add jtk_wake()

src/jtk/jtk.c

@@ -701,3 +701,13 @@ void jtk_wait_event(jtk_event_t * event, uint64_t time_to_wait)
         select(x_fd + 1, &fds, NULL, NULL, &tv);
     }
 }
+
+void jtk_wake(void)
+{
+    XEvent event = {
+        .type = GenericEvent,
+    };
+    XLockDisplay(g_display);
+    XPutBackEvent(g_display, &event);
+    XUnlockDisplay(g_display);
+}