435 180 void set_task(AbstractGangTask* value) { _task = value; }
duke@435 181 int sequence_number() const { return _sequence_number; }
duke@435 182 void set_sequence_number(int value) { _sequence_number = value; }
duke@435 183
duke@435 184 YieldingFlexibleGangTask* yf_task() const {
duke@435 185 return (YieldingFlexibleGangTask*)_task;
duke@435 186 }
duke@435 187 };
duke@435 188
duke@435 189 // Class WorkGang:
duke@435 190 class WorkGang: public AbstractWorkGang {
duke@435 191 public:
duke@435 192 // Constructor
duke@435 193 WorkGang(const char* name, int workers, bool are_GC_threads);
duke@435 194 // Run a task, returns when the task is done (or terminated).
duke@435 195 virtual void run_task(AbstractGangTask* task);
duke@435 196 };
duke@435 197
duke@435 198 // Class GangWorker:
duke@435 199 // Several instances of this class run in parallel as workers for a gang.
duke@435 200 class GangWorker: public WorkerThread {
duke@435 201 public:
duke@435 202 // Constructors and destructor.
duke@435 203 GangWorker(AbstractWorkGang* gang, uint id);
duke@435 204
duke@435 205 // The only real method: run a task for the gang.
duke@435 206 virtual void run();
duke@435 207 // Predicate for Thread
duke@435 208 virtual bool is_GC_task_thread() const;
duke@435 209 // Printing
duke@435 210 void print_on(outputStream* st) const;
duke@435 211 virtual void print() const { print_on(tty); }
duke@435 212 protected:
duke@435 213 AbstractWorkGang* _gang;
duke@435 214
duke@435 215 virtual void initialize();
duke@435 216 virtual void loop();
duke@435 217
duke@435 218 public:
duke@435 219 AbstractWorkGang* gang() const { return _gang; }
duke@435 220 };
duke@435 221
duke@435 222 // A class that acts as a synchronisation barrier. Workers enter
duke@435 223 // the barrier and must wait until all other workers have entered
duke@435 224 // before any of them may leave.
duke@435 225
duke@435 226 class WorkGangBarrierSync : public StackObj {
duke@435 227 protected:
duke@435 228 Monitor _monitor;
duke@435 229 int _n_workers;
duke@435 230 int _n_completed;
duke@435 231
duke@435 232 Monitor* monitor() { return &_monitor; }
duke@435 233 int n_workers() { return _n_workers; }
duke@435 234 int n_completed() { return _n_completed; }
duke@435 235
duke@435 236 void inc_completed() { _n_completed++; }
duke@435 237
duke@435 238 public:
duke@435 239 WorkGangBarrierSync();
duke@435 240 WorkGangBarrierSync(int n_workers, const char* name);
duke@435 241
duke@435 242 // Set the number of workers that will use the barrier.
duke@435 243 // Must be called before any of the workers start running.
duke@435 244 void set_n_workers(int n_workers);
duke@435 245
duke@435 246 // Enter the barrier. A worker that enters the barrier will
duke@435 247 // not be allowed to leave until all other threads have
duke@435 248 // also entered the barrier.
duke@435 249 void enter();
duke@435 250 };
duke@435 251
duke@435 252 // A class to manage claiming of subtasks within a group of tasks. The
duke@435 253 // subtasks will be identified by integer indices, usually elements of an
duke@435 254 // enumeration type.
duke@435 255
duke@435 256 class SubTasksDone: public CHeapObj {
duke@435 257 jint* _tasks;
duke@435 258 int _n_tasks;
duke@435 259 int _n_threads;
duke@435 260 jint _threads_completed;
duke@435 261 #ifdef ASSERT
duke@435 262 jint _claimed;
duke@435 263 #endif
duke@435 264
duke@435 265 // Set all tasks to unclaimed.
duke@435 266 void clear();
duke@435 267
duke@435 268 public:
duke@435 269 // Initializes "this" to a state in which there are "n" tasks to be
duke@435 270 // processed, none of the which are originally claimed. The number of
duke@435 271 // threads doing the tasks is initialized 1.
duke@435 272 SubTasksDone(int n);
duke@435 273
duke@435 274 // True iff the object is in a valid state.
duke@435 275 bool valid();
duke@435 276
duke@435 277 // Set the number of parallel threads doing the tasks to "t". Can only
duke@435 278 // be called before tasks start or after they are complete.
duke@435 279 void set_par_threads(int t);
duke@435 280
duke@435 281 // Returns "false" if the task "t" is unclaimed, and ensures that task is
duke@435 282 // claimed. The task "t" is required to be within the range of "this".
duke@435 283 bool is_task_claimed(int t);
duke@435 284
duke@435 285 // The calling thread asserts that it has attempted to claim all the
duke@435 286 // tasks that it will try to claim. Every thread in the parallel task
duke@435 287 // must execute this. (When the last thread does so, the task array is
duke@435 288 // cleared.)
duke@435 289 void all_tasks_completed();
duke@435 290
duke@435 291 // Destructor.
duke@435 292 ~SubTasksDone();
duke@435 293 };
duke@435 294
duke@435 295 // As above, but for sequential tasks, i.e. instead of claiming
duke@435 296 // sub-tasks from a set (possibly an enumeration), claim sub-tasks
duke@435 297 // in sequential order. This is ideal for claiming dynamically
duke@435 298 // partitioned tasks (like striding in the parallel remembered
duke@435 299 // set scanning). Note that unlike the above class this is
duke@435 300 // a stack object - is there any reason for it not to be?
duke@435 301
duke@435 302 class SequentialSubTasksDone : public StackObj {
duke@435 303 protected:
duke@435 304 jint _n_tasks; // Total number of tasks available.
duke@435 305 jint _n_claimed; // Number of tasks claimed.
duke@435 306 jint _n_threads; // Total number of parallel threads.
duke@435 307 jint _n_completed; // Number of completed threads.
duke@435 308
duke@435 309 void clear();
duke@435 310
duke@435 311 public:
duke@435 312 SequentialSubTasksDone() { clear(); }
duke@435 313 ~SequentialSubTasksDone() {}
duke@435 314
duke@435 315 // True iff the object is in a valid state.
duke@435 316 bool valid();
duke@435 317
duke@435 318 // number of tasks
duke@435 319 jint n_tasks() const { return _n_tasks; }
duke@435 320
duke@435 321 // Set the number of parallel threads doing the tasks to t.
duke@435 322 // Should be called before the task starts but it is safe
duke@435 323 // to call this once a task is running provided that all
duke@435 324 // threads agree on the number of threads.
duke@435 325 void set_par_threads(int t) { _n_threads = t; }
duke@435 326
duke@435 327 // Set the number of tasks to be claimed to t. As above,
duke@435 328 // should be called before the tasks start but it is safe
duke@435 329 // to call this once a task is running provided all threads
duke@435 330 // agree on the number of tasks.
duke@435 331 void set_n_tasks(int t) { _n_tasks = t; }
duke@435 332
duke@435 333 // Returns false if the next task in the sequence is unclaimed,
duke@435 334 // and ensures that it is claimed. Will set t to be the index
duke@435 335 // of the claimed task in the sequence. Will return true if
duke@435 336 // the task cannot be claimed and there are none left to claim.
duke@435 337 bool is_task_claimed(int& t);
duke@435 338
duke@435 339 // The calling thread asserts that it has attempted to claim
duke@435 340 // all the tasks it possibly can in the sequence. Every thread
duke@435 341 // claiming tasks must promise call this. Returns true if this
duke@435 342 // is the last thread to complete so that the thread can perform
duke@435 343 // cleanup if necessary.
duke@435 344 bool all_tasks_completed();
duke@435 345 };

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