From 2020191f677675f12e6376c36f21cd42a3782595 Mon Sep 17 00:00:00 2001
From: Russell Bryant <russell@russellbryant.com>
Date: Fri, 23 Feb 2007 23:24:18 +0000
Subject: [PATCH] Merged revisions 56504 via svnmerge from
 https://origsvn.digium.com/svn/asterisk/branches/1.2

........
r56504 | russell | 2007-02-23 17:20:55 -0600 (Fri, 23 Feb 2007) | 8 lines

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/1.4@56505 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
 main/asterisk.c | 70 +++++++++++++++++++++++++++++++++----------------
 1 file changed, 48 insertions(+), 22 deletions(-)

diff --git a/main/asterisk.c b/main/asterisk.c
index 507ca7fd76..bf7702aaa0 100644
--- a/main/asterisk.c
+++ b/main/asterisk.c
@@ -233,7 +233,11 @@ static pthread_t consolethread = AST_PTHREADT_NULL;
 
 static char randompool[256];
 
-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 {
@@ -1038,11 +1042,14 @@ 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);
 }
 
@@ -1234,7 +1241,12 @@ 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)
@@ -2202,11 +2214,6 @@ static void ast_remotecontrol(char * data)
 				}
 			}
 		}
-
-		if (need_reload) {
-			need_reload = 0;
-			ast_module_reload(NULL);
-		}
 	}
 	printf("\nDisconnected from Asterisk server\n");
 }
@@ -2410,6 +2417,26 @@ 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;
@@ -2819,6 +2846,9 @@ int main(int argc, char *argv[])
 	if (ast_opt_no_fork)
 		consolethread = pthread_self();
 
+	if (pipe(sig_alert_pipe))
+		sig_alert_pipe[0] = sig_alert_pipe[1] = -1;
+
 	ast_set_flag(&ast_options, AST_OPT_FLAG_FULLY_BOOTED);
 	pthread_sigmask(SIG_UNBLOCK, &sigs, NULL);
 
@@ -2833,6 +2863,14 @@ 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 %ld)", hostname, (long)ast_mainpid);
 		set_title(title);
@@ -2856,22 +2894,10 @@ int main(int argc, char *argv[])
 					ast_log(LOG_WARNING, "Failed to open /dev/null to recover from dead console. Bad things will happen!\n");
 				break;
 			}
-			if (need_reload) {
-				need_reload = 0;
-				ast_module_reload(NULL);
-			}
 		}
 	}
-	/* Do nothing */
-	for (;;) {	/* apparently needed for Mac OS X */
-		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;
 }