X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.cpp;h=df76dcca7a2e1fe990c4859bd23219afcc8188f8;hp=ac0be89fdcaee7766bbe8a3ede5765f90d7c691f;hb=d58176bfead421088bb3543b3cb6d1c359a3c91b;hpb=b69d9ee3f720ba04bbc22eb24203123f4b79707f diff --git a/src/thread.cpp b/src/thread.cpp index ac0be89f..df76dcca 100644 --- a/src/thread.cpp +++ b/src/thread.cpp @@ -19,6 +19,7 @@ #include +#include "search.h" #include "thread.h" #include "ucioption.h" @@ -27,27 +28,26 @@ ThreadsManager Threads; // Global object definition namespace { extern "C" { // start_routine() is the C function which is called when a new thread - // is launched. It simply calls idle_loop() of the supplied thread. - // There are two versions of this function; one for POSIX threads and - // one for Windows threads. + // is launched. It simply calls idle_loop() of the supplied thread. The + // last two threads are dedicated to read input from GUI and to mimic a + // timer, so they run in listener_loop() and timer_loop() respectively. #if defined(_MSC_VER) - DWORD WINAPI start_routine(LPVOID thread) { - - ((Thread*)thread)->idle_loop(NULL); - return 0; - } - #else - void* start_routine(void* thread) { +#endif - ((Thread*)thread)->idle_loop(NULL); - return NULL; - } + if (((Thread*)thread)->threadID == MAX_THREADS) + ((Thread*)thread)->listener_loop(); -#endif + else if (((Thread*)thread)->threadID == MAX_THREADS + 1) + ((Thread*)thread)->timer_loop(); + else + ((Thread*)thread)->idle_loop(NULL); + + return 0; + } } } @@ -84,7 +84,7 @@ bool Thread::cutoff_occurred() const { bool Thread::is_available_to(int master) const { - if (state != AVAILABLE) + if (is_searching) return false; // Make a local copy to be sure doesn't become zero under our feet while @@ -147,11 +147,14 @@ void ThreadsManager::set_size(int cnt) { void ThreadsManager::init() { + // Initialize sleep condition used to block waiting for GUI input + cond_init(&sleepCond); + // Initialize threads lock, used when allocating slaves during splitting lock_init(&threadsLock); // Initialize sleep and split point locks - for (int i = 0; i < MAX_THREADS; i++) + for (int i = 0; i < MAX_THREADS + 2; i++) { lock_init(&threads[i].sleepLock); cond_init(&threads[i].sleepCond); @@ -161,15 +164,15 @@ void ThreadsManager::init() { } // Initialize main thread's associated data - threads[0].state = Thread::SEARCHING; + threads[0].is_searching = true; threads[0].threadID = 0; set_size(1); // This makes all the threads but the main to go to sleep // Create and launch all the threads but the main that is already running, // threads will go immediately to sleep. - for (int i = 1; i < MAX_THREADS; i++) + for (int i = 1; i < MAX_THREADS + 2; i++) { - threads[i].state = Thread::AVAILABLE; + threads[i].is_searching = false; threads[i].threadID = i; #if defined(_MSC_VER) @@ -192,14 +195,14 @@ void ThreadsManager::init() { void ThreadsManager::exit() { - for (int i = 0; i < MAX_THREADS; i++) + for (int i = 0; i < MAX_THREADS + 2; i++) { - // Wake up all the slave threads and wait for termination if (i != 0) { threads[i].do_terminate = true; threads[i].wake_up(); + // Wait for slave termination #if defined(_MSC_VER) WaitForSingleObject(threads[i].handle, 0); CloseHandle(threads[i].handle); @@ -217,6 +220,7 @@ void ThreadsManager::exit() { } lock_destroy(&threadsLock); + cond_destroy(&sleepCond); } @@ -248,7 +252,7 @@ template 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(pos.pos_is_ok()); assert(bestValue >= -VALUE_INFINITE); assert(bestValue <= alpha); assert(alpha < beta); @@ -286,7 +290,7 @@ Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value b sp->is_slave[i] = false; // If we are here it means we are not available - assert(masterThread.state == Thread::SEARCHING); + assert(masterThread.is_searching); int workersCnt = 1; // At least the master is included @@ -303,7 +307,7 @@ Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value b threads[i].splitPoint = sp; // This makes the slave to exit from idle_loop() - threads[i].state = Thread::WORKISWAITING; + threads[i].is_searching = true; if (useSleepingThreads) threads[i].wake_up(); @@ -317,25 +321,24 @@ Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value b masterThread.splitPoint = sp; masterThread.activeSplitPoints++; - 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 - // loop when all threads have finished their work at this split point. + // Everything is set up. The master thread enters the idle loop, from which + // it will instantly launch a search, because its is_searching flag is set. + // We pass the split point as a parameter to the idle loop, which means that + // the thread will return from the idle loop when all slaves have finished + // their work at this split point. 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); + assert(!masterThread.is_searching); // We have returned from the idle loop, which means that all threads are // 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.is_searching = true; masterThread.activeSplitPoints--; lock_release(&threadsLock); @@ -349,3 +352,142 @@ Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value b // Explicit template instantiations 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); + + +// Thread::timer_loop() is where the timer thread waits maxPly milliseconds +// and then calls do_timer_event(). + +void Thread::timer_loop() { + + while (!do_terminate) + { + lock_grab(&sleepLock); + timed_wait(&sleepCond, &sleepLock, maxPly ? maxPly : INT_MAX); + lock_release(&sleepLock); + do_timer_event(); + } +} + + +// ThreadsManager::set_timer() is used to set the timer to trigger after msec +// milliseconds. If msec is 0 then timer is stopped. + +void ThreadsManager::set_timer(int msec) { + + Thread& timer = threads[MAX_THREADS + 1]; + + lock_grab(&timer.sleepLock); + timer.maxPly = msec; + cond_signal(&timer.sleepCond); // Wake up and restart the timer + lock_release(&timer.sleepLock); +} + + +// Thread::listener_loop() is where the listener thread, used for I/O, waits for +// input. When is_searching is false then input is read in sync with main thread +// (that blocks), otherwise the listener thread reads any input asynchronously +// and processes the input line calling do_uci_async_cmd(). + +void Thread::listener_loop() { + + std::string cmd; + + while (true) + { + lock_grab(&sleepLock); + + Threads.inputLine = cmd; + do_sleep = !is_searching; + + // Here the thread is parked in sync mode after a line has been read + while (do_sleep && !do_terminate) // Catches spurious wake ups + { + cond_signal(&Threads.sleepCond); // Wake up main thread + cond_wait(&sleepCond, &sleepLock); // Sleep here + } + + lock_release(&sleepLock); + + if (do_terminate) + return; + + if (!std::getline(std::cin, cmd)) // Block waiting for input + cmd = "quit"; + + lock_grab(&sleepLock); + + // If we are in async mode then process the command now + if (is_searching) + { + // Command "quit" is the last one received by the GUI, so park the + // thread waiting for exiting. + if (cmd == "quit") + is_searching = false; + + do_uci_async_cmd(cmd); + cmd = ""; // Input has been consumed + } + + lock_release(&sleepLock); + } +} + + +// ThreadsManager::getline() is used by main thread to block and wait for input, +// the behaviour mimics std::getline(). + +void ThreadsManager::getline(std::string& cmd) { + + Thread& listener = threads[MAX_THREADS]; + + lock_grab(&listener.sleepLock); + + listener.is_searching = false; // Set sync mode + + // If there is already some input to grab then skip without to wake up the + // listener. This can happen if after we send the "bestmove", the GUI sends + // a command that the listener buffers in inputLine before going to sleep. + if (inputLine.empty()) + { + listener.do_sleep = false; + cond_signal(&listener.sleepCond); // Wake up listener thread + + while (!listener.do_sleep) + cond_wait(&sleepCond, &listener.sleepLock); // Wait for input + } + + cmd = inputLine; + inputLine = ""; // Input has been consumed + + lock_release(&listener.sleepLock); +} + + +// ThreadsManager::start_listener() is called at the beginning of the search to +// swith from sync behaviour (default) to async and so be able to read from UCI +// while other threads are searching. This avoids main thread polling for input. + +void ThreadsManager::start_listener() { + + Thread& listener = threads[MAX_THREADS]; + + lock_grab(&listener.sleepLock); + listener.is_searching = true; + listener.do_sleep = false; + cond_signal(&listener.sleepCond); // Wake up listener thread + lock_release(&listener.sleepLock); +} + + +// ThreadsManager::stop_listener() is called before to send "bestmove" to GUI to +// return to in-sync behaviour. This is needed because while in async mode any +// command is discarded without being processed (except for a very few ones). + +void ThreadsManager::stop_listener() { + + Thread& listener = threads[MAX_THREADS]; + + lock_grab(&listener.sleepLock); + listener.is_searching = false; + lock_release(&listener.sleepLock); +}