From: Po Lu <luangruo@yahoo.com>
Date: Wed, 3 Aug 2022 12:17:18 +0000 (+0800)
Subject: ; * src/xterm.c (x_if_event): Minor speed improvements.
X-Git-Tag: emacs-29.0.90~1447^2~506
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=6fb206329f9c3f14154bd425e08b2e72e7f31855;p=emacs.git

; * src/xterm.c (x_if_event): Minor speed improvements.
---

diff --git a/src/xterm.c b/src/xterm.c
index eb1a557e883..f82340958e5 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -6605,12 +6605,17 @@ x_if_event (Display *dpy, XEvent *event_return,
   current_time = current_timespec ();
   target = timespec_add (current_time, timeout);
 
+  /* Check if an event is already in the queue.  If it is, avoid
+     syncing.  */
+  if (XCheckIfEvent (dpy, event_return, predicate, arg))
+    return 0;
+
   while (true)
     {
       /* Get events into the queue.  */
       XSync (dpy, False);
 
-      /* Check if an event is now in the queue.  */
+      /* Look for an event again.  */
       if (XCheckIfEvent (dpy, event_return, predicate, arg))
 	return 0;