X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.cpp;h=9bd7498979761942ba0b0e01f315e2c444385c26;hp=ce2f41f2ffeae29008890a7917fdc3302807d827;hb=c465f4c4df1a8ad3d5c1e3759c6aa27b777b8a77;hpb=cbd7ce468c97ac74efcd497e5196f011b5a646c9 diff --git a/src/thread.cpp b/src/thread.cpp index ce2f41f2..9bd74989 100644 --- a/src/thread.cpp +++ b/src/thread.cpp @@ -32,26 +32,23 @@ ThreadPool Threads; // Global object namespace { extern "C" { // start_routine() is the C function which is called when a new thread - // is launched. It is a wrapper to member function pointed by start_fn. + // is launched. It is a wrapper to the virtual function idle_loop(). - long start_routine(Thread* th) { (th->*(th->start_fn))(); return 0; } + long start_routine(Thread* th) { th->idle_loop(); return 0; } } } // Thread c'tor starts a newly-created thread of execution that will call -// the idle loop function pointed by start_fn going immediately to sleep. +// the the virtual function idle_loop(), going immediately to sleep. -Thread::Thread(Fn fn) { +Thread::Thread() : splitPoints() { is_searching = do_exit = false; maxPly = splitPointsCnt = 0; curSplitPoint = NULL; - start_fn = fn; idx = Threads.size(); - do_sleep = (fn != &Thread::main_loop); // Avoid a race with start_searching() - if (!thread_create(handle, start_routine, this)) { std::cerr << "Failed to create thread number " << idx << std::endl; @@ -60,47 +57,50 @@ Thread::Thread(Fn fn) { } -// Thread d'tor waits for thread termination before to return. +// Thread d'tor waits for thread termination before to return Thread::~Thread() { - assert(do_sleep); - do_exit = true; // Search must be already finished - wake_up(); + notify_one(); thread_join(handle); // Wait for thread termination } -// Thread::timer_loop() is where the timer thread waits maxPly milliseconds and -// then calls check_time(). If maxPly is 0 thread sleeps until is woken up. +// TimerThread::idle_loop() is where the timer thread waits msec milliseconds +// and then calls check_time(). If msec is 0 thread sleeps until is woken up. extern void check_time(); -void Thread::timer_loop() { +void TimerThread::idle_loop() { while (!do_exit) { mutex.lock(); - sleepCondition.wait_for(mutex, maxPly ? maxPly : INT_MAX); + + if (!do_exit) + sleepCondition.wait_for(mutex, msec ? msec : INT_MAX); + mutex.unlock(); - check_time(); + + if (msec) + check_time(); } } -// Thread::main_loop() is where the main thread is parked waiting to be started +// MainThread::idle_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. -void Thread::main_loop() { +void MainThread::idle_loop() { while (true) { mutex.lock(); - do_sleep = true; // Always return to sleep after a search + is_finished = true; // Always return to sleep after a search is_searching = false; - while (do_sleep && !do_exit) + while (is_finished && !do_exit) { Threads.sleepCondition.notify_one(); // Wake up UI thread if needed sleepCondition.wait(mutex); @@ -120,10 +120,9 @@ void Thread::main_loop() { } -// Thread::wake_up() wakes up the thread, normally at the beginning of the search -// or, if "sleeping threads" is used at split time. +// Thread::notify_one() wakes up the thread, normally at split time -void Thread::wake_up() { +void Thread::notify_one() { mutex.lock(); sleepCondition.notify_one(); @@ -131,19 +130,12 @@ void Thread::wake_up() { } -// Thread::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. +// Thread::wait_for() set the thread to sleep until condition 'b' turns true -void Thread::wait_for_stop_or_ponderhit() { - - Signals.stopOnPonderhit = true; +void Thread::wait_for(volatile const bool& b) { mutex.lock(); - while (!Signals.stop) sleepCondition.wait(mutex);; + while (!b) sleepCondition.wait(mutex); mutex.unlock(); } @@ -190,20 +182,21 @@ bool Thread::is_available_to(Thread* master) const { void ThreadPool::init() { - timer = new Thread(&Thread::timer_loop); - threads.push_back(new Thread(&Thread::main_loop)); + sleepWhileIdle = true; + timer = new TimerThread(); + threads.push_back(new MainThread()); read_uci_options(); } -// d'tor cleanly terminates the threads when the program exits. +// exit() cleanly terminates the threads before the program exits. + +void ThreadPool::exit() { -ThreadPool::~ThreadPool() { + delete timer; // As first becuase check_time() accesses threads data for (size_t i = 0; i < threads.size(); i++) delete threads[i]; - - delete timer; } @@ -216,13 +209,12 @@ void ThreadPool::read_uci_options() { maxThreadsPerSplitPoint = Options["Max Threads per Split Point"]; minimumSplitDepth = Options["Min Split Depth"] * ONE_PLY; - useSleepingThreads = Options["Use Sleeping Threads"]; size_t requested = Options["Threads"]; assert(requested > 0); while (threads.size() < requested) - threads.push_back(new Thread(&Thread::idle_loop)); + threads.push_back(new Thread()); while (threads.size() > requested) { @@ -232,34 +224,6 @@ void ThreadPool::read_uci_options() { } -// wake_up() is called before a new search to start the threads that are waiting -// on the sleep condition and to reset maxPly. When useSleepingThreads is set -// threads will be woken up at split time. - -void ThreadPool::wake_up() const { - - for (size_t i = 0; i < threads.size(); i++) - { - threads[i]->maxPly = 0; - threads[i]->do_sleep = false; - - if (!useSleepingThreads) - threads[i]->wake_up(); - } -} - - -// sleep() is called after the search finishes to ask all the threads but the -// main one to go waiting on a sleep condition. - -void ThreadPool::sleep() const { - - // Main thread will go to sleep by itself to avoid a race with start_searching() - for (size_t i = 1; i < threads.size(); i++) - threads[i]->do_sleep = true; -} - - // available_slave_exists() tries to find an idle thread which is available as // a slave for the thread 'master'. @@ -284,8 +248,8 @@ bool ThreadPool::available_slave_exists(Thread* master) const { template Value ThreadPool::split(Position& pos, Stack* ss, Value alpha, Value beta, - Value bestValue, Move* bestMove, Depth depth, - Move threatMove, int moveCount, MovePicker* mp, int nodeType) { + Value bestValue, Move* bestMove, Depth depth, Move threatMove, + int moveCount, MovePicker& mp, int nodeType) { assert(pos.pos_is_ok()); assert(bestValue > -VALUE_INFINITE); @@ -313,7 +277,7 @@ Value ThreadPool::split(Position& pos, Stack* ss, Value alpha, Value beta, sp.beta = beta; sp.nodeType = nodeType; sp.bestValue = bestValue; - sp.mp = mp; + sp.mp = ∓ sp.moveCount = moveCount; sp.pos = &pos; sp.nodes = 0; @@ -327,8 +291,8 @@ Value ThreadPool::split(Position& pos, Stack* ss, Value alpha, Value beta, // Try to allocate available threads and ask them to start searching setting // is_searching flag. This must be done under lock protection to avoid concurrent // allocation of the same slave by another master. - sp.mutex.lock(); mutex.lock(); + sp.mutex.lock(); for (size_t i = 0; i < threads.size() && !Fake; ++i) if (threads[i]->is_available_to(master)) @@ -336,9 +300,7 @@ Value ThreadPool::split(Position& pos, Stack* ss, Value alpha, Value beta, sp.slavesMask |= 1ULL << i; threads[i]->curSplitPoint = &sp; threads[i]->is_searching = true; // Slave leaves idle_loop() - - if (useSleepingThreads) - threads[i]->wake_up(); + threads[i]->notify_one(); // Could be sleeping if (++slavesCnt + 1 >= maxThreadsPerSplitPoint) // Master is always included break; @@ -346,8 +308,8 @@ Value ThreadPool::split(Position& pos, Stack* ss, Value alpha, Value beta, master->splitPointsCnt++; - mutex.unlock(); sp.mutex.unlock(); + mutex.unlock(); // 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. @@ -355,7 +317,7 @@ Value ThreadPool::split(Position& pos, Stack* ss, Value alpha, Value beta, // their work at this split point. if (slavesCnt || Fake) { - master->idle_loop(); + master->Thread::idle_loop(); // Force a call to base class idle_loop() // 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. @@ -365,8 +327,8 @@ Value ThreadPool::split(Position& pos, Stack* ss, Value alpha, Value beta, // We have returned from the idle loop, which means that all threads are // finished. Note that setting is_searching and decreasing splitPointsCnt is // done under lock protection to avoid a race with Thread::is_available_to(). - sp.mutex.lock(); // To protect sp.nodes mutex.lock(); + sp.mutex.lock(); master->is_searching = true; master->splitPointsCnt--; @@ -374,27 +336,15 @@ Value ThreadPool::split(Position& pos, Stack* ss, Value alpha, Value beta, pos.set_nodes_searched(pos.nodes_searched() + sp.nodes); *bestMove = sp.bestMove; - mutex.unlock(); sp.mutex.unlock(); + mutex.unlock(); return sp.bestValue; } // Explicit template instantiations -template Value ThreadPool::split(Position&, Stack*, Value, Value, Value, Move*, Depth, Move, int, MovePicker*, int); -template Value ThreadPool::split(Position&, Stack*, Value, Value, Value, Move*, Depth, Move, int, MovePicker*, int); - - -// set_timer() is used to set the timer to trigger after msec milliseconds. -// If msec is 0 then timer is stopped. - -void ThreadPool::set_timer(int msec) { - - timer->mutex.lock(); - timer->maxPly = msec; - timer->sleepCondition.notify_one(); // Wake up and restart the timer - timer->mutex.unlock(); -} +template Value ThreadPool::split(Position&, Stack*, Value, Value, Value, Move*, Depth, Move, int, MovePicker&, int); +template Value ThreadPool::split(Position&, Stack*, Value, Value, Value, Move*, Depth, Move, int, MovePicker&, int); // wait_for_search_finished() waits for main thread to go to sleep, this means @@ -402,10 +352,9 @@ void ThreadPool::set_timer(int msec) { void ThreadPool::wait_for_search_finished() { - Thread* t = main_thread(); + MainThread* t = main_thread(); t->mutex.lock(); - t->sleepCondition.notify_one(); // In case is waiting for stop or ponderhit - while (!t->do_sleep) sleepCondition.wait(t->mutex); + while (!t->is_finished) sleepCondition.wait(t->mutex); t->mutex.unlock(); } @@ -414,22 +363,23 @@ void ThreadPool::wait_for_search_finished() { // a new search, then returns immediately. void ThreadPool::start_searching(const Position& pos, const LimitsType& limits, - const std::vector& searchMoves) { + const std::vector& searchMoves, StateStackPtr& states) { wait_for_search_finished(); - SearchTime.restart(); // As early as possible + SearchTime = Time::now(); // As early as possible Signals.stopOnPonderhit = Signals.firstRootMove = false; Signals.stop = Signals.failedLowAtRoot = false; - RootPosition = pos; + RootPos = pos; Limits = limits; + SetupStates = states; // Ownership transfer here RootMoves.clear(); for (MoveList ml(pos); !ml.end(); ++ml) if (searchMoves.empty() || count(searchMoves.begin(), searchMoves.end(), ml.move())) RootMoves.push_back(RootMove(ml.move())); - main_thread()->do_sleep = false; - main_thread()->wake_up(); + main_thread()->is_finished = false; + main_thread()->notify_one(); // Starts main thread }