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) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+ Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, 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
#include <cstring> // For std::memset
#include <iostream>
+#include <thread>
#include "bitboard.h"
+#include "misc.h"
#include "tt.h"
+#include "uci.h"
TranspositionTable TT; // Our global transposition table
void TranspositionTable::resize(size_t mbSize) {
- size_t newClusterCount = size_t(1) << msb((mbSize * 1024 * 1024) / sizeof(Cluster));
-
- if (newClusterCount == clusterCount)
- return;
-
- clusterCount = newClusterCount;
+ clusterCount = mbSize * 1024 * 1024 / sizeof(Cluster);
free(mem);
- mem = calloc(clusterCount * sizeof(Cluster) + CacheLineSize - 1, 1);
+ mem = malloc(clusterCount * sizeof(Cluster) + CacheLineSize - 1);
if (!mem)
{
}
table = (Cluster*)((uintptr_t(mem) + CacheLineSize - 1) & ~(CacheLineSize - 1));
+ clear();
}
/// TranspositionTable::clear() overwrites the entire transposition table
/// with zeros. It is called whenever the table is resized, or when the
/// user asks the program to clear the table (from the UCI interface).
+/// It starts as many threads as allowed by the Threads option.
void TranspositionTable::clear() {
- std::memset(table, 0, clusterCount * sizeof(Cluster));
-}
+ const size_t stride = clusterCount / Options["Threads"];
+ std::vector<std::thread> threads;
+ for (size_t idx = 0; idx < Options["Threads"]; idx++)
+ {
+ const size_t start = stride * idx,
+ len = idx != Options["Threads"] - 1 ?
+ stride :
+ clusterCount - start;
+ threads.push_back(std::thread([this, idx, start, len]() {
+ if (Options["Threads"] >= 8)
+ WinProcGroup::bindThisThread(idx);
+ std::memset(&table[start], 0, len * sizeof(Cluster));
+ }));
+ }
+ for (std::thread& th: threads)
+ th.join();
+}
/// TranspositionTable::probe() looks up the current position in the transposition
/// table. It returns true and a pointer to the TTEntry if the position is found.
}
-/// Returns an approximation of the hashtable occupation during a search. The
-/// hash is x permill full, as per UCI protocol.
+/// TranspositionTable::hashfull() returns an approximation of the hashtable
+/// occupation during a search. The hash is x permill full, as per UCI protocol.
+
+int TranspositionTable::hashfull() const {
-int TranspositionTable::hashfull() const
-{
int cnt = 0;
for (int i = 0; i < 1000 / ClusterSize; i++)
{