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1 | /* |
2 | * Licensed to the Apache Software Foundation (ASF) under one | |
3 | * or more contributor license agreements. See the NOTICE file | |
4 | * distributed with this work for additional information | |
5 | * regarding copyright ownership. The ASF licenses this file | |
6 | * to you under the Apache License, Version 2.0 (the | |
7 | * "License"); you may not use this file except in compliance | |
8 | * with the License. You may obtain a copy of the License at | |
9 | * | |
10 | * http://www.apache.org/licenses/LICENSE-2.0 | |
11 | * | |
12 | * Unless required by applicable law or agreed to in writing, | |
13 | * software distributed under the License is distributed on an | |
14 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY | |
15 | * KIND, either express or implied. See the License for the | |
16 | * specific language governing permissions and limitations | |
17 | * under the License. | |
18 | */ | |
19 | ||
20 | #include <thrift/thrift-config.h> | |
21 | ||
22 | #include <thrift/concurrency/ThreadManager.h> | |
23 | #include <thrift/concurrency/Exception.h> | |
24 | #include <thrift/concurrency/Monitor.h> | |
25 | ||
26 | #include <memory> | |
27 | ||
28 | #include <stdexcept> | |
29 | #include <deque> | |
30 | #include <set> | |
31 | ||
32 | namespace apache { | |
33 | namespace thrift { | |
34 | namespace concurrency { | |
35 | ||
36 | using std::shared_ptr; | |
37 | using std::unique_ptr; | |
38 | using std::dynamic_pointer_cast; | |
39 | ||
40 | /** | |
41 | * ThreadManager class | |
42 | * | |
43 | * This class manages a pool of threads. It uses a ThreadFactory to create | |
44 | * threads. It never actually creates or destroys worker threads, rather | |
45 | * it maintains statistics on number of idle threads, number of active threads, | |
46 | * task backlog, and average wait and service times. | |
47 | * | |
48 | * There are three different monitors used for signaling different conditions | |
49 | * however they all share the same mutex_. | |
50 | * | |
51 | * @version $Id:$ | |
52 | */ | |
53 | class ThreadManager::Impl : public ThreadManager { | |
54 | ||
55 | public: | |
56 | Impl() | |
57 | : workerCount_(0), | |
58 | workerMaxCount_(0), | |
59 | idleCount_(0), | |
60 | pendingTaskCountMax_(0), | |
61 | expiredCount_(0), | |
62 | state_(ThreadManager::UNINITIALIZED), | |
63 | monitor_(&mutex_), | |
64 | maxMonitor_(&mutex_), | |
65 | workerMonitor_(&mutex_) {} | |
66 | ||
67 | ~Impl() override { stop(); } | |
68 | ||
69 | void start() override; | |
70 | void stop() override; | |
71 | ||
72 | ThreadManager::STATE state() const override { return state_; } | |
73 | ||
74 | shared_ptr<ThreadFactory> threadFactory() const override { | |
75 | Guard g(mutex_); | |
76 | return threadFactory_; | |
77 | } | |
78 | ||
79 | void threadFactory(shared_ptr<ThreadFactory> value) override { | |
80 | Guard g(mutex_); | |
81 | if (threadFactory_ && threadFactory_->isDetached() != value->isDetached()) { | |
82 | throw InvalidArgumentException(); | |
83 | } | |
84 | threadFactory_ = value; | |
85 | } | |
86 | ||
87 | void addWorker(size_t value) override; | |
88 | ||
89 | void removeWorker(size_t value) override; | |
90 | ||
91 | size_t idleWorkerCount() const override { return idleCount_; } | |
92 | ||
93 | size_t workerCount() const override { | |
94 | Guard g(mutex_); | |
95 | return workerCount_; | |
96 | } | |
97 | ||
98 | size_t pendingTaskCount() const override { | |
99 | Guard g(mutex_); | |
100 | return tasks_.size(); | |
101 | } | |
102 | ||
103 | size_t totalTaskCount() const override { | |
104 | Guard g(mutex_); | |
105 | return tasks_.size() + workerCount_ - idleCount_; | |
106 | } | |
107 | ||
108 | size_t pendingTaskCountMax() const override { | |
109 | Guard g(mutex_); | |
110 | return pendingTaskCountMax_; | |
111 | } | |
112 | ||
113 | size_t expiredTaskCount() const override { | |
114 | Guard g(mutex_); | |
115 | return expiredCount_; | |
116 | } | |
117 | ||
118 | void pendingTaskCountMax(const size_t value) { | |
119 | Guard g(mutex_); | |
120 | pendingTaskCountMax_ = value; | |
121 | } | |
122 | ||
123 | void add(shared_ptr<Runnable> value, int64_t timeout, int64_t expiration) override; | |
124 | ||
125 | void remove(shared_ptr<Runnable> task) override; | |
126 | ||
127 | shared_ptr<Runnable> removeNextPending() override; | |
128 | ||
129 | void removeExpiredTasks() override { | |
130 | removeExpired(false); | |
131 | } | |
132 | ||
133 | void setExpireCallback(ExpireCallback expireCallback) override; | |
134 | ||
135 | private: | |
136 | /** | |
137 | * Remove one or more expired tasks. | |
138 | * \param[in] justOne if true, try to remove just one task and return | |
139 | */ | |
140 | void removeExpired(bool justOne); | |
141 | ||
142 | /** | |
143 | * \returns whether it is acceptable to block, depending on the current thread id | |
144 | */ | |
145 | bool canSleep() const; | |
146 | ||
147 | /** | |
148 | * Lowers the maximum worker count and blocks until enough worker threads complete | |
149 | * to get to the new maximum worker limit. The caller is responsible for acquiring | |
150 | * a lock on the class mutex_. | |
151 | */ | |
152 | void removeWorkersUnderLock(size_t value); | |
153 | ||
154 | size_t workerCount_; | |
155 | size_t workerMaxCount_; | |
156 | size_t idleCount_; | |
157 | size_t pendingTaskCountMax_; | |
158 | size_t expiredCount_; | |
159 | ExpireCallback expireCallback_; | |
160 | ||
161 | ThreadManager::STATE state_; | |
162 | shared_ptr<ThreadFactory> threadFactory_; | |
163 | ||
164 | friend class ThreadManager::Task; | |
165 | typedef std::deque<shared_ptr<Task> > TaskQueue; | |
166 | TaskQueue tasks_; | |
167 | Mutex mutex_; | |
168 | Monitor monitor_; | |
169 | Monitor maxMonitor_; | |
170 | Monitor workerMonitor_; // used to synchronize changes in worker count | |
171 | ||
172 | friend class ThreadManager::Worker; | |
173 | std::set<shared_ptr<Thread> > workers_; | |
174 | std::set<shared_ptr<Thread> > deadWorkers_; | |
175 | std::map<const Thread::id_t, shared_ptr<Thread> > idMap_; | |
176 | }; | |
177 | ||
178 | class ThreadManager::Task : public Runnable { | |
179 | ||
180 | public: | |
181 | enum STATE { WAITING, EXECUTING, TIMEDOUT, COMPLETE }; | |
182 | ||
183 | Task(shared_ptr<Runnable> runnable, uint64_t expiration = 0ULL) | |
184 | : runnable_(runnable), | |
185 | state_(WAITING) { | |
186 | if (expiration != 0ULL) { | |
187 | expireTime_.reset(new std::chrono::steady_clock::time_point(std::chrono::steady_clock::now() + std::chrono::milliseconds(expiration))); | |
188 | } | |
189 | } | |
190 | ||
191 | ~Task() override = default; | |
192 | ||
193 | void run() override { | |
194 | if (state_ == EXECUTING) { | |
195 | runnable_->run(); | |
196 | state_ = COMPLETE; | |
197 | } | |
198 | } | |
199 | ||
200 | shared_ptr<Runnable> getRunnable() { return runnable_; } | |
201 | ||
202 | const unique_ptr<std::chrono::steady_clock::time_point> & getExpireTime() const { return expireTime_; } | |
203 | ||
204 | private: | |
205 | shared_ptr<Runnable> runnable_; | |
206 | friend class ThreadManager::Worker; | |
207 | STATE state_; | |
208 | unique_ptr<std::chrono::steady_clock::time_point> expireTime_; | |
209 | }; | |
210 | ||
211 | class ThreadManager::Worker : public Runnable { | |
212 | enum STATE { UNINITIALIZED, STARTING, STARTED, STOPPING, STOPPED }; | |
213 | ||
214 | public: | |
215 | Worker(ThreadManager::Impl* manager) : manager_(manager), state_(UNINITIALIZED) {} | |
216 | ||
217 | ~Worker() override = default; | |
218 | ||
219 | private: | |
220 | bool isActive() const { | |
221 | return (manager_->workerCount_ <= manager_->workerMaxCount_) | |
222 | || (manager_->state_ == JOINING && !manager_->tasks_.empty()); | |
223 | } | |
224 | ||
225 | public: | |
226 | /** | |
227 | * Worker entry point | |
228 | * | |
229 | * As long as worker thread is running, pull tasks off the task queue and | |
230 | * execute. | |
231 | */ | |
232 | void run() override { | |
233 | Guard g(manager_->mutex_); | |
234 | ||
235 | /** | |
236 | * This method has three parts; one is to check for and account for | |
237 | * admitting a task which happens under a lock. Then the lock is released | |
238 | * and the task itself is executed. Finally we do some accounting | |
239 | * under lock again when the task completes. | |
240 | */ | |
241 | ||
242 | /** | |
243 | * Admitting | |
244 | */ | |
245 | ||
246 | /** | |
247 | * Increment worker semaphore and notify manager if worker count reached | |
248 | * desired max | |
249 | */ | |
250 | bool active = manager_->workerCount_ < manager_->workerMaxCount_; | |
251 | if (active) { | |
252 | if (++manager_->workerCount_ == manager_->workerMaxCount_) { | |
253 | manager_->workerMonitor_.notify(); | |
254 | } | |
255 | } | |
256 | ||
257 | while (active) { | |
258 | /** | |
259 | * While holding manager monitor block for non-empty task queue (Also | |
260 | * check that the thread hasn't been requested to stop). Once the queue | |
261 | * is non-empty, dequeue a task, release monitor, and execute. If the | |
262 | * worker max count has been decremented such that we exceed it, mark | |
263 | * ourself inactive, decrement the worker count and notify the manager | |
264 | * (technically we're notifying the next blocked thread but eventually | |
265 | * the manager will see it. | |
266 | */ | |
267 | active = isActive(); | |
268 | ||
269 | while (active && manager_->tasks_.empty()) { | |
270 | manager_->idleCount_++; | |
271 | manager_->monitor_.wait(); | |
272 | active = isActive(); | |
273 | manager_->idleCount_--; | |
274 | } | |
275 | ||
276 | shared_ptr<ThreadManager::Task> task; | |
277 | ||
278 | if (active) { | |
279 | if (!manager_->tasks_.empty()) { | |
280 | task = manager_->tasks_.front(); | |
281 | manager_->tasks_.pop_front(); | |
282 | if (task->state_ == ThreadManager::Task::WAITING) { | |
283 | // If the state is changed to anything other than EXECUTING or TIMEDOUT here | |
284 | // then the execution loop needs to be changed below. | |
285 | task->state_ = | |
286 | (task->getExpireTime() && *(task->getExpireTime()) < std::chrono::steady_clock::now()) ? | |
287 | ThreadManager::Task::TIMEDOUT : | |
288 | ThreadManager::Task::EXECUTING; | |
289 | } | |
290 | } | |
291 | ||
292 | /* If we have a pending task max and we just dropped below it, wakeup any | |
293 | thread that might be blocked on add. */ | |
294 | if (manager_->pendingTaskCountMax_ != 0 | |
295 | && manager_->tasks_.size() <= manager_->pendingTaskCountMax_ - 1) { | |
296 | manager_->maxMonitor_.notify(); | |
297 | } | |
298 | } | |
299 | ||
300 | /** | |
301 | * Execution - not holding a lock | |
302 | */ | |
303 | if (task) { | |
304 | if (task->state_ == ThreadManager::Task::EXECUTING) { | |
305 | ||
306 | // Release the lock so we can run the task without blocking the thread manager | |
307 | manager_->mutex_.unlock(); | |
308 | ||
309 | try { | |
310 | task->run(); | |
311 | } catch (const std::exception& e) { | |
312 | GlobalOutput.printf("[ERROR] task->run() raised an exception: %s", e.what()); | |
313 | } catch (...) { | |
314 | GlobalOutput.printf("[ERROR] task->run() raised an unknown exception"); | |
315 | } | |
316 | ||
317 | // Re-acquire the lock to proceed in the thread manager | |
318 | manager_->mutex_.lock(); | |
319 | ||
320 | } else if (manager_->expireCallback_) { | |
321 | // The only other state the task could have been in is TIMEDOUT (see above) | |
322 | manager_->expireCallback_(task->getRunnable()); | |
323 | manager_->expiredCount_++; | |
324 | } | |
325 | } | |
326 | } | |
327 | ||
328 | /** | |
329 | * Final accounting for the worker thread that is done working | |
330 | */ | |
331 | manager_->deadWorkers_.insert(this->thread()); | |
332 | if (--manager_->workerCount_ == manager_->workerMaxCount_) { | |
333 | manager_->workerMonitor_.notify(); | |
334 | } | |
335 | } | |
336 | ||
337 | private: | |
338 | ThreadManager::Impl* manager_; | |
339 | friend class ThreadManager::Impl; | |
340 | STATE state_; | |
341 | }; | |
342 | ||
343 | void ThreadManager::Impl::addWorker(size_t value) { | |
344 | std::set<shared_ptr<Thread> > newThreads; | |
345 | for (size_t ix = 0; ix < value; ix++) { | |
346 | shared_ptr<ThreadManager::Worker> worker | |
347 | = std::make_shared<ThreadManager::Worker>(this); | |
348 | newThreads.insert(threadFactory_->newThread(worker)); | |
349 | } | |
350 | ||
351 | Guard g(mutex_); | |
352 | workerMaxCount_ += value; | |
353 | workers_.insert(newThreads.begin(), newThreads.end()); | |
354 | ||
355 | for (const auto & newThread : newThreads) { | |
356 | shared_ptr<ThreadManager::Worker> worker | |
357 | = dynamic_pointer_cast<ThreadManager::Worker, Runnable>(newThread->runnable()); | |
358 | worker->state_ = ThreadManager::Worker::STARTING; | |
359 | newThread->start(); | |
360 | idMap_.insert(std::pair<const Thread::id_t, shared_ptr<Thread> >(newThread->getId(), newThread)); | |
361 | } | |
362 | ||
363 | while (workerCount_ != workerMaxCount_) { | |
364 | workerMonitor_.wait(); | |
365 | } | |
366 | } | |
367 | ||
368 | void ThreadManager::Impl::start() { | |
369 | Guard g(mutex_); | |
370 | if (state_ == ThreadManager::STOPPED) { | |
371 | return; | |
372 | } | |
373 | ||
374 | if (state_ == ThreadManager::UNINITIALIZED) { | |
375 | if (!threadFactory_) { | |
376 | throw InvalidArgumentException(); | |
377 | } | |
378 | state_ = ThreadManager::STARTED; | |
379 | monitor_.notifyAll(); | |
380 | } | |
381 | ||
382 | while (state_ == STARTING) { | |
383 | monitor_.wait(); | |
384 | } | |
385 | } | |
386 | ||
387 | void ThreadManager::Impl::stop() { | |
388 | Guard g(mutex_); | |
389 | bool doStop = false; | |
390 | ||
391 | if (state_ != ThreadManager::STOPPING && state_ != ThreadManager::JOINING | |
392 | && state_ != ThreadManager::STOPPED) { | |
393 | doStop = true; | |
394 | state_ = ThreadManager::JOINING; | |
395 | } | |
396 | ||
397 | if (doStop) { | |
398 | removeWorkersUnderLock(workerCount_); | |
399 | } | |
400 | ||
401 | state_ = ThreadManager::STOPPED; | |
402 | } | |
403 | ||
404 | void ThreadManager::Impl::removeWorker(size_t value) { | |
405 | Guard g(mutex_); | |
406 | removeWorkersUnderLock(value); | |
407 | } | |
408 | ||
409 | void ThreadManager::Impl::removeWorkersUnderLock(size_t value) { | |
410 | if (value > workerMaxCount_) { | |
411 | throw InvalidArgumentException(); | |
412 | } | |
413 | ||
414 | workerMaxCount_ -= value; | |
415 | ||
416 | if (idleCount_ > value) { | |
417 | // There are more idle workers than we need to remove, | |
418 | // so notify enough of them so they can terminate. | |
419 | for (size_t ix = 0; ix < value; ix++) { | |
420 | monitor_.notify(); | |
421 | } | |
422 | } else { | |
423 | // There are as many or less idle workers than we need to remove, | |
424 | // so just notify them all so they can terminate. | |
425 | monitor_.notifyAll(); | |
426 | } | |
427 | ||
428 | while (workerCount_ != workerMaxCount_) { | |
429 | workerMonitor_.wait(); | |
430 | } | |
431 | ||
432 | for (const auto & deadWorker : deadWorkers_) { | |
433 | ||
434 | // when used with a joinable thread factory, we join the threads as we remove them | |
435 | if (!threadFactory_->isDetached()) { | |
436 | deadWorker->join(); | |
437 | } | |
438 | ||
439 | idMap_.erase(deadWorker->getId()); | |
440 | workers_.erase(deadWorker); | |
441 | } | |
442 | ||
443 | deadWorkers_.clear(); | |
444 | } | |
445 | ||
446 | bool ThreadManager::Impl::canSleep() const { | |
447 | const Thread::id_t id = threadFactory_->getCurrentThreadId(); | |
448 | return idMap_.find(id) == idMap_.end(); | |
449 | } | |
450 | ||
451 | void ThreadManager::Impl::add(shared_ptr<Runnable> value, int64_t timeout, int64_t expiration) { | |
452 | Guard g(mutex_, timeout); | |
453 | ||
454 | if (!g) { | |
455 | throw TimedOutException(); | |
456 | } | |
457 | ||
458 | if (state_ != ThreadManager::STARTED) { | |
459 | throw IllegalStateException( | |
460 | "ThreadManager::Impl::add ThreadManager " | |
461 | "not started"); | |
462 | } | |
463 | ||
464 | // if we're at a limit, remove an expired task to see if the limit clears | |
465 | if (pendingTaskCountMax_ > 0 && (tasks_.size() >= pendingTaskCountMax_)) { | |
466 | removeExpired(true); | |
467 | } | |
468 | ||
469 | if (pendingTaskCountMax_ > 0 && (tasks_.size() >= pendingTaskCountMax_)) { | |
470 | if (canSleep() && timeout >= 0) { | |
471 | while (pendingTaskCountMax_ > 0 && tasks_.size() >= pendingTaskCountMax_) { | |
472 | // This is thread safe because the mutex is shared between monitors. | |
473 | maxMonitor_.wait(timeout); | |
474 | } | |
475 | } else { | |
476 | throw TooManyPendingTasksException(); | |
477 | } | |
478 | } | |
479 | ||
480 | tasks_.push_back(std::make_shared<ThreadManager::Task>(value, expiration)); | |
481 | ||
482 | // If idle thread is available notify it, otherwise all worker threads are | |
483 | // running and will get around to this task in time. | |
484 | if (idleCount_ > 0) { | |
485 | monitor_.notify(); | |
486 | } | |
487 | } | |
488 | ||
489 | void ThreadManager::Impl::remove(shared_ptr<Runnable> task) { | |
490 | Guard g(mutex_); | |
491 | if (state_ != ThreadManager::STARTED) { | |
492 | throw IllegalStateException( | |
493 | "ThreadManager::Impl::remove ThreadManager not " | |
494 | "started"); | |
495 | } | |
496 | ||
497 | for (auto it = tasks_.begin(); it != tasks_.end(); ++it) | |
498 | { | |
499 | if ((*it)->getRunnable() == task) | |
500 | { | |
501 | tasks_.erase(it); | |
502 | return; | |
503 | } | |
504 | } | |
505 | } | |
506 | ||
507 | std::shared_ptr<Runnable> ThreadManager::Impl::removeNextPending() { | |
508 | Guard g(mutex_); | |
509 | if (state_ != ThreadManager::STARTED) { | |
510 | throw IllegalStateException( | |
511 | "ThreadManager::Impl::removeNextPending " | |
512 | "ThreadManager not started"); | |
513 | } | |
514 | ||
515 | if (tasks_.empty()) { | |
516 | return std::shared_ptr<Runnable>(); | |
517 | } | |
518 | ||
519 | shared_ptr<ThreadManager::Task> task = tasks_.front(); | |
520 | tasks_.pop_front(); | |
521 | ||
522 | return task->getRunnable(); | |
523 | } | |
524 | ||
525 | void ThreadManager::Impl::removeExpired(bool justOne) { | |
526 | // this is always called under a lock | |
527 | if (tasks_.empty()) { | |
528 | return; | |
529 | } | |
530 | auto now = std::chrono::steady_clock::now(); | |
531 | ||
532 | for (auto it = tasks_.begin(); it != tasks_.end(); ) | |
533 | { | |
534 | if ((*it)->getExpireTime() && *((*it)->getExpireTime()) < now) { | |
535 | if (expireCallback_) { | |
536 | expireCallback_((*it)->getRunnable()); | |
537 | } | |
538 | it = tasks_.erase(it); | |
539 | ++expiredCount_; | |
540 | if (justOne) { | |
541 | return; | |
542 | } | |
543 | } | |
544 | else | |
545 | { | |
546 | ++it; | |
547 | } | |
548 | } | |
549 | } | |
550 | ||
551 | void ThreadManager::Impl::setExpireCallback(ExpireCallback expireCallback) { | |
552 | Guard g(mutex_); | |
553 | expireCallback_ = expireCallback; | |
554 | } | |
555 | ||
556 | class SimpleThreadManager : public ThreadManager::Impl { | |
557 | ||
558 | public: | |
559 | SimpleThreadManager(size_t workerCount = 4, size_t pendingTaskCountMax = 0) | |
560 | : workerCount_(workerCount), pendingTaskCountMax_(pendingTaskCountMax) {} | |
561 | ||
562 | void start() override { | |
563 | ThreadManager::Impl::pendingTaskCountMax(pendingTaskCountMax_); | |
564 | ThreadManager::Impl::start(); | |
565 | addWorker(workerCount_); | |
566 | } | |
567 | ||
568 | private: | |
569 | const size_t workerCount_; | |
570 | const size_t pendingTaskCountMax_; | |
571 | }; | |
572 | ||
573 | shared_ptr<ThreadManager> ThreadManager::newThreadManager() { | |
574 | return shared_ptr<ThreadManager>(new ThreadManager::Impl()); | |
575 | } | |
576 | ||
577 | shared_ptr<ThreadManager> ThreadManager::newSimpleThreadManager(size_t count, | |
578 | size_t pendingTaskCountMax) { | |
579 | return shared_ptr<ThreadManager>(new SimpleThreadManager(count, pendingTaskCountMax)); | |
580 | } | |
581 | } | |
582 | } | |
583 | } // apache::thrift::concurrency |