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