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