X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.cpp;h=7d85db8618ca982059b96466d963e29d3b1b5ba7;hp=b04b8adbb1719e586e818e366b2077fdc01053ab;hb=49e110c52b19f5c99954d4797b8e991b0b60007c;hpb=bf706c4a4ff06e91edf8c24685d24130146f88d4 diff --git a/src/thread.cpp b/src/thread.cpp index b04b8adb..7d85db86 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) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2013 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 @@ -19,7 +19,6 @@ #include // For std::count #include -#include #include "movegen.h" #include "search.h" @@ -30,41 +29,64 @@ using namespace Search; ThreadPool Threads; // Global object -namespace { extern "C" { +namespace { // start_routine() is the C function which is called when a new thread // is launched. It is a wrapper to the virtual function idle_loop(). - long start_routine(Thread* th) { th->idle_loop(); return 0; } + extern "C" { long start_routine(ThreadBase* th) { th->idle_loop(); return 0; } } -} } + // Helpers to launch a thread after creation and joining before delete. Must be + // outside Thread c'tor and d'tor because object shall be fully initialized + // when start_routine (and hence virtual idle_loop) is called and when joining. -// Thread c'tor starts a newly-created thread of execution that will call -// the the virtual function idle_loop(), going immediately to sleep. + template T* new_thread() { + T* th = new T(); + thread_create(th->handle, start_routine, th); // Will go to sleep + return th; + } -Thread::Thread() : splitPoints() { + void delete_thread(ThreadBase* th) { + th->exit = true; // Search must be already finished + th->notify_one(); + thread_join(th->handle); // Wait for thread termination + delete th; + } - searching = exit = false; - maxPly = splitPointsSize = 0; - activeSplitPoint = NULL; - idx = Threads.size(); +} - if (!thread_create(handle, start_routine, this)) - { - std::cerr << "Failed to create thread number " << idx << std::endl; - ::exit(EXIT_FAILURE); - } + +// ThreadBase::notify_one() wakes up the thread when there is some work to do + +void ThreadBase::notify_one() { + + mutex.lock(); + sleepCondition.notify_one(); + mutex.unlock(); } -// Thread d'tor waits for thread termination before to return +// ThreadBase::wait_for() set the thread to sleep until condition 'b' turns true -Thread::~Thread() { +void ThreadBase::wait_for(volatile const bool& b) { - exit = true; // Search must be already finished - notify_one(); - thread_join(handle); // Wait for thread termination + mutex.lock(); + while (!b) sleepCondition.wait(mutex); + mutex.unlock(); +} + + +// Thread c'tor just inits data but does not launch any thread of execution that +// instead will be started only upon c'tor returns. + +Thread::Thread() /* : splitPoints() */ { // Value-initialization bug in MSVC + + searching = false; + maxPly = splitPointsSize = 0; + activeSplitPoint = NULL; + activePosition = NULL; + idx = Threads.size(); } @@ -122,26 +144,6 @@ void MainThread::idle_loop() { } -// Thread::notify_one() wakes up the thread when there is some search to do - -void Thread::notify_one() { - - mutex.lock(); - sleepCondition.notify_one(); - mutex.unlock(); -} - - -// Thread::wait_for() set the thread to sleep until condition 'b' turns true - -void Thread::wait_for(volatile const bool& b) { - - mutex.lock(); - while (!b) sleepCondition.wait(mutex); - mutex.unlock(); -} - - // Thread::cutoff_occurred() checks whether a beta cutoff has occurred in the // current active split point, or in some ancestor of the split point. @@ -162,7 +164,7 @@ bool Thread::cutoff_occurred() const { // which are busy searching the split point at the top of slaves split point // stack (the "helpful master concept" in YBWC terminology). -bool Thread::is_available_to(Thread* master) const { +bool Thread::is_available_to(const Thread* master) const { if (searching) return false; @@ -185,8 +187,8 @@ bool Thread::is_available_to(Thread* master) const { void ThreadPool::init() { sleepWhileIdle = true; - timer = new TimerThread(); - push_back(new MainThread()); + timer = new_thread(); + push_back(new_thread()); read_uci_options(); } @@ -195,10 +197,10 @@ void ThreadPool::init() { void ThreadPool::exit() { - delete timer; // As first because check_time() accesses threads data + delete_thread(timer); // As first because check_time() accesses threads data for (iterator it = begin(); it != end(); ++it) - delete *it; + delete_thread(*it); } @@ -215,12 +217,19 @@ void ThreadPool::read_uci_options() { assert(requested > 0); + // Value 0 has a special meaning: We determine the optimal minimum split depth + // automatically. Anyhow the minimumSplitDepth should never be under 4 plies. + if (!minimumSplitDepth) + minimumSplitDepth = (requested < 8 ? 4 : 7) * ONE_PLY; + else + minimumSplitDepth = std::max(4 * ONE_PLY, minimumSplitDepth); + while (size() < requested) - push_back(new Thread()); + push_back(new_thread()); while (size() > requested) { - delete back(); + delete_thread(back()); pop_back(); } } @@ -229,13 +238,13 @@ void ThreadPool::read_uci_options() { // slave_available() tries to find an idle thread which is available as a slave // for the thread 'master'. -bool ThreadPool::slave_available(Thread* master) const { +Thread* ThreadPool::available_slave(const Thread* master) const { for (const_iterator it = begin(); it != end(); ++it) if ((*it)->is_available_to(master)) - return true; + return *it; - return false; + return NULL; } @@ -249,9 +258,9 @@ bool ThreadPool::slave_available(Thread* master) const { // search() then split() returns. template -void Thread::split(Position& pos, Stack* ss, Value alpha, Value beta, Value* bestValue, +void Thread::split(Position& pos, const Stack* ss, Value alpha, Value beta, Value* bestValue, Move* bestMove, Depth depth, Move threatMove, int moveCount, - MovePicker* movePicker, int nodeType) { + MovePicker* movePicker, int nodeType, bool cutNode) { assert(pos.pos_is_ok()); assert(*bestValue <= alpha && alpha < beta && beta <= VALUE_INFINITE); @@ -273,6 +282,7 @@ void Thread::split(Position& pos, Stack* ss, Value alpha, Value beta, Value* bes sp.alpha = alpha; sp.beta = beta; sp.nodeType = nodeType; + sp.cutNode = cutNode; sp.movePicker = movePicker; sp.moveCount = moveCount; sp.pos = &pos; @@ -288,47 +298,47 @@ void Thread::split(Position& pos, Stack* ss, Value alpha, Value beta, Value* bes splitPointsSize++; activeSplitPoint = &sp; + activePosition = NULL; size_t slavesCnt = 1; // This thread is always included + Thread* slave; - for (ThreadPool::iterator it = Threads.begin(); it != Threads.end() && !Fake; ++it) + while ( (slave = Threads.available_slave(this)) != NULL + && ++slavesCnt <= Threads.maxThreadsPerSplitPoint && !Fake) { - Thread* slave = *it; - - if (slave->is_available_to(this) && ++slavesCnt <= Threads.maxThreadsPerSplitPoint) - { - sp.slavesMask |= 1ULL << slave->idx; - slave->activeSplitPoint = &sp; - slave->searching = true; // Slave leaves idle_loop() - slave->notify_one(); // Could be sleeping - } + sp.slavesMask |= 1ULL << slave->idx; + slave->activeSplitPoint = &sp; + slave->searching = true; // Slave leaves idle_loop() + slave->notify_one(); // Could be sleeping } - sp.mutex.unlock(); - Threads.mutex.unlock(); - // Everything is set up. The master thread enters the idle loop, from which // it will instantly launch a search, because its 'searching' flag is set. // The thread will return from the idle loop when all slaves have finished // their work at this split point. if (slavesCnt > 1 || Fake) { + sp.mutex.unlock(); + Threads.mutex.unlock(); + 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. assert(!searching); - } + assert(!activePosition); - // We have returned from the idle loop, which means that all threads are - // finished. Note that setting 'searching' and decreasing splitPointsSize is - // done under lock protection to avoid a race with Thread::is_available_to(). - Threads.mutex.lock(); - sp.mutex.lock(); + // We have returned from the idle loop, which means that all threads are + // finished. Note that setting 'searching' and decreasing splitPointsSize is + // done under lock protection to avoid a race with Thread::is_available_to(). + Threads.mutex.lock(); + sp.mutex.lock(); + } searching = true; splitPointsSize--; activeSplitPoint = sp.parentSplitPoint; + activePosition = &pos; pos.set_nodes_searched(pos.nodes_searched() + sp.nodes); *bestMove = sp.bestMove; *bestValue = sp.bestValue; @@ -338,15 +348,15 @@ void Thread::split(Position& pos, Stack* ss, Value alpha, Value beta, Value* bes } // Explicit template instantiations -template void Thread::split(Position&, Stack*, Value, Value, Value*, Move*, Depth, Move, int, MovePicker*, int); -template void Thread::split< true>(Position&, Stack*, Value, Value, Value*, Move*, Depth, Move, int, MovePicker*, int); +template void Thread::split(Position&, const Stack*, Value, Value, Value*, Move*, Depth, Move, int, MovePicker*, int, bool); +template void Thread::split< true>(Position&, const Stack*, Value, Value, Value*, Move*, Depth, Move, int, MovePicker*, int, bool); // wait_for_think_finished() waits for main thread to go to sleep then returns void ThreadPool::wait_for_think_finished() { - MainThread* t = main_thread(); + MainThread* t = main(); t->mutex.lock(); while (t->thinking) sleepCondition.wait(t->mutex); t->mutex.unlock(); @@ -365,16 +375,20 @@ void ThreadPool::start_thinking(const Position& pos, const LimitsType& limits, Signals.stopOnPonderhit = Signals.firstRootMove = false; Signals.stop = Signals.failedLowAtRoot = false; + RootMoves.clear(); RootPos = pos; Limits = limits; - SetupStates = states; // Ownership transfer here - RootMoves.clear(); + if (states.get()) // If we don't set a new position, preserve current state + { + SetupStates = states; // Ownership transfer here + assert(!states.get()); + } - for (MoveList ml(pos); !ml.end(); ++ml) + for (MoveList it(pos); *it; ++it) if ( searchMoves.empty() - || std::count(searchMoves.begin(), searchMoves.end(), ml.move())) - RootMoves.push_back(RootMove(ml.move())); + || std::count(searchMoves.begin(), searchMoves.end(), *it)) + RootMoves.push_back(RootMove(*it)); - main_thread()->thinking = true; - main_thread()->notify_one(); // Starts main thread + main()->thinking = true; + main()->notify_one(); // Starts main thread }