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1 | /***************************************************************************** |
2 | * x265: singleton thread pool and interface classes | |
3 | ***************************************************************************** | |
4 | * Copyright (C) 2013 x265 project | |
5 | * | |
6 | * Authors: Steve Borho <steve@borho.org> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; either version 2 of the License, or | |
11 | * (at your option) any later version. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * along with this program; if not, write to the Free Software | |
20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111, USA. | |
21 | * | |
22 | * This program is also available under a commercial proprietary license. | |
23 | * For more information, contact us at license @ x265.com | |
24 | *****************************************************************************/ | |
25 | ||
26 | #include "common.h" | |
27 | #include "threadpool.h" | |
28 | #include "threading.h" | |
29 | ||
30 | #include <new> | |
31 | ||
32 | #if MACOS | |
33 | #include <sys/param.h> | |
34 | #include <sys/sysctl.h> | |
35 | #endif | |
36 | ||
37 | namespace x265 { | |
38 | // x265 private namespace | |
39 | ||
40 | class ThreadPoolImpl; | |
41 | ||
42 | class PoolThread : public Thread | |
43 | { | |
44 | private: | |
45 | ||
46 | ThreadPoolImpl &m_pool; | |
47 | ||
48 | PoolThread& operator =(const PoolThread&); | |
49 | ||
50 | int m_id; | |
51 | ||
52 | bool m_dirty; | |
53 | ||
54 | bool m_exited; | |
55 | ||
56 | Event m_wakeEvent; | |
57 | ||
58 | public: | |
59 | ||
60 | PoolThread(ThreadPoolImpl& pool, int id) | |
61 | : m_pool(pool) | |
62 | , m_id(id) | |
63 | , m_dirty(false) | |
64 | , m_exited(false) | |
65 | { | |
66 | } | |
67 | ||
68 | bool isDirty() const { return m_dirty; } | |
69 | ||
70 | void markDirty() { m_dirty = true; } | |
71 | ||
72 | bool isExited() const { return m_exited; } | |
73 | ||
74 | void poke() { m_wakeEvent.trigger(); } | |
75 | ||
76 | virtual ~PoolThread() {} | |
77 | ||
78 | void threadMain(); | |
79 | }; | |
80 | ||
81 | class ThreadPoolImpl : public ThreadPool | |
82 | { | |
83 | private: | |
84 | ||
85 | bool m_ok; | |
86 | int m_referenceCount; | |
87 | int m_numThreads; | |
88 | int m_numSleepMapWords; | |
89 | PoolThread *m_threads; | |
90 | volatile uint64_t *m_sleepMap; | |
91 | ||
92 | /* Lock for write access to the provider lists. Threads are | |
93 | * always allowed to read m_firstProvider and follow the | |
94 | * linked list. Providers must zero their m_nextProvider | |
95 | * pointers before removing themselves from this list */ | |
96 | Lock m_writeLock; | |
97 | ||
98 | public: | |
99 | ||
100 | static ThreadPoolImpl *s_instance; | |
101 | static Lock s_createLock; | |
102 | ||
103 | JobProvider *m_firstProvider; | |
104 | JobProvider *m_lastProvider; | |
105 | ||
106 | public: | |
107 | ||
108 | ThreadPoolImpl(int numthreads); | |
109 | ||
110 | virtual ~ThreadPoolImpl(); | |
111 | ||
112 | ThreadPoolImpl *AddReference() | |
113 | { | |
114 | m_referenceCount++; | |
115 | ||
116 | return this; | |
117 | } | |
118 | ||
119 | void markThreadAsleep(int id); | |
120 | ||
121 | void waitForAllIdle(); | |
122 | ||
123 | int getThreadCount() const { return m_numThreads; } | |
124 | ||
125 | bool IsValid() const { return m_ok; } | |
126 | ||
127 | void release(); | |
128 | ||
129 | void Stop(); | |
130 | ||
131 | void enqueueJobProvider(JobProvider &); | |
132 | ||
133 | void dequeueJobProvider(JobProvider &); | |
134 | ||
135 | void FlushProviderList(); | |
136 | ||
137 | void pokeIdleThread(); | |
138 | }; | |
139 | ||
140 | void PoolThread::threadMain() | |
141 | { | |
142 | #if _WIN32 | |
143 | SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_BELOW_NORMAL); | |
144 | #else | |
145 | __attribute__((unused)) int val = nice(10); | |
146 | #endif | |
147 | ||
148 | while (m_pool.IsValid()) | |
149 | { | |
150 | /* Walk list of job providers, looking for work */ | |
151 | JobProvider *cur = m_pool.m_firstProvider; | |
152 | while (cur) | |
153 | { | |
154 | // FindJob() may perform actual work and return true. If | |
155 | // it does we restart the job search | |
156 | if (cur->findJob(m_id) == true) | |
157 | break; | |
158 | ||
159 | cur = cur->m_nextProvider; | |
160 | } | |
161 | ||
162 | // this thread has reached the end of the provider list | |
163 | m_dirty = false; | |
164 | ||
165 | if (cur == NULL) | |
166 | { | |
167 | m_pool.markThreadAsleep(m_id); | |
168 | m_wakeEvent.wait(); | |
169 | } | |
170 | } | |
171 | ||
172 | m_exited = true; | |
173 | } | |
174 | ||
175 | void ThreadPoolImpl::markThreadAsleep(int id) | |
176 | { | |
177 | int word = id >> 6; | |
178 | uint64_t bit = 1LL << (id & 63); | |
179 | ||
180 | ATOMIC_OR(&m_sleepMap[word], bit); | |
181 | } | |
182 | ||
183 | void ThreadPoolImpl::pokeIdleThread() | |
184 | { | |
185 | /* Find a bit in the sleeping thread bitmap and poke it awake, do | |
186 | * not give up until a thread is awakened or all of them are awake */ | |
187 | for (int i = 0; i < m_numSleepMapWords; i++) | |
188 | { | |
189 | uint64_t oldval = m_sleepMap[i]; | |
190 | while (oldval) | |
191 | { | |
192 | unsigned long id; | |
193 | CTZ64(id, oldval); | |
194 | ||
195 | uint64_t newval = oldval & ~(1LL << id); | |
196 | if (ATOMIC_CAS(&m_sleepMap[i], oldval, newval) == oldval) | |
197 | { | |
198 | m_threads[(i << 6) | id].poke(); | |
199 | return; | |
200 | } | |
201 | ||
202 | oldval = m_sleepMap[i]; | |
203 | } | |
204 | } | |
205 | } | |
206 | ||
207 | ThreadPoolImpl *ThreadPoolImpl::s_instance; | |
208 | Lock ThreadPoolImpl::s_createLock; | |
209 | ||
210 | /* static */ | |
211 | ThreadPool *ThreadPool::allocThreadPool(int numthreads) | |
212 | { | |
213 | if (ThreadPoolImpl::s_instance) | |
214 | return ThreadPoolImpl::s_instance->AddReference(); | |
215 | ||
216 | /* acquire the lock to create the instance */ | |
217 | ThreadPoolImpl::s_createLock.acquire(); | |
218 | ||
219 | if (ThreadPoolImpl::s_instance) | |
220 | /* pool was allocated while we waited for the lock */ | |
221 | ThreadPoolImpl::s_instance->AddReference(); | |
222 | else | |
223 | ThreadPoolImpl::s_instance = new ThreadPoolImpl(numthreads); | |
224 | ThreadPoolImpl::s_createLock.release(); | |
225 | ||
226 | return ThreadPoolImpl::s_instance; | |
227 | } | |
228 | ||
229 | ThreadPool *ThreadPool::getThreadPool() | |
230 | { | |
231 | X265_CHECK(ThreadPoolImpl::s_instance, "getThreadPool() called prior to allocThreadPool()\n"); | |
232 | return ThreadPoolImpl::s_instance; | |
233 | } | |
234 | ||
235 | void ThreadPoolImpl::release() | |
236 | { | |
237 | if (--m_referenceCount == 0) | |
238 | { | |
239 | X265_CHECK(this == ThreadPoolImpl::s_instance, "multiple thread pool instances detected\n"); | |
240 | ThreadPoolImpl::s_instance = NULL; | |
241 | this->Stop(); | |
242 | delete this; | |
243 | } | |
244 | } | |
245 | ||
246 | ThreadPoolImpl::ThreadPoolImpl(int numThreads) | |
247 | : m_ok(false) | |
248 | , m_referenceCount(1) | |
249 | , m_firstProvider(NULL) | |
250 | , m_lastProvider(NULL) | |
251 | { | |
252 | m_numSleepMapWords = (numThreads + 63) >> 6; | |
253 | m_sleepMap = X265_MALLOC(uint64_t, m_numSleepMapWords); | |
254 | ||
255 | char *buffer = (char*)X265_MALLOC(PoolThread, numThreads); | |
256 | m_threads = reinterpret_cast<PoolThread*>(buffer); | |
257 | m_numThreads = numThreads; | |
258 | ||
259 | if (m_threads && m_sleepMap) | |
260 | { | |
261 | for (int i = 0; i < m_numSleepMapWords; i++) | |
262 | { | |
263 | m_sleepMap[i] = 0; | |
264 | } | |
265 | ||
266 | m_ok = true; | |
267 | int i; | |
268 | for (i = 0; i < numThreads; i++) | |
269 | { | |
270 | new (buffer)PoolThread(*this, i); | |
271 | buffer += sizeof(PoolThread); | |
272 | if (!m_threads[i].start()) | |
273 | { | |
274 | m_ok = false; | |
275 | break; | |
276 | } | |
277 | } | |
278 | ||
279 | if (m_ok) | |
280 | { | |
281 | waitForAllIdle(); | |
282 | } | |
283 | else | |
284 | { | |
285 | // stop threads that did start up | |
286 | for (int j = 0; j < i; j++) | |
287 | { | |
288 | m_threads[j].poke(); | |
289 | m_threads[j].stop(); | |
290 | } | |
291 | } | |
292 | } | |
293 | } | |
294 | ||
295 | void ThreadPoolImpl::waitForAllIdle() | |
296 | { | |
297 | if (!m_ok) | |
298 | return; | |
299 | ||
300 | int id = 0; | |
301 | do | |
302 | { | |
303 | int word = id >> 6; | |
304 | uint64_t bit = 1LL << (id & 63); | |
305 | if (m_sleepMap[word] & bit) | |
306 | { | |
307 | id++; | |
308 | } | |
309 | else | |
310 | { | |
311 | GIVE_UP_TIME(); | |
312 | } | |
313 | } | |
314 | while (id < m_numThreads); | |
315 | } | |
316 | ||
317 | void ThreadPoolImpl::Stop() | |
318 | { | |
319 | if (m_ok) | |
320 | { | |
321 | waitForAllIdle(); | |
322 | ||
323 | // set invalid flag, then wake them up so they exit their main func | |
324 | m_ok = false; | |
325 | for (int i = 0; i < m_numThreads; i++) | |
326 | { | |
327 | m_threads[i].poke(); | |
328 | m_threads[i].stop(); | |
329 | } | |
330 | } | |
331 | } | |
332 | ||
333 | ThreadPoolImpl::~ThreadPoolImpl() | |
334 | { | |
335 | X265_FREE((void*)m_sleepMap); | |
336 | ||
337 | if (m_threads) | |
338 | { | |
339 | // cleanup thread handles | |
340 | for (int i = 0; i < m_numThreads; i++) | |
341 | { | |
342 | m_threads[i].~PoolThread(); | |
343 | } | |
344 | ||
345 | X265_FREE(reinterpret_cast<char*>(m_threads)); | |
346 | } | |
347 | } | |
348 | ||
349 | void ThreadPoolImpl::enqueueJobProvider(JobProvider &p) | |
350 | { | |
351 | // only one list writer at a time | |
352 | ScopedLock l(m_writeLock); | |
353 | ||
354 | p.m_nextProvider = NULL; | |
355 | p.m_prevProvider = m_lastProvider; | |
356 | m_lastProvider = &p; | |
357 | ||
358 | if (p.m_prevProvider) | |
359 | p.m_prevProvider->m_nextProvider = &p; | |
360 | else | |
361 | m_firstProvider = &p; | |
362 | } | |
363 | ||
364 | void ThreadPoolImpl::dequeueJobProvider(JobProvider &p) | |
365 | { | |
366 | // only one list writer at a time | |
367 | ScopedLock l(m_writeLock); | |
368 | ||
369 | // update pool entry pointers first | |
370 | if (m_firstProvider == &p) | |
371 | m_firstProvider = p.m_nextProvider; | |
372 | ||
373 | if (m_lastProvider == &p) | |
374 | m_lastProvider = p.m_prevProvider; | |
375 | ||
376 | // extract self from doubly linked lists | |
377 | if (p.m_nextProvider) | |
378 | p.m_nextProvider->m_prevProvider = p.m_prevProvider; | |
379 | ||
380 | if (p.m_prevProvider) | |
381 | p.m_prevProvider->m_nextProvider = p.m_nextProvider; | |
382 | ||
383 | p.m_nextProvider = NULL; | |
384 | p.m_prevProvider = NULL; | |
385 | } | |
386 | ||
387 | /* Ensure all threads have made a full pass through the provider list, ensuring | |
388 | * dequeued providers are safe for deletion. */ | |
389 | void ThreadPoolImpl::FlushProviderList() | |
390 | { | |
391 | for (int i = 0; i < m_numThreads; i++) | |
392 | { | |
393 | m_threads[i].markDirty(); | |
394 | m_threads[i].poke(); | |
395 | } | |
396 | ||
397 | int i; | |
398 | do | |
399 | { | |
400 | for (i = 0; i < m_numThreads; i++) | |
401 | { | |
402 | if (m_threads[i].isDirty()) | |
403 | { | |
404 | GIVE_UP_TIME(); | |
405 | break; | |
406 | } | |
407 | } | |
408 | } | |
409 | while (i < m_numThreads); | |
410 | } | |
411 | ||
412 | void JobProvider::flush() | |
413 | { | |
414 | if (m_nextProvider || m_prevProvider) | |
415 | dequeue(); | |
416 | dynamic_cast<ThreadPoolImpl*>(m_pool)->FlushProviderList(); | |
417 | } | |
418 | ||
419 | void JobProvider::enqueue() | |
420 | { | |
421 | // Add this provider to the end of the thread pool's job provider list | |
422 | X265_CHECK(!m_nextProvider && !m_prevProvider && m_pool, "job provider was already queued\n"); | |
423 | m_pool->enqueueJobProvider(*this); | |
424 | m_pool->pokeIdleThread(); | |
425 | } | |
426 | ||
427 | void JobProvider::dequeue() | |
428 | { | |
429 | // Remove this provider from the thread pool's job provider list | |
430 | m_pool->dequeueJobProvider(*this); | |
431 | // Ensure no jobs were missed while the provider was being removed | |
432 | m_pool->pokeIdleThread(); | |
433 | } | |
434 | ||
435 | int getCpuCount() | |
436 | { | |
437 | #if _WIN32 | |
438 | SYSTEM_INFO sysinfo; | |
439 | GetSystemInfo(&sysinfo); | |
440 | return sysinfo.dwNumberOfProcessors; | |
441 | #elif __unix__ | |
442 | return sysconf(_SC_NPROCESSORS_ONLN); | |
443 | #elif MACOS | |
444 | int nm[2]; | |
445 | size_t len = 4; | |
446 | uint32_t count; | |
447 | ||
448 | nm[0] = CTL_HW; | |
449 | nm[1] = HW_AVAILCPU; | |
450 | sysctl(nm, 2, &count, &len, NULL, 0); | |
451 | ||
452 | if (count < 1) | |
453 | { | |
454 | nm[1] = HW_NCPU; | |
455 | sysctl(nm, 2, &count, &len, NULL, 0); | |
456 | if (count < 1) | |
457 | count = 1; | |
458 | } | |
459 | ||
460 | return count; | |
461 | #else // if _WIN32 | |
462 | return 2; // default to 2 threads, everywhere else | |
463 | #endif // if _WIN32 | |
464 | } | |
465 | } // end namespace x265 |