Added system signal handling to Linux version

(with http://www.cons.org/cracauer/sigint.html in mind)

Change-Id: I15f559bc1122a408c3fb9338ba55c16fab3187e1
Signed-off-by: Mateusz Manowiecki <segmentation@fault.pl>
Reviewed-on: http://openocd.zylin.com/2443
Tested-by: jenkins
Reviewed-by: Paul Fertser <fercerpav@gmail.com>

src/openocd.c

@@ -277,30 +277,28 @@ static int openocd_thread(int argc, char *argv[], struct command_context *cmd_ct
 	int ret;
 
 	if (parse_cmdline_args(cmd_ctx, argc, argv) != ERROR_OK)
-		return EXIT_FAILURE;
+		return ERROR_FAIL;
 
 	if (server_preinit() != ERROR_OK)
-		return EXIT_FAILURE;
+		return ERROR_FAIL;
 
 	ret = parse_config_file(cmd_ctx);
 	if (ret != ERROR_OK)
-		return EXIT_FAILURE;
+		return ERROR_FAIL;
 
 	ret = server_init(cmd_ctx);
 	if (ERROR_OK != ret)
-		return EXIT_FAILURE;
+		return ERROR_FAIL;
 
 	if (init_at_startup) {
 		ret = command_run_line(cmd_ctx, "init");
 		if (ERROR_OK != ret)
-			return EXIT_FAILURE;
+			return ERROR_FAIL;
 	}
 
 	server_loop(cmd_ctx);
 
-	server_quit();
-
-	return ret;
+	return server_quit();
 }
 
 /* normally this is the main() function entry, but if OpenOCD is linked
@@ -338,5 +336,10 @@ int openocd_main(int argc, char *argv[])
 
 	adapter_quit();
 
+	if (ERROR_FAIL == ret)
+		return EXIT_FAILURE;
+	else if (ERROR_OK != ret)
+		exit_on_signal(ret);
+
 	return ret;
 }

src/server/server.c

@@ -47,6 +47,9 @@ static struct service *services;
 /* shutdown_openocd == 1: exit the main event loop, and quit the debugger */
 static int shutdown_openocd;
 
+/* store received signal to exit application by killing ourselves */
+static int last_signal;
+
 /* set the polling period to 100ms */
 static int polling_period = 100;
 
@@ -505,12 +508,15 @@ BOOL WINAPI ControlHandler(DWORD dwCtrlType)
 	shutdown_openocd = 1;
 	return TRUE;
 }
+#endif
 
 void sig_handler(int sig)
 {
+	/* store only first signal that hits us */
+	if (!last_signal)
+		last_signal = sig;
 	shutdown_openocd = 1;
 }
-#endif
 
 int server_preinit(void)
 {
@@ -532,11 +538,11 @@ int server_preinit(void)
 	/* register ctrl-c handler */
 	SetConsoleCtrlHandler(ControlHandler, TRUE);
 
+	signal(SIGBREAK, sig_handler);
+#endif
 	signal(SIGINT, sig_handler);
 	signal(SIGTERM, sig_handler);
-	signal(SIGBREAK, sig_handler);
 	signal(SIGABRT, sig_handler);
-#endif
 
 	return ERROR_OK;
 }
@@ -557,9 +563,21 @@ int server_quit(void)
 #ifdef _WIN32
 	WSACleanup();
 	SetConsoleCtrlHandler(ControlHandler, FALSE);
-#endif
 
 	return ERROR_OK;
+#endif
+
+	/* return signal number so we can kill ourselves */
+	return last_signal;
+}
+
+void exit_on_signal(int sig)
+{
+#ifndef _WIN32
+	/* bring back default system handler and kill yourself */
+	signal(sig, SIG_DFL);
+	kill(getpid(), sig);
+#endif
 }
 
 int connection_write(struct connection *connection, const void *data, int len)

src/server/server.h

@@ -78,6 +78,7 @@ int add_service(char *name, const char *port,
 int server_preinit(void);
 int server_init(struct command_context *cmd_ctx);
 int server_quit(void);
+void exit_on_signal(int);
 
 int server_loop(struct command_context *command_context);