timeinfo.c

   1 #include <assert.h>
   2 #include <ctype.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <math.h>
   6 #include <time.h>
   7
   8 #define DEBUG
   9
  10 #include "debug.h"
  11 #include "timeinfo.h"
  12
  13 #define MAX_NET_LAG 2.0 /* Max net lag in seconds. TODO: estimate dynamically. */
  14 #define RESERVED_BYOYOMI_PERCENT 15 /* Reserve 15% of byoyomi time as safety margin if risk of losing on time */
  15
  16 bool
  17 time_parse(struct time_info *ti, char *s)
  18 {
  19         switch (s[0]) {
  20                 case '_': ti->period = TT_TOTAL; s++; break;
  21                 default: ti->period = TT_MOVE; break;
  22         }
  23         switch (s[0]) {
  24                 case '=':
  25                         ti->dim = TD_GAMES;
  26                         ti->len.games = atoi(++s);
  27                         break;
  28                 default:
  29                         if (!isdigit(s[0]))
  30                                 return false;
  31                         ti->dim = TD_WALLTIME;
  32                         ti->len.t.recommended_time = atof(s);
  33                         ti->len.t.max_time = ti->len.t.recommended_time;
  34                         ti->len.t.net_lag = MAX_NET_LAG;
  35                         ti->len.t.timer_start = 0;
  36                         ti->len.t.byoyomi_time = 0.0;
  37                         ti->len.t.byoyomi_periods = 0;
  38                         break;
  39         }
  40         return true;
  41 }
  42
  43 /* Update time settings according to gtp time_settings or kgs-time_settings command. */
  44 void
  45 time_settings(struct time_info *ti, int main_time, int byoyomi_time, int byoyomi_stones, int byoyomi_periods)
  46 {
  47         if (byoyomi_time > 0 && byoyomi_stones == 0) {
  48                 ti->period = TT_NULL; // no time limit, rely on engine default
  49         } else {
  50                 ti->period = TT_TOTAL;
  51                 ti->dim = TD_WALLTIME;
  52                 ti->len.t.max_time = (double) main_time; // byoyomi will be added at next genmove
  53                 ti->len.t.recommended_time = ti->len.t.max_time;
  54                 ti->len.t.timer_start = 0;
  55                 ti->len.t.net_lag = MAX_NET_LAG;
  56                 ti->len.t.byoyomi_time = (double) byoyomi_time;
  57                 if (byoyomi_stones > 0)
  58                         ti->len.t.byoyomi_time /= byoyomi_stones;
  59                 ti->len.t.byoyomi_periods = byoyomi_periods;
  60         }
  61 }
  62
  63 /* Update time information according to gtp time_left command.
  64  * kgs doesn't give time_left for the first move, so make sure
  65  * that just time_settings + time_select_best still work. */
  66 void
  67 time_left(struct time_info *ti, int time_left, int stones_left)
  68 {
  69         assert(ti->period != TT_NULL);
  70         ti->dim = TD_WALLTIME;
  71         ti->len.t.max_time = (double)time_left;
  72
  73         if (ti->len.t.byoyomi_periods > 0 && stones_left > 0) {
  74                 ti->len.t.byoyomi_periods = stones_left; // field misused by kgs
  75                 stones_left = 1;
  76         }
  77         if (stones_left == 0) {
  78                 /* Main time */
  79                 ti->period = TT_TOTAL;
  80                 ti->len.t.recommended_time = ti->len.t.max_time;
  81                 /* byoyomi_time, net_lag & timer_start unchanged. */
  82         } else {
  83                 ti->period = TT_MOVE;
  84                 ti->len.t.byoyomi_time = ((double)time_left)/stones_left;
  85                 ti->len.t.recommended_time = ti->len.t.byoyomi_time;
  86                 /* net_lag & timer_start unchanged. */
  87         }
  88 }
  89
  90 /* Set correct time information before making a move, and
  91  * always make it time per move for the engine. */
  92 void
  93 time_prepare_move(struct time_info *ti, struct board *board)
  94 {
  95         int moves_left;
  96
  97         if (ti->period == TT_TOTAL) {
  98                 moves_left = board_estimated_moves_left(board);
  99                 assert(moves_left > 0);
 100                 if (ti->dim == TD_GAMES) {
 101                         ti->period = TT_MOVE;
 102                         ti->len.games /= moves_left;
 103                 }
 104         }
 105         if (ti->period == TT_NULL || ti->dim != TD_WALLTIME)
 106                 return;
 107
 108         double now = time_now();
 109         double lag;
 110         if (!ti->len.t.timer_start) {
 111                 ti->len.t.timer_start = now; // we're playing the first game move
 112                 lag = 0;
 113         } else {
 114                 lag = now - ti->len.t.timer_start;
 115                 // TODO: keep statistics to get good estimate of lag not just current move
 116                 ti->len.t.max_time -= lag; // can become < 0, taken into account below
 117                 ti->len.t.recommended_time -= lag;
 118                 if (DEBUGL(1) && lag > MAX_NET_LAG)
 119                         fprintf(stderr, "lag %0.2f > max_net_lag %0.2f\n", lag, MAX_NET_LAG);
 120         }
 121         if (ti->period == TT_TOTAL) {
 122                 /* For non-canadian byoyomi with N>1 periods, we use N-1 periods as main time,
 123                  * keeping the last one as insurance against unexpected net lag. */
 124                 if (ti->len.t.byoyomi_periods > 2) {
 125                         ti->len.t.max_time += (ti->len.t.byoyomi_periods - 2) * ti->len.t.byoyomi_time;
 126                         // Will add 1 more byoyomi_time just below
 127                 }
 128                 if (ti->len.t.byoyomi_time > 0) {
 129                         ti->len.t.max_time += ti->len.t.byoyomi_time;
 130                         ti->len.t.recommended_time = ti->len.t.max_time;
 131
 132                         /* Maximize the number of moves played uniformly in main time, while
 133                          * not playing faster in main time than in byoyomi. At this point,
 134                          * the main time remaining is ti->len.t.max_time and already includes
 135                          * the first (canadian) or N-1 byoyomi periods.
 136                          *    main_speed = max_time / main_moves >= byoyomi_time
 137                          * => main_moves <= max_time / byoyomi_time */
 138                         double actual_byoyomi = ti->len.t.byoyomi_time - MAX_NET_LAG;
 139                         if (actual_byoyomi > 0) {
 140                                 int main_moves = (int)(ti->len.t.max_time / actual_byoyomi);
 141                                 if (moves_left > main_moves)
 142                                         moves_left = main_moves; // will do the rest in byoyomi
 143                                 if (moves_left <= 0) // possible if too much lag
 144                                         moves_left = 1;
 145                         }
 146                 }
 147                 ti->period = TT_MOVE;
 148                 ti->len.t.recommended_time /= moves_left;
 149         }
 150         // To simplify the engine code, do not leave negative times:
 151         if (ti->len.t.recommended_time < 0)
 152                 ti->len.t.recommended_time = 0;
 153         if (ti->len.t.max_time < 0)
 154                 ti->len.t.max_time = 0;
 155         assert(ti->len.t.recommended_time <= ti->len.t.max_time + 0.001);
 156
 157         /* Use a larger safety margin if we risk losing on time on this move: */
 158         double safe_margin = RESERVED_BYOYOMI_PERCENT * ti->len.t.byoyomi_time/100;
 159         if (safe_margin > MAX_NET_LAG && ti->len.t.recommended_time >= ti->len.t.max_time - MAX_NET_LAG) {
 160                 ti->len.t.net_lag = safe_margin;
 161         } else {
 162                 ti->len.t.net_lag = MAX_NET_LAG;
 163         }
 164
 165         if (DEBUGL(1))
 166                 fprintf(stderr, "recommended_time %0.2f, max_time %0.2f, byoyomi %0.2f, lag %0.2f max %0.2f\n",
 167                         ti->len.t.recommended_time, ti->len.t.max_time, ti->len.t.byoyomi_time, lag,
 168                         ti->len.t.net_lag);
 169 }
 170
 171 /* Start our timer. kgs does this (correctly) on "play" not "genmove"
 172  * unless we are making the first move of the game. */
 173 void
 174 time_start_timer(struct time_info *ti)
 175 {
 176         if (ti->period != TT_NULL && ti->dim == TD_WALLTIME)
 177                 ti->len.t.timer_start = time_now();
 178 }
 179
 180 /* Returns true if we are in byoyomi (or should play as if in byo yomi
 181  * because remaining time per move in main time is less than byoyomi time
 182  * per move). */
 183 bool
 184 time_in_byoyomi(struct time_info *ti) {
 185         return ti->period == TT_MOVE && ti->dim == TD_WALLTIME && ti->len.t.byoyomi_time > 0
 186                && ti->len.t.recommended_time <= ti->len.t.byoyomi_time + 0.001;
 187 }
 188
 189 /* Returns the current time. */
 190 double
 191 time_now(void)
 192 {
 193         struct timespec now;
 194         clock_gettime(CLOCK_REALTIME, &now);
 195         return now.tv_sec + now.tv_nsec/1000000000.0;
 196 }
 197
 198 /* Sleep for a given interval (in seconds). Return immediately if interval < 0. */
 199 void
 200 time_sleep(double interval)
 201 {
 202         struct timespec ts;
 203         double sec;
 204         ts.tv_nsec = (int)(modf(interval, &sec)*1000000000.0);
 205         ts.tv_sec = (int)sec;
 206         nanosleep(&ts, NULL); /* ignore error if interval was < 0 */
 207 }