From 0b12bb29adc33255b97d2fb995ef145f0127d950 Mon Sep 17 00:00:00 2001
From: Tavian Barnes <tavianator@gmail.com>
Date: Sun, 20 Sep 2009 16:09:53 +0000
Subject: Make SANDGLASS_REALTICKS accurate to 1 clock cycle.
---
src/sandglass.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
(limited to 'src')
diff --git a/src/sandglass.c b/src/sandglass.c
index c3435d0..b9316e5 100644
--- a/src/sandglass.c
+++ b/src/sandglass.c
@@ -179,15 +179,25 @@ int
sandglass_elapse(sandglass_t *sandglass)
{
long oldgrains = sandglass->grains;
+ sandglass_t baseline;
if (sandglass_real_gettime(sandglass) != 0)
return -1;
sandglass->grains -= oldgrains;
- /* Magical correction for timespec-based grains */
if (sandglass->grains < 0)
+ /* Magical correction for timespec-based grains */
sandglass->grains += sandglass->adjustment;
- sandglass->grains /= sandglass->loops;
+
+ if (sandglass->attributes.resolution == SANDGLASS_REALTICKS) {
+ baseline.attributes.incrementation = SANDGLASS_MONOTONIC;
+ baseline.attributes.resolution = SANDGLASS_CPUTIME;
+ baseline.loops = sandglass->loops;
+
+ sandglass_bench(&baseline, { });
+ sandglass->grains -= baseline.grains;
+ sandglass->grains /= sandglass->loops;
+ }
return 0;
}
--
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