along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <algorithm> // For std::count
#include <cassert>
#include <iostream>
bool Thread::cutoff_occurred() const {
- for (SplitPoint* sp = activeSplitPoint; sp; sp = sp->parent)
+ for (SplitPoint* sp = activeSplitPoint; sp; sp = sp->parentSplitPoint)
if (sp->cutoff)
return true;
}
-// init() is called at startup. Initializes lock and condition variable and
-// launches requested threads sending them immediately to sleep. We cannot use
+// 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
-// engine at this point due to allocation of endgames in Thread c'tor.
+// engine at this point due to allocation of Endgames in Thread c'tor.
void ThreadPool::init() {
}
-// exit() cleanly terminates the threads before the program exits.
+// exit() cleanly terminates the threads before the program exits
void ThreadPool::exit() {
- delete timer; // As first becuase check_time() accesses threads data
+ delete timer; // As first because check_time() accesses threads data
for (size_t i = 0; i < threads.size(); i++)
delete threads[i];
// 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 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.
+// (because no idle threads are available), 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 <bool Fake>
-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 Thread::split(Position& pos, Stack* ss, Value alpha, Value beta,
+ Value bestValue, Move* bestMove, Depth depth, Move threatMove,
+ int moveCount, MovePicker& mp, int nodeType) {
assert(pos.pos_is_ok());
+ assert(bestValue <= alpha && alpha < beta && beta <= VALUE_INFINITE);
assert(bestValue > -VALUE_INFINITE);
- assert(bestValue <= alpha);
- assert(alpha < beta);
- assert(beta <= VALUE_INFINITE);
- assert(depth > DEPTH_ZERO);
+ assert(depth >= Threads.minimumSplitDepth);
- Thread* master = pos.this_thread();
-
- if (master->splitPointsSize >= MAX_SPLITPOINTS_PER_THREAD)
- return bestValue;
+ assert(searching);
+ assert(splitPointsSize < MAX_SPLITPOINTS_PER_THREAD);
// Pick the next available split point from the split point stack
- SplitPoint& sp = master->splitPoints[master->splitPointsSize];
+ SplitPoint& sp = splitPoints[splitPointsSize];
- sp.master = master;
- sp.parent = master->activeSplitPoint;
- sp.slavesMask = 1ULL << master->idx;
+ sp.masterThread = this;
+ sp.parentSplitPoint = activeSplitPoint;
+ sp.slavesMask = 1ULL << idx;
sp.depth = depth;
sp.bestMove = *bestMove;
sp.threatMove = threatMove;
sp.beta = beta;
sp.nodeType = nodeType;
sp.bestValue = bestValue;
- sp.mp = ∓
+ sp.movePicker = ∓
sp.moveCount = moveCount;
sp.pos = &pos;
sp.nodes = 0;
sp.cutoff = false;
sp.ss = ss;
- master->activeSplitPoint = &sp;
- int slavesCnt = 0;
-
- assert(master->searching);
-
// Try to allocate available threads and ask them to start searching setting
// 'searching' flag. This must be done under lock protection to avoid concurrent
// allocation of the same slave by another master.
- mutex.lock();
+ Threads.mutex.lock();
sp.mutex.lock();
- for (size_t i = 0; i < threads.size() && !Fake; ++i)
- if (threads[i]->is_available_to(master))
- {
- sp.slavesMask |= 1ULL << i;
- threads[i]->activeSplitPoint = &sp;
- threads[i]->searching = true; // Slave leaves idle_loop()
- threads[i]->notify_one(); // Could be sleeping
+ splitPointsSize++;
+ activeSplitPoint = &sp;
- if (++slavesCnt + 1 >= maxThreadsPerSplitPoint) // Include master
- break;
- }
+ size_t slavesCnt = 1; // Master is always included
- master->splitPointsSize++;
+ for (size_t i = 0; i < Threads.size() && !Fake; ++i)
+ if (Threads[i].is_available_to(this) && ++slavesCnt <= Threads.maxThreadsPerSplitPoint)
+ {
+ sp.slavesMask |= 1ULL << Threads[i].idx;
+ Threads[i].activeSplitPoint = &sp;
+ Threads[i].searching = true; // Slave leaves idle_loop()
+ Threads[i].notify_one(); // Could be sleeping
+ }
sp.mutex.unlock();
- 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 || Fake)
+ if (slavesCnt > 1 || Fake)
{
- master->Thread::idle_loop(); // Force a call to base class idle_loop()
+ 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(!master->searching);
+ assert(!searching);
}
// 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().
- mutex.lock();
+ Threads.mutex.lock();
sp.mutex.lock();
- master->searching = true;
- master->splitPointsSize--;
- master->activeSplitPoint = sp.parent;
+ searching = true;
+ splitPointsSize--;
+ activeSplitPoint = sp.parentSplitPoint;
pos.set_nodes_searched(pos.nodes_searched() + sp.nodes);
*bestMove = sp.bestMove;
sp.mutex.unlock();
- mutex.unlock();
+ Threads.mutex.unlock();
return sp.bestValue;
}
// Explicit template instantiations
-template Value ThreadPool::split<false>(Position&, Stack*, Value, Value, Value, Move*, Depth, Move, int, MovePicker&, int);
-template Value ThreadPool::split<true>(Position&, Stack*, Value, Value, Value, Move*, Depth, Move, int, MovePicker&, int);
+template Value Thread::split<false>(Position&, Stack*, Value, Value, Value, Move*, Depth, Move, int, MovePicker&, int);
+template Value Thread::split<true>(Position&, Stack*, Value, Value, Value, Move*, Depth, Move, int, MovePicker&, int);
// wait_for_think_finished() waits for main thread to go to sleep then returns
}
-// start_thinking() wakes up the main thread sleeping in main_loop() so to start
-// a new search, then returns immediately.
+// start_thinking() wakes up the main thread sleeping in MainThread::idle_loop()
+// so to start a new search, then returns immediately.
void ThreadPool::start_thinking(const Position& pos, const LimitsType& limits,
const std::vector<Move>& searchMoves, StateStackPtr& states) {
RootMoves.clear();
for (MoveList<LEGAL> ml(pos); !ml.end(); ++ml)
- if (searchMoves.empty() || count(searchMoves.begin(), searchMoves.end(), ml.move()))
+ if ( searchMoves.empty()
+ || std::count(searchMoves.begin(), searchMoves.end(), ml.move()))
RootMoves.push_back(RootMove(ml.move()));
main_thread()->thinking = true;
projects / stockfish / blobdiff