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.

5 files changed, 61 insertions, 16 deletions

diff --git a/ChangeLog b/ChangeLog
index e313d7bc..580f5979 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+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.
+
 2005-12-07  Graydon Hoare  <graydon@redhat.com>
 
 	* staptree.cxx (traversing_visitor::visit_foreach_loop): Visit
diff --git a/buildrun.cxx b/buildrun.cxx
index ade972be..05d903d5 100644
--- a/buildrun.cxx
+++ b/buildrun.cxx
@@ -14,6 +14,7 @@
 
 extern "C" {
 #include "signal.h"
+#include <sys/wait.h>
 }
 
 
@@ -41,6 +42,17 @@ lex_cast_qstring(IN const & in)
 }
 
 
+template <typename T>
+static string
+stringify(T t)
+{
+  ostringstream s;
+  s << t;
+  return s.str ();
+}
+
+
+
 int
 compile_pass (systemtap_session& s)
 {
@@ -117,16 +129,6 @@ compile_pass (systemtap_session& s)
 }
 
 
-template <typename T>
-static string
-stringify(T t)
-{
-  ostringstream s;
-  s << t;
-  return s.str ();
-}
-
-
 int
 run_pass (systemtap_session& s)
 {
@@ -141,9 +143,6 @@ run_pass (systemtap_session& s)
     }
   else // real run
     {
-      // leave parent process alone
-      sighandler_t oldsig = signal (SIGINT, SIG_IGN);
-
       // for now, just spawn stpd
       string stpd_cmd = string("sudo ") 
         + string(PKGLIBDIR) + "/stpd "
@@ -151,6 +150,8 @@ run_pass (systemtap_session& s)
         + (s.verbose ? "" : "-q ")
         + (s.output_file.empty() ? "" : "-o " + s.output_file + " ");
 
+      stpd_cmd += "-d " + stringify(getpid()) + " ";
+
       if (s.cmd != "")
 	stpd_cmd += "-c \"" + s.cmd + "\" ";
 
@@ -163,9 +164,10 @@ run_pass (systemtap_session& s)
       stpd_cmd += s.tmpdir + "/" + s.module_name + ".ko";
 
       if (s.verbose) clog << "Running " << stpd_cmd << endl;
+
+      signal (SIGHUP, SIG_IGN);
+      signal (SIGINT, SIG_IGN);
       rc = system (stpd_cmd.c_str ());
-      
-      signal (SIGINT, oldsig);
     }      
 
   return rc;
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;