From: Corinna Vinschen <corinna@vinschen.de>
Date: Mon, 21 Jan 2019 09:05:13 +0000 (+0100)
Subject: Cygwin: timerfd: settime: fix computing DueTime on non-realtime clocks
X-Git-Tag: cygwin-3_0_0-release~93
X-Git-Url: https://sourceware.org/git/?a=commitdiff_plain;h=6ed50a68a133e7e0c0d10e328bce94f98944dbe5;p=newlib-cygwin.git

Cygwin: timerfd: settime: fix computing DueTime on non-realtime clocks

Non-CLOCK_REALTIME counters always use a relative DueTime in NtSetTimer.
However, relative DueTime has to be negative, but the code

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
---

diff --git a/winsup/cygwin/timerfd.cc b/winsup/cygwin/timerfd.cc
index e5c17fb4e..64836b021 100644
--- a/winsup/cygwin/timerfd.cc
+++ b/winsup/cygwin/timerfd.cc
@@ -532,7 +532,7 @@ timerfd_shared::arm_timer (int flags, const struct itimerspec *new_value)
 	DueTime.QuadPart = ts + FACTOR;
       else /* non-REALTIME clocks require relative DueTime. */
 	{
-	  DueTime.QuadPart = ts - get_clock_now ();
+	  DueTime.QuadPart = get_clock_now () - ts;
 	  /* If the timestamp was earlier than now, compute number
 	     of overruns and offset DueTime to expire immediately. */
 	  if (DueTime.QuadPart >= 0)