From: Keith Packard <keithp@keithp.com>
Date: Sat, 19 Dec 2009 23:31:36 +0000 (-0800)
Subject: Ensure that ao_alarm waits at least the specified time
X-Git-Tag: debian/0.6+85+g82fdbfe~23
X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=commitdiff_plain;h=eddb82390a0ecb07ef83c04861993842906b03ab;ds=sidebyside

Ensure that ao_alarm waits at least the specified time

Because the timer tick may happen soon, it's important to delay by
another tick to ensure that we don't wake up early.

Signed-off-by: Keith Packard <keithp@keithp.com>
---

diff --git a/src/ao_task.c b/src/ao_task.c
index 4664163d..4a78766e 100644
--- a/src/ao_task.c
+++ b/src/ao_task.c
@@ -217,7 +217,10 @@ ao_wakeup(__xdata void *wchan)
 void
 ao_alarm(uint16_t delay)
 {
-	if (!(ao_cur_task->alarm = ao_time() + delay))
+	/* Make sure we sleep *at least* delay ticks, which means adding
+	 * one to account for the fact that we may be close to the next tick
+	 */
+	if (!(ao_cur_task->alarm = ao_time() + delay + 1))
 		ao_cur_task->alarm = 1;
 }