io_thread: add function io_thread_quit()

src/io_thread.c

@@ -75,12 +75,19 @@ io_thread_start(GError **error_r)
 }
 
 void
+io_thread_quit(void)
+{
+	assert(io.loop != NULL);
+
+	g_main_loop_quit(io.loop);
+}
+
+void
 io_thread_deinit(void)
 {
 	if (io.thread != NULL) {
-		assert(io.loop != NULL);
+		io_thread_quit();
 
-		g_main_loop_quit(io.loop);
 		g_thread_join(io.thread);
 	}
 

src/io_thread.h

@@ -37,6 +37,14 @@ io_thread_start(GError **error_r);
 void
 io_thread_run(void);
 
+/**
+ * Ask the I/O thread to quit, but does not wait for it.  Usually, you
+ * don't need to call this function, because io_thread_deinit()
+ * includes this.
+ */
+void
+io_thread_quit(void);
+
 void
 io_thread_deinit(void);