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