| 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 |