From: Pierre-Marc Fournier <pierre-marc.fournier@polymtl.ca>
Date: Mon, 26 Oct 2009 14:07:11 +0000 (-0400)
Subject: usttrace: deal correctly with ustd creation and termination
X-Git-Tag: v0.1~79
X-Git-Url: http://git.lttng.org/?p=ust.git;a=commitdiff_plain;h=2b3c64a412053525cff6233a963f37f4bfbdb284

usttrace: deal correctly with ustd creation and termination
---

diff --git a/ustd/ustd.c b/ustd/ustd.c
index 6d8680c..858bdf5 100644
--- a/ustd/ustd.c
+++ b/ustd/ustd.c
@@ -542,6 +542,24 @@ void sigterm_handler(int sig)
 	terminate_req = 1;
 }
 
+static int write_pidfile(const char *file_name, pid_t pid)
+{
+	FILE *pidfp;
+
+	pidfp = fopen(file_name, "w+");
+	if(!pidfp) {
+		PERROR("fopen (%s)", pidfile);
+		WARN("killing child process");
+		return -1;
+	}
+
+	fprintf(pidfp, "%d\n", pid);
+
+	fclose(pidfp);
+
+	return 0;
+}
+
 int start_ustd(int fd)
 {
 	struct ustcomm_ustd ustd;
@@ -586,6 +604,15 @@ int start_ustd(int fd)
 		return 1;
 	}
 
+	/* Write pidfile */
+	if(pidfile) {
+		result = write_pidfile(pidfile, getpid());
+		if(result == -1) {
+			ERR("failed to write pidfile");
+			return 1;
+		}
+	}
+
 	/* Notify parent that we are successfully started. */
 	if(fd != -1) {
 		/* write any one character */
@@ -674,26 +701,6 @@ int start_ustd_daemon()
 		char buf;
 		FILE *pidfp;
 
-		/* It's important to write the file *before*
-		 * the parent ends, because the file may be
-		 * read as soon as the parent ends.
-		 */
-		if(pidfile) {
-			pidfp = fopen(pidfile, "w+");
-			if(!pidfp) {
-				PERROR("fopen (%s)", pidfile);
-				WARN("killing child process");
-				result = kill(child_pid, SIGTERM);
-				if(result == -1) {
-					PERROR("kill");
-				}
-				return -1;
-			}
-
-			fprintf(pidfp, "%d\n", child_pid);
-			fclose(pidfp);
-		}
-
 		result = read(fd[0], &buf, 1);
 		if(result == -1) {
 			PERROR("read");
diff --git a/usttrace b/usttrace
index b3af05d..52c378d 100755
--- a/usttrace
+++ b/usttrace
@@ -80,7 +80,7 @@ then
 	pidfilepath="/tmp/usttrace-$USER-$(date +%Y%m%d%H%M%S%N)-ustd-pid"
 	mkfifo -m 0600 "$pidfilepath"
 	# Start daemon
-	$USTD -d --pidfile "$pidfilepath" -s "$SOCKPATH" -o "$OUTDIR" >"$OUTDIR/ustd.log" 2>&1 &
+	$USTD --pidfile "$pidfilepath" -s "$SOCKPATH" -o "$OUTDIR" >"$OUTDIR/ustd.log" 2>&1 &
 	USTDPID="$(<$pidfilepath)"
 	export UST_DAEMON_SOCKET="$SOCKPATH"
 fi
@@ -129,7 +129,7 @@ then
 	kill -SIGTERM "$USTDPID"
 
 	echo "Waiting for ustd to shutdown..."
-	wait
+	wait "$(USTDPID)"
 
 	rm "$pidfilepath"
 fi