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 /* For safety, use at most 3 times the desired time on a single move
  17  * in main time, and 1.1 times in byoyomi. */
  18 #define MAX_MAIN_TIME_EXTENSION 3.0
  19 #define MAX_BYOYOMI_TIME_EXTENSION 1.1
  20
  21 bool
  22 time_parse(struct time_info *ti, char *s)
  23 {
  24         switch (s[0]) {
  25                 case '_': ti->period = TT_TOTAL; s++; break;
  26                 default: ti->period = TT_MOVE; break;
  27         }
  28         switch (s[0]) {
  29                 case '=':
  30                         ti->dim = TD_GAMES;
  31                         ti->len.games = atoi(++s);
  32                         break;
  33                 default:
  34                         if (!isdigit(s[0]))
  35                                 return false;
  36                         ti->dim = TD_WALLTIME;
  37                         ti->len.t.timer_start = 0;
  38                         if (ti->period == TT_TOTAL) {
  39                                 ti->len.t.main_time = atof(s);
  40                                 ti->len.t.byoyomi_time = 0.0;
  41                                 ti->len.t.byoyomi_time_max = 0.0;
  42                                 ti->len.t.byoyomi_periods = 0;
  43                                 ti->len.t.byoyomi_stones = 0;
  44                                 ti->len.t.byoyomi_stones_max = 0;
  45                         } else { assert(ti->period == TT_MOVE);
  46                                 ti->len.t.main_time = 0.0;
  47                                 ti->len.t.byoyomi_time = atof(s);
  48                                 ti->len.t.byoyomi_time_max = ti->len.t.byoyomi_time;
  49                                 ti->len.t.byoyomi_periods = 1;
  50                                 ti->len.t.byoyomi_stones = 1;
  51                                 ti->len.t.byoyomi_stones_max = 1;
  52                         }
  53                         break;
  54         }
  55         return true;
  56 }
  57
  58 /* Update time settings according to gtp time_settings or kgs-time_settings command. */
  59 void
  60 time_settings(struct time_info *ti, int main_time, int byoyomi_time, int byoyomi_stones, int byoyomi_periods)
  61 {
  62         if (main_time < 0) {
  63                 ti->period = TT_NULL; // no time limit, rely on engine default
  64         } else {
  65                 ti->period = main_time > 0 ? TT_TOTAL : TT_MOVE;
  66                 ti->dim = TD_WALLTIME;
  67                 ti->len.t.timer_start = 0;
  68                 ti->len.t.main_time = (double) main_time;
  69                 ti->len.t.byoyomi_time = (double) byoyomi_time;
  70                 ti->len.t.byoyomi_periods = byoyomi_periods;
  71                 ti->len.t.byoyomi_stones = byoyomi_stones;
  72                 ti->len.t.canadian = byoyomi_stones > 0;
  73                 if (byoyomi_time > 0) {
  74                         /* Normally, only one of byoyomi_periods and
  75                          * byoyomi_stones arguments will be > 0. However,
  76                          * our data structure uses generalized byoyomi
  77                          * specification that will assume "1 byoyomi period
  78                          * of N stones" for Canadian byoyomi and "N byoyomi
  79                          * periods of 1 stone" for Japanese byoyomi. */
  80                         if (ti->len.t.byoyomi_periods < 1)
  81                                 ti->len.t.byoyomi_periods = 1;
  82                         if (ti->len.t.byoyomi_stones < 1)
  83                                 ti->len.t.byoyomi_stones = 1;
  84                 } else {
  85                         assert(!ti->len.t.byoyomi_periods && !ti->len.t.byoyomi_stones);
  86                 }
  87                 ti->len.t.byoyomi_time_max = ti->len.t.byoyomi_time;
  88                 ti->len.t.byoyomi_stones_max = ti->len.t.byoyomi_stones;
  89         }
  90 }
  91
  92 /* Update time information according to gtp time_left command.
  93  * kgs doesn't give time_left for the first move, so make sure
  94  * that just time_settings + time_stop_conditions still work. */
  95 void
  96 time_left(struct time_info *ti, int time_left, int stones_left)
  97 {
  98         assert(ti->period != TT_NULL);
  99         ti->dim = TD_WALLTIME;
 100
 101         if (!time_left && !stones_left) {
 102                 /* Some GTP peers send time_left 0 0 at the end of main time. */
 103                 ti->period = TT_MOVE;
 104                 ti->len.t.main_time = 0;
 105                 /* byoyomi_time kept fully charged. */
 106
 107         } else if (!stones_left) {
 108                 /* Main time */
 109                 ti->period = TT_TOTAL;
 110                 ti->len.t.main_time = time_left;
 111                 /* byoyomi_time kept fully charged. */
 112
 113         } else {
 114                 /* Byoyomi */
 115                 ti->period = TT_MOVE;
 116                 ti->len.t.main_time = 0;
 117                 ti->len.t.byoyomi_time = time_left;
 118                 if (ti->len.t.canadian) {
 119                         ti->len.t.byoyomi_stones = stones_left;
 120                 } else {
 121                         // field misused by kgs
 122                         ti->len.t.byoyomi_periods = stones_left;
 123                 }
 124         }
 125 }
 126
 127 /* Start our timer. kgs does this (correctly) on "play" not "genmove"
 128  * unless we are making the first move of the game. */
 129 void
 130 time_start_timer(struct time_info *ti)
 131 {
 132         if (ti->period != TT_NULL && ti->dim == TD_WALLTIME)
 133                 ti->len.t.timer_start = time_now();
 134 }
 135
 136 void
 137 time_sub(struct time_info *ti, double interval)
 138 {
 139         assert(ti->dim == TD_WALLTIME && ti->period != TT_NULL);
 140
 141         if (ti->period == TT_TOTAL) {
 142                 ti->len.t.main_time -= interval;
 143                 if (ti->len.t.main_time >= 0)
 144                         return;
 145                 /* Fall-through to byoyomi. */
 146                 ti->period = TT_MOVE;
 147                 interval = -ti->len.t.main_time;
 148                 ti->len.t.main_time = 0;
 149         }
 150
 151         ti->len.t.byoyomi_time -= interval;
 152         if (ti->len.t.byoyomi_time < 0) {
 153                 /* Lost a period. */
 154                 if (--ti->len.t.byoyomi_periods < 1) {
 155                         fprintf(stderr, "*** LOST ON TIME internally! (%0.2f, spent %0.2fs on last move)\n",
 156                                 ti->len.t.byoyomi_time, interval);
 157                         /* Well, what can we do? Pretend this didn't happen. */
 158                         ti->len.t.byoyomi_periods = 1;
 159                 }
 160                 ti->len.t.byoyomi_time = ti->len.t.byoyomi_time_max;
 161                 ti->len.t.byoyomi_stones = ti->len.t.byoyomi_stones_max;
 162                 return;
 163         }
 164         if (--ti->len.t.byoyomi_stones < 1) {
 165                 /* Finished a period. */
 166                 ti->len.t.byoyomi_time = ti->len.t.byoyomi_time_max;
 167                 ti->len.t.byoyomi_stones = ti->len.t.byoyomi_stones_max;
 168         }
 169 }
 170
 171 /* Returns the current time. */
 172 double
 173 time_now(void)
 174 {
 175         struct timespec now;
 176         clock_gettime(CLOCK_REALTIME, &now);
 177         return now.tv_sec + now.tv_nsec/1000000000.0;
 178 }
 179
 180 /* Sleep for a given interval (in seconds). Return immediately if interval < 0. */
 181 void
 182 time_sleep(double interval)
 183 {
 184         struct timespec ts;
 185         double sec;
 186         ts.tv_nsec = (int)(modf(interval, &sec)*1000000000.0);
 187         ts.tv_sec = (int)sec;
 188         nanosleep(&ts, NULL); /* ignore error if interval was < 0 */
 189 }
 190
 191
 192 /* Returns true if we are in byoyomi (or should play as if in byo yomi
 193  * because remaining time per move in main time is less than byoyomi time
 194  * per move). */
 195 static bool
 196 time_in_byoyomi(struct time_info *ti) {
 197         assert(ti->dim == TD_WALLTIME);
 198         if (!ti->len.t.byoyomi_time)
 199                 return false; // there is no byoyomi!
 200         assert(ti->len.t.byoyomi_stones > 0);
 201         if (!ti->len.t.main_time)
 202                 return true; // we _are_ in byoyomi
 203         if (ti->len.t.main_time <= ti->len.t.byoyomi_time / ti->len.t.byoyomi_stones + 0.001)
 204                 return true; // our basic time left is less than byoyomi time per move
 205         return false;
 206 }
 207
 208 /* Set worst.time to all available remaining time (main time plus usable
 209  * byoyomi), to be spread over returned number of moves (expected game
 210  * length minus moves to be played in final byoyomi - if we would not be
 211  * able to spend more time on them in main time anyway). */
 212 static int
 213 time_stop_set_remaining(struct time_info *ti, struct board *b, double net_lag, struct time_stop *stop)
 214 {
 215         int moves_left = board_estimated_moves_left(b);
 216         stop->worst.time = ti->len.t.main_time;
 217
 218         if (!ti->len.t.byoyomi_time)
 219                 return moves_left;
 220
 221         /* Time for one move in byoyomi. */
 222         assert(ti->len.t.byoyomi_stones > 0);
 223         double move_time = ti->len.t.byoyomi_time / ti->len.t.byoyomi_stones;
 224
 225         /* (i) Plan to extend our thinking time to make use of byoyom. */
 226
 227         /* For Japanese byoyomi with N>1 periods, we use N-1 periods
 228          * as main time, keeping the last one as insurance against
 229          * unexpected net lag. */
 230         if (ti->len.t.byoyomi_periods > 2) {
 231                 stop->worst.time += (ti->len.t.byoyomi_periods - 2) * move_time;
 232                 // Will add 1 more byoyomi_time just below
 233         }
 234
 235         /* In case of Canadian byoyomi, include time that can be spent
 236          * on its first move. */
 237         stop->worst.time += move_time;
 238
 239         /* (ii) Do not play faster in main time than we would in byoyomi. */
 240
 241         /* Maximize the number of moves played uniformly in main time,
 242          * while not playing faster in main time than in byoyomi.
 243          * At this point, the main time remaining is stop->worst.time and
 244          * already includes the first (canadian) or N-1 byoyomi periods. */
 245         double real_move_time = move_time - net_lag;
 246         if (real_move_time > 0) {
 247                 int main_moves = stop->worst.time / real_move_time;
 248                 if (moves_left > main_moves) {
 249                         /* We plan to do too many moves in main time,
 250                          * do the rest in byoyomi. */
 251                         moves_left = main_moves;
 252                 }
 253                 if (moves_left <= 0) // possible if too much lag
 254                         moves_left = 1;
 255         }
 256
 257         return moves_left;
 258 }
 259
 260 /* Adjust the recommended per-move time based on the current game phase.
 261  * We expect stop->worst to be total time available, stop->desired the current
 262  * per-move time allocation, and set stop->desired to adjusted per-move time. */
 263 static void
 264 time_stop_phase_adjust(struct board *b, int fuseki_end, int yose_start, struct time_stop *stop)
 265 {
 266         int bsize = (board_size(b)-2)*(board_size(b)-2);
 267         fuseki_end = fuseki_end * bsize / 100; // move nb at fuseki end
 268         yose_start = yose_start * bsize / 100; // move nb at yose start
 269         assert(fuseki_end < yose_start);
 270
 271         /* No adjustments in yose. */
 272         if (b->moves >= yose_start)
 273                 return;
 274         int moves_to_yose = (yose_start - b->moves) / 2;
 275         // ^- /2 because we only consider the moves we have to play ourselves
 276         int left_at_yose_start = board_estimated_moves_left(b) - moves_to_yose;
 277         if (left_at_yose_start < MIN_MOVES_LEFT)
 278                 left_at_yose_start = MIN_MOVES_LEFT;
 279
 280         /* This particular value of middlegame_time will continuously converge
 281          * to effective "yose_time" value as we approach yose_start. */
 282         double middlegame_time = stop->worst.time / left_at_yose_start;
 283         if (middlegame_time < stop->desired.time)
 284                 return;
 285
 286         if (b->moves < fuseki_end) {
 287                 assert(fuseki_end > 0);
 288                 /* At the game start, use stop->desired.time (rather
 289                  * conservative estimate), then gradually prolong it. */
 290                 double beta = b->moves / fuseki_end;
 291                 stop->desired.time = middlegame_time * beta + stop->desired.time * (1 - beta);
 292
 293         } else { assert(b->moves < yose_start);
 294                 /* Middlegame, start with relatively large value, then
 295                  * converge to the uniform-timeslice yose value. */
 296                 stop->desired.time = middlegame_time;
 297         }
 298 }
 299
 300 /* Pre-process time_info for search control and sets the desired stopping conditions. */
 301 void
 302 time_stop_conditions(struct time_info *ti, struct board *b, int fuseki_end, int yose_start, struct time_stop *stop)
 303 {
 304         /* We must have _some_ limits by now, be it random default values! */
 305         assert(ti->period != TT_NULL);
 306
 307         /* Special-case limit by number of simulations. */
 308         if (ti->dim == TD_GAMES) {
 309                 if (ti->period == TT_TOTAL) {
 310                         ti->period = TT_MOVE;
 311                         ti->len.games /= board_estimated_moves_left(b);
 312                 }
 313
 314                 stop->desired.playouts = ti->len.games;
 315                 /* We force worst == desired, so note that we will NOT loop
 316                  * until best == winner. */
 317                 stop->worst.playouts = ti->len.games;
 318                 return;
 319         }
 320
 321         assert(ti->dim == TD_WALLTIME);
 322
 323
 324         /* Minimum net lag (seconds) to be reserved in the time for move. */
 325         double net_lag = MAX_NET_LAG;
 326         if (!ti->len.t.timer_start) {
 327                 ti->len.t.timer_start = time_now(); // we're playing the first game move
 328         } else {
 329                 net_lag += time_now() - ti->len.t.timer_start;
 330                 // TODO: keep statistics to get good estimate of lag not just current move
 331         }
 332
 333
 334         if (ti->period == TT_TOTAL && time_in_byoyomi(ti)) {
 335                 /* Technically, we are still in main time, but we can
 336                  * effectively switch to byoyomi scheduling since we
 337                  * have less time available than one byoyomi move takes. */
 338                 ti->period = TT_MOVE;
 339         }
 340
 341
 342         if (ti->period == TT_MOVE) {
 343                 /* We are in byoyomi, or almost! */
 344
 345                 /* The period can still include some tiny remnant of main
 346                  * time if we are just switching to byoyomi. */
 347                 double period_len = ti->len.t.byoyomi_time + ti->len.t.main_time;
 348
 349                 stop->worst.time = period_len;
 350                 assert(ti->len.t.byoyomi_stones > 0);
 351                 stop->desired.time = period_len / ti->len.t.byoyomi_stones;
 352
 353                 /* Use a larger safety margin if we risk losing on time on
 354                  * this move; it makes no sense to have 30s byoyomi and wait
 355                  * until 28s to play our move). */
 356                 if (stop->desired.time >= period_len - net_lag) {
 357                         double safe_margin = RESERVED_BYOYOMI_PERCENT * stop->desired.time / 100;
 358                         if (safe_margin > net_lag)
 359                                 net_lag = safe_margin;
 360                 }
 361
 362                 /* Make recommended_old == average(recommended_new, max) */
 363                 double worst_time = stop->desired.time * MAX_BYOYOMI_TIME_EXTENSION;
 364                 if (worst_time < stop->worst.time)
 365                         stop->worst.time = worst_time;
 366                 stop->desired.time *= (2 - MAX_BYOYOMI_TIME_EXTENSION);
 367
 368         } else { assert(ti->period == TT_TOTAL);
 369                 /* We are in main time. */
 370
 371                 assert(ti->len.t.main_time > 0);
 372                 /* Set worst.time to all available remaining time, to be spread
 373                  * over returned number of moves. */
 374                 int moves_left = time_stop_set_remaining(ti, b, net_lag, stop);
 375
 376                 /* Allocate even slice of the remaining time for next move. */
 377                 stop->desired.time = stop->worst.time / moves_left;
 378                 assert(stop->desired.time > 0 && stop->worst.time > 0);
 379                 assert(stop->desired.time <= stop->worst.time + 0.001);
 380
 381                 /* Furthermore, tweak the slice based on the game phase. */
 382                 time_stop_phase_adjust(b, fuseki_end, yose_start, stop);
 383
 384                 /* Put final upper bound on maximal time spent on the move. */
 385                 double worst_time = stop->desired.time * MAX_MAIN_TIME_EXTENSION;
 386                 if (worst_time < stop->worst.time)
 387                         stop->worst.time = worst_time;
 388                 if (stop->desired.time > stop->worst.time)
 389                         stop->desired.time = stop->worst.time;
 390         }
 391
 392         if (DEBUGL(1))
 393                 fprintf(stderr, "desired %0.2f, worst %0.2f, clock [%d] %0.2f + %0.2f/%d*%d, lag %0.2f\n",
 394                         stop->desired.time, stop->worst.time,
 395                         ti->dim, ti->len.t.main_time,
 396                         ti->len.t.byoyomi_time, ti->len.t.byoyomi_stones,
 397                         ti->len.t.byoyomi_periods, net_lag);
 398
 399         /* Account for lag. */
 400         stop->desired.time -= net_lag;
 401         stop->worst.time -= net_lag;
 402 }