server: add function to get openocd shutdown status

In the app-trace module we are polling the target in the while loops
outside of the server.c
In that loops, we need to catch ctrl+c signal by checking shutdown_openocd
status

Signed-off-by: Erhan Kurubas <erhan.kurubas@espressif.com>
Change-Id: Id87c709a01470bf6d3642078b160a68ca85f4406
Reviewed-on: https://review.openocd.org/c/openocd/+/7142
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

src/server/server.c

@@ -747,6 +747,11 @@ int connection_read(struct connection *connection, void *data, int len)
 		return read(connection->fd, data, len);
 }
 
+bool openocd_is_shutdown_pending(void)
+{
+	return shutdown_openocd != CONTINUE_MAIN_LOOP;
+}
+
 /* tell the server we want to shut down */
 COMMAND_HANDLER(handle_shutdown_command)
 {

src/server/server.h

@@ -104,6 +104,8 @@ int server_register_commands(struct command_context *context);
 int connection_write(struct connection *connection, const void *data, int len);
 int connection_read(struct connection *connection, void *data, int len);
 
+bool openocd_is_shutdown_pending(void);
+
 /**
  * Defines an extended command handler function declaration to enable
  * access to (and manipulation of) the server port number.