From 77ba250597e73ffc192e376527b9a2a3afe75a7c Mon Sep 17 00:00:00 2001
From: Jean-loup Gailly <jloup@gailly.net>
Date: Wed, 10 Mar 2010 23:41:06 +0100
Subject: [PATCH] board_print_custom: construct a string and print it in one
 step to minimize race conditions.

---
 board.c   | 76 ++++++++++++++++++++++++++++++++++-----------------------------
 board.h   |  2 +-
 uct/uct.c |  7 +++---
 3 files changed, 46 insertions(+), 39 deletions(-)

diff --git a/board.c b/board.c
index 1134cd2..48428c3 100644
--- a/board.c
+++ b/board.c
@@ -328,77 +328,83 @@ board_clear(struct board *board)
 #endif
 }
 
-
-static void
-board_print_top(struct board *board, FILE *f, int c)
+static char *
+board_print_top(struct board *board, char *s, char *end, int c)
 {
 	for (int i = 0; i < c; i++) {
 		char asdf[] = "ABCDEFGHJKLMNOPQRSTUVWXYZ";
-		fprintf(f, "      ");
+		s += snprintf(s, end - s, "      ");
 		for (int x = 1; x < board_size(board) - 1; x++)
-			fprintf(f, "%c ", asdf[x - 1]);
-		fprintf(f, " ");
+			s += snprintf(s, end - s, "%c ", asdf[x - 1]);
+		s += snprintf(s, end -s, " ");
 	}
-	fprintf(f, "\n");
+	s += snprintf(s, end - s, "\n");
 	for (int i = 0; i < c; i++) {
-		fprintf(f, "    +-");
+		s += snprintf(s, end - s, "    +-");
 		for (int x = 1; x < board_size(board) - 1; x++)
-			fprintf(f, "--");
-		fprintf(f, "+");
+			s += snprintf(s, end - s, "--");
+		s += snprintf(s, end - s, "+");
 	}
-	fprintf(f, "\n");
+	s += snprintf(s, end - s, "\n");
+	return s;
 }
 
-static void
-board_print_bottom(struct board *board, FILE *f, int c)
+static char *
+board_print_bottom(struct board *board, char *s, char *end, int c)
 {
 	for (int i = 0; i < c; i++) {
-		fprintf(f, "    +-");
+		s += snprintf(s, end - s, "    +-");
 		for (int x = 1; x < board_size(board) - 1; x++)
-			fprintf(f, "--");
-		fprintf(f, "+");
+			s += snprintf(s, end - s, "--");
+		s += snprintf(s, end - s, "+");
 	}
-	fprintf(f, "\n");
+	s += snprintf(s, end - s, "\n");
+	return s;
 }
 
-static void
-board_print_row(struct board *board, int y, FILE *f, board_cprint cprint)
+static char *
+board_print_row(struct board *board, int y, char *s, char *end, board_cprint cprint)
 {
-	fprintf(f, " %2d | ", y);
+	s += snprintf(s, end - s, " %2d | ", y);
 	for (int x = 1; x < board_size(board) - 1; x++) {
 		if (coord_x(board->last_move.coord, board) == x && coord_y(board->last_move.coord, board) == y)
-			fprintf(f, "%c)", stone2char(board_atxy(board, x, y)));
+			s += snprintf(s, end - s, "%c)", stone2char(board_atxy(board, x, y)));
 		else
-			fprintf(f, "%c ", stone2char(board_atxy(board, x, y)));
+			s += snprintf(s, end - s, "%c ", stone2char(board_atxy(board, x, y)));
 	}
-	fprintf(f, "|");
+	s += snprintf(s, end - s, "|");
 	if (cprint) {
-		fprintf(f, " %2d | ", y);
+		s += snprintf(s, end - s, " %2d | ", y);
 		for (int x = 1; x < board_size(board) - 1; x++) {
-			cprint(board, coord_xy(board, x, y), f);
+			s = cprint(board, coord_xy(board, x, y), s, end);
 		}
-		fprintf(f, "|");
+		s += snprintf(s, end - s, "|");
 	}
-	fprintf(f, "\n");
+	s += snprintf(s, end - s, "\n");
+	return s;
 }
 
 void
 board_print_custom(struct board *board, FILE *f, board_cprint cprint)
 {
-	fprintf(f, "Move: % 3d  Komi: %2.1f  Handicap: %d  Captures B: %d W: %d\n",
+	char buf[10240];
+	char *s = buf;
+	char *end = buf + sizeof(buf);
+	s += snprintf(s, end - s, "Move: % 3d  Komi: %2.1f  Handicap: %d  Captures B: %d W: %d\n",
 		board->moves, board->komi, board->handicap,
 		board->captures[S_BLACK], board->captures[S_WHITE]);
-	board_print_top(board, f, 1 + !!cprint);
+	s = board_print_top(board, s, end, 1 + !!cprint);
 	for (int y = board_size(board) - 2; y >= 1; y--)
-		board_print_row(board, y, f, cprint);
-	board_print_bottom(board, f, 1 + !!cprint);
-	fprintf(f, "\n");
+		s = board_print_row(board, y, s, end, cprint);
+	board_print_bottom(board, s, end, 1 + !!cprint);
+	fprintf(f, "%s\n", buf);
 }
 
-static void
-cprint_group(struct board *board, coord_t c, FILE *f)
+static char *
+cprint_group(struct board *board, coord_t c, char *s, char *end)
 {
-	fprintf(f, "%d ", group_base(group_at(board, c)));
+	s += snprintf(s, end - s, "%d ", group_base(group_at(board, c)));
+	return s;
 }
 
 void
diff --git a/board.h b/board.h
index bc2e0bd..8003069 100644
--- a/board.h
+++ b/board.h
@@ -274,7 +274,7 @@ void board_resize(struct board *board, int size);
 void board_clear(struct board *board);
 
 struct FILE;
-typedef void (*board_cprint)(struct board *b, coord_t c, FILE *f);
+typedef char *(*board_cprint)(struct board *b, coord_t c, char *s, char *end);
 void board_print(struct board *board, FILE *f);
 void board_print_custom(struct board *board, FILE *f, board_cprint cprint);
 
diff --git a/uct/uct.c b/uct/uct.c
index bc2aefb..a4c295e 100644
--- a/uct/uct.c
+++ b/uct/uct.c
@@ -160,8 +160,8 @@ uct_notify(struct engine *e, struct board *b, int id, char *cmd, char *args, cha
 	return reply_disabled(id) ? P_NOREPLY : P_OK;
 }
 
-static void
-uct_printhook_ownermap(struct board *board, coord_t c, FILE *f)
+static char *
+uct_printhook_ownermap(struct board *board, coord_t c, char *s, char *end)
 {
 	struct uct *u = board->es;
 	assert(u);
@@ -171,7 +171,8 @@ uct_printhook_ownermap(struct board *board, coord_t c, FILE *f)
 	if (ch == ',') { // less precise estimate then?
 		ch = chm[board_ownermap_judge_point(&u->ownermap, c, 0.67)];
 	}
-	fprintf(f, "%c ", ch);
+	s += snprintf(s, end - s, "%c ", ch);
+	return s;
 }
 
 static char *
-- 
2.11.4.GIT