From: Andre Noll <maan@systemlinux.org>
Date: Mon, 15 Aug 2011 20:56:01 +0000 (+0200)
Subject: sched: Zero-out fd sets on min delay.
X-Git-Tag: v0.4.8~2
X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=commitdiff_plain;h=ec0c9721b6dfcbd70d7a1b318fb9b94e2aab9a5d

sched: Zero-out fd sets on min delay.

If at least one pre_select method requests a minimal delay, we don't
call select() anymore as it would return immediately anyway. However,
the fds that have already been set by previous pre_select methods are
then treated as ready for IO in post_seelect which they most likely
are not. This causes unnecessary calls to readv() and friends which
returned EAGAIN.

Fix this by clearing all fd sets in case of minimal timeouts.
---

diff --git a/sched.c b/sched.c
index 385dde61..06aabe02 100644
--- a/sched.c
+++ b/sched.c
@@ -159,6 +159,9 @@ again:
 			FD_ZERO(&s->wfds);
 		}
 		gettimeofday(now, NULL);
+	} else {
+		FD_ZERO(&s->rfds);
+		FD_ZERO(&s->wfds);
 	}
 	sched_post_select(s);
 	if (list_empty(&pre_select_list) && list_empty(&post_select_list))