X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.cpp;h=1db61a20671e77376de2c7501175f2699f02b1c3;hp=4a37d393edff4ca6f83eaa9a7f86917ec8dcc6ef;hb=103b368ab7f5fd696e0c6925917344d15a3c2d9c;hpb=44c78fdb7ad4c82656f25e4da11f3f9d56a4c6aa diff --git a/src/thread.cpp b/src/thread.cpp index 4a37d393..1db61a20 100644 --- a/src/thread.cpp +++ b/src/thread.cpp @@ -1,7 +1,7 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -19,18 +19,21 @@ #include +#include "movegen.h" #include "search.h" #include "thread.h" #include "ucioption.h" -ThreadsManager Threads; // Global object definition +using namespace Search; + +ThreadsManager Threads; // Global object 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. 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. + // is launched. It simply calls idle_loop() of the supplied thread. The first + // and last thread are special. First one is the main search thread while the + // last one mimics a timer, they run in main_loop() and timer_loop(). #if defined(_MSC_VER) DWORD WINAPI start_routine(LPVOID thread) { @@ -38,13 +41,16 @@ namespace { extern "C" { void* start_routine(void* thread) { #endif - if (((Thread*)thread)->threadID == MAX_THREADS) - ((Thread*)thread)->listener_loop(); + Thread* th = (Thread*)thread; + + if (th->threadID == 0) + th->main_loop(); + + else if (th->threadID == MAX_THREADS) + th->timer_loop(); - else if (((Thread*)thread)->threadID == MAX_THREADS + 1) - ((Thread*)thread)->timer_loop(); else - ((Thread*)thread)->idle_loop(NULL); + th->idle_loop(NULL); return 0; } @@ -71,6 +77,7 @@ bool Thread::cutoff_occurred() const { for (SplitPoint* sp = splitPoint; sp; sp = sp->parent) if (sp->is_betaCutoff) return true; + return false; } @@ -101,17 +108,16 @@ bool Thread::is_available_to(int master) const { } -// read_uci_options() updates number of active threads and other internal -// parameters according to the UCI options values. It is called before -// to start a new search. +// read_uci_options() updates number of active threads and other parameters +// according to the UCI options values. It is called before to start a new search. 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(); + maxThreadsPerSplitPoint = Options["Max Threads per Split Point"]; + minimumSplitDepth = Options["Min Split Depth"] * ONE_PLY; + useSleepingThreads = Options["Use Sleeping Threads"]; - set_size(Options["Threads"].value()); + set_size(Options["Threads"]); } @@ -124,14 +130,12 @@ void ThreadsManager::set_size(int cnt) { activeThreads = cnt; - for (int i = 0; i < MAX_THREADS; i++) + for (int i = 1; i < MAX_THREADS; i++) // Ignore main thread if (i < activeThreads) { // Dynamically allocate pawn and material hash tables according to the // number of active threads. This avoids preallocating memory for all - // possible threads if only few are used as, for instance, on mobile - // devices where memory is scarce and allocating for MAX_THREADS could - // even result in a crash. + // possible threads if only few are used. threads[i].pawnTable.init(); threads[i].materialTable.init(); @@ -147,14 +151,12 @@ void ThreadsManager::set_size(int cnt) { void ThreadsManager::init() { - // Initialize sleep condition used to block waiting for GUI input + // Initialize sleep condition and lock used by thread manager 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 + 2; i++) + // Initialize thread's sleep conditions and split point locks + for (int i = 0; i <= MAX_THREADS; i++) { lock_init(&threads[i].sleepLock); cond_init(&threads[i].sleepCond); @@ -163,23 +165,22 @@ void ThreadsManager::init() { lock_init(&(threads[i].splitPoints[j].lock)); } - // Initialize main thread's associated data - threads[0].is_searching = true; - threads[0].threadID = 0; - set_size(1); // This makes all the threads but the main to go to sleep + // Allocate main thread tables to call evaluate() also when not searching + threads[0].pawnTable.init(); + threads[0].materialTable.init(); - // 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 + 2; i++) + // Create and launch all the threads, threads will go immediately to sleep + for (int i = 0; i <= MAX_THREADS; i++) { threads[i].is_searching = false; + threads[i].do_sleep = (i != 0); // Avoid a race with start_thinking() threads[i].threadID = i; #if defined(_MSC_VER) - threads[i].handle = CreateThread(NULL, 0, start_routine, (LPVOID)&threads[i], 0, NULL); + threads[i].handle = CreateThread(NULL, 0, start_routine, &threads[i], 0, NULL); bool ok = (threads[i].handle != NULL); #else - bool ok = (pthread_create(&threads[i].handle, NULL, start_routine, (void*)&threads[i]) == 0); + bool ok = !pthread_create(&threads[i].handle, NULL, start_routine, &threads[i]); #endif if (!ok) @@ -195,23 +196,20 @@ void ThreadsManager::init() { void ThreadsManager::exit() { - for (int i = 0; i < MAX_THREADS + 2; i++) + for (int i = 0; i <= MAX_THREADS; i++) { - if (i != 0) - { - threads[i].do_terminate = true; - threads[i].wake_up(); + threads[i].do_terminate = true; // Search must be already finished + threads[i].wake_up(); - // Wait for slave termination + // Wait for thread termination #if defined(_MSC_VER) - WaitForSingleObject(threads[i].handle, 0); - CloseHandle(threads[i].handle); + WaitForSingleObject(threads[i].handle, INFINITE); + CloseHandle(threads[i].handle); #else - pthread_join(threads[i].handle, NULL); + pthread_join(threads[i].handle, NULL); #endif - } - // Now we can safely destroy locks and wait conditions + // Now we can safely destroy associated locks and wait conditions lock_destroy(&threads[i].sleepLock); cond_destroy(&threads[i].sleepCond); @@ -225,14 +223,14 @@ void ThreadsManager::exit() { // available_slave_exists() tries to find an idle thread which is available as -// a slave for the thread with threadID "master". +// a slave for the thread with threadID 'master'. bool ThreadsManager::available_slave_exists(int master) const { assert(master >= 0 && master < activeThreads); for (int i = 0; i < activeThreads; i++) - if (i != master && threads[i].is_available_to(master)) + if (threads[i].is_available_to(master)) return true; return false; @@ -253,20 +251,20 @@ bool ThreadsManager::split_point_finished(SplitPoint* sp) const { // split() does the actual work of distributing the work at a node between -// several available threads. If it does not succeed in splitting the -// node (because no idle threads are available, or because we have no unused -// split point objects), the function immediately returns. If splitting is -// possible, a SplitPoint object is initialized with all the data that must be -// copied to the helper threads and we tell our helper threads that they have -// been assigned work. This will cause them to instantly leave their idle loops and -// call search().When all threads have returned from search() then split() returns. +// several available threads. If it does not succeed in splitting the node +// (because no idle threads are available, or because we have no unused split +// point objects), the function immediately returns. If splitting is possible, a +// SplitPoint object is initialized with all the data that must be copied to the +// helper threads and then helper threads are told that they have been assigned +// work. This will cause them to instantly leave their idle loops and call +// search(). When all threads have returned from search() then split() returns. template -Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value beta, +Value ThreadsManager::split(Position& pos, Stack* ss, Value alpha, Value beta, Value bestValue, Depth depth, Move threatMove, int moveCount, MovePicker* mp, int nodeType) { assert(pos.pos_is_ok()); - assert(bestValue >= -VALUE_INFINITE); + assert(bestValue > -VALUE_INFINITE); assert(bestValue <= alpha); assert(alpha < beta); assert(beta <= VALUE_INFINITE); @@ -281,10 +279,10 @@ Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value b if (masterThread.activeSplitPoints >= MAX_ACTIVE_SPLIT_POINTS) return bestValue; - // Pick the next available split point object from the split point stack - SplitPoint* sp = masterThread.splitPoints + masterThread.activeSplitPoints; + // Pick the next available split point from the split point stack + SplitPoint* sp = &masterThread.splitPoints[masterThread.activeSplitPoints]; - // Initialize the split point object + // Initialize the split point sp->parent = masterThread.splitPoint; sp->master = master; sp->is_betaCutoff = false; @@ -299,6 +297,7 @@ Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value b sp->pos = &pos; sp->nodes = 0; sp->ss = ss; + for (i = 0; i < activeThreads; i++) sp->is_slave[i] = false; @@ -308,12 +307,12 @@ Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value b int workersCnt = 1; // At least the master is included // 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. + // is_searching flag. 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 && workersCnt < maxThreadsPerSplitPoint; i++) - if (i != master && threads[i].is_available_to(master)) + if (threads[i].is_available_to(master)) { workersCnt++; sp->is_slave[i] = true; @@ -342,8 +341,8 @@ Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value b // 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. + // In helpful master concept a master can help only a sub-tree of its split + // point, and because here is all finished is not possible master is booked. assert(!masterThread.is_searching); // We have returned from the idle loop, which means that all threads are @@ -363,12 +362,13 @@ 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); +template Value ThreadsManager::split(Position&, Stack*, Value, Value, Value, Depth, Move, int, MovePicker*, int); +template Value ThreadsManager::split(Position&, Stack*, 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(). +// Thread::timer_loop() is where the timer thread waits maxPly milliseconds and +// then calls do_timer_event(). If maxPly is 0 thread sleeps until is woken up. +extern void check_time(); void Thread::timer_loop() { @@ -377,7 +377,7 @@ void Thread::timer_loop() { lock_grab(&sleepLock); timed_wait(&sleepCond, &sleepLock, maxPly ? maxPly : INT_MAX); lock_release(&sleepLock); - do_timer_event(); + check_time(); } } @@ -387,7 +387,7 @@ void Thread::timer_loop() { void ThreadsManager::set_timer(int msec) { - Thread& timer = threads[MAX_THREADS + 1]; + Thread& timer = threads[MAX_THREADS]; lock_grab(&timer.sleepLock); timer.maxPly = msec; @@ -396,113 +396,115 @@ void ThreadsManager::set_timer(int msec) { } -// 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() { +// Thread::main_loop() is where the main thread is parked waiting to be started +// when there is a new search. Main thread will launch all the slave threads. - std::string cmd; +void Thread::main_loop() { while (true) { lock_grab(&sleepLock); - Threads.inputLine = cmd; - do_sleep = !is_searching; + do_sleep = true; // Always return to sleep after a search + is_searching = false; - // Here the thread is parked in sync mode after a line has been read - while (do_sleep && !do_terminate) // Catches spurious wake ups + while (do_sleep && !do_terminate) { - cond_signal(&Threads.sleepCond); // Wake up main thread - cond_wait(&sleepCond, &sleepLock); // Sleep here + cond_signal(&Threads.sleepCond); // Wake up UI thread if needed + cond_wait(&sleepCond, &sleepLock); } + is_searching = true; + 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. Also, after a "stop", for instance on a - // ponder miss, GUI can immediately send the new position to search, - // so return to in-sync mode to avoid discarding good data. - if (cmd == "quit" || cmd == "stop") - is_searching = false; - - do_uci_async_cmd(cmd); - cmd = ""; // Input has been consumed - } - - lock_release(&sleepLock); + Search::think(); } } -// ThreadsManager::getline() is used by main thread to block and wait for input, -// the behaviour mimics std::getline(). +// ThreadsManager::start_thinking() is used by UI thread to wake up the main +// thread parked in main_loop() and starting a new search. If asyncMode is true +// then function returns immediately, otherwise caller is blocked waiting for +// the search to finish. -void ThreadsManager::getline(std::string& cmd) { +void ThreadsManager::start_thinking(const Position& pos, const LimitsType& limits, + const std::set& searchMoves, bool async) { + Thread& main = threads[0]; - Thread& listener = threads[MAX_THREADS]; + lock_grab(&main.sleepLock); - lock_grab(&listener.sleepLock); + // Wait main thread has finished before to launch a new search + while (!main.do_sleep) + cond_wait(&sleepCond, &main.sleepLock); - listener.is_searching = false; // Set sync mode + // Copy input arguments to initialize the search + RootPosition.copy(pos, 0); + Limits = limits; + RootMoves.clear(); - // 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 + // Populate RootMoves with all the legal moves (default) or, if a searchMoves + // set is given, with the subset of legal moves to search. + for (MoveList ml(pos); !ml.end(); ++ml) + if (searchMoves.empty() || searchMoves.count(ml.move())) + RootMoves.push_back(RootMove(ml.move())); - while (!listener.do_sleep) - cond_wait(&sleepCond, &listener.sleepLock); // Wait for input - } + // Reset signals before to start the new search + Signals.stopOnPonderhit = Signals.firstRootMove = false; + Signals.stop = Signals.failedLowAtRoot = false; + + main.do_sleep = false; + cond_signal(&main.sleepCond); // Wake up main thread and start searching - cmd = inputLine; - inputLine = ""; // Input has been consumed + if (!async) + while (!main.do_sleep) + cond_wait(&sleepCond, &main.sleepLock); - lock_release(&listener.sleepLock); + lock_release(&main.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. +// ThreadsManager::stop_thinking() is used by UI thread to raise a stop request +// and to wait for the main thread finishing the search. Needed to wait exiting +// and terminate the threads after a 'quit' command. + +void ThreadsManager::stop_thinking() { -void ThreadsManager::start_listener() { + Thread& main = threads[0]; - Thread& listener = threads[MAX_THREADS]; + Search::Signals.stop = true; - lock_grab(&listener.sleepLock); - listener.is_searching = true; - listener.do_sleep = false; - cond_signal(&listener.sleepCond); // Wake up listener thread - lock_release(&listener.sleepLock); + lock_grab(&main.sleepLock); + + cond_signal(&main.sleepCond); // In case is waiting for stop or ponderhit + + while (!main.do_sleep) + cond_wait(&sleepCond, &main.sleepLock); + + lock_release(&main.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). +// ThreadsManager::wait_for_stop_or_ponderhit() is called when the maximum depth +// is reached while the program is pondering. The point is to work around a wrinkle +// in the UCI protocol: When pondering, the engine is not allowed to give a +// "bestmove" before the GUI sends it a "stop" or "ponderhit" command. We simply +// wait here until one of these commands (that raise StopRequest) is sent and +// then return, after which the bestmove and pondermove will be printed. + +void ThreadsManager::wait_for_stop_or_ponderhit() { + + Signals.stopOnPonderhit = true; + + Thread& main = threads[0]; -void ThreadsManager::stop_listener() { + lock_grab(&main.sleepLock); - Thread& listener = threads[MAX_THREADS]; + while (!Signals.stop) + cond_wait(&main.sleepCond, &main.sleepLock); - lock_grab(&listener.sleepLock); - listener.is_searching = false; - lock_release(&listener.sleepLock); + lock_release(&main.sleepLock); }