X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Ftimeman.cpp;h=1253d434672709094cb7496dea0b37f08dc02fb5;hb=e277dda7166992536124891e212d6d6a866f8a12;hp=0021e96b7b7dc7c2a869efbf6d900945ab132a4a;hpb=83c9e5911ef7fe6ff71dc116856fac85bb9076eb;p=stockfish
diff --git a/src/timeman.cpp b/src/timeman.cpp
index 0021e96b..1253d434 100644
--- a/src/timeman.cpp
+++ b/src/timeman.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) 2015-2020 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
@@ -18,82 +16,97 @@
along with this program. If not, see .
*/
+#include "timeman.h"
+
#include
-#include
#include
#include "search.h"
-#include "timeman.h"
#include "uci.h"
-TimeManagement Time; // Our global time management object
+namespace Stockfish {
-/// init() is called at the beginning of the search and calculates the bounds
-/// of time allowed for the current game ply. We currently support:
-// 1) x basetime (+z increment)
-// 2) x moves in y seconds (+z increment)
+TimeManagement Time; // Our global time management object
+
+// Called at the beginning of the search and calculates
+// the bounds of time allowed for the current game ply. We currently support:
+// 1) x basetime (+ z increment)
+// 2) x moves in y seconds (+ z increment)
void TimeManagement::init(Search::LimitsType& limits, Color us, int ply) {
- TimePoint minThinkingTime = Options["Minimum Thinking Time"];
- TimePoint moveOverhead = Options["Move Overhead"];
- TimePoint slowMover = Options["Slow Mover"];
- TimePoint npmsec = Options["nodestime"];
-
- // opt_scale is a percentage of available time to use for the current move.
- // max_scale is a multiplier applied to optimumTime.
- double opt_scale, max_scale;
-
- // If we have to play in 'nodes as time' mode, then convert from time
- // to nodes, and use resulting values in time management formulas.
- // WARNING: to avoid time losses, the given npmsec (nodes per millisecond)
- // must be much lower than the real engine speed.
- if (npmsec)
- {
- if (!availableNodes) // Only once at game start
- availableNodes = npmsec * limits.time[us]; // Time is in msec
-
- // Convert from milliseconds to nodes
- limits.time[us] = TimePoint(availableNodes);
- limits.inc[us] *= npmsec;
- limits.npmsec = npmsec;
- }
-
- startTime = limits.startTime;
-
- //Maximum move horizon of 50 moves
- int mtg = limits.movestogo ? std::min(limits.movestogo, 50) : 50;
-
- // Make sure timeLeft is > 0 since we may use it as a divisor
- TimePoint timeLeft = std::max(TimePoint(1),
- limits.time[us] + limits.inc[us] * (mtg - 1) - moveOverhead * (2 + mtg));
-
- // A user may scale time usage by setting UCI option "Slow Mover"
- // Default is 100 and changing this value will probably lose elo.
- timeLeft = slowMover * timeLeft / 100;
-
- // x basetime (+ z increment)
- // If there is a healthy increment, timeLeft can exceed actual available
- // game time for the current move, so also cap to 20% of available game time.
- if (limits.movestogo == 0)
- {
- opt_scale = std::min(0.007 + std::pow(ply + 3.0, 0.5) / 250.0,
- 0.2 * limits.time[us] / double(timeLeft));
- max_scale = 4 + std::pow(ply + 3, 0.3);
- }
-
- // x moves in y seconds (+ z increment)
- else
- {
- opt_scale = std::min((0.8 + ply / 128.0) / mtg,
- 0.8 * limits.time[us] / double(timeLeft));
- max_scale = std::min(6.3, 1.5 + 0.11 * mtg);
- }
-
- // Never use more than 80% of the available time for this move
- optimumTime = std::max(minThinkingTime, opt_scale * timeLeft);
- maximumTime = std::min(0.8 * limits.time[us] - moveOverhead, max_scale * optimumTime);
-
- if (Options["Ponder"])
- optimumTime += optimumTime / 4;
+ // If we have no time, no need to initialize TM, except for the start time,
+ // which is used by movetime.
+ startTime = limits.startTime;
+ if (limits.time[us] == 0)
+ return;
+
+ TimePoint moveOverhead = TimePoint(Options["Move Overhead"]);
+ TimePoint slowMover = TimePoint(Options["Slow Mover"]);
+ TimePoint npmsec = TimePoint(Options["nodestime"]);
+
+ // optScale is a percentage of available time to use for the current move.
+ // maxScale is a multiplier applied to optimumTime.
+ double optScale, maxScale;
+
+ // If we have to play in 'nodes as time' mode, then convert from time
+ // to nodes, and use resulting values in time management formulas.
+ // WARNING: to avoid time losses, the given npmsec (nodes per millisecond)
+ // must be much lower than the real engine speed.
+ if (npmsec)
+ {
+ if (!availableNodes) // Only once at game start
+ availableNodes = npmsec * limits.time[us]; // Time is in msec
+
+ // Convert from milliseconds to nodes
+ limits.time[us] = TimePoint(availableNodes);
+ limits.inc[us] *= npmsec;
+ limits.npmsec = npmsec;
+ }
+
+ // Maximum move horizon of 50 moves
+ int mtg = limits.movestogo ? std::min(limits.movestogo, 50) : 50;
+
+ // Make sure timeLeft is > 0 since we may use it as a divisor
+ TimePoint timeLeft = std::max(TimePoint(1), limits.time[us] + limits.inc[us] * (mtg - 1)
+ - moveOverhead * (2 + mtg));
+
+ // Use extra time with larger increments
+ double optExtra = std::clamp(1.0 + 12.5 * limits.inc[us] / limits.time[us], 1.0, 1.12);
+
+ // Calculate time constants based on current time left.
+ double optConstant = std::min(0.00335 + 0.0003 * std::log10(limits.time[us] / 1000.0), 0.0048);
+ double maxConstant = std::max(3.6 + 3.0 * std::log10(limits.time[us] / 1000.0), 2.7);
+
+ // A user may scale time usage by setting UCI option "Slow Mover"
+ // Default is 100 and changing this value will probably lose elo.
+ timeLeft = slowMover * timeLeft / 100;
+
+ // x basetime (+ z increment)
+ // If there is a healthy increment, timeLeft can exceed actual available
+ // game time for the current move, so also cap to 20% of available game time.
+ if (limits.movestogo == 0)
+ {
+ optScale = std::min(0.0120 + std::pow(ply + 3.3, 0.44) * optConstant,
+ 0.2 * limits.time[us] / double(timeLeft))
+ * optExtra;
+ maxScale = std::min(6.8, maxConstant + ply / 12.2);
+ }
+
+ // x moves in y seconds (+ z increment)
+ else
+ {
+ optScale = std::min((0.88 + ply / 116.4) / mtg, 0.88 * limits.time[us] / double(timeLeft));
+ maxScale = std::min(6.3, 1.5 + 0.11 * mtg);
+ }
+
+ // Limit the maximum possible time for this move
+ optimumTime = TimePoint(optScale * timeLeft);
+ maximumTime =
+ TimePoint(std::min(0.84 * limits.time[us] - moveOverhead, maxScale * optimumTime)) - 10;
+
+ if (Options["Ponder"])
+ optimumTime += optimumTime / 4;
}
+
+} // namespace Stockfish