OpenShot Library | OpenShotAudio 0.2.2
juce_ThreadPool.cpp
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
23namespace juce
24{
25
27{
28 ThreadPoolThread (ThreadPool& p, size_t stackSize)
29 : Thread ("Pool", stackSize), pool (p)
30 {
31 }
32
33 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//==============================================================================
47ThreadPoolJob::ThreadPoolJob (const String& name) : jobName (name)
48{
49}
50
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
59{
60 return jobName;
61}
62
63void ThreadPoolJob::setJobName (const String& newName)
64{
65 jobName = newName;
66}
67
69{
70 shouldStop = true;
71 listeners.call ([] (Thread::Listener& l) { l.exitSignalSent(); });
72}
73
75{
76 listeners.add (listener);
77}
78
80{
81 listeners.remove (listener);
82}
83
85{
86 if (auto* t = dynamic_cast<ThreadPool::ThreadPoolThread*> (Thread::getCurrentThread()))
87 return t->currentJob.load();
88
89 return nullptr;
90}
91
92//==============================================================================
93ThreadPool::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
101{
102 createThreads (SystemStats::getNumCpus());
103}
104
106{
107 removeAllJobs (true, 5000);
108 stopThreads();
109}
110
111void 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
120void ThreadPool::stopThreads()
121{
122 for (auto* t : threads)
123 t->signalThreadShouldExit();
124
125 for (auto* t : threads)
126 t->stopThread (500);
127}
128
129void 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
151void 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
164void 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
177int ThreadPool::getNumJobs() const noexcept
178{
179 const ScopedLock sl (lock);
180 return jobs.size();
181}
182
183int ThreadPool::getNumThreads() const noexcept
184{
185 return threads.size();
186}
187
188ThreadPoolJob* ThreadPool::getJob (int index) const noexcept
189{
190 const ScopedLock sl (lock);
191 return jobs [index];
192}
193
194bool ThreadPool::contains (const ThreadPoolJob* job) const noexcept
195{
196 const ScopedLock sl (lock);
197 return jobs.contains (const_cast<ThreadPoolJob*> (job));
198}
199
200bool 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
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
216bool 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
234bool 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
263bool 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
321StringArray 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
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
344ThreadPoolJob* 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
375bool 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
423void 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
Holds a resizable array of primitive or copy-by-value objects.
Definition: juce_Array.h:60
ElementType getUnchecked(int index) const
Returns one of the elements in the array, without checking the index passed in.
Definition: juce_Array.h:256
int size() const noexcept
Returns the current number of elements in the array.
Definition: juce_Array.h:219
void remove(int indexToRemove)
Removes an element from the array.
Definition: juce_Array.h:771
void add(const ElementType &newElement)
Appends a new element at the end of the array.
Definition: juce_Array.h:422
Automatically locks and unlocks a mutex object.
An array designed for holding objects.
A special array for holding a list of strings.
void add(String stringToAdd)
Appends a string at the end of the array.
The JUCE String class!
Definition: juce_String.h:43
static int getNumCpus() noexcept
Returns the number of logical CPU cores.
A task that is executed by a ThreadPool object.
void signalJobShouldExit()
Calling this will cause the shouldExit() method to return true, and the job should (if it's been impl...
JobStatus
These are the values that can be returned by the runJob() method.
@ jobHasFinished
indicates that the job has finished and can be removed from the pool.
@ jobNeedsRunningAgain
indicates that the job would like to be called again when a thread is free.
void setJobName(const String &newName)
Changes the job's name.
String getJobName() const
Returns the name of this job.
void addListener(Thread::Listener *)
Add a listener to this thread job which will receive a callback when signalJobShouldExit was called o...
virtual ~ThreadPoolJob()
Destructor.
static ThreadPoolJob * getCurrentThreadPoolJob()
If the calling thread is being invoked inside a runJob() method, this will return the ThreadPoolJob t...
void removeListener(Thread::Listener *)
Removes a listener added with addListener.
ThreadPoolJob(const String &name)
Creates a thread pool job object.
A callback class used when you need to select which ThreadPoolJob objects are suitable for some kind ...
virtual bool isJobSuitable(ThreadPoolJob *job)=0
Should return true if the specified thread matches your criteria for whatever operation that this obj...
A set of threads that will run a list of jobs.
void moveJobToFront(const ThreadPoolJob *jobToMove) noexcept
If the given job is in the queue, this will move it to the front so that it is the next one to be exe...
void addJob(ThreadPoolJob *job, bool deleteJobWhenFinished)
Adds a job to the queue.
int getNumThreads() const noexcept
Returns the number of threads assigned to this thread pool.
ThreadPoolJob * getJob(int index) const noexcept
Returns one of the jobs in the queue.
int getNumJobs() const noexcept
Returns the number of jobs currently running or queued.
bool removeAllJobs(bool interruptRunningJobs, int timeOutMilliseconds, JobSelector *selectedJobsToRemove=nullptr)
Tries to remove all jobs from the pool.
~ThreadPool()
Destructor.
StringArray getNamesOfAllJobs(bool onlyReturnActiveJobs) const
Returns a list of the names of all the jobs currently running or queued.
bool isJobRunning(const ThreadPoolJob *job) const noexcept
Returns true if the given job is currently being run by a thread.
bool setThreadPriorities(int newPriority)
Changes the priority of all the threads.
bool removeJob(ThreadPoolJob *job, bool interruptIfRunning, int timeOutMilliseconds)
Tries to remove a job from the pool.
bool contains(const ThreadPoolJob *job) const noexcept
Returns true if the given job is currently queued or running.
bool waitForJobToFinish(const ThreadPoolJob *job, int timeOutMilliseconds) const
Waits until a job has finished running and has been removed from the pool.
ThreadPool()
Creates a thread pool with one thread per CPU core.
Used to receive callbacks for thread exit calls.
Definition: juce_Thread.h:185
virtual void exitSignalSent()=0
Called if Thread::signalThreadShouldExit was called.
Encapsulates a thread.
Definition: juce_Thread.h:47
static Thread *JUCE_CALLTYPE getCurrentThread()
Finds the thread object that is currently running.
bool wait(int timeOutMilliseconds) const
Suspends the execution of this thread until either the specified timeout period has elapsed,...
Thread(const String &threadName, size_t threadStackSize=0)
Creates a thread.
Definition: juce_Thread.cpp:26
bool threadShouldExit() const
Checks whether the thread has been told to stop running.
static uint32 getMillisecondCounter() noexcept
Returns the number of millisecs since a fixed event (usually system startup).
Definition: juce_Time.cpp:226
bool wait(int timeOutMilliseconds=-1) const
Suspends the calling thread until the event has been signalled.
void signal() const
Wakes up any threads that are currently waiting on this object.
void run() override
Must be implemented to perform the thread's actual code.