X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.cpp;h=5c10eee0635e8ddbf531d3e84577629aa74b0c01;hp=5d2b39f57c8c4791dd6b28975448a55d89fa2622;hb=ba85c59d96d962dddaa0f1a2608ebea2e8ae694b;hpb=9a542d96981e6cb45b6b01f17258a078cf27da36 diff --git a/src/thread.cpp b/src/thread.cpp index 5d2b39f5..5c10eee0 100644 --- a/src/thread.cpp +++ b/src/thread.cpp @@ -35,7 +35,7 @@ namespace { extern "C" { DWORD WINAPI start_routine(LPVOID threadID) { - Threads.idle_loop(*(int*)threadID, NULL); + Threads[*(int*)threadID].idle_loop(NULL); return 0; } @@ -43,7 +43,7 @@ namespace { extern "C" { void* start_routine(void* threadID) { - Threads.idle_loop(*(int*)threadID, NULL); + Threads[*(int*)threadID].idle_loop(NULL); return NULL; } @@ -111,7 +111,22 @@ void ThreadsManager::read_uci_options() { maxThreadsPerSplitPoint = Options["Maximum Number of Threads per Split Point"].value(); minimumSplitDepth = Options["Minimum Split Depth"].value() * ONE_PLY; useSleepingThreads = Options["Use Sleeping Threads"].value(); - activeThreads = Options["Threads"].value(); + + set_size(Options["Threads"].value()); +} + + +// set_size() changes the number of active threads and raises do_sleep flag for +// all the unused threads that will go immediately to sleep. + +void ThreadsManager::set_size(int cnt) { + + assert(cnt > 0 && cnt <= MAX_THREADS); + + activeThreads = cnt; + + for (int i = 0; i < MAX_THREADS; i++) + threads[i].do_sleep = !(i < activeThreads); } @@ -120,21 +135,18 @@ void ThreadsManager::read_uci_options() { void ThreadsManager::init() { - int threadID[MAX_THREADS]; - - // This flag is needed to properly end the threads when program exits - allThreadsShouldExit = false; - // Threads will sent to sleep as soon as created, only main thread is kept alive - activeThreads = 1; + set_size(1); threads[0].state = Thread::SEARCHING; + threads[0].threadID = 0; // Allocate pawn and material hash tables for main thread init_hash_tables(); + // Initialize threads lock, used when allocating slaves during splitting lock_init(&threadsLock); - // Initialize thread and split point locks + // Initialize sleep and split point locks for (int i = 0; i < MAX_THREADS; i++) { lock_init(&threads[i].sleepLock); @@ -148,13 +160,13 @@ void ThreadsManager::init() { for (int i = 1; i < MAX_THREADS; i++) { threads[i].state = Thread::INITIALIZING; - threadID[i] = i; + threads[i].threadID = i; #if defined(_MSC_VER) - bool ok = (CreateThread(NULL, 0, start_routine, (LPVOID)&threadID[i], 0, NULL) != NULL); + bool ok = (CreateThread(NULL, 0, start_routine, (LPVOID)&threads[i].threadID , 0, NULL) != NULL); #else pthread_t pthreadID; - bool ok = (pthread_create(&pthreadID, NULL, start_routine, (void*)&threadID[i]) == 0); + bool ok = (pthread_create(&pthreadID, NULL, start_routine, (void*)&threads[i].threadID) == 0); pthread_detach(pthreadID); #endif if (!ok) @@ -169,23 +181,21 @@ void ThreadsManager::init() { } -// exit() is called to cleanly exit the threads when the program finishes +// exit() is called to cleanly terminate the threads when the program finishes void ThreadsManager::exit() { - // Force the woken up threads to exit idle_loop() and hence terminate - allThreadsShouldExit = true; - for (int i = 0; i < MAX_THREADS; i++) { - // Wake up all the threads and waits for termination + // Wake up all the slave threads and wait for termination if (i != 0) { + threads[i].do_terminate = true; threads[i].wake_up(); while (threads[i].state != Thread::TERMINATED) {} } - // Now we can safely destroy the locks and wait conditions + // Now we can safely destroy locks and wait conditions lock_destroy(&threads[i].sleepLock); cond_destroy(&threads[i].sleepCond); @@ -238,13 +248,13 @@ bool ThreadsManager::available_slave_exists(int master) const { // call search().When all threads have returned from search() then split() returns. template -void ThreadsManager::split(Position& pos, SearchStack* ss, Value* alpha, const Value beta, - Value* bestValue, Depth depth, Move threatMove, - int moveCount, MovePicker* mp, int nodeType) { +Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value beta, + Value bestValue, Depth depth, Move threatMove, + int moveCount, MovePicker* mp, int nodeType) { assert(pos.is_ok()); - assert(*bestValue >= -VALUE_INFINITE); - assert(*bestValue <= *alpha); - assert(*alpha < beta); + assert(bestValue >= -VALUE_INFINITE); + assert(bestValue <= alpha); + assert(alpha < beta); assert(beta <= VALUE_INFINITE); assert(depth > DEPTH_ZERO); assert(pos.thread() >= 0 && pos.thread() < activeThreads); @@ -255,95 +265,90 @@ void ThreadsManager::split(Position& pos, SearchStack* ss, Value* alpha, const V // If we already have too many active split points, don't split if (masterThread.activeSplitPoints >= MAX_ACTIVE_SPLIT_POINTS) - return; + return bestValue; // Pick the next available split point object from the split point stack - SplitPoint& splitPoint = masterThread.splitPoints[masterThread.activeSplitPoints]; + SplitPoint* sp = masterThread.splitPoints + masterThread.activeSplitPoints; // Initialize the split point object - splitPoint.parent = masterThread.splitPoint; - splitPoint.master = master; - splitPoint.is_betaCutoff = false; - splitPoint.depth = depth; - splitPoint.threatMove = threatMove; - splitPoint.alpha = *alpha; - splitPoint.beta = beta; - splitPoint.nodeType = nodeType; - splitPoint.bestValue = *bestValue; - splitPoint.mp = mp; - splitPoint.moveCount = moveCount; - splitPoint.pos = &pos; - splitPoint.nodes = 0; - splitPoint.ss = ss; + sp->parent = masterThread.splitPoint; + sp->master = master; + sp->is_betaCutoff = false; + sp->depth = depth; + sp->threatMove = threatMove; + sp->alpha = alpha; + sp->beta = beta; + sp->nodeType = nodeType; + sp->bestValue = bestValue; + sp->mp = mp; + sp->moveCount = moveCount; + sp->pos = &pos; + sp->nodes = 0; + sp->ss = ss; for (i = 0; i < activeThreads; i++) - splitPoint.is_slave[i] = false; + sp->is_slave[i] = false; // If we are here it means we are not available assert(masterThread.state == Thread::SEARCHING); - int booked = 0; + int workersCnt = 1; // At least the master is included - // Try to allocate available threads setting state to Thread::BOOKED, this - // must be done under lock protection to avoid concurrent allocation of - // the same slave by another master. + // Try to allocate available threads and ask them to start searching setting + // the state to Thread::WORKISWAITING, this must be done under lock protection + // to avoid concurrent allocation of the same slave by another master. lock_grab(&threadsLock); - for (i = 0; !Fake && i < activeThreads && booked < maxThreadsPerSplitPoint; i++) + for (i = 0; !Fake && i < activeThreads && workersCnt < maxThreadsPerSplitPoint; i++) if (i != master && threads[i].is_available_to(master)) { - threads[i].state = Thread::BOOKED; - threads[i].splitPoint = &splitPoint; - splitPoint.is_slave[i] = true; - booked++; + workersCnt++; + sp->is_slave[i] = true; + threads[i].splitPoint = sp; + + // This makes the slave to exit from idle_loop() + threads[i].state = Thread::WORKISWAITING; + + if (useSleepingThreads) + threads[i].wake_up(); } lock_release(&threadsLock); // We failed to allocate even one slave, return - if (!Fake && !booked) - return; + if (!Fake && workersCnt == 1) + return bestValue; + masterThread.splitPoint = sp; masterThread.activeSplitPoints++; - masterThread.splitPoint = &splitPoint; - - // Tell the threads that they have work to do. This will make them leave - // their idle loop. - for (i = 0; i < activeThreads; i++) - if (i == master || splitPoint.is_slave[i]) - { - assert(i == master || threads[i].state == Thread::BOOKED); - - // This makes the slave to exit from idle_loop() - threads[i].state = Thread::WORKISWAITING; - - if (useSleepingThreads && i != master) - threads[i].wake_up(); - } + masterThread.state = Thread::WORKISWAITING; // Everything is set up. The master thread enters the idle loop, from // which it will instantly launch a search, because its state is - // THREAD_WORKISWAITING. We send the split point as a second parameter to the - // idle loop, which means that the main thread will return from the idle + // Thread::WORKISWAITING. We send the split point as a second parameter to + // the idle loop, which means that the main thread will return from the idle // loop when all threads have finished their work at this split point. - idle_loop(master, &splitPoint); + masterThread.idle_loop(sp); + + // In helpful master concept a master can help only a sub-tree, and + // because here is all finished is not possible master is booked. + assert(masterThread.state == Thread::AVAILABLE); // We have returned from the idle loop, which means that all threads are - // finished. Update alpha and bestValue, and return. Note that changing - // state and decreasing activeSplitPoints is done under lock protection - // to avoid a race with Thread::is_available_to(). + // finished. Note that changing state and decreasing activeSplitPoints is done + // under lock protection to avoid a race with Thread::is_available_to(). lock_grab(&threadsLock); masterThread.state = Thread::SEARCHING; masterThread.activeSplitPoints--; - masterThread.splitPoint = splitPoint.parent; lock_release(&threadsLock); - *alpha = splitPoint.alpha; - *bestValue = splitPoint.bestValue; - pos.set_nodes_searched(pos.nodes_searched() + splitPoint.nodes); + masterThread.splitPoint = sp->parent; + pos.set_nodes_searched(pos.nodes_searched() + sp->nodes); + + return sp->bestValue; } // Explicit template instantiations -template void ThreadsManager::split(Position&, SearchStack*, Value*, const Value, Value*, Depth, Move, int, MovePicker*, int); -template void ThreadsManager::split(Position&, SearchStack*, Value*, const Value, Value*, Depth, Move, int, MovePicker*, int); +template Value ThreadsManager::split(Position&, SearchStack*, Value, Value, Value, Depth, Move, int, MovePicker*, int); +template Value ThreadsManager::split(Position&, SearchStack*, Value, Value, Value, Depth, Move, int, MovePicker*, int);