X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=daemon.c;h=0bf2f0ac9e81d72dff8623d7ebc54014007c40e4;hp=ffdec4e35f3e8cdbd113a780f6d6ade7faf9fcfe;hb=1b5c824581612cf5bf6c34f7f4472ed7a2eedbdd;hpb=b307a25ed895caa33684302b502e9e0e70dc78b7

diff --git a/daemon.c b/daemon.c
index ffdec4e3..0bf2f0ac 100644
--- a/daemon.c
+++ b/daemon.c
@@ -12,6 +12,7 @@
 #include <grp.h>
 #include <sys/time.h>
 #include <stdbool.h>
+#include <signal.h>
 
 #include "para.h"
 #include "daemon.h"
@@ -142,14 +143,25 @@ static bool daemon_test_flag(unsigned flag)
 	return me->flags & flag;
 }
 
+static void dummy_sighandler(__a_unused int s)
+{
+}
+
 /**
  * Do the usual stuff to become a daemon.
  *
- * Fork, become session leader, dup fd 0, 1, 2 to /dev/null.
+ * \param parent_waits Whether the parent process should pause before exit.
  *
- * \sa fork(2), setsid(2), dup(2).
+ * Fork, become session leader, cd to /, and dup fd 0, 1, 2 to /dev/null. If \a
+ * parent_waits is false, the parent process terminates immediately.
+ * Otherwise, it calls pause() to sleep until it receives \p SIGTERM or \p
+ * SIGCHLD and exits successfully thereafter. This behaviour is useful if the
+ * daemon process should not detach from the console until the child process
+ * has completed its setup.
+ *
+ * \sa fork(2), setsid(2), dup(2), pause(2).
  */
-void daemonize(void)
+void daemonize(bool parent_waits)
 {
 	pid_t pid;
 	int null;
@@ -158,8 +170,14 @@ void daemonize(void)
 	pid = fork();
 	if (pid < 0)
 		goto err;
-	if (pid)
+	if (pid) {
+		if (parent_waits) {
+			signal(SIGTERM, dummy_sighandler);
+			signal(SIGCHLD, dummy_sighandler);
+			pause();
+		}
 		exit(EXIT_SUCCESS); /* parent exits */
+	}
 	/* become session leader */
 	if (setsid() < 0)
 		goto err;