gistfile1.txt

From 53f2f7aef15c89f60a6a75b2b55cd124600d0c23 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gon=C3=A7alo=20Silva?= <goncalossilva@gmail.com>
Date: Mon, 3 Jan 2011 18:51:57 +0000
Subject: [PATCH] use clock_gettime() instead of clock() when measuring process time under Linux

clock() limits it to centisecond precision on Linux
---
 ext/ruby_prof/measure_process_time.h |   13 ++++++++++++-
 1 files changed, 12 insertions(+), 1 deletions(-)

diff --git a/ext/ruby_prof/measure_process_time.h b/ext/ruby_prof/measure_process_time.h
index 82a9e44..e09d9fc 100644
--- a/ext/ruby_prof/measure_process_time.h
+++ b/ext/ruby_prof/measure_process_time.h
@@ -31,13 +31,24 @@
 static prof_measure_t
 measure_process_time()
 {
-    return clock(); // cpu usage (with poor precision) in linux (TODO), wall time in doze (TODO)
+#if defined(__linux__)
+    struct timespec time;
+    clock_gettime(CLOCK_MONOTONIC, &time);
+    return time.tv_sec * 1000000000 + time.tv_nsec ;
+#else
+    return clock();
+#endif
 }
 
+
 static double
 convert_process_time(prof_measure_t c)
 {
+#if defined(__linux__)
+    return (double) c / 1000000000;
+#else
     return (double) c / CLOCKS_PER_SEC;
+#endif
 }
 
 /* Document-method: measure_process_time
-- 
1.7.1