autoservice: stop thread on graceful shutdown

This change adds thread shutdown to autoservice for graceful shutdowns only.
ast_register_cleanup is backported to 1.8 to allow this.  The logger callid
is also released on shutdown in 11+.

ASTERISK-23827 #close
Reported by: Corey Farrell
Review: https://reviewboard.asterisk.org/r/3594/
........

Merged revisions 415463 from http://svn.asterisk.org/svn/asterisk/branches/1.8


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@415464 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/autoservice.c

@@ -72,6 +72,7 @@ static AST_LIST_HEAD_STATIC(aslist, asent);
 static ast_cond_t as_cond;
 
 static pthread_t asthread = AST_PTHREADT_NULL;
+static volatile int asexit = 0;
 
 static int as_chan_list_state;
 
@@ -83,7 +84,7 @@ static void *autoservice_run(void *ign)
 		.subclass.integer = AST_CONTROL_HANGUP,
 	};
 
-	for (;;) {
+	while (!asexit) {
 		struct ast_channel *mons[MAX_AUTOMONS];
 		struct asent *ents[MAX_AUTOMONS];
 		struct ast_channel *chan;
@@ -177,6 +178,7 @@ static void *autoservice_run(void *ign)
 		}
 	}
 
+	ast_callid_threadassoc_change(NULL);
 	asthread = AST_PTHREADT_NULL;
 
 	return NULL;
@@ -337,7 +339,19 @@ int ast_autoservice_ignore(struct ast_channel *chan, enum ast_frame_type ftype)
 	return res;
 }
 
+static void autoservice_shutdown(void)
+{
+	pthread_t th = asthread;
+	asexit = 1;
+	if (th != AST_PTHREADT_NULL) {
+		ast_cond_signal(&as_cond);
+		pthread_kill(th, SIGURG);
+		pthread_join(th, NULL);
+	}
+}
+
 void ast_autoservice_init(void)
 {
+	ast_register_cleanup(autoservice_shutdown);
 	ast_cond_init(&as_cond, NULL);
 }