X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;ds=sidebyside;f=ustd%2Fustd.c;h=fef0eae1680336dfe83eb05b8ca16b37d1d6fa39;hb=6af64c431c0a521fc927fa72b9f4015397ce11d4;hp=001977660a6ec0c86d809ce4a0ccb298a638427b;hpb=bce2937acead6988b0f0b84b2b339f1fd8d54122;p=ust.git

diff --git a/ustd/ustd.c b/ustd/ustd.c
index 0019776..fef0eae 100644
--- a/ustd/ustd.c
+++ b/ustd/ustd.c
@@ -33,7 +33,7 @@
 #include <getopt.h>
 
 #include "ustd.h"
-#include "localerr.h"
+#include "usterr.h"
 #include "ustcomm.h"
 #include "share.h"
 
@@ -53,6 +53,7 @@
 char *sock_path=NULL;
 char *trace_path=NULL;
 int daemon_mode = 0;
+char *pidfile = NULL;
 
 /* Number of active buffers and the mutex to protect it. */
 int active_buffers = 0;
@@ -516,6 +517,9 @@ int parse_args(int argc, char **argv)
 		case 'd':
 			daemon_mode = 1;
 			break;
+		case 'p':
+			pidfile = strdup(optarg);
+			break;
 		case 'h':
 			usage();
 			exit(0);
@@ -654,10 +658,11 @@ int start_ustd_daemon()
 {
 	int result;
 	int fd[2];
+	pid_t child_pid;
 
 	result = pipe(fd);
 
-	result = fork();
+	result = child_pid = fork();
 	if(result == -1) {
 		PERROR("fork");
 		return -1;
@@ -667,6 +672,27 @@ int start_ustd_daemon()
 	}
 	else {
 		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) {