From e671a4c0a71f984a97c48a975baf012335e51650 Mon Sep 17 00:00:00 2001
From: Jean-loup Gailly <jloup@gailly.net>
Date: Thu, 11 Mar 2010 17:08:49 +0100
Subject: [PATCH] Distributed master sends time info to slaves in genmoves
 command.

---
 distributed/distributed.c | 25 +++++++++++++++++++++----
 gtp.c                     | 16 +++++++++++-----
 2 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/distributed/distributed.c b/distributed/distributed.c
index 870dad5..6653170 100644
--- a/distributed/distributed.c
+++ b/distributed/distributed.c
@@ -514,20 +514,37 @@ distributed_genmove(struct engine *e, struct board *b, struct time_info *ti, enu
 	long time_limit = 0;
 	int min_playouts = 0;
 
+	char *cmd = pass_all_alive ? "pachi-genmoves_cleanup" : "pachi-genmoves";
+	char args[128];
+
 	if (ti->period == TT_NULL) *ti = default_ti;
 	struct time_stop stop;
 	time_stop_conditions(ti, b, FUSEKI_END, YOSE_START, &stop);
+
 	if (ti->dim == TD_WALLTIME) {
 		time_limit = ti->len.t.timer_start + stop.worst.time;
+
+		/* Send time info to the slaves to make sure they all
+		 * reply in time, particularly if they were out of sync
+		 * and there are no time_left commands. We cannot send
+		 * the absolute time limit because slaves may have a
+		 * different system time.
+		 * Keep this code in sync with gtp_parse(). */
+		snprintf(args, sizeof(args), "%s %.3f %.3f %d %d\n",
+			 stone2str(color), ti->len.t.main_time,
+			 ti->len.t.byoyomi_time, ti->len.t.byoyomi_periods,
+			 ti->len.t.byoyomi_stones);
 	} else {
 		min_playouts = stop.desired.playouts;
+
+		/* For absolute number of simulations, slaves still
+		 * use their own -t =NUM parameter. (The master
+		 * needs to know the total number of simulations over
+		 * all slaves so it has a different -t parameter.) */
+		snprintf(args, sizeof(args), "%s\n", stone2str(color));
 	}
 
 	pthread_mutex_lock(&slave_lock);
-
-	char *cmd = pass_all_alive ? "pachi-genmoves_cleanup" : "pachi-genmoves";
-	char args[64];
-	snprintf(args, sizeof(args), "%s\n", stone2str(color));
 	new_cmd(b, cmd, args);
 
 	get_replies(time_limit, min_playouts, b);
diff --git a/gtp.c b/gtp.c
index 986de0b..643177c 100644
--- a/gtp.c
+++ b/gtp.c
@@ -252,8 +252,18 @@ gtp_parse(struct board *board, struct engine *engine, struct time_info *ti, char
 		char *arg;
 		next_tok(arg);
 		enum stone color = str2stone(arg);
+		struct time_info *myti = &ti[color];
+		/* Get correct time from master. Keep this code in sync
+		 * with distributed_genmove(). */
+		if (myti->dim == TD_WALLTIME &&
+		    sscanf(next, "%lf %lf %d %d", &myti->len.t.main_time,
+			   &myti->len.t.byoyomi_time, &myti->len.t.byoyomi_periods,
+			   &myti->len.t.byoyomi_stones) != 4) {
+			gtp_error(id, "incorrect time info", NULL);
+			return P_OK;
+		}
 
-		char *reply = engine->genmoves(engine, board, &ti[color], color, !strcasecmp(cmd, "pachi-genmoves_cleanup"));
+		char *reply = engine->genmoves(engine, board, myti, color, !strcasecmp(cmd, "pachi-genmoves_cleanup"));
 		if (DEBUGL(2))
 			fprintf(stderr, "proposing moves %s\n", reply);
 		if (DEBUGL(1)) {
@@ -261,10 +271,6 @@ gtp_parse(struct board *board, struct engine *engine, struct time_info *ti, char
 		}
 		gtp_reply(id, reply, NULL);
 
-		/* See "genmove" above about time management. */
-		if (ti[color].period != TT_NULL && ti[color].dim == TD_WALLTIME)
-			time_sub(&ti[color], time_now() - ti[color].len.t.timer_start);
-
 	} else if (!strcasecmp(cmd, "set_free_handicap")) {
 		struct move m;
 		m.color = S_BLACK;
-- 
2.11.4.GIT