(x_make_frame_visible): Raise a signal to cause the pending X I/O to be read.

diff --git a/src/xterm.c b/src/xterm.c
index 3c15fb417da606f09ea8abe83d13476d6f288c5d..a900a6e15dde0c2863c9ab099ea71810a0ed15b3 100644 (file)
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -5668,22 +5668,16 @@ x_make_frame_visible (f)
      so that incoming events are handled.  */
   {
     Lisp_Object frame;
-    int one_in_four = 1;
     XSET (frame, Lisp_Frame, f);
     while (! f->async_visible)
       {
        x_sync (frame);
-       /* On HPUX on the HP800, the sleep is needed sometimes.  */
-       if ((one_in_four & 3) == 0)
-         {
-           QUIT;
-#ifdef EMACS_HAS_USECS
-           Fsleep_for (make_number (1), make_number (0));
-#else
-           Fsleep_for (make_number (0), make_number (250));
+       /* Machines that do polling rather than SIGIO have been observed
+          to go into a busy-wait here.  Send the alarm signal to let
+          the handler know that there's something to be read.  */
+#ifndef SIGIO
+       kill (getpid(), SIGALRM);
 #endif
-         }
-       one_in_four++;
       }
     FRAME_SAMPLE_VISIBILITY (f);
   }