From: Sam Steingold <sds@gnu.org>
Date: Sun, 11 Mar 2007 21:08:45 +0000 (+0000)
Subject: tweak last patch: add comment and avoid the first sleep
X-Git-Tag: emacs-pretest-22.0.96~143
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=9b73fa0b88684652935aae9edfadd2fd309b0ace;p=emacs.git

tweak last patch: add comment and avoid the first sleep
---

diff --git a/src/process.c b/src/process.c
index 0fbbd5d34c3..975d92f36f1 100644
--- a/src/process.c
+++ b/src/process.c
@@ -6495,13 +6495,16 @@ sigchld_handler (signo)
 #define WUNTRACED 0
 #endif /* no WUNTRACED */
       /* Keep trying to get a status until we get a definitive result.  */
-      do
-	{
-          sleep (1);
-	  errno = 0;
-	  pid = wait3 (&w, WNOHANG | WUNTRACED, 0);
-	}
-      while (pid < 0 && errno == EINTR);
+      while (1) {
+        errno = 0;
+        pid = wait3 (&w, WNOHANG | WUNTRACED, 0);
+	if (! (pid < 0 && errno == EINTR))
+          break;
+        /* avoid a busyloop: wait3 is a system call, so we do not want
+           to prevent the kernel from actually sending SIGCHLD to emacs
+           by asking for it all the time */
+        sleep (1);
+      }
 
       if (pid <= 0)
 	{