From: Andre Noll <maan@systemlinux.org>
Date: Sat, 21 Mar 2009 16:46:43 +0000 (+0100)
Subject: server: Use a temporary SIGCHLD handler to catch afs init failures.
X-Git-Tag: v0.3.4~24
X-Git-Url: http://git.tue.mpg.de/?a=commitdiff_plain;h=ab6470e0146493969887781bc8efd5a615f879c7;p=paraslash.git

server: Use a temporary SIGCHLD handler to catch afs init failures.

If afs dies immediately on startup (because of dirty tables) para_server
would not notice as the SIGCHLD handler is being intalled after the
call to afs_init().
---

diff --git a/server.c b/server.c
index 9c069913..4415cdcd 100644
--- a/server.c
+++ b/server.c
@@ -467,6 +467,12 @@ static int init_afs(void)
 	return afs_server_socket[0];
 }
 
+__noreturn static void tmp_sigchld_handler(__a_unused int s)
+{
+	PARA_EMERG_LOG("caught early SIGCHLD\n");
+	exit(EXIT_FAILURE);
+}
+
 static void server_init(int argc, char **argv)
 {
 	struct server_cmdline_parser_params params = {
@@ -509,6 +515,15 @@ static void server_init(int argc, char **argv)
 		PARA_EMERG_LOG("failed to ignore SIGUSR1\n");
 		exit(EXIT_FAILURE);
 	}
+	/*
+	 * We have to install a SIGCHLD handler before the afs process is being
+	 * forked off. Otherwise, para_server does not notice if afs dies before
+	 * the SIGCHLD handler has been installed by init_signal_task() below.
+	 */
+	if (signal(SIGCHLD, tmp_sigchld_handler) == SIG_ERR) {
+		PARA_EMERG_LOG("failed to install temporary SIGCHLD handler\n");
+		exit(EXIT_FAILURE);
+	}
 	PARA_NOTICE_LOG("initializing the audio file selector\n");
 	afs_socket = init_afs();
 	init_signal_task();