Mercurial > hg > graal-compiler
annotate src/share/vm/utilities/workgroup.cpp @ 1833:8b10f48633dc
6984287: Regularize how GC parallel workers are specified.
Summary: Associate number of GC workers with the workgang as opposed to the task.
Reviewed-by: johnc, ysr
| author | jmasa |
|---|---|
| date | Mon, 20 Sep 2010 14:38:38 -0700 |
| parents | c18cbe5936b8 |
| children | f95d63e2154a |
| rev | line source |
|---|---|
| 0 | 1 /* |
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2 * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. |
| 0 | 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 * | |
|
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 25 # include "incls/_precompiled.incl" | |
| 26 # include "incls/_workgroup.cpp.incl" | |
| 27 | |
| 28 // Definitions of WorkGang methods. | |
| 29 | |
| 30 AbstractWorkGang::AbstractWorkGang(const char* name, | |
| 342 | 31 bool are_GC_task_threads, |
| 32 bool are_ConcurrentGC_threads) : | |
| 0 | 33 _name(name), |
| 342 | 34 _are_GC_task_threads(are_GC_task_threads), |
| 35 _are_ConcurrentGC_threads(are_ConcurrentGC_threads) { | |
| 36 | |
| 37 assert(!(are_GC_task_threads && are_ConcurrentGC_threads), | |
| 38 "They cannot both be STW GC and Concurrent threads" ); | |
| 39 | |
| 0 | 40 // Other initialization. |
| 41 _monitor = new Monitor(/* priority */ Mutex::leaf, | |
| 42 /* name */ "WorkGroup monitor", | |
| 342 | 43 /* allow_vm_block */ are_GC_task_threads); |
| 0 | 44 assert(monitor() != NULL, "Failed to allocate monitor"); |
| 45 _terminate = false; | |
| 46 _task = NULL; | |
| 47 _sequence_number = 0; | |
| 48 _started_workers = 0; | |
| 49 _finished_workers = 0; | |
| 50 } | |
| 51 | |
| 52 WorkGang::WorkGang(const char* name, | |
| 342 | 53 int workers, |
| 54 bool are_GC_task_threads, | |
| 55 bool are_ConcurrentGC_threads) : | |
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56 AbstractWorkGang(name, are_GC_task_threads, are_ConcurrentGC_threads) { |
| 0 | 57 // Save arguments. |
| 58 _total_workers = workers; | |
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59 } |
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60 |
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61 GangWorker* WorkGang::allocate_worker(int which) { |
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62 GangWorker* new_worker = new GangWorker(this, which); |
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63 return new_worker; |
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64 } |
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65 |
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66 // The current implementation will exit if the allocation |
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67 // of any worker fails. Still, return a boolean so that |
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68 // a future implementation can possibly do a partial |
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69 // initialization of the workers and report such to the |
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70 // caller. |
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71 bool WorkGang::initialize_workers() { |
| 342 | 72 |
| 0 | 73 if (TraceWorkGang) { |
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74 tty->print_cr("Constructing work gang %s with %d threads", |
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75 name(), |
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76 total_workers()); |
| 0 | 77 } |
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78 _gang_workers = NEW_C_HEAP_ARRAY(GangWorker*, total_workers()); |
| 342 | 79 if (gang_workers() == NULL) { |
| 80 vm_exit_out_of_memory(0, "Cannot create GangWorker array."); | |
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81 return false; |
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82 } |
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83 os::ThreadType worker_type; |
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84 if (are_ConcurrentGC_threads()) { |
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85 worker_type = os::cgc_thread; |
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86 } else { |
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87 worker_type = os::pgc_thread; |
| 342 | 88 } |
| 0 | 89 for (int worker = 0; worker < total_workers(); worker += 1) { |
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90 GangWorker* new_worker = allocate_worker(worker); |
| 0 | 91 assert(new_worker != NULL, "Failed to allocate GangWorker"); |
| 92 _gang_workers[worker] = new_worker; | |
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93 if (new_worker == NULL || !os::create_thread(new_worker, worker_type)) { |
| 0 | 94 vm_exit_out_of_memory(0, "Cannot create worker GC thread. Out of system resources."); |
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95 return false; |
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96 } |
| 0 | 97 if (!DisableStartThread) { |
| 98 os::start_thread(new_worker); | |
| 99 } | |
| 100 } | |
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101 return true; |
| 0 | 102 } |
| 103 | |
| 104 AbstractWorkGang::~AbstractWorkGang() { | |
| 105 if (TraceWorkGang) { | |
| 106 tty->print_cr("Destructing work gang %s", name()); | |
| 107 } | |
| 108 stop(); // stop all the workers | |
| 109 for (int worker = 0; worker < total_workers(); worker += 1) { | |
| 110 delete gang_worker(worker); | |
| 111 } | |
| 112 delete gang_workers(); | |
| 113 delete monitor(); | |
| 114 } | |
| 115 | |
| 116 GangWorker* AbstractWorkGang::gang_worker(int i) const { | |
| 117 // Array index bounds checking. | |
| 118 GangWorker* result = NULL; | |
| 119 assert(gang_workers() != NULL, "No workers for indexing"); | |
| 120 assert(((i >= 0) && (i < total_workers())), "Worker index out of bounds"); | |
| 121 result = _gang_workers[i]; | |
| 122 assert(result != NULL, "Indexing to null worker"); | |
| 123 return result; | |
| 124 } | |
| 125 | |
| 126 void WorkGang::run_task(AbstractGangTask* task) { | |
| 127 // This thread is executed by the VM thread which does not block | |
| 128 // on ordinary MutexLocker's. | |
| 129 MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag); | |
| 130 if (TraceWorkGang) { | |
| 131 tty->print_cr("Running work gang %s task %s", name(), task->name()); | |
| 132 } | |
| 133 // Tell all the workers to run a task. | |
| 134 assert(task != NULL, "Running a null task"); | |
| 135 // Initialize. | |
| 136 _task = task; | |
| 137 _sequence_number += 1; | |
| 138 _started_workers = 0; | |
| 139 _finished_workers = 0; | |
| 140 // Tell the workers to get to work. | |
| 141 monitor()->notify_all(); | |
| 142 // Wait for them to be finished | |
| 143 while (finished_workers() < total_workers()) { | |
| 144 if (TraceWorkGang) { | |
| 145 tty->print_cr("Waiting in work gang %s: %d/%d finished sequence %d", | |
| 146 name(), finished_workers(), total_workers(), | |
| 147 _sequence_number); | |
| 148 } | |
| 149 monitor()->wait(/* no_safepoint_check */ true); | |
| 150 } | |
| 151 _task = NULL; | |
| 152 if (TraceWorkGang) { | |
| 153 tty->print_cr("/nFinished work gang %s: %d/%d sequence %d", | |
| 154 name(), finished_workers(), total_workers(), | |
| 155 _sequence_number); | |
| 156 } | |
| 157 } | |
| 158 | |
| 159 void AbstractWorkGang::stop() { | |
| 160 // Tell all workers to terminate, then wait for them to become inactive. | |
| 161 MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag); | |
| 162 if (TraceWorkGang) { | |
| 163 tty->print_cr("Stopping work gang %s task %s", name(), task()->name()); | |
| 164 } | |
| 165 _task = NULL; | |
| 166 _terminate = true; | |
| 167 monitor()->notify_all(); | |
| 168 while (finished_workers() < total_workers()) { | |
| 169 if (TraceWorkGang) { | |
| 170 tty->print_cr("Waiting in work gang %s: %d/%d finished", | |
| 171 name(), finished_workers(), total_workers()); | |
| 172 } | |
| 173 monitor()->wait(/* no_safepoint_check */ true); | |
| 174 } | |
| 175 } | |
| 176 | |
| 177 void AbstractWorkGang::internal_worker_poll(WorkData* data) const { | |
| 178 assert(monitor()->owned_by_self(), "worker_poll is an internal method"); | |
| 179 assert(data != NULL, "worker data is null"); | |
| 180 data->set_terminate(terminate()); | |
| 181 data->set_task(task()); | |
| 182 data->set_sequence_number(sequence_number()); | |
| 183 } | |
| 184 | |
| 185 void AbstractWorkGang::internal_note_start() { | |
| 186 assert(monitor()->owned_by_self(), "note_finish is an internal method"); | |
| 187 _started_workers += 1; | |
| 188 } | |
| 189 | |
| 190 void AbstractWorkGang::internal_note_finish() { | |
| 191 assert(monitor()->owned_by_self(), "note_finish is an internal method"); | |
| 192 _finished_workers += 1; | |
| 193 } | |
| 194 | |
| 195 void AbstractWorkGang::print_worker_threads_on(outputStream* st) const { | |
| 196 uint num_thr = total_workers(); | |
| 197 for (uint i = 0; i < num_thr; i++) { | |
| 198 gang_worker(i)->print_on(st); | |
| 199 st->cr(); | |
| 200 } | |
| 201 } | |
| 202 | |
| 203 void AbstractWorkGang::threads_do(ThreadClosure* tc) const { | |
| 204 assert(tc != NULL, "Null ThreadClosure"); | |
| 205 uint num_thr = total_workers(); | |
| 206 for (uint i = 0; i < num_thr; i++) { | |
| 207 tc->do_thread(gang_worker(i)); | |
| 208 } | |
| 209 } | |
| 210 | |
| 211 // GangWorker methods. | |
| 212 | |
| 213 GangWorker::GangWorker(AbstractWorkGang* gang, uint id) { | |
| 214 _gang = gang; | |
| 215 set_id(id); | |
| 216 set_name("Gang worker#%d (%s)", id, gang->name()); | |
| 217 } | |
| 218 | |
| 219 void GangWorker::run() { | |
| 220 initialize(); | |
| 221 loop(); | |
| 222 } | |
| 223 | |
| 224 void GangWorker::initialize() { | |
| 225 this->initialize_thread_local_storage(); | |
| 226 assert(_gang != NULL, "No gang to run in"); | |
| 227 os::set_priority(this, NearMaxPriority); | |
| 228 if (TraceWorkGang) { | |
| 229 tty->print_cr("Running gang worker for gang %s id %d", | |
| 230 gang()->name(), id()); | |
| 231 } | |
| 232 // The VM thread should not execute here because MutexLocker's are used | |
| 233 // as (opposed to MutexLockerEx's). | |
| 234 assert(!Thread::current()->is_VM_thread(), "VM thread should not be part" | |
| 235 " of a work gang"); | |
| 236 } | |
| 237 | |
| 238 void GangWorker::loop() { | |
| 239 int previous_sequence_number = 0; | |
| 240 Monitor* gang_monitor = gang()->monitor(); | |
| 241 for ( ; /* !terminate() */; ) { | |
| 242 WorkData data; | |
| 243 int part; // Initialized below. | |
| 244 { | |
| 245 // Grab the gang mutex. | |
| 246 MutexLocker ml(gang_monitor); | |
| 247 // Wait for something to do. | |
| 248 // Polling outside the while { wait } avoids missed notifies | |
| 249 // in the outer loop. | |
| 250 gang()->internal_worker_poll(&data); | |
| 251 if (TraceWorkGang) { | |
| 252 tty->print("Polled outside for work in gang %s worker %d", | |
| 253 gang()->name(), id()); | |
| 254 tty->print(" terminate: %s", | |
| 255 data.terminate() ? "true" : "false"); | |
| 256 tty->print(" sequence: %d (prev: %d)", | |
| 257 data.sequence_number(), previous_sequence_number); | |
| 258 if (data.task() != NULL) { | |
| 259 tty->print(" task: %s", data.task()->name()); | |
| 260 } else { | |
| 261 tty->print(" task: NULL"); | |
| 262 } | |
| 263 tty->cr(); | |
| 264 } | |
| 265 for ( ; /* break or return */; ) { | |
| 266 // Terminate if requested. | |
| 267 if (data.terminate()) { | |
| 268 gang()->internal_note_finish(); | |
| 269 gang_monitor->notify_all(); | |
| 270 return; | |
| 271 } | |
| 272 // Check for new work. | |
| 273 if ((data.task() != NULL) && | |
| 274 (data.sequence_number() != previous_sequence_number)) { | |
| 275 gang()->internal_note_start(); | |
| 276 gang_monitor->notify_all(); | |
| 277 part = gang()->started_workers() - 1; | |
| 278 break; | |
| 279 } | |
| 280 // Nothing to do. | |
| 281 gang_monitor->wait(/* no_safepoint_check */ true); | |
| 282 gang()->internal_worker_poll(&data); | |
| 283 if (TraceWorkGang) { | |
| 284 tty->print("Polled inside for work in gang %s worker %d", | |
| 285 gang()->name(), id()); | |
| 286 tty->print(" terminate: %s", | |
| 287 data.terminate() ? "true" : "false"); | |
| 288 tty->print(" sequence: %d (prev: %d)", | |
| 289 data.sequence_number(), previous_sequence_number); | |
| 290 if (data.task() != NULL) { | |
| 291 tty->print(" task: %s", data.task()->name()); | |
| 292 } else { | |
| 293 tty->print(" task: NULL"); | |
| 294 } | |
| 295 tty->cr(); | |
| 296 } | |
| 297 } | |
| 298 // Drop gang mutex. | |
| 299 } | |
| 300 if (TraceWorkGang) { | |
| 301 tty->print("Work for work gang %s id %d task %s part %d", | |
| 302 gang()->name(), id(), data.task()->name(), part); | |
| 303 } | |
| 304 assert(data.task() != NULL, "Got null task"); | |
| 305 data.task()->work(part); | |
| 306 { | |
| 307 if (TraceWorkGang) { | |
| 308 tty->print("Finish for work gang %s id %d task %s part %d", | |
| 309 gang()->name(), id(), data.task()->name(), part); | |
| 310 } | |
| 311 // Grab the gang mutex. | |
| 312 MutexLocker ml(gang_monitor); | |
| 313 gang()->internal_note_finish(); | |
| 314 // Tell the gang you are done. | |
| 315 gang_monitor->notify_all(); | |
| 316 // Drop the gang mutex. | |
| 317 } | |
| 318 previous_sequence_number = data.sequence_number(); | |
| 319 } | |
| 320 } | |
| 321 | |
| 322 bool GangWorker::is_GC_task_thread() const { | |
| 342 | 323 return gang()->are_GC_task_threads(); |
| 324 } | |
| 325 | |
| 326 bool GangWorker::is_ConcurrentGC_thread() const { | |
| 327 return gang()->are_ConcurrentGC_threads(); | |
| 0 | 328 } |
| 329 | |
| 330 void GangWorker::print_on(outputStream* st) const { | |
| 331 st->print("\"%s\" ", name()); | |
| 332 Thread::print_on(st); | |
| 333 st->cr(); | |
| 334 } | |
| 335 | |
| 336 // Printing methods | |
| 337 | |
| 338 const char* AbstractWorkGang::name() const { | |
| 339 return _name; | |
| 340 } | |
| 341 | |
| 342 #ifndef PRODUCT | |
| 343 | |
| 344 const char* AbstractGangTask::name() const { | |
| 345 return _name; | |
| 346 } | |
| 347 | |
| 348 #endif /* PRODUCT */ | |
| 349 | |
| 350 // *** WorkGangBarrierSync | |
| 351 | |
| 352 WorkGangBarrierSync::WorkGangBarrierSync() | |
| 353 : _monitor(Mutex::safepoint, "work gang barrier sync", true), | |
| 342 | 354 _n_workers(0), _n_completed(0), _should_reset(false) { |
| 0 | 355 } |
| 356 | |
| 357 WorkGangBarrierSync::WorkGangBarrierSync(int n_workers, const char* name) | |
| 358 : _monitor(Mutex::safepoint, name, true), | |
| 342 | 359 _n_workers(n_workers), _n_completed(0), _should_reset(false) { |
| 0 | 360 } |
| 361 | |
| 362 void WorkGangBarrierSync::set_n_workers(int n_workers) { | |
| 363 _n_workers = n_workers; | |
| 364 _n_completed = 0; | |
| 342 | 365 _should_reset = false; |
| 0 | 366 } |
| 367 | |
| 368 void WorkGangBarrierSync::enter() { | |
| 369 MutexLockerEx x(monitor(), Mutex::_no_safepoint_check_flag); | |
| 342 | 370 if (should_reset()) { |
| 371 // The should_reset() was set and we are the first worker to enter | |
| 372 // the sync barrier. We will zero the n_completed() count which | |
| 373 // effectively resets the barrier. | |
| 374 zero_completed(); | |
| 375 set_should_reset(false); | |
| 376 } | |
| 0 | 377 inc_completed(); |
| 378 if (n_completed() == n_workers()) { | |
| 342 | 379 // At this point we would like to reset the barrier to be ready in |
| 380 // case it is used again. However, we cannot set n_completed() to | |
| 381 // 0, even after the notify_all(), given that some other workers | |
| 382 // might still be waiting for n_completed() to become == | |
| 383 // n_workers(). So, if we set n_completed() to 0, those workers | |
| 384 // will get stuck (as they will wake up, see that n_completed() != | |
| 385 // n_workers() and go back to sleep). Instead, we raise the | |
| 386 // should_reset() flag and the barrier will be reset the first | |
| 387 // time a worker enters it again. | |
| 388 set_should_reset(true); | |
| 0 | 389 monitor()->notify_all(); |
| 342 | 390 } else { |
| 0 | 391 while (n_completed() != n_workers()) { |
| 392 monitor()->wait(/* no_safepoint_check */ true); | |
| 393 } | |
| 394 } | |
| 395 } | |
| 396 | |
| 397 // SubTasksDone functions. | |
| 398 | |
| 399 SubTasksDone::SubTasksDone(int n) : | |
| 400 _n_tasks(n), _n_threads(1), _tasks(NULL) { | |
| 401 _tasks = NEW_C_HEAP_ARRAY(jint, n); | |
| 402 guarantee(_tasks != NULL, "alloc failure"); | |
| 403 clear(); | |
| 404 } | |
| 405 | |
| 406 bool SubTasksDone::valid() { | |
| 407 return _tasks != NULL; | |
| 408 } | |
| 409 | |
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410 void SubTasksDone::set_n_threads(int t) { |
| 0 | 411 #ifdef ASSERT |
| 412 assert(_claimed == 0 || _threads_completed == _n_threads, | |
| 413 "should not be called while tasks are being processed!"); | |
| 414 #endif | |
| 415 _n_threads = (t == 0 ? 1 : t); | |
| 416 } | |
| 417 | |
| 418 void SubTasksDone::clear() { | |
| 419 for (int i = 0; i < _n_tasks; i++) { | |
| 420 _tasks[i] = 0; | |
| 421 } | |
| 422 _threads_completed = 0; | |
| 423 #ifdef ASSERT | |
| 424 _claimed = 0; | |
| 425 #endif | |
| 426 } | |
| 427 | |
| 428 bool SubTasksDone::is_task_claimed(int t) { | |
| 429 assert(0 <= t && t < _n_tasks, "bad task id."); | |
| 430 jint old = _tasks[t]; | |
| 431 if (old == 0) { | |
| 432 old = Atomic::cmpxchg(1, &_tasks[t], 0); | |
| 433 } | |
| 434 assert(_tasks[t] == 1, "What else?"); | |
| 435 bool res = old != 0; | |
| 436 #ifdef ASSERT | |
| 437 if (!res) { | |
| 438 assert(_claimed < _n_tasks, "Too many tasks claimed; missing clear?"); | |
| 439 Atomic::inc(&_claimed); | |
| 440 } | |
| 441 #endif | |
| 442 return res; | |
| 443 } | |
| 444 | |
| 445 void SubTasksDone::all_tasks_completed() { | |
| 446 jint observed = _threads_completed; | |
| 447 jint old; | |
| 448 do { | |
| 449 old = observed; | |
| 450 observed = Atomic::cmpxchg(old+1, &_threads_completed, old); | |
| 451 } while (observed != old); | |
| 452 // If this was the last thread checking in, clear the tasks. | |
| 453 if (observed+1 == _n_threads) clear(); | |
| 454 } | |
| 455 | |
| 456 | |
| 457 SubTasksDone::~SubTasksDone() { | |
| 458 if (_tasks != NULL) FREE_C_HEAP_ARRAY(jint, _tasks); | |
| 459 } | |
| 460 | |
| 461 // *** SequentialSubTasksDone | |
| 462 | |
| 463 void SequentialSubTasksDone::clear() { | |
| 464 _n_tasks = _n_claimed = 0; | |
| 465 _n_threads = _n_completed = 0; | |
| 466 } | |
| 467 | |
| 468 bool SequentialSubTasksDone::valid() { | |
| 469 return _n_threads > 0; | |
| 470 } | |
| 471 | |
| 472 bool SequentialSubTasksDone::is_task_claimed(int& t) { | |
| 473 jint* n_claimed_ptr = &_n_claimed; | |
| 474 t = *n_claimed_ptr; | |
| 475 while (t < _n_tasks) { | |
| 476 jint res = Atomic::cmpxchg(t+1, n_claimed_ptr, t); | |
| 477 if (res == t) { | |
| 478 return false; | |
| 479 } | |
| 480 t = *n_claimed_ptr; | |
| 481 } | |
| 482 return true; | |
| 483 } | |
| 484 | |
| 485 bool SequentialSubTasksDone::all_tasks_completed() { | |
| 486 jint* n_completed_ptr = &_n_completed; | |
| 487 jint complete = *n_completed_ptr; | |
| 488 while (true) { | |
| 489 jint res = Atomic::cmpxchg(complete+1, n_completed_ptr, complete); | |
| 490 if (res == complete) { | |
| 491 break; | |
| 492 } | |
| 493 complete = res; | |
| 494 } | |
| 495 if (complete+1 == _n_threads) { | |
| 496 clear(); | |
| 497 return true; | |
| 498 } | |
| 499 return false; | |
| 500 } | |
| 342 | 501 |
| 502 bool FreeIdSet::_stat_init = false; | |
| 503 FreeIdSet* FreeIdSet::_sets[NSets]; | |
| 504 bool FreeIdSet::_safepoint; | |
| 505 | |
| 506 FreeIdSet::FreeIdSet(int sz, Monitor* mon) : | |
| 507 _sz(sz), _mon(mon), _hd(0), _waiters(0), _index(-1), _claimed(0) | |
| 508 { | |
| 509 _ids = new int[sz]; | |
| 510 for (int i = 0; i < sz; i++) _ids[i] = i+1; | |
| 511 _ids[sz-1] = end_of_list; // end of list. | |
| 512 if (_stat_init) { | |
| 513 for (int j = 0; j < NSets; j++) _sets[j] = NULL; | |
| 514 _stat_init = true; | |
| 515 } | |
| 516 // Add to sets. (This should happen while the system is still single-threaded.) | |
| 517 for (int j = 0; j < NSets; j++) { | |
| 518 if (_sets[j] == NULL) { | |
| 519 _sets[j] = this; | |
| 520 _index = j; | |
| 521 break; | |
| 522 } | |
| 523 } | |
| 524 guarantee(_index != -1, "Too many FreeIdSets in use!"); | |
| 525 } | |
| 526 | |
| 527 FreeIdSet::~FreeIdSet() { | |
| 528 _sets[_index] = NULL; | |
| 529 } | |
| 530 | |
| 531 void FreeIdSet::set_safepoint(bool b) { | |
| 532 _safepoint = b; | |
| 533 if (b) { | |
| 534 for (int j = 0; j < NSets; j++) { | |
| 535 if (_sets[j] != NULL && _sets[j]->_waiters > 0) { | |
| 536 Monitor* mon = _sets[j]->_mon; | |
| 537 mon->lock_without_safepoint_check(); | |
| 538 mon->notify_all(); | |
| 539 mon->unlock(); | |
| 540 } | |
| 541 } | |
| 542 } | |
| 543 } | |
| 544 | |
| 545 #define FID_STATS 0 | |
| 546 | |
| 547 int FreeIdSet::claim_par_id() { | |
| 548 #if FID_STATS | |
| 549 thread_t tslf = thr_self(); | |
| 550 tty->print("claim_par_id[%d]: sz = %d, claimed = %d\n", tslf, _sz, _claimed); | |
| 551 #endif | |
| 552 MutexLockerEx x(_mon, Mutex::_no_safepoint_check_flag); | |
| 553 while (!_safepoint && _hd == end_of_list) { | |
| 554 _waiters++; | |
| 555 #if FID_STATS | |
| 556 if (_waiters > 5) { | |
| 557 tty->print("claim_par_id waiting[%d]: %d waiters, %d claimed.\n", | |
| 558 tslf, _waiters, _claimed); | |
| 559 } | |
| 560 #endif | |
| 561 _mon->wait(Mutex::_no_safepoint_check_flag); | |
| 562 _waiters--; | |
| 563 } | |
| 564 if (_hd == end_of_list) { | |
| 565 #if FID_STATS | |
| 566 tty->print("claim_par_id[%d]: returning EOL.\n", tslf); | |
| 567 #endif | |
| 568 return -1; | |
| 569 } else { | |
| 570 int res = _hd; | |
| 571 _hd = _ids[res]; | |
| 572 _ids[res] = claimed; // For debugging. | |
| 573 _claimed++; | |
| 574 #if FID_STATS | |
| 575 tty->print("claim_par_id[%d]: returning %d, claimed = %d.\n", | |
| 576 tslf, res, _claimed); | |
| 577 #endif | |
| 578 return res; | |
| 579 } | |
| 580 } | |
| 581 | |
| 582 bool FreeIdSet::claim_perm_id(int i) { | |
| 583 assert(0 <= i && i < _sz, "Out of range."); | |
| 584 MutexLockerEx x(_mon, Mutex::_no_safepoint_check_flag); | |
| 585 int prev = end_of_list; | |
| 586 int cur = _hd; | |
| 587 while (cur != end_of_list) { | |
| 588 if (cur == i) { | |
| 589 if (prev == end_of_list) { | |
| 590 _hd = _ids[cur]; | |
| 591 } else { | |
| 592 _ids[prev] = _ids[cur]; | |
| 593 } | |
| 594 _ids[cur] = claimed; | |
| 595 _claimed++; | |
| 596 return true; | |
| 597 } else { | |
| 598 prev = cur; | |
| 599 cur = _ids[cur]; | |
| 600 } | |
| 601 } | |
| 602 return false; | |
| 603 | |
| 604 } | |
| 605 | |
| 606 void FreeIdSet::release_par_id(int id) { | |
| 607 MutexLockerEx x(_mon, Mutex::_no_safepoint_check_flag); | |
| 608 assert(_ids[id] == claimed, "Precondition."); | |
| 609 _ids[id] = _hd; | |
| 610 _hd = id; | |
| 611 _claimed--; | |
| 612 #if FID_STATS | |
| 613 tty->print("[%d] release_par_id(%d), waiters =%d, claimed = %d.\n", | |
| 614 thr_self(), id, _waiters, _claimed); | |
| 615 #endif | |
| 616 if (_waiters > 0) | |
| 617 // Notify all would be safer, but this is OK, right? | |
| 618 _mon->notify_all(); | |
| 619 } |