Execute an implied ucinewgame at startup

[stockfish] / src / uci.cpp

diff --git a/src/uci.cpp b/src/uci.cpp
index 83a8b930090333ebd68732c8a62c3b9b5bb07c36..f3b5f54c60f0d9c0acbdbc2358008146f339afe4 100644 (file)
--- a/src/uci.cpp
+++ b/src/uci.cpp
@@ -2,6 +2,7 @@
   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) 2015-2017 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
@@ -17,6 +18,7 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <cassert>
 #include <iostream>
 #include <sstream>
 #include <string>
@@ -26,8 +28,10 @@
 #include "position.h"
 #include "search.h"
 #include "thread.h"
+#include "tt.h"
 #include "timeman.h"
 #include "uci.h"
+#include "syzygy/tbprobe.h"
 
 using namespace std;
 
@@ -38,10 +42,10 @@ namespace {
   // FEN string of the initial position, normal chess
   const char* StartFEN = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
 
-  // Stack to keep track of the position states along the setup moves (from the
+  // A list to keep track of the position states along the setup moves (from the
   // start position to the position just before the search starts). Needed by
   // 'draw by repetition' detection.
-  Search::StateStackPtr SetupStates;
+  StateListPtr States(new std::deque<StateInfo>(1));
 
 
   // position() is called when engine receives the "position" UCI command.
@@ -67,14 +71,14 @@ namespace {
     else
         return;
 
-    pos.set(fen, Options["UCI_Chess960"], Threads.main());
-    SetupStates = Search::StateStackPtr(new std::stack<StateInfo>);
+    States = StateListPtr(new std::deque<StateInfo>(1));
+    pos.set(fen, Options["UCI_Chess960"], &States->back(), Threads.main());
 
     // Parse move list (if any)
     while (is >> token && (m = UCI::to_move(pos, token)) != MOVE_NONE)
     {
-        SetupStates->push(StateInfo());
-        pos.do_move(m, SetupStates->top(), pos.gives_check(m, CheckInfo(pos)));
+        States->push_back(StateInfo());
+        pos.do_move(m, States->back());
     }
   }
 
@@ -107,7 +111,7 @@ namespace {
   // the thinking time and other parameters from the input string, then starts
   // the search.
 
-  void go(const Position& pos, istringstream& is) {
+  void go(Position& pos, istringstream& is) {
 
     Search::LimitsType limits;
     string token;
@@ -131,7 +135,16 @@ namespace {
         else if (token == "infinite")  limits.infinite = 1;
         else if (token == "ponder")    limits.ponder = 1;
 
-    Threads.start_thinking(pos, limits, SetupStates);
+    Threads.start_thinking(pos, States, limits);
+  }
+
+  // On ucinewgame following steps are needed to reset the state
+  void newgame() {
+
+    TT.resize(Options["Hash"]);
+    Search::clear();
+    Tablebases::init(Options["SyzygyPath"]);
+    Time.availableNodes = 0;
   }
 
 } // namespace
@@ -145,9 +158,13 @@ namespace {
 
 void UCI::loop(int argc, char* argv[]) {
 
-  Position pos(StartFEN, false, Threads.main()); // The root position
+  Position pos;
   string token, cmd;
 
+  newgame(); // Implied ucinewgame before the first position command
+
+  pos.set(StartFEN, false, &States->back(), Threads.main());
+
   for (int i = 1; i < argc; ++i)
       cmd += std::string(argv[i]) + " ";
 
@@ -180,11 +197,7 @@ void UCI::loop(int argc, char* argv[]) {
                     << "\n"       << Options
                     << "\nuciok"  << sync_endl;
 
-      else if (token == "ucinewgame")
-      {
-          Search::clear();
-          Time.availableNodes = 0;
-      }
+      else if (token == "ucinewgame") newgame();
       else if (token == "isready")    sync_cout << "readyok" << sync_endl;
       else if (token == "go")         go(pos, is);
       else if (token == "position")   position(pos, is);
@@ -224,6 +237,8 @@ void UCI::loop(int argc, char* argv[]) {
 
 string UCI::value(Value v) {
 
+  assert(-VALUE_INFINITE < v && v < VALUE_INFINITE);
+
   stringstream ss;
 
   if (abs(v) < VALUE_MATE - MAX_PLY)