X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fthread.cpp;h=ca1a7c852731d11b530b10ccea2d42ea5d5573e6;hb=5a88c5bb9b3e5ee431ac85abb8981b1571b68b2d;hp=5e990fdc680c0549a58f6412256d61ddf4642ac2;hpb=cf5d683408a2ef8a1c80be9bf7d6790a38b16277;p=stockfish
diff --git a/src/thread.cpp b/src/thread.cpp
index 5e990fdc..ca1a7c85 100644
--- a/src/thread.cpp
+++ b/src/thread.cpp
@@ -1,8 +1,6 @@
/*
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) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+ Copyright (C) 2004-2023 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
@@ -18,9 +16,9 @@
along with this program. If not, see .
*/
-#include // For std::count
#include
+#include // For std::count
#include "movegen.h"
#include "search.h"
#include "thread.h"
@@ -28,11 +26,13 @@
#include "syzygy/tbprobe.h"
#include "tt.h"
+namespace Stockfish {
+
ThreadPool Threads; // Global object
/// 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) {
@@ -60,20 +60,22 @@ void Thread::clear() {
counterMoves.fill(MOVE_NONE);
mainHistory.fill(0);
captureHistory.fill(0);
+ previousDepth = 0;
- for (auto& to : continuationHistory)
- for (auto& h : to)
- h->fill(0);
-
- continuationHistory[NO_PIECE][0]->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(-71);
}
+
/// Thread::start_searching() wakes up the thread that will start the search
void Thread::start_searching() {
-
- std::lock_guard lk(mutex);
+ mutex.lock();
searching = true;
+ mutex.unlock(); // Unlock before notifying saves a few CPU-cycles
cv.notify_one(); // Wake up the thread in idle_loop()
}
@@ -83,7 +85,7 @@ void Thread::start_searching() {
void Thread::wait_for_search_finished() {
- std::unique_lock lk(mutex);
+ std::unique_lock lk(mutex);
cv.wait(lk, [&]{ return !searching; });
}
@@ -103,7 +105,7 @@ void Thread::idle_loop() {
while (true)
{
- std::unique_lock lk(mutex);
+ std::unique_lock lk(mutex);
searching = false;
cv.notify_one(); // Wake up anyone waiting for search finished
cv.wait(lk, [&]{ return searching; });
@@ -118,42 +120,50 @@ void Thread::idle_loop() {
}
/// ThreadPool::set() creates/destroys threads to match the requested number.
-/// Created and launched threads will 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) {
- if (size() > 0) { // destroy any existing thread(s)
+ if (threads.size() > 0) // destroy any existing thread(s)
+ {
main()->wait_for_search_finished();
- while (size() > 0)
- delete back(), pop_back();
+ while (threads.size() > 0)
+ delete threads.back(), threads.pop_back();
}
- if (requested > 0) { // create new thread(s)
- push_back(new MainThread(0));
+ if (requested > 0) // create new thread(s)
+ {
+ threads.push_back(new MainThread(0));
- while (size() < requested)
- push_back(new Thread(size()));
+ while (threads.size() < requested)
+ threads.push_back(new Thread(threads.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() {
- for (Thread* th : *this)
+ for (Thread* th : threads)
th->clear();
main()->callsCnt = 0;
- main()->previousScore = VALUE_INFINITE;
+ main()->bestPreviousScore = VALUE_INFINITE;
+ main()->bestPreviousAverageScore = 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.
@@ -162,8 +172,9 @@ void ThreadPool::start_thinking(Position& pos, StateListPtr& states,
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;
@@ -176,7 +187,7 @@ void ThreadPool::start_thinking(Position& pos, StateListPtr& states,
Tablebases::rank_root_moves(pos, rootMoves);
// After ownership transfer 'states' becomes empty, so if we stop the search
- // and call 'go' again without setting a new position states.get() == NULL.
+ // and call 'go' again without setting a new position states.get() == nullptr.
assert(states.get() || setupStates.get());
if (states.get())
@@ -184,20 +195,75 @@ void ThreadPool::start_thinking(Position& pos, StateListPtr& states,
// 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();
-
- for (Thread* th : *this)
+ // 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 : threads)
{
- th->nodes = th->tbHits = th->nmpMinPly = 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 = threads.front();
+ std::map votes;
+ Value minScore = VALUE_NONE;
+
+ // Find minimum score of all threads
+ for (Thread* th: threads)
+ minScore = std::min(minScore, th->rootMoves[0].score);
+
+ // Vote according to score and depth, and select the best thread
+ auto thread_value = [minScore](Thread* th) {
+ return (th->rootMoves[0].score - minScore + 14) * int(th->completedDepth);
+ };
+
+ for (Thread* th : threads)
+ votes[th->rootMoves[0].pv[0]] += thread_value(th);
+
+ for (Thread* th : threads)
+ 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]]
+ || ( votes[th->rootMoves[0].pv[0]] == votes[bestThread->rootMoves[0].pv[0]]
+ && thread_value(th) * int(th->rootMoves[0].pv.size() > 2)
+ > thread_value(bestThread) * int(bestThread->rootMoves[0].pv.size() > 2)))))
+ bestThread = th;
+
+ return bestThread;
+}
+
+
+/// Start non-main threads
+
+void ThreadPool::start_searching() {
+
+ for (Thread* th : threads)
+ if (th != threads.front())
+ th->start_searching();
+}
+
+
+/// Wait for non-main threads
+
+void ThreadPool::wait_for_search_finished() const {
+
+ for (Thread* th : threads)
+ if (th != threads.front())
+ th->wait_for_search_finished();
+}
+
+} // namespace Stockfish