Maintain a `necessary' marker to indicate that we *probably*

need to process a signal (usually a SIGALRM).  Check to see
if we need to process a signal both before *and* after calling
select() as older (pre-2.0) versions of ppp used to.

This handles the possibility that ppp may block at some
point (maybe due to an open() of a misconfigured device).
Previously, we'd potentially lock up in select().

The `necessary' marker reduces the increased signal checking
overhead so that at full speed with no compression transferring
an 83Mb file via a ``!ppp -direct'' device, we get a 1%
throughput gain.

1 files changed, 12 insertions, 1 deletions

diff --git a/usr.sbin/ppp/main.c b/usr.sbin/ppp/main.c
index 958a16d..4eb99d4 100644
--- a/usr.sbin/ppp/main.c
+++ b/usr.sbin/ppp/main.c
@@ -17,7 +17,7 @@
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
- * $Id: main.c,v 1.150 1999/02/06 02:54:46 brian Exp $
+ * $Id: main.c,v 1.151 1999/03/07 01:02:38 brian Exp $
  *
  *	TODO:
  */
@@ -474,6 +474,17 @@ DoLoop(struct bundle *bundle)
       /* Don't select - we'll be here forever */
       break;
 
+    /*
+     * It's possible that we've had a signal since we last checked.  If
+     * we don't check again before calling select(), we may end up stuck
+     * after having missed the event.... sig_Handle() tries to be as
+     * quick as possible if nothing is likely to have happened.
+     * This is only really likely if we block in open(... O_NONBLOCK)
+     * which will happen with a misconfigured device.
+     */
+    if (sig_Handle())
+      continue;
+
     i = select(nfds, &rfds, &wfds, &efds, NULL);
 
     if (i < 0 && errno != EINTR) {