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 #include <sys/time.h>
   8
   9 #define DEBUG
  10
  11 #include "debug.h"
  12 #include "tactics.h"
  13 #include "timeinfo.h"
  14
  15 /* Max net lag in seconds. TODO: estimate dynamically. */
  16 #define MAX_NET_LAG 2.0
  17 /* Minimal thinking time; in case reserved time gets smaller than MAX_NET_LAG,
  18  * this makes sure we play minimally sensible moves even in massive time
  19  * pressure; we still keep MAX_NET_LAG-MIN_THINK_WITH_LAG safety margin.
  20  * Note that this affects only lag adjustmnet - if reserved time *before*
  21  * lag adjustment gets too small, we still respect it and don't apply
  22  * MIN_THINK_WITH_LAG. */
  23 #define MIN_THINK_WITH_LAG (MAX_NET_LAG / 2)
  24 /* Reserve 15% of byoyomi time as safety margin if risk of losing on time */
  25 #define RESERVED_BYOYOMI_PERCENT 15
  26
  27 /* For safety, use at most 3 times the desired time on a single move
  28  * in main time, 2 times in sudden death and 1.1 times in byoyomi. */
  29 #define MAX_MAIN_TIME_EXTENSION 3.0
  30 #define MAX_SUDDEN_DEATH_EXTENSION 2.0
  31 #define MAX_BYOYOMI_TIME_EXTENSION 1.1
  32
  33 bool
  34 time_parse(struct time_info *ti, char *s)
  35 {
  36         switch (s[0]) {
  37                 case '_': ti->period = TT_TOTAL; s++; break;
  38                 default: ti->period = TT_MOVE; break;
  39         }
  40         switch (s[0]) {
  41                 case '=':
  42                         ti->dim = TD_GAMES;
  43                         ti->len.games = atoi(++s);
  44                         break;
  45                 default:
  46                         if (!isdigit(s[0]))
  47                                 return false;
  48                         ti->dim = TD_WALLTIME;
  49                         ti->len.t.timer_start = 0;
  50                         if (ti->period == TT_TOTAL) {
  51                                 ti->len.t.main_time = atof(s);
  52                                 ti->len.t.byoyomi_time = 0.0;
  53                                 ti->len.t.byoyomi_time_max = 0.0;
  54                                 ti->len.t.byoyomi_periods = 0;
  55                                 ti->len.t.byoyomi_stones = 0;
  56                                 ti->len.t.byoyomi_stones_max = 0;
  57                         } else { assert(ti->period == TT_MOVE);
  58                                 ti->len.t.main_time = 0.0;
  59                                 ti->len.t.byoyomi_time = atof(s);
  60                                 ti->len.t.byoyomi_time_max = ti->len.t.byoyomi_time;
  61                                 ti->len.t.byoyomi_periods = 1;
  62                                 ti->len.t.byoyomi_stones = 1;
  63                                 ti->len.t.byoyomi_stones_max = 1;
  64                         }
  65                         break;
  66         }
  67         return true;
  68 }
  69
  70 /* Update time settings according to gtp time_settings or kgs-time_settings command. */
  71 void
  72 time_settings(struct time_info *ti, int main_time, int byoyomi_time, int byoyomi_stones, int byoyomi_periods)
  73 {
  74         if (main_time < 0) {
  75                 ti->period = TT_NULL; // no time limit, rely on engine default
  76         } else {
  77                 ti->period = main_time > 0 ? TT_TOTAL : TT_MOVE;
  78                 ti->dim = TD_WALLTIME;
  79                 ti->len.t.timer_start = 0;
  80                 ti->len.t.main_time = (double) main_time;
  81                 ti->len.t.byoyomi_time = (double) byoyomi_time;
  82                 ti->len.t.byoyomi_periods = byoyomi_periods;
  83                 ti->len.t.byoyomi_stones = byoyomi_stones;
  84                 ti->len.t.canadian = byoyomi_stones > 0;
  85                 if (byoyomi_time > 0) {
  86                         /* Normally, only one of byoyomi_periods and
  87                          * byoyomi_stones arguments will be > 0. However,
  88                          * our data structure uses generalized byoyomi
  89                          * specification that will assume "1 byoyomi period
  90                          * of N stones" for Canadian byoyomi and "N byoyomi
  91                          * periods of 1 stone" for Japanese byoyomi. */
  92                         if (ti->len.t.byoyomi_periods < 1)
  93                                 ti->len.t.byoyomi_periods = 1;
  94                         if (ti->len.t.byoyomi_stones < 1)
  95                                 ti->len.t.byoyomi_stones = 1;
  96                 } else {
  97                         assert(!ti->len.t.byoyomi_periods && !ti->len.t.byoyomi_stones);
  98                 }
  99                 ti->len.t.byoyomi_time_max = ti->len.t.byoyomi_time;
 100                 ti->len.t.byoyomi_stones_max = ti->len.t.byoyomi_stones;
 101         }
 102 }
 103
 104 /* Update time information according to gtp time_left command.
 105  * kgs doesn't give time_left for the first move, so make sure
 106  * that just time_settings + time_stop_conditions still work. */
 107 void
 108 time_left(struct time_info *ti, int time_left, int stones_left)
 109 {
 110         assert(ti->period != TT_NULL);
 111         ti->dim = TD_WALLTIME;
 112
 113         if (!time_left && !stones_left) {
 114                 /* Some GTP peers send time_left 0 0 at the end of main time. */
 115                 ti->period = TT_MOVE;
 116                 ti->len.t.main_time = 0;
 117                 /* byoyomi_time kept fully charged. */
 118
 119         } else if (!stones_left) {
 120                 /* Main time */
 121                 ti->period = TT_TOTAL;
 122                 ti->len.t.main_time = time_left;
 123                 /* byoyomi_time kept fully charged. */
 124
 125         } else {
 126                 /* Byoyomi */
 127                 ti->period = TT_MOVE;
 128                 ti->len.t.main_time = 0;
 129                 ti->len.t.byoyomi_time = time_left;
 130                 if (ti->len.t.canadian) {
 131                         ti->len.t.byoyomi_stones = stones_left;
 132                 } else {
 133                         // field misused by kgs
 134                         ti->len.t.byoyomi_periods = stones_left;
 135                 }
 136         }
 137 }
 138
 139 /* Start our timer. kgs does this (correctly) on "play" not "genmove"
 140  * unless we are making the first move of the game. */
 141 void
 142 time_start_timer(struct time_info *ti)
 143 {
 144         if (ti->period != TT_NULL && ti->dim == TD_WALLTIME)
 145                 ti->len.t.timer_start = time_now();
 146 }
 147
 148 void
 149 time_sub(struct time_info *ti, double interval, bool new_move)
 150 {
 151         assert(ti->dim == TD_WALLTIME && ti->period != TT_NULL);
 152
 153         if (ti->period == TT_TOTAL) {
 154                 ti->len.t.main_time -= interval;
 155                 if (ti->len.t.main_time >= 0)
 156                         return;
 157                 if (ti->len.t.byoyomi_time <= 0) {
 158                         /* No byoyomi to save us. */
 159                         fprintf(stderr, "*** LOST ON TIME internally! (%0.2f, spent %0.2fs on last move)\n",
 160                                 ti->len.t.main_time, interval);
 161                         /* What can we do? Pretend this didn't happen. */
 162                         ti->len.t.main_time = 1.0f;
 163                         return;
 164                 }
 165                 /* Fall-through to byoyomi. */
 166                 ti->period = TT_MOVE;
 167                 interval = -ti->len.t.main_time;
 168                 ti->len.t.main_time = 0;
 169         }
 170
 171         ti->len.t.byoyomi_time -= interval;
 172         if (ti->len.t.byoyomi_time < 0) {
 173                 /* Lost a period. */
 174                 if (--ti->len.t.byoyomi_periods < 1) {
 175                         fprintf(stderr, "*** LOST ON TIME internally! (%0.2f, spent %0.2fs on last move)\n",
 176                                 ti->len.t.byoyomi_time, interval);
 177                         /* Well, what can we do? Pretend this didn't happen. */
 178                         ti->len.t.byoyomi_periods = 1;
 179                 }
 180                 ti->len.t.byoyomi_time = ti->len.t.byoyomi_time_max;
 181                 ti->len.t.byoyomi_stones = ti->len.t.byoyomi_stones_max;
 182                 return;
 183         }
 184         if (new_move && --ti->len.t.byoyomi_stones < 1) {
 185                 /* Finished a period. */
 186                 ti->len.t.byoyomi_time = ti->len.t.byoyomi_time_max;
 187                 ti->len.t.byoyomi_stones = ti->len.t.byoyomi_stones_max;
 188         }
 189 }
 190
 191 /* Returns the current time. */
 192 double
 193 time_now(void)
 194 {
 195 #if _POSIX_TIMERS > 0
 196         struct timespec now;
 197         clock_gettime(CLOCK_REALTIME, &now);
 198         return now.tv_sec + now.tv_nsec/1000000000.0;
 199 #else
 200         struct timeval now;
 201         gettimeofday(&now, NULL);
 202         return now.tv_sec + now.tv_usec/1000000.0;
 203 #endif
 204 }
 205
 206 /* Sleep for a given interval (in seconds). Return immediately if interval < 0. */
 207 void
 208 time_sleep(double interval)
 209 {
 210         struct timespec ts;
 211         double sec;
 212         ts.tv_nsec = (int)(modf(interval, &sec)*1000000000.0);
 213         ts.tv_sec = (int)sec;
 214         nanosleep(&ts, NULL); /* ignore error if interval was < 0 */
 215 }
 216
 217
 218 /* Returns true if we are in byoyomi (or should play as if in byo yomi
 219  * because remaining time per move in main time is less than byoyomi time
 220  * per move). */
 221 static bool
 222 time_in_byoyomi(struct time_info *ti) {
 223         assert(ti->dim == TD_WALLTIME);
 224         if (!ti->len.t.byoyomi_time)
 225                 return false; // there is no byoyomi!
 226         assert(ti->len.t.byoyomi_stones > 0);
 227         if (!ti->len.t.main_time)
 228                 return true; // we _are_ in byoyomi
 229         if (ti->len.t.main_time <= ti->len.t.byoyomi_time / ti->len.t.byoyomi_stones + 0.001)
 230                 return true; // our basic time left is less than byoyomi time per move
 231         return false;
 232 }
 233
 234 /* Set worst.time to all available remaining time (main time plus usable
 235  * byoyomi), to be spread over returned number of moves (expected game
 236  * length minus moves to be played in final byoyomi - if we would not be
 237  * able to spend more time on them in main time anyway). */
 238 static int
 239 time_stop_set_remaining(struct time_info *ti, struct board *b, double net_lag, struct time_stop *stop)
 240 {
 241         int moves_left = board_estimated_moves_left(b);
 242         stop->worst.time = ti->len.t.main_time;
 243
 244         if (!ti->len.t.byoyomi_time)
 245                 return moves_left;
 246
 247         /* Time for one move in byoyomi. */
 248         assert(ti->len.t.byoyomi_stones > 0);
 249         double move_time = ti->len.t.byoyomi_time / ti->len.t.byoyomi_stones;
 250
 251         /* (i) Plan to extend our thinking time to make use of byoyom. */
 252
 253         /* For Japanese byoyomi with N>1 periods, we use N-1 periods
 254          * as main time, keeping the last one as insurance against
 255          * unexpected net lag. */
 256         if (ti->len.t.byoyomi_periods > 2) {
 257                 stop->worst.time += (ti->len.t.byoyomi_periods - 2) * move_time;
 258                 // Will add 1 more byoyomi_time just below
 259         }
 260
 261         /* In case of Canadian byoyomi, include time that can be spent
 262          * on its first move. */
 263         stop->worst.time += move_time;
 264
 265         /* (ii) Do not play faster in main time than we would in byoyomi. */
 266
 267         /* Maximize the number of moves played uniformly in main time,
 268          * while not playing faster in main time than in byoyomi.
 269          * At this point, the main time remaining is stop->worst.time and
 270          * already includes the first (canadian) or N-1 byoyomi periods. */
 271         double real_move_time = move_time - net_lag;
 272         if (real_move_time > 0) {
 273                 int main_moves = stop->worst.time / real_move_time;
 274                 if (moves_left > main_moves) {
 275                         /* We plan to do too many moves in main time,
 276                          * do the rest in byoyomi. */
 277                         moves_left = main_moves;
 278                 }
 279                 if (moves_left <= 0) // possible if too much lag
 280                         moves_left = 1;
 281         }
 282
 283         return moves_left;
 284 }
 285
 286 /* Adjust the recommended per-move time based on the current game phase.
 287  * We expect stop->worst to be total time available, stop->desired the current
 288  * per-move time allocation, and set stop->desired to adjusted per-move time. */
 289 static void
 290 time_stop_phase_adjust(struct board *b, int fuseki_end, int yose_start, struct time_stop *stop)
 291 {
 292         int bsize = (board_size(b)-2)*(board_size(b)-2);
 293         fuseki_end = fuseki_end * bsize / 100; // move nb at fuseki end
 294         yose_start = yose_start * bsize / 100; // move nb at yose start
 295         assert(fuseki_end < yose_start);
 296
 297         /* No adjustments in yose. */
 298         if (b->moves >= yose_start)
 299                 return;
 300         int moves_to_yose = (yose_start - b->moves) / 2;
 301         // ^- /2 because we only consider the moves we have to play ourselves
 302         int left_at_yose_start = board_estimated_moves_left(b) - moves_to_yose;
 303         if (left_at_yose_start < MIN_MOVES_LEFT)
 304                 left_at_yose_start = MIN_MOVES_LEFT;
 305
 306         /* This particular value of middlegame_time will continuously converge
 307          * to effective "yose_time" value as we approach yose_start. */
 308         double middlegame_time = stop->worst.time / left_at_yose_start;
 309         if (middlegame_time < stop->desired.time)
 310                 return;
 311
 312         if (b->moves < fuseki_end) {
 313                 assert(fuseki_end > 0);
 314                 /* At the game start, use stop->desired.time (rather
 315                  * conservative estimate), then gradually prolong it. */
 316                 double beta = b->moves / fuseki_end;
 317                 stop->desired.time = middlegame_time * beta + stop->desired.time * (1 - beta);
 318
 319         } else { assert(b->moves < yose_start);
 320                 /* Middlegame, start with relatively large value, then
 321                  * converge to the uniform-timeslice yose value. */
 322                 stop->desired.time = middlegame_time;
 323         }
 324 }
 325
 326 void
 327 lag_adjust(double *time, double net_lag)
 328 {
 329         double nolag_time = *time;
 330         *time -= net_lag;
 331         if (*time < MIN_THINK_WITH_LAG && nolag_time > MIN_THINK_WITH_LAG)
 332                 *time = MIN_THINK_WITH_LAG;
 333 }
 334
 335 /* Pre-process time_info for search control and sets the desired stopping conditions. */
 336 void
 337 time_stop_conditions(struct time_info *ti, struct board *b, int fuseki_end, int yose_start, struct time_stop *stop)
 338 {
 339         /* We must have _some_ limits by now, be it random default values! */
 340         assert(ti->period != TT_NULL);
 341
 342         /* Special-case limit by number of simulations. */
 343         if (ti->dim == TD_GAMES) {
 344                 if (ti->period == TT_TOTAL) {
 345                         ti->period = TT_MOVE;
 346                         ti->len.games /= board_estimated_moves_left(b);
 347                 }
 348
 349                 stop->desired.playouts = ti->len.games;
 350                 /* We force worst == desired, so note that we will NOT loop
 351                  * until best == winner. */
 352                 stop->worst.playouts = ti->len.games;
 353                 return;
 354         }
 355
 356         assert(ti->dim == TD_WALLTIME);
 357
 358
 359         /* Minimum net lag (seconds) to be reserved in the time for move. */
 360         double net_lag = MAX_NET_LAG;
 361         if (!ti->len.t.timer_start) {
 362                 ti->len.t.timer_start = time_now(); // we're playing the first game move
 363         } else {
 364                 net_lag += time_now() - ti->len.t.timer_start;
 365                 // TODO: keep statistics to get good estimate of lag not just current move
 366         }
 367
 368
 369         if (ti->period == TT_TOTAL && time_in_byoyomi(ti)) {
 370                 /* Technically, we are still in main time, but we can
 371                  * effectively switch to byoyomi scheduling since we
 372                  * have less time available than one byoyomi move takes. */
 373                 ti->period = TT_MOVE;
 374         }
 375
 376
 377         if (ti->period == TT_MOVE) {
 378                 /* We are in byoyomi, or almost! */
 379
 380                 /* The period can still include some tiny remnant of main
 381                  * time if we are just switching to byoyomi. */
 382                 double period_len = ti->len.t.byoyomi_time + ti->len.t.main_time;
 383
 384                 stop->worst.time = period_len;
 385                 assert(ti->len.t.byoyomi_stones > 0);
 386                 stop->desired.time = period_len / ti->len.t.byoyomi_stones;
 387
 388                 /* Use a larger safety margin if we risk losing on time on
 389                  * this move; it makes no sense to have 30s byoyomi and wait
 390                  * until 28s to play our move). */
 391                 if (stop->desired.time >= period_len - net_lag) {
 392                         double safe_margin = RESERVED_BYOYOMI_PERCENT * stop->desired.time / 100;
 393                         if (safe_margin > net_lag)
 394                                 net_lag = safe_margin;
 395                 }
 396
 397                 /* Make recommended_old == average(recommended_new, max) */
 398                 double worst_time = stop->desired.time * MAX_BYOYOMI_TIME_EXTENSION;
 399                 if (worst_time < stop->worst.time)
 400                         stop->worst.time = worst_time;
 401                 stop->desired.time *= (2 - MAX_BYOYOMI_TIME_EXTENSION);
 402
 403         } else { assert(ti->period == TT_TOTAL);
 404                 /* We are in main time. */
 405
 406                 assert(ti->len.t.main_time > 0);
 407                 /* Set worst.time to all available remaining time, to be spread
 408                  * over returned number of moves. */
 409                 int moves_left = time_stop_set_remaining(ti, b, net_lag, stop);
 410
 411                 /* Allocate even slice of the remaining time for next move. */
 412                 stop->desired.time = stop->worst.time / moves_left;
 413                 assert(stop->desired.time > 0 && stop->worst.time > 0);
 414                 assert(stop->desired.time <= stop->worst.time + 0.001);
 415
 416                 /* Furthermore, tweak the slice based on the game phase. */
 417                 time_stop_phase_adjust(b, fuseki_end, yose_start, stop);
 418
 419                 /* Put final upper bound on maximal time spent on the move.
 420                  * Keep enough time for sudden death (or near SD) games. */
 421                 double worst_time = stop->desired.time;
 422                 if (ti->len.t.byoyomi_time_max > ti->len.t.byoyomi_stones_max) {
 423                         worst_time *= MAX_MAIN_TIME_EXTENSION;
 424                 } else {
 425                         worst_time *= MAX_SUDDEN_DEATH_EXTENSION;
 426                 }
 427                 if (worst_time < stop->worst.time)
 428                         stop->worst.time = worst_time;
 429                 if (stop->desired.time > stop->worst.time)
 430                         stop->desired.time = stop->worst.time;
 431         }
 432
 433         if (DEBUGL(1))
 434                 fprintf(stderr, "desired %0.2f, worst %0.2f, clock [%d] %0.2f + %0.2f/%d*%d, lag %0.2f\n",
 435                         stop->desired.time, stop->worst.time,
 436                         ti->dim, ti->len.t.main_time,
 437                         ti->len.t.byoyomi_time, ti->len.t.byoyomi_stones,
 438                         ti->len.t.byoyomi_periods, net_lag);
 439
 440         /* Account for lag. */
 441         lag_adjust(&stop->desired.time, net_lag);
 442         lag_adjust(&stop->worst.time, net_lag);
 443 }