Mercurial > hg > truffle
annotate src/share/vm/utilities/workgroup.cpp @ 7090:05ce1defa4f9
Common out some parts of UnsafeLoad/Store in UnsafeAccess
author | Gilles Duboscq <duboscq@ssw.jku.at> |
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date | Thu, 29 Nov 2012 13:24:08 +0100 |
parents | b9a9ed0f8eeb |
children | 6f817ce50129 |
rev | line source |
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0 | 1 /* |
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2 * Copyright (c) 2001, 2012, 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 | |
1972 | 25 #include "precompiled.hpp" |
26 #include "memory/allocation.hpp" | |
27 #include "memory/allocation.inline.hpp" | |
28 #include "runtime/os.hpp" | |
29 #include "utilities/workgroup.hpp" | |
0 | 30 |
31 // Definitions of WorkGang methods. | |
32 | |
33 AbstractWorkGang::AbstractWorkGang(const char* name, | |
342 | 34 bool are_GC_task_threads, |
35 bool are_ConcurrentGC_threads) : | |
0 | 36 _name(name), |
342 | 37 _are_GC_task_threads(are_GC_task_threads), |
38 _are_ConcurrentGC_threads(are_ConcurrentGC_threads) { | |
39 | |
40 assert(!(are_GC_task_threads && are_ConcurrentGC_threads), | |
41 "They cannot both be STW GC and Concurrent threads" ); | |
42 | |
0 | 43 // Other initialization. |
44 _monitor = new Monitor(/* priority */ Mutex::leaf, | |
45 /* name */ "WorkGroup monitor", | |
342 | 46 /* allow_vm_block */ are_GC_task_threads); |
0 | 47 assert(monitor() != NULL, "Failed to allocate monitor"); |
48 _terminate = false; | |
49 _task = NULL; | |
50 _sequence_number = 0; | |
51 _started_workers = 0; | |
52 _finished_workers = 0; | |
53 } | |
54 | |
55 WorkGang::WorkGang(const char* name, | |
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56 uint workers, |
342 | 57 bool are_GC_task_threads, |
58 bool are_ConcurrentGC_threads) : | |
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59 AbstractWorkGang(name, are_GC_task_threads, are_ConcurrentGC_threads) { |
0 | 60 _total_workers = workers; |
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61 } |
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62 |
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63 GangWorker* WorkGang::allocate_worker(uint which) { |
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64 GangWorker* new_worker = new GangWorker(this, which); |
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65 return new_worker; |
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66 } |
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67 |
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68 // The current implementation will exit if the allocation |
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69 // of any worker fails. Still, return a boolean so that |
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70 // a future implementation can possibly do a partial |
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71 // initialization of the workers and report such to the |
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72 // caller. |
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73 bool WorkGang::initialize_workers() { |
342 | 74 |
0 | 75 if (TraceWorkGang) { |
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76 tty->print_cr("Constructing work gang %s with %d threads", |
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77 name(), |
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78 total_workers()); |
0 | 79 } |
6197 | 80 _gang_workers = NEW_C_HEAP_ARRAY(GangWorker*, total_workers(), mtInternal); |
342 | 81 if (gang_workers() == NULL) { |
82 vm_exit_out_of_memory(0, "Cannot create GangWorker array."); | |
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83 return false; |
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84 } |
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85 os::ThreadType worker_type; |
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86 if (are_ConcurrentGC_threads()) { |
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87 worker_type = os::cgc_thread; |
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88 } else { |
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89 worker_type = os::pgc_thread; |
342 | 90 } |
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91 for (uint worker = 0; worker < total_workers(); worker += 1) { |
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92 GangWorker* new_worker = allocate_worker(worker); |
0 | 93 assert(new_worker != NULL, "Failed to allocate GangWorker"); |
94 _gang_workers[worker] = new_worker; | |
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95 if (new_worker == NULL || !os::create_thread(new_worker, worker_type)) { |
0 | 96 vm_exit_out_of_memory(0, "Cannot create worker GC thread. Out of system resources."); |
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97 return false; |
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98 } |
0 | 99 if (!DisableStartThread) { |
100 os::start_thread(new_worker); | |
101 } | |
102 } | |
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103 return true; |
0 | 104 } |
105 | |
106 AbstractWorkGang::~AbstractWorkGang() { | |
107 if (TraceWorkGang) { | |
108 tty->print_cr("Destructing work gang %s", name()); | |
109 } | |
110 stop(); // stop all the workers | |
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111 for (uint worker = 0; worker < total_workers(); worker += 1) { |
0 | 112 delete gang_worker(worker); |
113 } | |
114 delete gang_workers(); | |
115 delete monitor(); | |
116 } | |
117 | |
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118 GangWorker* AbstractWorkGang::gang_worker(uint i) const { |
0 | 119 // Array index bounds checking. |
120 GangWorker* result = NULL; | |
121 assert(gang_workers() != NULL, "No workers for indexing"); | |
122 assert(((i >= 0) && (i < total_workers())), "Worker index out of bounds"); | |
123 result = _gang_workers[i]; | |
124 assert(result != NULL, "Indexing to null worker"); | |
125 return result; | |
126 } | |
127 | |
128 void WorkGang::run_task(AbstractGangTask* task) { | |
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129 run_task(task, total_workers()); |
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130 } |
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131 |
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132 void WorkGang::run_task(AbstractGangTask* task, uint no_of_parallel_workers) { |
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133 task->set_for_termination(no_of_parallel_workers); |
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134 |
0 | 135 // This thread is executed by the VM thread which does not block |
136 // on ordinary MutexLocker's. | |
137 MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag); | |
138 if (TraceWorkGang) { | |
139 tty->print_cr("Running work gang %s task %s", name(), task->name()); | |
140 } | |
141 // Tell all the workers to run a task. | |
142 assert(task != NULL, "Running a null task"); | |
143 // Initialize. | |
144 _task = task; | |
145 _sequence_number += 1; | |
146 _started_workers = 0; | |
147 _finished_workers = 0; | |
148 // Tell the workers to get to work. | |
149 monitor()->notify_all(); | |
150 // Wait for them to be finished | |
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151 while (finished_workers() < no_of_parallel_workers) { |
0 | 152 if (TraceWorkGang) { |
153 tty->print_cr("Waiting in work gang %s: %d/%d finished sequence %d", | |
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154 name(), finished_workers(), no_of_parallel_workers, |
0 | 155 _sequence_number); |
156 } | |
157 monitor()->wait(/* no_safepoint_check */ true); | |
158 } | |
159 _task = NULL; | |
160 if (TraceWorkGang) { | |
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161 tty->print_cr("\nFinished work gang %s: %d/%d sequence %d", |
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162 name(), finished_workers(), no_of_parallel_workers, |
0 | 163 _sequence_number); |
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164 Thread* me = Thread::current(); |
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165 tty->print_cr(" T: 0x%x VM_thread: %d", me, me->is_VM_thread()); |
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166 } |
0 | 167 } |
168 | |
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169 void FlexibleWorkGang::run_task(AbstractGangTask* task) { |
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170 // If active_workers() is passed, _finished_workers |
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171 // must only be incremented for workers that find non_null |
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172 // work (as opposed to all those that just check that the |
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173 // task is not null). |
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174 WorkGang::run_task(task, (uint) active_workers()); |
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175 } |
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176 |
0 | 177 void AbstractWorkGang::stop() { |
178 // Tell all workers to terminate, then wait for them to become inactive. | |
179 MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag); | |
180 if (TraceWorkGang) { | |
181 tty->print_cr("Stopping work gang %s task %s", name(), task()->name()); | |
182 } | |
183 _task = NULL; | |
184 _terminate = true; | |
185 monitor()->notify_all(); | |
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186 while (finished_workers() < active_workers()) { |
0 | 187 if (TraceWorkGang) { |
188 tty->print_cr("Waiting in work gang %s: %d/%d finished", | |
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189 name(), finished_workers(), active_workers()); |
0 | 190 } |
191 monitor()->wait(/* no_safepoint_check */ true); | |
192 } | |
193 } | |
194 | |
195 void AbstractWorkGang::internal_worker_poll(WorkData* data) const { | |
196 assert(monitor()->owned_by_self(), "worker_poll is an internal method"); | |
197 assert(data != NULL, "worker data is null"); | |
198 data->set_terminate(terminate()); | |
199 data->set_task(task()); | |
200 data->set_sequence_number(sequence_number()); | |
201 } | |
202 | |
203 void AbstractWorkGang::internal_note_start() { | |
204 assert(monitor()->owned_by_self(), "note_finish is an internal method"); | |
205 _started_workers += 1; | |
206 } | |
207 | |
208 void AbstractWorkGang::internal_note_finish() { | |
209 assert(monitor()->owned_by_self(), "note_finish is an internal method"); | |
210 _finished_workers += 1; | |
211 } | |
212 | |
213 void AbstractWorkGang::print_worker_threads_on(outputStream* st) const { | |
214 uint num_thr = total_workers(); | |
215 for (uint i = 0; i < num_thr; i++) { | |
216 gang_worker(i)->print_on(st); | |
217 st->cr(); | |
218 } | |
219 } | |
220 | |
221 void AbstractWorkGang::threads_do(ThreadClosure* tc) const { | |
222 assert(tc != NULL, "Null ThreadClosure"); | |
223 uint num_thr = total_workers(); | |
224 for (uint i = 0; i < num_thr; i++) { | |
225 tc->do_thread(gang_worker(i)); | |
226 } | |
227 } | |
228 | |
229 // GangWorker methods. | |
230 | |
231 GangWorker::GangWorker(AbstractWorkGang* gang, uint id) { | |
232 _gang = gang; | |
233 set_id(id); | |
234 set_name("Gang worker#%d (%s)", id, gang->name()); | |
235 } | |
236 | |
237 void GangWorker::run() { | |
238 initialize(); | |
239 loop(); | |
240 } | |
241 | |
242 void GangWorker::initialize() { | |
243 this->initialize_thread_local_storage(); | |
6197 | 244 this->record_stack_base_and_size(); |
0 | 245 assert(_gang != NULL, "No gang to run in"); |
246 os::set_priority(this, NearMaxPriority); | |
247 if (TraceWorkGang) { | |
248 tty->print_cr("Running gang worker for gang %s id %d", | |
249 gang()->name(), id()); | |
250 } | |
251 // The VM thread should not execute here because MutexLocker's are used | |
252 // as (opposed to MutexLockerEx's). | |
253 assert(!Thread::current()->is_VM_thread(), "VM thread should not be part" | |
254 " of a work gang"); | |
255 } | |
256 | |
257 void GangWorker::loop() { | |
258 int previous_sequence_number = 0; | |
259 Monitor* gang_monitor = gang()->monitor(); | |
260 for ( ; /* !terminate() */; ) { | |
261 WorkData data; | |
262 int part; // Initialized below. | |
263 { | |
264 // Grab the gang mutex. | |
265 MutexLocker ml(gang_monitor); | |
266 // Wait for something to do. | |
267 // Polling outside the while { wait } avoids missed notifies | |
268 // in the outer loop. | |
269 gang()->internal_worker_poll(&data); | |
270 if (TraceWorkGang) { | |
271 tty->print("Polled outside for work in gang %s worker %d", | |
272 gang()->name(), id()); | |
273 tty->print(" terminate: %s", | |
274 data.terminate() ? "true" : "false"); | |
275 tty->print(" sequence: %d (prev: %d)", | |
276 data.sequence_number(), previous_sequence_number); | |
277 if (data.task() != NULL) { | |
278 tty->print(" task: %s", data.task()->name()); | |
279 } else { | |
280 tty->print(" task: NULL"); | |
281 } | |
282 tty->cr(); | |
283 } | |
284 for ( ; /* break or return */; ) { | |
285 // Terminate if requested. | |
286 if (data.terminate()) { | |
287 gang()->internal_note_finish(); | |
288 gang_monitor->notify_all(); | |
289 return; | |
290 } | |
291 // Check for new work. | |
292 if ((data.task() != NULL) && | |
293 (data.sequence_number() != previous_sequence_number)) { | |
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294 if (gang()->needs_more_workers()) { |
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295 gang()->internal_note_start(); |
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296 gang_monitor->notify_all(); |
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297 part = gang()->started_workers() - 1; |
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298 break; |
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299 } |
0 | 300 } |
301 // Nothing to do. | |
302 gang_monitor->wait(/* no_safepoint_check */ true); | |
303 gang()->internal_worker_poll(&data); | |
304 if (TraceWorkGang) { | |
305 tty->print("Polled inside for work in gang %s worker %d", | |
306 gang()->name(), id()); | |
307 tty->print(" terminate: %s", | |
308 data.terminate() ? "true" : "false"); | |
309 tty->print(" sequence: %d (prev: %d)", | |
310 data.sequence_number(), previous_sequence_number); | |
311 if (data.task() != NULL) { | |
312 tty->print(" task: %s", data.task()->name()); | |
313 } else { | |
314 tty->print(" task: NULL"); | |
315 } | |
316 tty->cr(); | |
317 } | |
318 } | |
319 // Drop gang mutex. | |
320 } | |
321 if (TraceWorkGang) { | |
322 tty->print("Work for work gang %s id %d task %s part %d", | |
323 gang()->name(), id(), data.task()->name(), part); | |
324 } | |
325 assert(data.task() != NULL, "Got null task"); | |
326 data.task()->work(part); | |
327 { | |
328 if (TraceWorkGang) { | |
329 tty->print("Finish for work gang %s id %d task %s part %d", | |
330 gang()->name(), id(), data.task()->name(), part); | |
331 } | |
332 // Grab the gang mutex. | |
333 MutexLocker ml(gang_monitor); | |
334 gang()->internal_note_finish(); | |
335 // Tell the gang you are done. | |
336 gang_monitor->notify_all(); | |
337 // Drop the gang mutex. | |
338 } | |
339 previous_sequence_number = data.sequence_number(); | |
340 } | |
341 } | |
342 | |
343 bool GangWorker::is_GC_task_thread() const { | |
342 | 344 return gang()->are_GC_task_threads(); |
345 } | |
346 | |
347 bool GangWorker::is_ConcurrentGC_thread() const { | |
348 return gang()->are_ConcurrentGC_threads(); | |
0 | 349 } |
350 | |
351 void GangWorker::print_on(outputStream* st) const { | |
352 st->print("\"%s\" ", name()); | |
353 Thread::print_on(st); | |
354 st->cr(); | |
355 } | |
356 | |
357 // Printing methods | |
358 | |
359 const char* AbstractWorkGang::name() const { | |
360 return _name; | |
361 } | |
362 | |
363 #ifndef PRODUCT | |
364 | |
365 const char* AbstractGangTask::name() const { | |
366 return _name; | |
367 } | |
368 | |
369 #endif /* PRODUCT */ | |
370 | |
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371 // FlexibleWorkGang |
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372 |
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373 |
0 | 374 // *** WorkGangBarrierSync |
375 | |
376 WorkGangBarrierSync::WorkGangBarrierSync() | |
377 : _monitor(Mutex::safepoint, "work gang barrier sync", true), | |
342 | 378 _n_workers(0), _n_completed(0), _should_reset(false) { |
0 | 379 } |
380 | |
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381 WorkGangBarrierSync::WorkGangBarrierSync(uint n_workers, const char* name) |
0 | 382 : _monitor(Mutex::safepoint, name, true), |
342 | 383 _n_workers(n_workers), _n_completed(0), _should_reset(false) { |
0 | 384 } |
385 | |
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386 void WorkGangBarrierSync::set_n_workers(uint n_workers) { |
0 | 387 _n_workers = n_workers; |
388 _n_completed = 0; | |
342 | 389 _should_reset = false; |
0 | 390 } |
391 | |
392 void WorkGangBarrierSync::enter() { | |
393 MutexLockerEx x(monitor(), Mutex::_no_safepoint_check_flag); | |
342 | 394 if (should_reset()) { |
395 // The should_reset() was set and we are the first worker to enter | |
396 // the sync barrier. We will zero the n_completed() count which | |
397 // effectively resets the barrier. | |
398 zero_completed(); | |
399 set_should_reset(false); | |
400 } | |
0 | 401 inc_completed(); |
402 if (n_completed() == n_workers()) { | |
342 | 403 // At this point we would like to reset the barrier to be ready in |
404 // case it is used again. However, we cannot set n_completed() to | |
405 // 0, even after the notify_all(), given that some other workers | |
406 // might still be waiting for n_completed() to become == | |
407 // n_workers(). So, if we set n_completed() to 0, those workers | |
408 // will get stuck (as they will wake up, see that n_completed() != | |
409 // n_workers() and go back to sleep). Instead, we raise the | |
410 // should_reset() flag and the barrier will be reset the first | |
411 // time a worker enters it again. | |
412 set_should_reset(true); | |
0 | 413 monitor()->notify_all(); |
342 | 414 } else { |
0 | 415 while (n_completed() != n_workers()) { |
416 monitor()->wait(/* no_safepoint_check */ true); | |
417 } | |
418 } | |
419 } | |
420 | |
421 // SubTasksDone functions. | |
422 | |
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423 SubTasksDone::SubTasksDone(uint n) : |
0 | 424 _n_tasks(n), _n_threads(1), _tasks(NULL) { |
6197 | 425 _tasks = NEW_C_HEAP_ARRAY(uint, n, mtInternal); |
0 | 426 guarantee(_tasks != NULL, "alloc failure"); |
427 clear(); | |
428 } | |
429 | |
430 bool SubTasksDone::valid() { | |
431 return _tasks != NULL; | |
432 } | |
433 | |
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434 void SubTasksDone::set_n_threads(uint t) { |
0 | 435 assert(_claimed == 0 || _threads_completed == _n_threads, |
436 "should not be called while tasks are being processed!"); | |
437 _n_threads = (t == 0 ? 1 : t); | |
438 } | |
439 | |
440 void SubTasksDone::clear() { | |
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441 for (uint i = 0; i < _n_tasks; i++) { |
0 | 442 _tasks[i] = 0; |
443 } | |
444 _threads_completed = 0; | |
445 #ifdef ASSERT | |
446 _claimed = 0; | |
447 #endif | |
448 } | |
449 | |
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450 bool SubTasksDone::is_task_claimed(uint t) { |
0 | 451 assert(0 <= t && t < _n_tasks, "bad task id."); |
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452 uint old = _tasks[t]; |
0 | 453 if (old == 0) { |
454 old = Atomic::cmpxchg(1, &_tasks[t], 0); | |
455 } | |
456 assert(_tasks[t] == 1, "What else?"); | |
457 bool res = old != 0; | |
458 #ifdef ASSERT | |
459 if (!res) { | |
460 assert(_claimed < _n_tasks, "Too many tasks claimed; missing clear?"); | |
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461 Atomic::inc((volatile jint*) &_claimed); |
0 | 462 } |
463 #endif | |
464 return res; | |
465 } | |
466 | |
467 void SubTasksDone::all_tasks_completed() { | |
468 jint observed = _threads_completed; | |
469 jint old; | |
470 do { | |
471 old = observed; | |
472 observed = Atomic::cmpxchg(old+1, &_threads_completed, old); | |
473 } while (observed != old); | |
474 // If this was the last thread checking in, clear the tasks. | |
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475 if (observed+1 == (jint)_n_threads) clear(); |
0 | 476 } |
477 | |
478 | |
479 SubTasksDone::~SubTasksDone() { | |
6197 | 480 if (_tasks != NULL) FREE_C_HEAP_ARRAY(jint, _tasks, mtInternal); |
0 | 481 } |
482 | |
483 // *** SequentialSubTasksDone | |
484 | |
485 void SequentialSubTasksDone::clear() { | |
486 _n_tasks = _n_claimed = 0; | |
487 _n_threads = _n_completed = 0; | |
488 } | |
489 | |
490 bool SequentialSubTasksDone::valid() { | |
491 return _n_threads > 0; | |
492 } | |
493 | |
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494 bool SequentialSubTasksDone::is_task_claimed(uint& t) { |
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495 uint* n_claimed_ptr = &_n_claimed; |
0 | 496 t = *n_claimed_ptr; |
497 while (t < _n_tasks) { | |
498 jint res = Atomic::cmpxchg(t+1, n_claimed_ptr, t); | |
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499 if (res == (jint)t) { |
0 | 500 return false; |
501 } | |
502 t = *n_claimed_ptr; | |
503 } | |
504 return true; | |
505 } | |
506 | |
507 bool SequentialSubTasksDone::all_tasks_completed() { | |
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508 uint* n_completed_ptr = &_n_completed; |
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509 uint complete = *n_completed_ptr; |
0 | 510 while (true) { |
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511 uint res = Atomic::cmpxchg(complete+1, n_completed_ptr, complete); |
0 | 512 if (res == complete) { |
513 break; | |
514 } | |
515 complete = res; | |
516 } | |
517 if (complete+1 == _n_threads) { | |
518 clear(); | |
519 return true; | |
520 } | |
521 return false; | |
522 } | |
342 | 523 |
524 bool FreeIdSet::_stat_init = false; | |
525 FreeIdSet* FreeIdSet::_sets[NSets]; | |
526 bool FreeIdSet::_safepoint; | |
527 | |
528 FreeIdSet::FreeIdSet(int sz, Monitor* mon) : | |
529 _sz(sz), _mon(mon), _hd(0), _waiters(0), _index(-1), _claimed(0) | |
530 { | |
531 _ids = new int[sz]; | |
532 for (int i = 0; i < sz; i++) _ids[i] = i+1; | |
533 _ids[sz-1] = end_of_list; // end of list. | |
534 if (_stat_init) { | |
535 for (int j = 0; j < NSets; j++) _sets[j] = NULL; | |
536 _stat_init = true; | |
537 } | |
538 // Add to sets. (This should happen while the system is still single-threaded.) | |
539 for (int j = 0; j < NSets; j++) { | |
540 if (_sets[j] == NULL) { | |
541 _sets[j] = this; | |
542 _index = j; | |
543 break; | |
544 } | |
545 } | |
546 guarantee(_index != -1, "Too many FreeIdSets in use!"); | |
547 } | |
548 | |
549 FreeIdSet::~FreeIdSet() { | |
550 _sets[_index] = NULL; | |
551 } | |
552 | |
553 void FreeIdSet::set_safepoint(bool b) { | |
554 _safepoint = b; | |
555 if (b) { | |
556 for (int j = 0; j < NSets; j++) { | |
557 if (_sets[j] != NULL && _sets[j]->_waiters > 0) { | |
558 Monitor* mon = _sets[j]->_mon; | |
559 mon->lock_without_safepoint_check(); | |
560 mon->notify_all(); | |
561 mon->unlock(); | |
562 } | |
563 } | |
564 } | |
565 } | |
566 | |
567 #define FID_STATS 0 | |
568 | |
569 int FreeIdSet::claim_par_id() { | |
570 #if FID_STATS | |
571 thread_t tslf = thr_self(); | |
572 tty->print("claim_par_id[%d]: sz = %d, claimed = %d\n", tslf, _sz, _claimed); | |
573 #endif | |
574 MutexLockerEx x(_mon, Mutex::_no_safepoint_check_flag); | |
575 while (!_safepoint && _hd == end_of_list) { | |
576 _waiters++; | |
577 #if FID_STATS | |
578 if (_waiters > 5) { | |
579 tty->print("claim_par_id waiting[%d]: %d waiters, %d claimed.\n", | |
580 tslf, _waiters, _claimed); | |
581 } | |
582 #endif | |
583 _mon->wait(Mutex::_no_safepoint_check_flag); | |
584 _waiters--; | |
585 } | |
586 if (_hd == end_of_list) { | |
587 #if FID_STATS | |
588 tty->print("claim_par_id[%d]: returning EOL.\n", tslf); | |
589 #endif | |
590 return -1; | |
591 } else { | |
592 int res = _hd; | |
593 _hd = _ids[res]; | |
594 _ids[res] = claimed; // For debugging. | |
595 _claimed++; | |
596 #if FID_STATS | |
597 tty->print("claim_par_id[%d]: returning %d, claimed = %d.\n", | |
598 tslf, res, _claimed); | |
599 #endif | |
600 return res; | |
601 } | |
602 } | |
603 | |
604 bool FreeIdSet::claim_perm_id(int i) { | |
605 assert(0 <= i && i < _sz, "Out of range."); | |
606 MutexLockerEx x(_mon, Mutex::_no_safepoint_check_flag); | |
607 int prev = end_of_list; | |
608 int cur = _hd; | |
609 while (cur != end_of_list) { | |
610 if (cur == i) { | |
611 if (prev == end_of_list) { | |
612 _hd = _ids[cur]; | |
613 } else { | |
614 _ids[prev] = _ids[cur]; | |
615 } | |
616 _ids[cur] = claimed; | |
617 _claimed++; | |
618 return true; | |
619 } else { | |
620 prev = cur; | |
621 cur = _ids[cur]; | |
622 } | |
623 } | |
624 return false; | |
625 | |
626 } | |
627 | |
628 void FreeIdSet::release_par_id(int id) { | |
629 MutexLockerEx x(_mon, Mutex::_no_safepoint_check_flag); | |
630 assert(_ids[id] == claimed, "Precondition."); | |
631 _ids[id] = _hd; | |
632 _hd = id; | |
633 _claimed--; | |
634 #if FID_STATS | |
635 tty->print("[%d] release_par_id(%d), waiters =%d, claimed = %d.\n", | |
636 thr_self(), id, _waiters, _claimed); | |
637 #endif | |
638 if (_waiters > 0) | |
639 // Notify all would be safer, but this is OK, right? | |
640 _mon->notify_all(); | |
641 } |