1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473
|
#include <math.h>
#include "chess.h"
#include "data.h"
/* last modified 01/17/09 */
/*
*******************************************************************************
* *
* TimeAdjust() is called to adjust timing variables after each program move *
* is made. It simply increments the number of moves made, decrements the *
* amount of time used, and then makes any necessary adjustments based on *
* the time controls. *
* *
*******************************************************************************
*/
void TimeAdjust(int time_used, int side) {
/*
************************************************************
* *
* Decrement the number of moves remaining to the next *
* time control. Then subtract the time the program took *
* to choose its move from the time remaining. *
* *
************************************************************
*/
tc_moves_remaining[side]--;
tc_time_remaining[side] -=
(tc_time_remaining[side] >
time_used) ? time_used : tc_time_remaining[side];
if (!tc_moves_remaining[side]) {
if (tc_sudden_death == 2)
tc_sudden_death = 1;
tc_moves_remaining[side] += tc_secondary_moves;
tc_time_remaining[side] += tc_secondary_time;
Print(4095, "time control reached (%s)\n", (side) ? "white" : "black");
}
if (tc_increment)
tc_time_remaining[side] += tc_increment;
}
/* last modified 08/27/10 */
/*
*******************************************************************************
* *
* TimeCheck() is used to determine when the search should stop. It uses *
* several conditions to make this determination: (1) The search time has *
* exceeded the time per move limit; (2) The value at the root of the tree *
* has not dropped too low. (3) If the root move was flagged as "easy" and *
* no move has replaced it as best, the search can actually be stopped early *
* to save some time on the clock. If (2) is false, then the time is *
* extended up to 6x in an effort to avoid playing a poor move. *
* *
* We use one additional trick here to avoid stopping the search just before *
* we change to a better move. Once we reach the time limit, we set do not *
* immediately stop the search, rather, we let it continue until all root *
* moves that are "in progress" complete. This is important, particularly *
* on a parallel search that splits at the root like Crafty does. A new *
* best move will take quite a bit of time to search, and with just one CPU *
* working on it, we might not have time to complete it before the search *
* time limit is reached. Once we reach this point, we set a flag that *
* says "do not start searching a new root move, but do not abort any active *
* search. As processors finish their root moves, they will begin to help *
* those with incomplete root move searches to make sure that none of them *
* will become a new best move. This way, once we start searching any root *
* move, we will not give up on it until the search has completed and the *
* move was proved worse than the best root move so far, or until we *
* discover that this root move is actually better. *
* *
* This is implemented by having Search() call TimeCheck() passing it a *
* value of zero (0) for the parameter abort. TimeCheck() will only end the *
* search if we have exceeded the max time limit or we have not gotten a *
* best score at the root on the current iteration and we have reached the *
* normal time limit. Otherwise TimeCheck() will return the "abort" value *
* which is always zero when called from Search(). We also call TimeCheck() *
* from NextRootMove() and it passes TimeCheck() a value of 1 for the abort *
* flag. Once anyone posts the "abort" flag, NextRootMove() will return a *
* indication saying "no more root moves to search", which will eventually *
* end the search when all current root moves are completed and *
* NextRootMove() is called to obtain another root move to search. *
* *
* The global variable "abort_after_ply1" is initially set to zero, and so *
* long as it is zero, NextRootMove() will continue to return moves to *
* search until the iteration ends. Whenever the time_abort flag becomes *
* non-zero, NextRootMove() refuses to search any new moves, but the current *
* searches are allowed to continue until they all complete or the hard time *
* limit (absolute_time_limit) is reached where the search is terminated *
* immediately to avoid overstepping the time control limits. *
* *
*******************************************************************************
*/
int TimeCheck(TREE * RESTRICT tree, int abort) {
int time_used;
int i, ndone;
/*
************************************************************
* *
* Check to see if we need to "burp" the time to let the *
* operator know the search is progressing and how much *
* time has been used so far. *
* *
************************************************************
*/
time_used = (ReadClock() - start_time);
if (tree->nodes_searched > noise_level && display_options & 32 &&
time_used > burp) {
Lock(lock_io);
if (pondering)
printf(" %2i %s%7s? ", iteration_depth,
DisplayTime(time_used), tree->remaining_moves_text);
else
printf(" %2i %s%7s* ", iteration_depth,
DisplayTime(time_used), tree->remaining_moves_text);
if (display_options & 32 && display_options & 64)
printf("%d. ", move_number);
if ((display_options & 32) && (display_options & 64) && Flip(root_wtm))
printf("... ");
printf("%s(%snps) \r", tree->root_move_text,
DisplayKM(nodes_per_second));
burp = (time_used / 1500) * 1500 + 1500;
fflush(stdout);
Unlock(lock_io);
}
/*
************************************************************
* *
* First, check to see if there is only one root move. *
* If so, and we are not pondering, searching a book move *
* or annotating a game, we can return and make this move *
* instantly. We do need to finish iteration 1 so that *
* we actually back up a move to play. *
* *
************************************************************
*/
if (n_root_moves == 1 && !booking && !annotate_mode && !pondering &&
iteration_depth > 1)
return (1);
/*
************************************************************
* *
* Now, check to see if we are searching the first move *
* at this depth. If so, and we run out of time, we can *
* abort the search rather than waiting to complete this *
* ply=1 move to see if it's better. *
* *
************************************************************
*/
ndone = 0;
for (i = 0; i < n_root_moves; i++)
if (root_moves[i].status & 256)
ndone++;
if (ndone == 1)
abort = 1;
if (iteration_depth <= 2)
return (0);
/*
************************************************************
* *
* If we are pondering or in analyze mode, we do not *
* terminate on time since there is no time limit placed *
* on these searches. If we have reached the absolute *
* time limit, we stop the search instantly. *
* *
* If we are under the time limit already set, we do not *
* terminate the search. If the operator set a specific *
* search time limit, we stop when we hit that regardless *
* of the score. *
* *
* The only other case is an "easy move" which is a move *
* that looks significantly better than the rest of the *
* root moves when they are initially ordered, and this *
* move does not fail low during subsequent searches. *
* *
************************************************************
*/
if (pondering || analyze_mode)
return (0);
if (time_used > absolute_time_limit)
return (1);
if (easy_move && !search_time_limit) {
if (time_used >= (36 * time_limit) / 100)
return (1);
}
if (time_used < time_limit)
return (0);
if (search_time_limit)
return (1);
/*
************************************************************
* *
* Ok. We have used "time_limit" at this point, and we *
* have not gone over "absolute_time_limit". Now the *
* question is, can we stop the search? *
* *
* If we have a score at the root of the tree and if the *
* evaluation is not worse than the last evaluation *
* (from the previous iteration...) then we safely stop *
* the search. *
* *
************************************************************
*/
if (root_value == root_alpha && !(root_moves[0].status & 7) && ndone == 1)
return (1);
if ((root_value >= last_root_value && !(root_moves[0].status & 7)))
return (abort);
/*
************************************************************
* *
* We are in trouble at the root. We have now used the *
* allocated time limit, yet the score for the current *
* iteration is still worse than the score for the *
* previous iteration. We will continue to search until *
* we use 6x the normal target time in an effort to avoid *
* playing a move that might end up losing the game. *
* *
* One note for clarification. After the first root move *
* has been searched, the rest "fly by" thanks to the *
* reductions and forward-pruning stuff. It is not very *
* likely that we are going to go 6x before every root *
* move has been searched, unless one of them actually *
* has the potential to become a new best move. Most of *
* the time, we are going to end the current iteration *
* quickly and we won't start another since we are past *
* the time limit. It sounds risky to extend 6x for just *
* a 0.01 score drop, but using that much time is not so *
* common as to cause an unnecessary loss of time. We do *
* prefer to spend some additional time to stop any score *
* drop, if we can, as any drop is a bad thing overall. *
* *
************************************************************
*/
if (time_used > time_limit * 6 ||
time_used + 300 > tc_time_remaining[root_wtm])
return (1);
return (0);
}
/* last modified 01/17/09 */
/*
*******************************************************************************
* *
* TimeSet() is called to set the two variables "time_limit" and *
* "absolute_time_limit" which controls the amount of time taken by the *
* iterated search. It simply takes the timing controls as set by the user *
* and uses these values to calculate how much time should be spent on the *
* next search. *
* *
*******************************************************************************
*/
static int moves_left[64] = {
18, 18, 18, 18, 18, 18, 18, 18,
19, 19, 19, 19, 20, 20, 20, 20,
21, 21, 21, 21, 22, 22, 22, 22,
23, 23, 23, 23, 24, 24, 24, 24,
25, 25, 25, 25, 26, 26, 26, 26,
27, 27, 27, 27, 28, 28, 28, 28,
29, 29, 29, 29, 30, 30, 30, 30,
31, 31, 31, 31, 32, 32, 32, 32
};
void TimeSet(TREE * RESTRICT tree, int search_type) {
static const float behind[6] = { 32.0, 16.0, 8.0, 4.0, 2.0, 1.5 };
static const int reduce[6] = { 96, 48, 24, 12, 6, 3 };
int i, mult = 0, extra = 0;
int surplus, average;
int simple_average;
int phase =
moves_left[Min(63, TotalPieces(white, occupied) + TotalPieces(black,
occupied))] - 4;
surplus = 0;
average = 0;
/*
************************************************************
* *
* Check to see if we are in a sudden-death type of time *
* control. If so, we have a fixed amount of time *
* remaining. Set the search time accordingly and exit. *
* *
* If we have less than 5 seconds on the clock prior to *
* the increment, then limit our search to the increment. *
* *
* If we have less than 2.5 seconds on the clock prior to *
* the increment, then limit our search to half the *
* increment in an attempt to add some time to our buffer.*
* *
* Set our MAX search time to half the remaining time. *
* *
* If our search time will drop the clock below 1 second, *
* then limit our MAX search time to the normal search *
* time. This is done to stop any extensions from *
* dropping us too low. *
* *
************************************************************
*/
if (tc_sudden_death == 1) {
if (tc_increment) {
time_limit =
(tc_time_remaining[root_wtm] -
tc_operator_time * tc_moves_remaining[root_wtm]) /
(ponder ? phase : phase + 6) + tc_increment;
if (tc_time_remaining[root_wtm] < 500 + tc_increment) {
time_limit = tc_increment;
if (tc_time_remaining[root_wtm] < 250 + tc_increment)
time_limit /= 2;
}
absolute_time_limit = tc_time_remaining[root_wtm] / 2 + tc_increment;
if (absolute_time_limit < time_limit ||
tc_time_remaining[root_wtm] - time_limit < 100)
absolute_time_limit = time_limit;
// Safety.
if (tc_time_remaining[root_wtm] - time_limit < 50) {
time_limit = tc_time_remaining[root_wtm] - 50;
if (time_limit < 5)
time_limit = 5;
}
if (tc_time_remaining[root_wtm] - absolute_time_limit < 25) {
absolute_time_limit = tc_time_remaining[root_wtm] - 25;
if (absolute_time_limit < 5)
absolute_time_limit = 5;
}
} else {
time_limit =
tc_time_remaining[root_wtm] / (ponder ? phase + 6 : phase + 12);
absolute_time_limit =
Min(time_limit * 5, tc_time_remaining[root_wtm] / 2);
}
}
/*
************************************************************
* *
* We are not in a sudden_death situation. We now have *
* two choices: If the program has saved enough time to *
* meet the surplus requirement, then we simply divide *
* the time left evenly among the moves left. If we *
* haven't yet saved up a cushion so that "fail-lows" *
* have extra time to find a solution, we simply take the *
* number of moves divided into the total time less the *
* necessary operator time as the target. *
* *
************************************************************
*/
else {
if (move_number <= tc_moves)
simple_average =
(tc_time -
(tc_operator_time * tc_moves_remaining[root_wtm])) / tc_moves;
else
simple_average =
(tc_secondary_time -
(tc_operator_time * tc_moves_remaining[root_wtm])) /
tc_secondary_moves;
surplus =
Max(tc_time_remaining[root_wtm] -
(tc_operator_time * tc_moves_remaining[root_wtm]) -
simple_average * tc_moves_remaining[root_wtm], 0);
average =
(tc_time_remaining[root_wtm] -
(tc_operator_time * tc_moves_remaining[root_wtm]) +
tc_moves_remaining[root_wtm] * tc_increment)
/ tc_moves_remaining[root_wtm];
if (surplus < tc_safety_margin)
time_limit = (average < simple_average) ? average : simple_average;
else
time_limit =
(average < 2.0 * simple_average) ? average : 2.0 * simple_average;
}
if (surplus < 0)
surplus = 0;
if (tc_increment > 200 && moves_out_of_book < 2)
time_limit *= 1.2;
if (time_limit <= 0)
time_limit = 5;
absolute_time_limit =
time_limit + surplus / 2 + ((tc_time_remaining[root_wtm] -
tc_operator_time * tc_moves_remaining[root_wtm]) / 4);
if (absolute_time_limit > 6 * time_limit)
absolute_time_limit = 6 * time_limit;
if (absolute_time_limit > tc_time_remaining[root_wtm] / 2)
absolute_time_limit = tc_time_remaining[root_wtm] / 2;
/*
************************************************************
* *
* The "usage" option can be used to force the time limit *
* higher or lower than normal. The new "timebook" *
* command can also modify the target time making the *
* program use more time early in the game as it exits the *
* book, knowing it will save time later on by ponder hits *
* and instant moves. *
* *
************************************************************
*/
if (usage_level)
time_limit *= 1.0 + usage_level / 100.0;
if (first_nonbook_factor && moves_out_of_book < first_nonbook_span) {
mult =
(first_nonbook_span - moves_out_of_book + 1) * first_nonbook_factor;
extra = time_limit * mult / first_nonbook_span / 100;
time_limit += extra;
}
/*
************************************************************
* *
* This code is used to handle the case where someone is *
* trying to "blitz" Crafty by reaching a position where *
* things are locked up, and then just shuffling pieces *
* back and forth. When Crafty reaches the point where it *
* has less than 3/4 of the time the opponent has, it *
* starts decreasing the target time. At 1/2, it *
* decreases it further. *
* *
************************************************************
*/
if (mode != tournament_mode && !computer_opponent) {
for (i = 0; i < 6; i++) {
if ((float) tc_time_remaining[root_wtm] * behind[i] <
(float) tc_time_remaining[Flip(root_wtm)]) {
time_limit = time_limit / reduce[i];
Print(128, "Crafty is behind %4.1f on time, reducing by 1/%d.\n",
behind[i], reduce[i]);
break;
}
}
if (tc_increment == 0 &&
tc_time_remaining[Flip(root_wtm)] > tc_time_remaining[root_wtm]) {
if (tc_time_remaining[root_wtm] < 3000)
time_limit /= 2;
if (tc_time_remaining[root_wtm] < 2000)
time_limit /= 2;
if (tc_time_remaining[root_wtm] < 1000)
time_limit = 1;
}
}
/*
************************************************************
* *
* If the operator has set an absolute search time limit *
* already, then we simply copy this value and return. *
* *
************************************************************
*/
if (search_time_limit) {
time_limit = search_time_limit;
absolute_time_limit = time_limit;
}
if (search_type == puzzle || booking) {
time_limit /= 10;
absolute_time_limit = time_limit * 3;
}
if (!tc_sudden_death && !search_time_limit &&
time_limit > 3 * tc_time / tc_moves)
time_limit = 3 * tc_time / tc_moves;
time_limit = Min(time_limit, absolute_time_limit);
if (search_type != puzzle) {
if (!tc_sudden_death)
Print(128, " time surplus %s ", DisplayTime(surplus));
else
Print(128, " ");
Print(128, "time limit %s", DisplayTimeKibitz(time_limit));
Print(128, " (+%s)", DisplayTimeKibitz(extra));
Print(128, " (%s)", DisplayTimeKibitz(absolute_time_limit));
if (fabs(usage_level) > 0.0001) {
Print(128, "/");
Print(128, "(%d)", usage_level);
}
if (easy_move)
Print(128, " [easy move]");
Print(128, "\n");
}
if (time_limit <= 1) {
time_limit = 1;
usage_level = 0;
}
}
|