2005-12-08 Frank Ch. Eigler <fche@elastic.org>

	PR 1937
	* buildrun.cxx (run_pass): Pass new "-d PID" option to stpd.
	Set SIGHUP to SIG_IGN too.

2005-12-08  Frank Ch. Eigler  <fche@elastic.org>

	PR 1937
	* stpd.c (main): Support new "-d" option.
	(usage): Document it.
	* librelay.c (driver_poll): New function to react to death of
	driver process.
	(stp_main_loop): Call it if "-d PID" given.  Treat SIGHUP like others.

3 files changed, 38 insertions, 1 deletions

diff --git a/runtime/stpd/ChangeLog b/runtime/stpd/ChangeLog
index 2fd03259..e72ec4d0 100644
--- a/runtime/stpd/ChangeLog
+++ b/runtime/stpd/ChangeLog
@@ -1,3 +1,12 @@
+2005-12-08  Frank Ch. Eigler  <fche@elastic.org>
+
+	PR 1937
+	* stpd.c (main): Support new "-d" option.
+	(usage): Document it.
+	* librelay.c (driver_poll): New function to react to death of
+	driver process.
+	(stp_main_loop): Call it if "-d PID" given.  Treat SIGHUP like others.
+	
 2005-10-19  Tom Zanussi  <zanussi@us.ibm.com>
 
 	* librelay.c: Move output_file var to stpd.c.
diff --git a/runtime/stpd/librelay.c b/runtime/stpd/librelay.c
index 9ed408d9..e2beece2 100644
--- a/runtime/stpd/librelay.c
+++ b/runtime/stpd/librelay.c
@@ -84,6 +84,7 @@ extern unsigned int buffer_size;
 extern char *modname;
 extern char *modpath;
 extern int target_pid;
+extern int driver_pid;
 extern char *target_cmd;
 
 /* per-cpu buffer info */
@@ -641,6 +642,23 @@ static void sigproc(int signum __attribute__((unused)))
   send_request(STP_EXIT, NULL, 0);
 }
 
+static void driver_poll (int signum __attribute__((unused)))
+{
+  /* See if the driver process is still alive.  If not, time to exit.  */
+  if (kill (driver_pid, 0) < 0)
+    {
+      send_request(STP_EXIT, NULL, 0);
+      return;
+    }
+  else
+    {
+      /* Check again later. */
+      signal (SIGALRM, driver_poll);
+      alarm (10); // any reasonable poll interval
+    }
+}
+
+
 /**
  *	stp_main_loop - loop forever reading data
  */
@@ -659,6 +677,11 @@ int stp_main_loop(void)
 	signal(SIGINT, sigproc);
 	signal(SIGTERM, sigproc);
 	signal(SIGCHLD, sigproc);
+	signal(SIGHUP, sigproc);
+
+        if (driver_pid)
+          driver_poll(0); // And by the way, I'm also the signal handler.
+
 	dbug("in main loop\n");
 
 	while (1) { /* handle messages from control channel */
diff --git a/runtime/stpd/stpd.c b/runtime/stpd/stpd.c
index 9587d29f..c12ca096 100644
--- a/runtime/stpd/stpd.c
+++ b/runtime/stpd/stpd.c
@@ -37,6 +37,7 @@ int merge = 1;
 int verbose = 0;
 int enable_relayfs = 1;
 int target_pid = 0;
+int driver_pid = 0;
 unsigned int buffer_size = 0;
 char *modname = NULL;
 char *modpath = NULL;
@@ -66,6 +67,7 @@ static void usage(char *prog)
 	fprintf(stderr, "-c cmd.  Command \'cmd\' will be run and stpd will exit when it does.\n");
 	fprintf(stderr, "   _stp_target will contain the pid for the command.\n");
 	fprintf(stderr, "-t pid.  Sets _stp_target to pid.\n");
+	fprintf(stderr, "-d pid.  Pass the systemtap driver's pid.\n");
 	fprintf(stderr, "-b buffer size. The systemtap module will specify a buffer size.\n");
 	fprintf(stderr, "-o FILE. Send output to FILE.\n");
 	fprintf(stderr, "   Setting one here will override that value. The value should be\n");
@@ -79,7 +81,7 @@ int main(int argc, char **argv)
 	int c, status;
 	pid_t pid;
 
-	while ((c = getopt(argc, argv, "mpqrb:n:t:c:vo:")) != EOF)
+	while ((c = getopt(argc, argv, "mpqrb:n:t:d:c:vo:")) != EOF)
 	{
 		switch (c) {
 		case 'm':
@@ -112,6 +114,9 @@ int main(int argc, char **argv)
 		case 't':
 			target_pid = atoi(optarg);
 			break;
+		case 'd':
+			driver_pid = atoi(optarg);
+			break;
 		case 'c':
 			target_cmd = optarg;
 			break;