/*
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
// 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
+ // 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.
template<typename T> T* new_thread() {
}
-// 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 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() /* : splitPoints() */ { // Value-initialization bug in MSVC
// 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() {
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() {
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);
}
}
-// 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
// 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() {
// 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() {
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<Thread>());
// 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;
// search() then split() returns.
template <bool Fake>
-void Thread::split(Position& pos, Stack* ss, Value alpha, Value beta, Value* bestValue,
- Move* bestMove, Depth depth, Move threatMove, int moveCount,
+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());
sp.depth = depth;
sp.bestValue = *bestValue;
sp.bestMove = *bestMove;
- sp.threatMove = threatMove;
sp.alpha = alpha;
sp.beta = beta;
sp.nodeType = nodeType;
Threads.mutex.lock();
sp.mutex.lock();
- splitPointsSize++;
+ ++splitPointsSize;
activeSplitPoint = &sp;
activePosition = NULL;
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);
}
// Explicit template instantiations
-template void Thread::split<false>(Position&, Stack*, Value, Value, Value*, Move*, Depth, Move, int, MovePicker*, int, bool);
-template void Thread::split< true>(Position&, Stack*, Value, Value, Value*, Move*, Depth, Move, int, MovePicker*, int, bool);
+template void Thread::split<false>(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
projects / stockfish / blobdiff