static coord_t *
random_genmove(struct engine *e, struct board *b, struct time_info *ti, enum stone color, bool pass_all_alive)
{
/* Play a random coordinate. However, we must also guard
* against suicide moves; repeat playing while it's a suicide
* unless we keep suiciding; in that case, we probably don't
* have any other moves available and we pass. */
coord_t coord;
int i = 0; bool suicide = false;
do {
/* board_play_random() actually plays the move too;
* this is desirable for MC simulations but not within
* the genmove. Make a scratch new board for it. */
struct board b2;
board_copy(&b2, b);
board_play_random(&b2, color, &coord, NULL, NULL);
suicide = (coord != pass && !group_at(&b2, coord));
board_done_noalloc(&b2);
} while (suicide && i++ < 100);
return coord_copy(suicide ? pass : coord);
}
void
board_done(struct board *board)
{
board_done_noalloc(board);
free(board);
}
int
uct_playout(struct uct *u, struct board *b, enum stone player_color, struct tree *t)
{
struct board b2;
board_copy(&b2, b);
struct playout_amafmap amaf;
amaf.gamelen = amaf.game_baselen = 0;
/* Walk the tree until we find a leaf, then expand it and do
* a random playout. */
struct tree_node *n = t->root;
enum stone node_color = stone_other(player_color);
assert(node_color == t->root_color);
/* Make sure the root node is expanded. */
if (tree_leaf_node(n) && !__sync_lock_test_and_set(&n->is_expanded, 1))
tree_expand_node(t, n, &b2, player_color, u, 1);
/* Tree descent history. */
/* XXX: This is somewhat messy since @n and descent[dlen-1].node are
* redundant. */
struct uct_descent descent[DESCENT_DLEN];
descent[0].node = n; descent[0].lnode = NULL;
int dlen = 1;
/* Total value of the sequence. */
struct move_stats seq_value = { .playouts = 0 };
/* The last "significant" node along the descent (i.e. node
* with higher than configured number of playouts). For black
* and white. */
struct tree_node *significant[2] = { NULL, NULL };
if (n->u.playouts >= u->significant_threshold)
significant[node_color - 1] = n;
int result;
int pass_limit = (board_size(&b2) - 2) * (board_size(&b2) - 2) / 2;
int passes = is_pass(b->last_move.coord) && b->moves > 0;
/* debug */
static char spaces[] = "\0 ";
/* /debug */
if (UDEBUGL(8))
fprintf(stderr, "--- UCT walk with color %d\n", player_color);
while (!tree_leaf_node(n) && passes < 2) {
spaces[dlen - 1] = ' '; spaces[dlen] = 0;
/*** Choose a node to descend to: */
/* Parity is chosen already according to the child color, since
* it is applied to children. */
node_color = stone_other(node_color);
int parity = (node_color == player_color ? 1 : -1);
assert(dlen < DESCENT_DLEN);
descent[dlen] = descent[dlen - 1];
if (u->local_tree && (!descent[dlen].lnode || descent[dlen].node->d >= u->tenuki_d)) {
/* Start new local sequence. */
/* Remember that node_color already holds color of the
* to-be-found child. */
descent[dlen].lnode = node_color == S_BLACK ? t->ltree_black : t->ltree_white;
}
if (!u->random_policy_chance || fast_random(u->random_policy_chance))
u->policy->descend(u->policy, t, &descent[dlen], parity, b2.moves > pass_limit);
else
u->random_policy->descend(u->random_policy, t, &descent[dlen], parity, b2.moves > pass_limit);
/*** Perform the descent: */
if (descent[dlen].node->u.playouts >= u->significant_threshold) {
significant[node_color - 1] = descent[dlen].node;
}
seq_value.playouts += descent[dlen].value.playouts;
seq_value.value += descent[dlen].value.value * descent[dlen].value.playouts;
n = descent[dlen++].node;
assert(n == t->root || n->parent);
if (UDEBUGL(7))
fprintf(stderr, "%s+-- UCT sent us to [%s:%d] %d,%f\n",
spaces, coord2sstr(node_coord(n), t->board),
node_coord(n), n->u.playouts,
tree_node_get_value(t, parity, n->u.value));
/* Add virtual loss if we need to; this is used to discourage
* other threads from visiting this node in case of multiple
* threads doing the tree search. */
if (u->virtual_loss)
stats_add_result(&n->u, node_color == S_BLACK ? 0.0 : 1.0, u->virtual_loss);
assert(node_coord(n) >= -1);
record_amaf_move(&amaf, node_coord(n));
struct move m = { node_coord(n), node_color };
int res = board_play(&b2, &m);
if (res < 0 || (!is_pass(m.coord) && !group_at(&b2, m.coord)) /* suicide */
|| b2.superko_violation) {
if (UDEBUGL(4)) {
for (struct tree_node *ni = n; ni; ni = ni->parent)
fprintf(stderr, "%s<%"PRIhash"> ", coord2sstr(node_coord(ni), t->board), ni->hash);
fprintf(stderr, "marking invalid %s node %d,%d res %d group %d spk %d\n",
stone2str(node_color), coord_x(node_coord(n),b), coord_y(node_coord(n),b),
res, group_at(&b2, m.coord), b2.superko_violation);
}
n->hints |= TREE_HINT_INVALID;
result = 0;
goto end;
}
if (is_pass(node_coord(n)))
passes++;
else
passes = 0;
enum stone next_color = stone_other(node_color);
/* We need to make sure only one thread expands the node. If
* we are unlucky enough for two threads to meet in the same
* node, the latter one will simply do another simulation from
* the node itself, no big deal. t->nodes_size may exceed
* the maximum in multi-threaded case but not by much so it's ok.
* The size test must be before the test&set not after, to allow
* expansion of the node later if enough nodes have been freed. */
if (tree_leaf_node(n)
&& n->u.playouts - u->virtual_loss >= u->expand_p && t->nodes_size < u->max_tree_size
&& !__sync_lock_test_and_set(&n->is_expanded, 1))
tree_expand_node(t, n, &b2, next_color, u, -parity);
}
amaf.game_baselen = amaf.gamelen;
if (t->use_extra_komi && u->dynkomi->persim) {
b2.komi += round(u->dynkomi->persim(u->dynkomi, &b2, t, n));
}
if (passes >= 2) {
/* XXX: No dead groups support. */
floating_t score = board_official_score(&b2, NULL);
/* Result from black's perspective (no matter who
* the player; black's perspective is always
* what the tree stores. */
result = - (score * 2);
if (UDEBUGL(5))
fprintf(stderr, "[%d..%d] %s p-p scoring playout result %d (W %f)\n",
player_color, node_color, coord2sstr(node_coord(n), t->board), result, score);
if (UDEBUGL(6))
board_print(&b2, stderr);
board_ownermap_fill(&u->ownermap, &b2);
} else { // assert(tree_leaf_node(n));
/* In case of parallel tree search, the assertion might
* not hold if two threads chew on the same node. */
result = uct_leaf_node(u, &b2, player_color, &amaf, descent, &dlen, significant, t, n, node_color, spaces);
}
if (u->policy->wants_amaf && u->playout_amaf_cutoff) {
unsigned int cutoff = amaf.game_baselen;
cutoff += (amaf.gamelen - amaf.game_baselen) * u->playout_amaf_cutoff / 100;
amaf.gamelen = cutoff;
}
/* Record the result. */
assert(n == t->root || n->parent);
floating_t rval = scale_value(u, b, result);
u->policy->update(u->policy, t, n, node_color, player_color, &amaf, &b2, rval);
if (t->use_extra_komi) {
stats_add_result(&u->dynkomi->score, result / 2, 1);
stats_add_result(&u->dynkomi->value, rval, 1);
}
if (u->local_tree && n->parent && !is_pass(node_coord(n)) && dlen > 0) {
/* Get the local sequences and record them in ltree. */
/* We will look for sequence starts in our descent
* history, then run record_local_sequence() for each
* found sequence start; record_local_sequence() may
* pick longer sequences from descent history then,
* which is expected as it will create new lnodes. */
enum stone seq_color = player_color;
/* First move always starts a sequence. */
record_local_sequence(u, t, &b2, descent, dlen, 1, seq_color);
seq_color = stone_other(seq_color);
for (int dseqi = 2; dseqi < dlen; dseqi++, seq_color = stone_other(seq_color)) {
if (u->local_tree_allseq) {
/* We are configured to record all subsequences. */
record_local_sequence(u, t, &b2, descent, dlen, dseqi, seq_color);
continue;
}
if (descent[dseqi].node->d >= u->tenuki_d) {
/* Tenuki! Record the fresh sequence. */
record_local_sequence(u, t, &b2, descent, dlen, dseqi, seq_color);
continue;
}
if (descent[dseqi].lnode && !descent[dseqi].lnode) {
/* Record result for in-descent picked sequence. */
record_local_sequence(u, t, &b2, descent, dlen, dseqi, seq_color);
continue;
}
}
}
end:
/* We need to undo the virtual loss we added during descend. */
if (u->virtual_loss) {
floating_t loss = node_color == S_BLACK ? 0.0 : 1.0;
for (; n->parent; n = n->parent) {
stats_rm_result(&n->u, loss, u->virtual_loss);
loss = 1.0 - loss;
}
}
board_done_noalloc(&b2);
return result;
}
int
uct_playouts(struct uct *u, struct board *b, enum stone color, struct tree *t, struct time_info *ti)
{
int i;
if (ti && ti->dim == TD_GAMES) {
for (i = 0; t->root->u.playouts <= ti->len.games && !uct_halt; i++)
uct_playout(u, b, color, t);
} else {
for (i = 0; !uct_halt; i++)
uct_playout(u, b, color, t);
}
return i;
}
static coord_t *
montecarlo_genmove(struct engine *e, struct board *b, struct time_info *ti, enum stone color, bool pass_all_alive)
{
struct montecarlo *mc = e->data;
if (ti->dim == TD_WALLTIME) {
fprintf(stderr, "Warning: TD_WALLTIME time mode not supported, resetting to defaults.\n");
ti->period = TT_NULL;
}
if (ti->period == TT_NULL) {
ti->period = TT_MOVE;
ti->dim = TD_GAMES;
ti->len.games = MC_GAMES;
}
struct time_stop stop;
time_stop_conditions(ti, b, 20, 40, 3.0, &stop);
/* resign when the hope for win vanishes */
coord_t top_coord = resign;
floating_t top_ratio = mc->resign_ratio;
/* We use [0] for pass. Normally, this is an inaccessible corner
* of board margin. */
struct move_stat moves[board_size2(b)];
memset(moves, 0, sizeof(moves));
int losses = 0;
int i, superko = 0, good_games = 0;
for (i = 0; i < stop.desired.playouts; i++) {
assert(!b->superko_violation);
struct board b2;
board_copy(&b2, b);
coord_t coord;
board_play_random(&b2, color, &coord, NULL, NULL);
if (!is_pass(coord) && !group_at(&b2, coord)) {
/* Multi-stone suicide. We play chinese rules,
* so we can't consider this. (Note that we
* unfortunately still consider this in playouts.) */
if (DEBUGL(4)) {
fprintf(stderr, "SUICIDE DETECTED at %d,%d:\n", coord_x(coord, b), coord_y(coord, b));
board_print(b, stderr);
}
continue;
}
if (DEBUGL(3))
fprintf(stderr, "[%d,%d color %d] playing random game\n", coord_x(coord, b), coord_y(coord, b), color);
struct playout_setup ps = { .gamelen = mc->gamelen };
int result = play_random_game(&ps, &b2, color, NULL, NULL, mc->playout);
board_done_noalloc(&b2);
if (result == 0) {
/* Superko. We just ignore this playout.
* And play again. */
if (unlikely(superko > 2 * stop.desired.playouts)) {
/* Uhh. Triple ko, or something? */
if (MCDEBUGL(0))
fprintf(stderr, "SUPERKO LOOP. I will pass. Did we hit triple ko?\n");
goto pass_wins;
}
/* This playout didn't count; we should not
* disadvantage moves that lead to a superko.
* And it is supposed to be rare. */
i--, superko++;
continue;
}
if (MCDEBUGL(3))
fprintf(stderr, "\tresult for other player: %d\n", result);
int pos = is_pass(coord) ? 0 : coord;
good_games++;
moves[pos].games++;
losses += result > 0;
moves[pos].wins += 1 - (result > 0);
if (unlikely(!losses && i == mc->loss_threshold)) {
/* We played out many games and didn't lose once yet.
* This game is over. */
break;
}
}
if (!good_games) {
/* No moves to try??? */
if (MCDEBUGL(0)) {
fprintf(stderr, "OUT OF MOVES! I will pass. But how did this happen?\n");
board_print(b, stderr);
}
pass_wins:
top_coord = pass; top_ratio = 0.5;
goto move_found;
}
foreach_point(b) {
if (b->moves < 3) {
/* Simple heuristic: avoid opening too low. Do not
* play on second or first line as first white or
* first two black moves.*/
if (coord_x(c, b) < 3 || coord_x(c, b) > board_size(b) - 4
|| coord_y(c, b) < 3 || coord_y(c, b) > board_size(b) - 4)
continue;
}
floating_t ratio = (floating_t) moves[c].wins / moves[c].games;
/* Since pass is [0,0], we will pass only when we have nothing
* better to do. */
if (ratio >= top_ratio) {
top_ratio = ratio;
top_coord = c == 0 ? pass : c;
}
} foreach_point_end;
if (MCDEBUGL(2)) {
board_stats_print(b, moves, stderr);
}
move_found:
if (MCDEBUGL(1))
fprintf(stderr, "*** WINNER is %d,%d with score %1.4f (%d games, %d superko)\n", coord_x(top_coord, b), coord_y(top_coord, b), top_ratio, i, superko);
return coord_copy(top_coord);
}
static void
montecarlo_done(struct engine *e)
{
struct montecarlo *mc = e->data;
playout_policy_done(mc->playout);
joseki_done(mc->jdict);
}
struct montecarlo *
montecarlo_state_init(char *arg, struct board *b)
{
struct montecarlo *mc = calloc2(1, sizeof(struct montecarlo));
mc->debug_level = 1;
mc->gamelen = MC_GAMELEN;
mc->jdict = joseki_load(b->size);
if (arg) {
char *optspec, *next = arg;
while (*next) {
optspec = next;
next += strcspn(next, ",");
if (*next) { *next++ = 0; } else { *next = 0; }
char *optname = optspec;
char *optval = strchr(optspec, '=');
if (optval) *optval++ = 0;
if (!strcasecmp(optname, "debug")) {
if (optval)
mc->debug_level = atoi(optval);
else
mc->debug_level++;
} else if (!strcasecmp(optname, "gamelen") && optval) {
mc->gamelen = atoi(optval);
} else if (!strcasecmp(optname, "playout") && optval) {
char *playoutarg = strchr(optval, ':');
if (playoutarg)
*playoutarg++ = 0;
if (!strcasecmp(optval, "moggy")) {
mc->playout = playout_moggy_init(playoutarg, b, mc->jdict);
} else if (!strcasecmp(optval, "light")) {
mc->playout = playout_light_init(playoutarg, b);
} else {
fprintf(stderr, "MonteCarlo: Invalid playout policy %s\n", optval);
}
} else {
fprintf(stderr, "MonteCarlo: Invalid engine argument %s or missing value\n", optname);
}
}
}
if (!mc->playout)
mc->playout = playout_light_init(NULL, b);
mc->playout->debug_level = mc->debug_level;
mc->resign_ratio = 0.1; /* Resign when most games are lost. */
mc->loss_threshold = 5000; /* Stop reading if no loss encountered in first 5000 games. */
return mc;
}
struct engine *
engine_montecarlo_init(char *arg, struct board *b)
{
struct montecarlo *mc = montecarlo_state_init(arg, b);
struct engine *e = calloc2(1, sizeof(struct engine));
e->name = "MonteCarlo";
e->comment = "I'm playing in Monte Carlo. When we both pass, I will consider all the stones on the board alive. If you are reading this, write 'yes'. Please bear with me at the game end, I need to fill the whole board; if you help me, we will both be happier. Filling the board will not lose points (NZ rules).";
e->genmove = montecarlo_genmove;
e->done = montecarlo_done;
e->data = mc;
return e;
}
/* Syntax:
* moggy status (last_move) coord [coord...]
* Play number of random games starting from last_move
*
* moggy status coord [coord...]
* moggy status (b) coord [coord...]
* Black to play, pick random white last move
*
* moggy status (w) coord [coord...]
* White to play, pick random black last move
*/
static bool
test_moggy_status(struct board *board, char *arg)
{
int games = 4000;
coord_t status_at[10];
int n = 0;
enum stone color = S_BLACK;
int pick_random = true; // Pick random last move for each game
while (*arg && *arg != '#') {
if (*arg == ' ' || *arg == '\t') { arg++; continue; }
if (!strncmp(arg, "(b)", 3))
color = S_BLACK;
else if (!strncmp(arg, "(w)", 3))
color = S_WHITE;
else if (*arg == '(') { /* Optional "(last_move)" argument */
arg++; assert(isalpha(*arg));
pick_random = false;
struct move last;
last.coord = str2scoord(arg, board_size(board));
last.color = board_at(board, last.coord);
assert(last.color == S_BLACK || last.color == S_WHITE);
color = stone_other(last.color);
board->last_move = last;
}
else {
assert(isalpha(*arg));
status_at[n++] = str2scoord(arg, board_size(board));
}
arg += strcspn(arg, " \t");
}
board_print(board, stderr);
if (DEBUGL(1)) {
printf("moggy status ");
for (int i = 0; i < n; i++)
printf("%s%s", coord2sstr(status_at[i], board), (i != n-1 ? " " : ""));
printf(", %s to play. Playing %i games %s...\n",
stone2str(color), games, (pick_random ? "(random last move) " : ""));
}
struct playout_policy *policy = playout_moggy_init(NULL, board, NULL);
struct playout_setup setup = { .gamelen = MAX_GAMELEN };
struct board_ownermap ownermap;
ownermap.playouts = 0;
ownermap.map = malloc2(board_size2(board) * sizeof(ownermap.map[0]));
memset(ownermap.map, 0, board_size2(board) * sizeof(ownermap.map[0]));
/* Get final status estimate after a number of moggy games */
int wr = 0;
double time_start = time_now();
for (int i = 0; i < games; i++) {
struct board b;
board_copy(&b, board);
if (pick_random)
pick_random_last_move(&b, color);
int score = play_random_game(&setup, &b, color, NULL, &ownermap, policy);
if (color == S_WHITE)
score = -score;
wr += (score > 0);
board_done_noalloc(&b);
}
double elapsed = time_now() - time_start;
printf("moggy status in %.1fs, %i games/s\n\n", elapsed, (int)((float)games / elapsed));
int wr_black = wr * 100 / games;
int wr_white = (games - wr) * 100 / games;
if (wr_black > wr_white)
printf("Winrate: [ black %i%% ] white %i%%\n\n", wr_black, wr_white);
else
printf("Winrate: black %i%% [ white %i%% ]\n\n", wr_black, wr_white);
board_print_ownermap(board, stderr, &ownermap);
for (int i = 0; i < n; i++) {
coord_t c = status_at[i];
enum stone color = (ownermap.map[c][S_BLACK] > ownermap.map[c][S_WHITE] ? S_BLACK : S_WHITE);
fprintf(stderr, "%3s owned by %s: %i%%\n",
coord2sstr(c, board), stone2str(color),
ownermap.map[c][color] * 100 / ownermap.playouts);
}
free(ownermap.map);
playout_policy_done(policy);
return true; // Not much of a unit test right now =)
}
