1 /*
2 ==============================================================================
3
4 This file is part of the JUCE library.
5 Copyright (c) 2017 - ROLI Ltd.
6
7 JUCE is an open source library subject to commercial or open-source
8 licensing.
9
10 The code included in this file is provided under the terms of the ISC license
11 http://www.isc.org/downloads/software-support-policy/isc-license. Permission
12 To use, copy, modify, and/or distribute this software for any purpose with or
13 without fee is hereby granted provided that the above copyright notice and
14 this permission notice appear in all copies.
15
16 JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
17 EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
18 DISCLAIMED.
19
20 ==============================================================================
21 */
22
23 namespace juce
24 {
25
26 struct ThreadPool::ThreadPoolThread : public Thread
27 {
ThreadPoolThreadjuce::ThreadPool::ThreadPoolThread28 ThreadPoolThread (ThreadPool& p, size_t stackSize)
29 : Thread ("Pool", stackSize), pool (p)
30 {
31 }
32
runjuce::ThreadPool::ThreadPoolThread33 void run() override
34 {
35 while (! threadShouldExit())
36 if (! pool.runNextJob (*this))
37 wait (500);
38 }
39
40 std::atomic<ThreadPoolJob*> currentJob { nullptr };
41 ThreadPool& pool;
42
43 JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (ThreadPoolThread)
44 };
45
46 //==============================================================================
ThreadPoolJob(const String & name)47 ThreadPoolJob::ThreadPoolJob (const String& name) : jobName (name)
48 {
49 }
50
~ThreadPoolJob()51 ThreadPoolJob::~ThreadPoolJob()
52 {
53 // you mustn't delete a job while it's still in a pool! Use ThreadPool::removeJob()
54 // to remove it first!
55 jassert (pool == nullptr || ! pool->contains (this));
56 }
57
getJobName() const58 String ThreadPoolJob::getJobName() const
59 {
60 return jobName;
61 }
62
setJobName(const String & newName)63 void ThreadPoolJob::setJobName (const String& newName)
64 {
65 jobName = newName;
66 }
67
signalJobShouldExit()68 void ThreadPoolJob::signalJobShouldExit()
69 {
70 shouldStop = true;
71 listeners.call ([] (Thread::Listener& l) { l.exitSignalSent(); });
72 }
73
addListener(Thread::Listener * listener)74 void ThreadPoolJob::addListener (Thread::Listener* listener)
75 {
76 listeners.add (listener);
77 }
78
removeListener(Thread::Listener * listener)79 void ThreadPoolJob::removeListener (Thread::Listener* listener)
80 {
81 listeners.remove (listener);
82 }
83
getCurrentThreadPoolJob()84 ThreadPoolJob* ThreadPoolJob::getCurrentThreadPoolJob()
85 {
86 if (auto* t = dynamic_cast<ThreadPool::ThreadPoolThread*> (Thread::getCurrentThread()))
87 return t->currentJob.load();
88
89 return nullptr;
90 }
91
92 //==============================================================================
ThreadPool(int numThreads,size_t threadStackSize)93 ThreadPool::ThreadPool (int numThreads, size_t threadStackSize)
94 {
95 jassert (numThreads > 0); // not much point having a pool without any threads!
96
97 createThreads (numThreads, threadStackSize);
98 }
99
ThreadPool()100 ThreadPool::ThreadPool()
101 {
102 createThreads (SystemStats::getNumCpus());
103 }
104
~ThreadPool()105 ThreadPool::~ThreadPool()
106 {
107 removeAllJobs (true, 5000);
108 stopThreads();
109 }
110
createThreads(int numThreads,size_t threadStackSize)111 void ThreadPool::createThreads (int numThreads, size_t threadStackSize)
112 {
113 for (int i = jmax (1, numThreads); --i >= 0;)
114 threads.add (new ThreadPoolThread (*this, threadStackSize));
115
116 for (auto* t : threads)
117 t->startThread();
118 }
119
stopThreads()120 void ThreadPool::stopThreads()
121 {
122 for (auto* t : threads)
123 t->signalThreadShouldExit();
124
125 for (auto* t : threads)
126 t->stopThread (500);
127 }
128
addJob(ThreadPoolJob * job,bool deleteJobWhenFinished)129 void ThreadPool::addJob (ThreadPoolJob* job, bool deleteJobWhenFinished)
130 {
131 jassert (job != nullptr);
132 jassert (job->pool == nullptr);
133
134 if (job->pool == nullptr)
135 {
136 job->pool = this;
137 job->shouldStop = false;
138 job->isActive = false;
139 job->shouldBeDeleted = deleteJobWhenFinished;
140
141 {
142 const ScopedLock sl (lock);
143 jobs.add (job);
144 }
145
146 for (auto* t : threads)
147 t->notify();
148 }
149 }
150
addJob(std::function<ThreadPoolJob::JobStatus ()> jobToRun)151 void ThreadPool::addJob (std::function<ThreadPoolJob::JobStatus()> jobToRun)
152 {
153 struct LambdaJobWrapper : public ThreadPoolJob
154 {
155 LambdaJobWrapper (std::function<ThreadPoolJob::JobStatus()> j) : ThreadPoolJob ("lambda"), job (j) {}
156 JobStatus runJob() override { return job(); }
157
158 std::function<ThreadPoolJob::JobStatus()> job;
159 };
160
161 addJob (new LambdaJobWrapper (jobToRun), true);
162 }
163
addJob(std::function<void ()> jobToRun)164 void ThreadPool::addJob (std::function<void()> jobToRun)
165 {
166 struct LambdaJobWrapper : public ThreadPoolJob
167 {
168 LambdaJobWrapper (std::function<void()> j) : ThreadPoolJob ("lambda"), job (j) {}
169 JobStatus runJob() override { job(); return ThreadPoolJob::jobHasFinished; }
170
171 std::function<void()> job;
172 };
173
174 addJob (new LambdaJobWrapper (jobToRun), true);
175 }
176
getNumJobs() const177 int ThreadPool::getNumJobs() const noexcept
178 {
179 const ScopedLock sl (lock);
180 return jobs.size();
181 }
182
getNumThreads() const183 int ThreadPool::getNumThreads() const noexcept
184 {
185 return threads.size();
186 }
187
getJob(int index) const188 ThreadPoolJob* ThreadPool::getJob (int index) const noexcept
189 {
190 const ScopedLock sl (lock);
191 return jobs [index];
192 }
193
contains(const ThreadPoolJob * job) const194 bool ThreadPool::contains (const ThreadPoolJob* job) const noexcept
195 {
196 const ScopedLock sl (lock);
197 return jobs.contains (const_cast<ThreadPoolJob*> (job));
198 }
199
isJobRunning(const ThreadPoolJob * job) const200 bool ThreadPool::isJobRunning (const ThreadPoolJob* job) const noexcept
201 {
202 const ScopedLock sl (lock);
203 return jobs.contains (const_cast<ThreadPoolJob*> (job)) && job->isActive;
204 }
205
moveJobToFront(const ThreadPoolJob * job)206 void ThreadPool::moveJobToFront (const ThreadPoolJob* job) noexcept
207 {
208 const ScopedLock sl (lock);
209
210 auto index = jobs.indexOf (const_cast<ThreadPoolJob*> (job));
211
212 if (index > 0 && ! job->isActive)
213 jobs.move (index, 0);
214 }
215
waitForJobToFinish(const ThreadPoolJob * job,int timeOutMs) const216 bool ThreadPool::waitForJobToFinish (const ThreadPoolJob* job, int timeOutMs) const
217 {
218 if (job != nullptr)
219 {
220 auto start = Time::getMillisecondCounter();
221
222 while (contains (job))
223 {
224 if (timeOutMs >= 0 && Time::getMillisecondCounter() >= start + (uint32) timeOutMs)
225 return false;
226
227 jobFinishedSignal.wait (2);
228 }
229 }
230
231 return true;
232 }
233
removeJob(ThreadPoolJob * job,bool interruptIfRunning,int timeOutMs)234 bool ThreadPool::removeJob (ThreadPoolJob* job, bool interruptIfRunning, int timeOutMs)
235 {
236 bool dontWait = true;
237 OwnedArray<ThreadPoolJob> deletionList;
238
239 if (job != nullptr)
240 {
241 const ScopedLock sl (lock);
242
243 if (jobs.contains (job))
244 {
245 if (job->isActive)
246 {
247 if (interruptIfRunning)
248 job->signalJobShouldExit();
249
250 dontWait = false;
251 }
252 else
253 {
254 jobs.removeFirstMatchingValue (job);
255 addToDeleteList (deletionList, job);
256 }
257 }
258 }
259
260 return dontWait || waitForJobToFinish (job, timeOutMs);
261 }
262
removeAllJobs(bool interruptRunningJobs,int timeOutMs,ThreadPool::JobSelector * selectedJobsToRemove)263 bool ThreadPool::removeAllJobs (bool interruptRunningJobs, int timeOutMs,
264 ThreadPool::JobSelector* selectedJobsToRemove)
265 {
266 Array<ThreadPoolJob*> jobsToWaitFor;
267
268 {
269 OwnedArray<ThreadPoolJob> deletionList;
270
271 {
272 const ScopedLock sl (lock);
273
274 for (int i = jobs.size(); --i >= 0;)
275 {
276 auto* job = jobs.getUnchecked(i);
277
278 if (selectedJobsToRemove == nullptr || selectedJobsToRemove->isJobSuitable (job))
279 {
280 if (job->isActive)
281 {
282 jobsToWaitFor.add (job);
283
284 if (interruptRunningJobs)
285 job->signalJobShouldExit();
286 }
287 else
288 {
289 jobs.remove (i);
290 addToDeleteList (deletionList, job);
291 }
292 }
293 }
294 }
295 }
296
297 auto start = Time::getMillisecondCounter();
298
299 for (;;)
300 {
301 for (int i = jobsToWaitFor.size(); --i >= 0;)
302 {
303 auto* job = jobsToWaitFor.getUnchecked (i);
304
305 if (! isJobRunning (job))
306 jobsToWaitFor.remove (i);
307 }
308
309 if (jobsToWaitFor.size() == 0)
310 break;
311
312 if (timeOutMs >= 0 && Time::getMillisecondCounter() >= start + (uint32) timeOutMs)
313 return false;
314
315 jobFinishedSignal.wait (20);
316 }
317
318 return true;
319 }
320
getNamesOfAllJobs(bool onlyReturnActiveJobs) const321 StringArray ThreadPool::getNamesOfAllJobs (bool onlyReturnActiveJobs) const
322 {
323 StringArray s;
324 const ScopedLock sl (lock);
325
326 for (auto* job : jobs)
327 if (job->isActive || ! onlyReturnActiveJobs)
328 s.add (job->getJobName());
329
330 return s;
331 }
332
setThreadPriorities(int newPriority)333 bool ThreadPool::setThreadPriorities (int newPriority)
334 {
335 bool ok = true;
336
337 for (auto* t : threads)
338 if (! t->setPriority (newPriority))
339 ok = false;
340
341 return ok;
342 }
343
pickNextJobToRun()344 ThreadPoolJob* ThreadPool::pickNextJobToRun()
345 {
346 OwnedArray<ThreadPoolJob> deletionList;
347
348 {
349 const ScopedLock sl (lock);
350
351 for (int i = 0; i < jobs.size(); ++i)
352 {
353 if (auto* job = jobs[i])
354 {
355 if (! job->isActive)
356 {
357 if (job->shouldStop)
358 {
359 jobs.remove (i);
360 addToDeleteList (deletionList, job);
361 --i;
362 continue;
363 }
364
365 job->isActive = true;
366 return job;
367 }
368 }
369 }
370 }
371
372 return nullptr;
373 }
374
runNextJob(ThreadPoolThread & thread)375 bool ThreadPool::runNextJob (ThreadPoolThread& thread)
376 {
377 if (auto* job = pickNextJobToRun())
378 {
379 auto result = ThreadPoolJob::jobHasFinished;
380 thread.currentJob = job;
381
382 try
383 {
384 result = job->runJob();
385 }
386 catch (...)
387 {
388 jassertfalse; // Your runJob() method mustn't throw any exceptions!
389 }
390
391 thread.currentJob = nullptr;
392
393 OwnedArray<ThreadPoolJob> deletionList;
394
395 {
396 const ScopedLock sl (lock);
397
398 if (jobs.contains (job))
399 {
400 job->isActive = false;
401
402 if (result != ThreadPoolJob::jobNeedsRunningAgain || job->shouldStop)
403 {
404 jobs.removeFirstMatchingValue (job);
405 addToDeleteList (deletionList, job);
406
407 jobFinishedSignal.signal();
408 }
409 else
410 {
411 // move the job to the end of the queue if it wants another go
412 jobs.move (jobs.indexOf (job), -1);
413 }
414 }
415 }
416
417 return true;
418 }
419
420 return false;
421 }
422
addToDeleteList(OwnedArray<ThreadPoolJob> & deletionList,ThreadPoolJob * job) const423 void ThreadPool::addToDeleteList (OwnedArray<ThreadPoolJob>& deletionList, ThreadPoolJob* job) const
424 {
425 job->shouldStop = true;
426 job->pool = nullptr;
427
428 if (job->shouldBeDeleted)
429 deletionList.add (job);
430 }
431
432 } // namespace juce
433