/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
- Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+ Copyright (C) 2004-2020 The Stockfish developers (see AUTHORS file)
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-#include <algorithm> // For std::count
#include <cassert>
+#include <algorithm> // For std::count
#include "movegen.h"
#include "search.h"
#include "thread.h"
/// Thread constructor launches the thread and waits until it goes to sleep
-/// in idle_loop(). Note that 'searching' and 'exit' should be alredy set.
+/// in idle_loop(). Note that 'searching' and 'exit' should be already set.
Thread::Thread(size_t n) : idx(n), stdThread(&Thread::idle_loop, this) {
counterMoves.fill(MOVE_NONE);
mainHistory.fill(0);
+ lowPlyHistory.fill(0);
captureHistory.fill(0);
- for (auto& to : contHistory)
- for (auto& h : to)
- h.get()->fill(0);
-
- contHistory[NO_PIECE][0].get()->fill(Search::CounterMovePruneThreshold - 1);
+ for (bool inCheck : { false, true })
+ for (StatsType c : { NoCaptures, Captures })
+ {
+ for (auto& to : continuationHistory[inCheck][c])
+ for (auto& h : to)
+ h->fill(0);
+ continuationHistory[inCheck][c][NO_PIECE][0]->fill(Search::CounterMovePruneThreshold - 1);
+ }
}
+
/// Thread::start_searching() wakes up the thread that will start the search
void Thread::start_searching() {
- std::lock_guard<Mutex> lk(mutex);
+ std::lock_guard<std::mutex> lk(mutex);
searching = true;
cv.notify_one(); // Wake up the thread in idle_loop()
}
void Thread::wait_for_search_finished() {
- std::unique_lock<Mutex> lk(mutex);
+ std::unique_lock<std::mutex> lk(mutex);
cv.wait(lk, [&]{ return !searching; });
}
// some Windows NUMA hardware, for instance in fishtest. To make it simple,
// just check if running threads are below a threshold, in this case all this
// NUMA machinery is not needed.
- if (Options["Threads"] >= 8)
+ if (Options["Threads"] > 8)
WinProcGroup::bindThisThread(idx);
while (true)
{
- std::unique_lock<Mutex> lk(mutex);
+ std::unique_lock<std::mutex> lk(mutex);
searching = false;
cv.notify_one(); // Wake up anyone waiting for search finished
cv.wait(lk, [&]{ return searching; });
}
/// ThreadPool::set() creates/destroys threads to match the requested number.
-/// Created and launched threads wil go immediately to sleep in idle_loop.
+/// Created and launched threads will immediately go to sleep in idle_loop.
/// Upon resizing, threads are recreated to allow for binding if necessary.
void ThreadPool::set(size_t requested) {
while (size() < requested)
push_back(new Thread(size()));
clear();
- }
- // Reallocate the hash with the new threadpool size
- TT.resize(Options["Hash"]);
+ // Reallocate the hash with the new threadpool size
+ TT.resize(size_t(Options["Hash"]));
+
+ // Init thread number dependent search params.
+ Search::init();
+ }
}
-/// ThreadPool::clear() sets threadPool data to initial values.
+
+/// ThreadPool::clear() sets threadPool data to initial values
void ThreadPool::clear() {
th->clear();
main()->callsCnt = 0;
- main()->previousScore = VALUE_INFINITE;
+ main()->bestPreviousScore = VALUE_INFINITE;
main()->previousTimeReduction = 1.0;
}
+
/// ThreadPool::start_thinking() wakes up main thread waiting in idle_loop() and
/// returns immediately. Main thread will wake up other threads and start the search.
main()->wait_for_search_finished();
- stopOnPonderhit = stop = false;
- ponder = ponderMode;
+ main()->stopOnPonderhit = stop = false;
+ increaseDepth = true;
+ main()->ponder = ponderMode;
Search::Limits = limits;
Search::RootMoves rootMoves;
// We use Position::set() to set root position across threads. But there are
// some StateInfo fields (previous, pliesFromNull, capturedPiece) that cannot
- // be deduced from a fen string, so set() clears them and to not lose the info
- // we need to backup and later restore setupStates->back(). Note that setupStates
- // is shared by threads but is accessed in read-only mode.
- StateInfo tmp = setupStates->back();
-
+ // be deduced from a fen string, so set() clears them and they are set from
+ // setupStates->back() later. The rootState is per thread, earlier states are shared
+ // since they are read-only.
for (Thread* th : *this)
{
- th->nodes = th->tbHits = th->nmp_min_ply = 0;
- th->rootDepth = th->completedDepth = DEPTH_ZERO;
+ th->nodes = th->tbHits = th->nmpMinPly = th->bestMoveChanges = 0;
+ th->rootDepth = th->completedDepth = 0;
th->rootMoves = rootMoves;
- th->rootPos.set(pos.fen(), pos.is_chess960(), &setupStates->back(), th);
+ th->rootPos.set(pos.fen(), pos.is_chess960(), &th->rootState, th);
+ th->rootState = setupStates->back();
}
- setupStates->back() = tmp;
-
main()->start_searching();
}
+
+Thread* ThreadPool::get_best_thread() const {
+
+ Thread* bestThread = front();
+ std::map<Move, int64_t> votes;
+ Value minScore = VALUE_NONE;
+
+ // Find minimum score of all threads
+ for (Thread* th: *this)
+ minScore = std::min(minScore, th->rootMoves[0].score);
+
+ // Vote according to score and depth, and select the best thread
+ for (Thread* th : *this)
+ {
+ votes[th->rootMoves[0].pv[0]] +=
+ (th->rootMoves[0].score - minScore + 14) * int(th->completedDepth);
+
+ if (abs(bestThread->rootMoves[0].score) >= VALUE_TB_WIN_IN_MAX_PLY)
+ {
+ // Make sure we pick the shortest mate / TB conversion or stave off mate the longest
+ if (th->rootMoves[0].score > bestThread->rootMoves[0].score)
+ bestThread = th;
+ }
+ else if ( th->rootMoves[0].score >= VALUE_TB_WIN_IN_MAX_PLY
+ || ( th->rootMoves[0].score > VALUE_TB_LOSS_IN_MAX_PLY
+ && votes[th->rootMoves[0].pv[0]] > votes[bestThread->rootMoves[0].pv[0]]))
+ bestThread = th;
+ }
+
+ return bestThread;
+}
+
+
+/// Start non-main threads
+
+void ThreadPool::start_searching() {
+
+ for (Thread* th : *this)
+ if (th != front())
+ th->start_searching();
+}
+
+
+/// Wait for non-main threads
+
+void ThreadPool::wait_for_search_finished() const {
+
+ for (Thread* th : *this)
+ if (th != front())
+ th->wait_for_search_finished();
+}