From 1c26e1c7178db11cf18761feeb8aa62d8855b3b8 Mon Sep 17 00:00:00 2001
From: Russell Bryant <russell@russellbryant.com>
Date: Fri, 23 Feb 2007 23:20:55 +0000
Subject: [PATCH] Fix up a couple more signal handlers to not do bad things
 that could cause various undesirable results.  The other day, I made Asterisk
 deadlock by hitting Control-C because of a bad signal handler.  Now, signal
 handlers just set a flag and write to an alert pipe for the flag to be
 handled.  Then, there is another thread that is monitoring for these flags. 
 If being run in console mode, it is just the main thread.  If Asterisk is in
 the background, a thread is created to do it.

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.2@56504 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
 asterisk.c | 72 +++++++++++++++++++++++++++++++++++++-----------------
 1 file changed, 50 insertions(+), 22 deletions(-)

diff --git a/asterisk.c b/asterisk.c
index 763f56a888..228a1acd58 100644
--- a/asterisk.c
+++ b/asterisk.c
@@ -234,7 +234,11 @@ static int shuttingdown = 0;
 static int restartnow = 0;
 static pthread_t consolethread = AST_PTHREADT_NULL;
 
-static unsigned int need_reload;
+static int sig_alert_pipe[2] = { -1, -1 };
+static struct {
+	 unsigned int need_reload:1;
+	 unsigned int need_quit:1;
+} sig_flags;
 
 #if !defined(LOW_MEMORY)
 struct file_version {
@@ -745,11 +749,14 @@ static void urg_handler(int num)
 
 static void hup_handler(int num)
 {
+	int a = 0;
 	if (option_verbose > 1) 
 		printf("Received HUP signal -- Reloading configs\n");
 	if (restartnow)
 		execvp(_argv[0], _argv);
-	need_reload = 1;
+	sig_flags.need_reload = 1;
+	if (sig_alert_pipe[1] != -1)
+		write(sig_alert_pipe[1], &a, sizeof(a));
 	signal(num, hup_handler);
 }
 
@@ -942,7 +949,12 @@ static void quit_handler(int num, int nice, int safeshutdown, int restart)
 
 static void __quit_handler(int num)
 {
-	quit_handler(num, 0, 1, 0);
+	int a = 0;
+	sig_flags.need_quit = 1;
+	if (sig_alert_pipe[1] != -1)
+		write(sig_alert_pipe[1], &a, sizeof(a));
+	/* There is no need to restore the signal handler here, since the app
+	 * is going to exit */
 }
 
 static const char *fix_header(char *outbuf, int maxout, const char *s, char *cmp)
@@ -1817,11 +1829,6 @@ static void ast_remotecontrol(char * data)
 				}
 			}
 		}
-
-		if (need_reload) {
-			need_reload = 0;
-			ast_module_reload(NULL);
-		}
 	}
 	printf("\nDisconnected from Asterisk server\n");
 }
@@ -2005,6 +2012,26 @@ static void ast_readconfig(void) {
 	ast_config_destroy(cfg);
 }
 
+static void *monitor_sig_flags(void *unused)
+{
+	for (;;) {
+		struct pollfd p = { sig_alert_pipe[0], POLLIN, 0 };
+		int a;
+		poll(&p, 1, -1);
+		if (sig_flags.need_reload) {
+			sig_flags.need_reload = 0;
+			ast_module_reload(NULL);
+		}
+		if (sig_flags.need_quit) {
+			sig_flags.need_quit = 0;
+			quit_handler(0, 0, 1, 0);
+		}
+		read(sig_alert_pipe[0], &a, sizeof(a));
+	}
+
+	return NULL;
+}
+
 int main(int argc, char *argv[])
 {
 	int c;
@@ -2403,6 +2430,10 @@ int main(int argc, char *argv[])
 		ast_verbose(term_color(tmp, "Asterisk Ready.\n", COLOR_BRWHITE, COLOR_BLACK, sizeof(tmp)));
 	if (option_nofork)
 		consolethread = pthread_self();
+
+	if (pipe(sig_alert_pipe))
+		sig_alert_pipe[0] = sig_alert_pipe[1] = -1;
+
 	fully_booted = 1;
 	pthread_sigmask(SIG_UNBLOCK, &sigs, NULL);
 #ifdef __AST_DEBUG_MALLOC
@@ -2414,6 +2445,14 @@ int main(int argc, char *argv[])
 		/* Console stuff now... */
 		/* Register our quit function */
 		char title[256];
+		pthread_attr_t attr;
+		pthread_t dont_care;
+
+		pthread_attr_init(&attr);
+		pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+		ast_pthread_create(&dont_care, &attr, monitor_sig_flags, NULL);
+		pthread_attr_destroy(&attr);
+
 		set_icon("Asterisk");
 		snprintf(title, sizeof(title), "Asterisk Console on '%s' (pid %d)", hostname, ast_mainpid);
 		set_title(title);
@@ -2439,21 +2478,10 @@ int main(int argc, char *argv[])
 					break;
 				}
 			}
-			if (need_reload) {
-				need_reload = 0;
-				ast_module_reload(NULL);
-			}
-		}
-	}
-	/* Do nothing */
-	for(;;)  {	/* apparently needed for the MACos */
-		struct pollfd p = { -1 /* no descriptor */, 0, 0 };
-		poll(&p, 0, -1);
-		/* SIGHUP will cause this to break out of poll() */
-		if (need_reload) {
-			need_reload = 0;
-			ast_module_reload(NULL);
 		}
 	}
+
+	monitor_sig_flags(NULL);
+
 	return 0;
 }
-- 
2.47.2