From 95e09d4d4ff4fa122ef3a83948ce0efd09697a82 Mon Sep 17 00:00:00 2001
From: Francois van Niekerk <flash.slash@gmail.com>
Date: Tue, 7 Dec 2010 02:53:37 +0100
Subject: [PATCH] With TD_GAMES, perform an exact number of playouts

Patch by Francois, some enhancements by Pasky.
---
 uct/search.c |  6 ++++--
 uct/search.h |  1 +
 uct/uct.c    |  2 ++
 uct/walk.c   | 11 ++++++++---
 uct/walk.h   |  2 +-
 5 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/uct/search.c b/uct/search.c
index 0edbdc3..3e4e8e0 100644
--- a/uct/search.c
+++ b/uct/search.c
@@ -86,7 +86,7 @@ spawn_worker(void *ctx_)
 	/* Setup */
 	fast_srandom(ctx->seed);
 	/* Run */
-	ctx->games = uct_playouts(ctx->u, ctx->b, ctx->color, ctx->t);
+	ctx->games = uct_playouts(ctx->u, ctx->b, ctx->color, ctx->t, ctx->ti);
 	/* Finish */
 	pthread_mutex_lock(&finish_serializer);
 	pthread_mutex_lock(&finish_mutex);
@@ -130,6 +130,7 @@ spawn_thread_manager(void *ctx_)
 		ctx->u = u; ctx->b = mctx->b; ctx->color = mctx->color;
 		mctx->t = ctx->t = t;
 		ctx->tid = ti; ctx->seed = fast_random(65536) + ti;
+		ctx->ti = mctx->ti;
 		pthread_create(&threads[ti], NULL, spawn_worker, ctx);
 		if (UDEBUGL(3))
 			fprintf(stderr, "Spawned worker %d\n", ti);
@@ -193,7 +194,7 @@ uct_search_start(struct uct *u, struct board *b, enum stone color,
 	assert(u->threads > 0);
 	assert(!thread_manager_running);
 	static struct uct_thread_ctx mctx;
-	mctx = (struct uct_thread_ctx) { .u = u, .b = b, .color = color, .t = t, .seed = fast_random(65536) };
+	mctx = (struct uct_thread_ctx) { .u = u, .b = b, .color = color, .t = t, .seed = fast_random(65536), .ti = ti };
 	s->ctx = &mctx;
 	pthread_mutex_lock(&finish_mutex);
 	pthread_create(&thread_manager, NULL, spawn_thread_manager, s->ctx);
@@ -384,6 +385,7 @@ uct_search_check_stop(struct uct *u, struct board *b, enum stone color,
 	 * time pressure but the tree is going to be just too messed
 	 * up otherwise - we might even play invalid suicides or pass
 	 * when we mustn't. */
+	assert(!(ti->dim == TD_GAMES && ti->len.games < GJ_MINGAMES));
 	if (i < GJ_MINGAMES)
 		return false;
 
diff --git a/uct/search.h b/uct/search.h
index 732d2ed..e9757af 100644
--- a/uct/search.h
+++ b/uct/search.h
@@ -40,6 +40,7 @@ struct uct_thread_ctx {
 	struct tree *t;
 	unsigned long seed;
 	int games;
+	struct time_info *ti;
 };
 
 
diff --git a/uct/uct.c b/uct/uct.c
index 09d5764..4088dbd 100644
--- a/uct/uct.c
+++ b/uct/uct.c
@@ -297,6 +297,8 @@ uct_search(struct uct *u, struct board *b, struct time_info *ti, enum stone colo
 	 * thread manager will swap the tree pointer asynchronously. */
 
 	/* Now, just periodically poll the search tree. */
+	/* Note that in case of TD_GAMES, threads will terminate independently
+	 * of the uct_search_check_stop() signalization. */
 	while (1) {
 		time_sleep(TREE_BUSYWAIT_INTERVAL);
 		/* TREE_BUSYWAIT_INTERVAL should never be less than desired time, or the
diff --git a/uct/walk.c b/uct/walk.c
index 93cf127..3d80bc7 100644
--- a/uct/walk.c
+++ b/uct/walk.c
@@ -503,10 +503,15 @@ end:
 }
 
 int
-uct_playouts(struct uct *u, struct board *b, enum stone color, struct tree *t)
+uct_playouts(struct uct *u, struct board *b, enum stone color, struct tree *t, struct time_info *ti)
 {
 	int i;
-	for (i = 0; !uct_halt; i++)
-		uct_playout(u, b, color, t);
+	if (ti->dim == TD_GAMES) {
+		for (i = 0; t->root->u.playouts <= ti->len.games; i++)
+			uct_playout(u, b, color, t);
+	} else {
+		for (i = 0; !uct_halt; i++)
+			uct_playout(u, b, color, t);
+	}
 	return i;
 }
diff --git a/uct/walk.h b/uct/walk.h
index a20e38b..fe7e38e 100644
--- a/uct/walk.h
+++ b/uct/walk.h
@@ -10,6 +10,6 @@ struct board;
 void uct_progress_status(struct uct *u, struct tree *t, enum stone color, int playouts);
 
 int uct_playout(struct uct *u, struct board *b, enum stone player_color, struct tree *t);
-int uct_playouts(struct uct *u, struct board *b, enum stone color, struct tree *t);
+int uct_playouts(struct uct *u, struct board *b, enum stone color, struct tree *t, struct time_info *ti);
 
 #endif
-- 
2.11.4.GIT