X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.cpp;h=fdb99e62ac5e5c3ea79e00af7b8fec038235b157;hp=782cf1acc0dd5153fb8ba3bebad8cf69bc35da12;hb=c9dcda6ac488c0058ebd567e1f52e30b8cd0db20;hpb=d3608c4e79a29110f4c4a369d7207c6dd8e01f34 diff --git a/src/thread.cpp b/src/thread.cpp index 782cf1ac..fdb99e62 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) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2014 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" @@ -30,47 +29,69 @@ 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 the object will 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() */ { // Value-initialization bug in MSVC + 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; - activePosition = 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(); +} + + +// ThreadBase::wait_for() set the thread to sleep until condition 'b' turns true + +void ThreadBase::wait_for(volatile const bool& b) { + + mutex.lock(); + while (!b) sleepCondition.wait(mutex); + mutex.unlock(); } -// Thread d'tor waits for thread termination before to return +// Thread c'tor just inits data and does not launch any execution thread. +// Such a thread will only be started when c'tor returns. -Thread::~Thread() { +Thread::Thread() /* : splitPoints() */ { // Value-initialization bug in MSVC - exit = true; // Search must be already finished - notify_one(); - thread_join(handle); // Wait for thread termination + searching = false; + maxPly = splitPointsSize = 0; + activeSplitPoint = NULL; + activePosition = NULL; + idx = Threads.size(); } // 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. +// and then calls check_time(). If msec is 0 thread sleeps until it's woken up. extern void check_time(); void TimerThread::idle_loop() { @@ -80,18 +101,18 @@ void TimerThread::idle_loop() { mutex.lock(); if (!exit) - sleepCondition.wait_for(mutex, msec ? msec : INT_MAX); + sleepCondition.wait_for(mutex, run ? Resolution : INT_MAX); mutex.unlock(); - if (msec) + if (run) check_time(); } } // 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. +// when there is a new search. The main thread will launch all the slave threads. void MainThread::idle_loop() { @@ -103,7 +124,7 @@ void MainThread::idle_loop() { while (!thinking && !exit) { - Threads.sleepCondition.notify_one(); // Wake up UI thread if needed + Threads.sleepCondition.notify_one(); // Wake up the UI thread if needed sleepCondition.wait(mutex); } @@ -123,26 +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. @@ -156,20 +157,20 @@ bool Thread::cutoff_occurred() const { } -// Thread::is_available_to() checks whether the thread is available to help the +// Thread::available_to() checks whether the thread is available to help the // thread 'master' at a split point. An obvious requirement is that thread must // be idle. With more than two threads, this is not sufficient: If the thread is // the master of some split point, it is only available as a slave to the slaves -// which are busy searching the split point at the top of slaves split point +// which are busy searching the split point at the top of slave's split point // stack (the "helpful master concept" in YBWC terminology). -bool Thread::is_available_to(Thread* master) const { +bool Thread::available_to(const Thread* master) const { if (searching) return false; - // Make a local copy to be sure doesn't become zero under our feet while - // testing next condition and so leading to an out of bound access. + // Make a local copy to be sure it doesn't become zero under our feet while + // testing next condition and so leading to an out of bounds access. int size = splitPointsSize; // No split points means that the thread is available as a slave for any @@ -180,14 +181,14 @@ bool Thread::is_available_to(Thread* master) const { // init() is called at startup to create and launch requested threads, that will // go immediately to sleep due to 'sleepWhileIdle' set to true. We cannot use -// a c'tor becuase Threads is a static object and we need a fully initialized +// a c'tor because Threads is a static object and we need a fully initialized // engine at this point due to allocation of Endgames in Thread c'tor. void ThreadPool::init() { sleepWhileIdle = true; - timer = new TimerThread(); - push_back(new MainThread()); + timer = new_thread(); + push_back(new_thread()); read_uci_options(); } @@ -196,17 +197,18 @@ 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); } // read_uci_options() updates internal threads parameters from the corresponding // UCI options and creates/destroys threads to match the requested number. Thread -// objects are dynamically allocated to avoid creating in advance all possible -// threads, with included pawns and material tables, if only few are used. +// objects are dynamically allocated to avoid creating all possible threads +// in advance (which include pawns and material tables), even if only a few +// are to be used. void ThreadPool::read_uci_options() { @@ -216,12 +218,19 @@ 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(); } } @@ -230,10 +239,10 @@ void ThreadPool::read_uci_options() { // slave_available() tries to find an idle thread which is available as a slave // for the thread 'master'. -Thread* ThreadPool::available_slave(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)) + if ((*it)->available_to(master)) return *it; return NULL; @@ -250,9 +259,9 @@ Thread* ThreadPool::available_slave(Thread* master) const { // search() then split() returns. template -void Thread::split(Position& pos, Stack* ss, Value alpha, Value beta, Value* bestValue, - Move* bestMove, Depth depth, Move threatMove, int moveCount, - MovePicker* movePicker, int nodeType) { +void Thread::split(Position& pos, const Stack* ss, Value alpha, Value beta, Value* bestValue, + Move* bestMove, Depth depth, int moveCount, + MovePicker* movePicker, int nodeType, bool cutNode) { assert(pos.pos_is_ok()); assert(*bestValue <= alpha && alpha < beta && beta <= VALUE_INFINITE); @@ -270,10 +279,10 @@ void Thread::split(Position& pos, Stack* ss, Value alpha, Value beta, Value* bes sp.depth = depth; sp.bestValue = *bestValue; sp.bestMove = *bestMove; - sp.threatMove = threatMove; sp.alpha = alpha; sp.beta = beta; sp.nodeType = nodeType; + sp.cutNode = cutNode; sp.movePicker = movePicker; sp.moveCount = moveCount; sp.pos = &pos; @@ -287,7 +296,7 @@ void Thread::split(Position& pos, Stack* ss, Value alpha, Value beta, Value* bes Threads.mutex.lock(); sp.mutex.lock(); - splitPointsSize++; + ++splitPointsSize; activeSplitPoint = &sp; activePosition = NULL; @@ -314,20 +323,21 @@ void Thread::split(Position& pos, Stack* ss, Value alpha, Value beta, Value* bes 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. + // In the helpful master concept, a master can help only a sub-tree of its + // split point and because everything is finished here, it's not possible + // for the master to be 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(). + // done under lock protection to avoid a race with Thread::available_to(). Threads.mutex.lock(); sp.mutex.lock(); } searching = true; - splitPointsSize--; + --splitPointsSize; activeSplitPoint = sp.parentSplitPoint; activePosition = &pos; pos.set_nodes_searched(pos.nodes_searched() + sp.nodes); @@ -339,15 +349,15 @@ 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, int, MovePicker*, int, bool); +template void Thread::split< true>(Position&, const Stack*, Value, Value, Value*, Move*, Depth, 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(); @@ -366,16 +376,20 @@ 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 it(pos); *it; ++it) if ( searchMoves.empty() || 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 }