2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25 struct engine_t e
; /* engine parameters */
27 int history
[2][7][4096]; /* history for move ordering */
28 int hash_moves
[MAX_PLY
]; /* moves to try first */
29 struct killers_t killers
[MAX_PLY
]; /* moves to try after hash moves */
31 int pv
[MAX_PLY
][MAX_PLY
]; /* triangular array for PV */
32 int pv_length
[MAX_PLY
];
34 /* initial chess position */
35 char start_position
[] = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq -";
36 char book_file_name
[] = "book.bin";
38 /* statistic counters */
39 struct counters_t counters
;
42 * Return variable's value in thread-safe way
45 get_engine_value(int *val
)
49 pthread_mutex_lock(&e
.mutex
);
51 pthread_mutex_unlock(&e
.mutex
);
57 * Set value in thread-safe way
60 set_engine_value(int *src
, int new_value
)
62 pthread_mutex_lock(&e
.mutex
);
64 pthread_mutex_unlock(&e
.mutex
);
67 /* time from Epoc in second/100 units - xboard time units */
74 return t
.tv_sec
* 100 + t
.tv_usec
/ 10000;
77 /* check if we should abort search */
83 if (!(counters
.searched_nodes
& e
.chk_time
)) {
84 int stop_time
= get_engine_value((int *)&e
.stop_time
);
85 if (get_time() >= stop_time
) {
86 if (fail_high_root
&& (stop_time
< get_engine_value((int *)&e
.max_stop_time
) &&
87 !get_engine_value(&e
.fixed_time
))) {
88 set_engine_value((int *)&e
.stop_time
, stop_time
+ e
.max_time
);
89 fprintf(stderr
, "Extending because fail high at ply 1\n");
92 if (!safe_search
&& !get_engine_value(&e
.fixed_time
) &&
93 stop_time
< get_engine_value((int *)&e
.max_stop_time
)) {
94 set_engine_value((int *)&e
.stop_time
, stop_time
+ e
.max_time
/ 2);
95 fprintf(stderr
, "Extending...\n");
99 /* takeback all moves in search tree */
100 for (i
= 0; i
< ply
; i
++)
114 srand(get_time()); /* for opening book randomization */
115 setup_board(start_position
);
117 clear_main_hashtable();
118 clear_pawn_hashtable();
121 /* print brief stats to console. used mostly for debugging */
123 print_stats(int timediff
)
126 double move_ordering
;
129 search_time
= timediff
/ 100.0;
130 move_ordering
= counters
.failed_high_total
? \
131 (counters
.failed_high_first
/ (double) counters
.failed_high_total
) * \
133 nps
= counters
.searched_nodes
/ search_time
;
135 fprintf(stdout
, "Time: %.2f, nodes: %llu, NPS: %d/sec, MO: %.2f%%\n" \
136 "NULL: %llu, delta: %llu, LMR: %llu, razor: %llu, futility: %llu\n" \
137 "pawn hash evaluations: %llu, transposition: %llu\n" \
138 "evaluations: %llu, lazy: %.2f%%, phase: %d\n",
139 search_time
, counters
.searched_nodes
, nps
, move_ordering
,
140 counters
.null_move_prunings
, counters
.delta_prunings
,
141 counters
.reductions
, counters
.razorings
, counters
.futility_prunings
,
142 counters
.pawn_hash_evaluations
, counters
.transposition
,
143 counters
.evaluations
, ((double) counters
.lazy_evaluations
/ counters
.evaluations
) * 100, GAME_PHASE
);
146 /* if it's engine's turn to move we should search */
148 process_turn(void *args
)
152 char buf
[MAX_STRING
];
154 move_from_book
= TRUE
;
159 move_from_book
= FALSE
;
160 set_engine_value(&e
.thinking
, TRUE
);
162 set_engine_value(&e
.thinking
, FALSE
);
167 fprintf(stdout
, "resign\n");
168 if (get_engine_value(&e
.side
) == WHITE
)
169 fprintf(stdout
, "0-1 {WHITE resigns}\n");
171 fprintf(stdout
, "1-0 {BLACK resigns}\n");
172 set_engine_value(&e
.side
, NOBODY
);
174 /* free resources after termination */
175 pthread_detach(pthread_self());
180 if (!move
|| evaluate_draw() || reps() >= 3) {
181 if (evaluate_draw()) {
182 if (brd
.fifty_rule
>= 100)
183 fprintf(stdout
, "1/2-1/2 {Fifty move rule}\n");
185 fprintf(stdout
, "1/2-1/2 {draw}\n");
186 } else if (reps() >= 3)
187 fprintf(stdout
, "1/2-1/2 {draw by repetition}\n");
188 else if (IS_CHECKED(WHITE
))
189 fprintf(stdout
, "0-1 {BLACK mates}\n");
190 else if (IS_CHECKED(BLACK
))
191 fprintf(stdout
, "1-0 {WHITE mates}\n");
193 fprintf(stdout
, "1/2-1/2 {Stalemate}\n");
194 set_engine_value(&e
.side
, NOBODY
);
196 if (get_engine_value(&e
.san_notation
) || \
197 !get_engine_value(&e
.xboard_mode
)) {
199 make_move(move
, FALSE
);
200 fprintf(stdout
, "move %s\n", buf
);
202 make_move(move
, FALSE
);
203 fprintf(stdout
, "move %s\n", coord_move(move
, buf
));
206 if (!get_engine_value(&e
.xboard_mode
) && !move_from_book
)
207 fprintf(stdout
, "[%s]$ ", program_name
);
209 /* free resources after termination */
210 pthread_detach(pthread_self());
218 pthread_mutex_init(&e
.mutex
, 0);
220 set_engine_value(&e
.side
, NOBODY
);
221 set_engine_value(&e
.force_mode
, TRUE
);
222 set_engine_value(&e
.post_mode
, FALSE
);
223 set_engine_value(&e
.xboard_mode
, FALSE
);
224 set_engine_value(&e
.san_notation
, FALSE
);
226 /* set small limits for quick testing */
227 set_engine_value(&e
.max_depth
, 9);
228 set_engine_value(&e
.max_time
, 10000);
229 set_engine_value(&e
.inc_time
, 0);
231 /* check if we should abort search every 1024 nodes */
232 set_engine_value(&e
.chk_time
, 1023);
234 /* use 1/30 of total time for thinking */
235 set_engine_value(&e
.time_div
, 30);
237 set_engine_value(&e
.fixed_time
, FALSE
);
238 set_engine_value((int *)&e
.stop_time
, 0);
239 set_engine_value((int *)&e
.max_stop_time
, 0);
241 /* if FALSE we are playing to mate */
242 set_engine_value(&e
.resign
, TRUE
);
243 set_engine_value(&e
.resign_value
, -600);
245 /* if EPD tests are currently running */
246 set_engine_value(&e
.thinking
, FALSE
);
249 set_engine_value(&e
.delta_pruning
, TRUE
);
250 set_engine_value(&e
.futility_pruning
, TRUE
);
251 set_engine_value(&e
.iid
, TRUE
);
252 set_engine_value(&e
.null_pruning
, TRUE
);
253 set_engine_value(&e
.lmr
, TRUE
);
254 set_engine_value(&e
.razoring
, TRUE
);
256 /* used to calculate 'game phase' */
257 set_engine_value(&e
.phase_factor
, (piece_value
[KNIGHT
] * 2 + \
258 piece_value
[BISHOP
] * 2 + piece_value
[ROOK
] * 2 + \
259 piece_value
[QUEEN
]) / 128);
263 /* initialize hashtable */
264 e
.pawn_hash_size
= 2;
265 e
.main_hash_size
= 16;
266 e
.pawn_hash_enabled
= TRUE
;
267 e
.main_hash_enabled
= TRUE
;
269 book_open(book_file_name
);
274 void perform_cleanup(void)
277 if (get_engine_value(&e
.pawn_hash_enabled
))
278 free_pawn_hashtable();
280 /* destroy engine mutex */
281 pthread_mutex_destroy(&e
.mutex
);
283 /* close book file descriptor */