|
|
From a3c400a8553b598bc2fd01eb0f63c5748b2147e1 Mon Sep 17 00:00:00 2001 |
|
|
From: =?UTF-8?q?Petr=20P=C3=ADsa=C5=99?= <ppisar@redhat.com> |
|
|
Date: Wed, 8 Nov 2017 17:02:42 +0100 |
|
|
Subject: [PATCH] Prefer clock_gettime(CLOCK_MONOTONIC) |
|
|
MIME-Version: 1.0 |
|
|
Content-Type: text/plain; charset=UTF-8 |
|
|
Content-Transfer-Encoding: 8bit |
|
|
|
|
|
gettimeofday() reports wrong elapsed real time if a time step was |
|
|
inserted while running a program. This can happen on initial time |
|
|
adjustment from NTP server or by manual adjustement by date command. |
|
|
|
|
|
This patch uses clock_gettime(CLOCK_MONOTONIC) instead (if available) |
|
|
that does not suffer from the issue. |
|
|
|
|
|
<http://lists.gnu.org/archive/html/bug-gnu-utils/2013-09/msg00008.html> |
|
|
|
|
|
Signed-off-by: Petr Písař <ppisar@redhat.com> |
|
|
--- |
|
|
configure.ac | 3 +++ |
|
|
src/resuse.c | 27 +++++++++++++++++++++++++-- |
|
|
2 files changed, 28 insertions(+), 2 deletions(-) |
|
|
|
|
|
diff --git a/configure.ac b/configure.ac |
|
|
index ede8fd5..d2950bd 100644 |
|
|
--- a/configure.ac |
|
|
+++ b/configure.ac |
|
|
@@ -72,6 +72,9 @@ dnl Checks for library functions. |
|
|
AC_FUNC_VPRINTF |
|
|
AC_FUNC_WAIT3 |
|
|
AC_CHECK_FUNCS(strerror) |
|
|
+AC_SEARCH_LIBS(clock_gettime, [rt]) |
|
|
+test "$ac_cv_search_clock_gettime" != "no" && \ |
|
|
+ AC_DEFINE([HAVE_CLOCK_GETTIME], [1], [System provides clock_gettime() call]) |
|
|
|
|
|
|
|
|
# What memory units are reported by getrusage(2) ? |
|
|
diff --git a/src/resuse.c b/src/resuse.c |
|
|
index d2ab870..ec54863 100644 |
|
|
--- a/src/resuse.c |
|
|
+++ b/src/resuse.c |
|
|
@@ -26,7 +26,14 @@ |
|
|
#include <sys/wait.h> |
|
|
#include <sys/resource.h> |
|
|
|
|
|
-#if !HAVE_WAIT3 |
|
|
+#if HAVE_WAIT3 |
|
|
+# if HAVE_CLOCK_GETTIME |
|
|
+# ifndef _POSIX_C_SOURCE |
|
|
+# define _POSIX_C_SOURCE 199309L |
|
|
+# endif |
|
|
+# include <time.h> |
|
|
+# endif |
|
|
+#else |
|
|
# include <sys/times.h> |
|
|
# ifndef HZ |
|
|
# include <sys/param.h> |
|
|
@@ -51,7 +58,14 @@ resuse_start (resp) |
|
|
RESUSE *resp; |
|
|
{ |
|
|
#if HAVE_WAIT3 |
|
|
+#if HAVE_CLOCK_GETTIME |
|
|
+ struct timespec res; |
|
|
+ clock_gettime(CLOCK_MONOTONIC, &res); |
|
|
+ resp->start.tv_sec = res.tv_sec; |
|
|
+ resp->start.tv_usec = res.tv_nsec / 1000; |
|
|
+#else |
|
|
gettimeofday (&resp->start, (struct timezone *) 0); |
|
|
+#endif /* !HAVE_CLOCK_GETTIME */ |
|
|
#else |
|
|
long value; |
|
|
struct tms tms; |
|
|
@@ -59,7 +73,7 @@ resuse_start (resp) |
|
|
value = times (&tms); |
|
|
resp->start.tv_sec = value / HZ; |
|
|
resp->start.tv_usec = value % HZ * (1000000 / HZ); |
|
|
-#endif |
|
|
+#endif /* !HAVE_WAIT3 */ |
|
|
} |
|
|
|
|
|
/* Wait for and fill in data on child process PID. |
|
|
@@ -79,6 +93,9 @@ resuse_end (pid, resp) |
|
|
int status; |
|
|
|
|
|
#if HAVE_WAIT3 |
|
|
+#if HAVE_CLOCK_GETTIME |
|
|
+ struct timespec res; |
|
|
+#endif |
|
|
pid_t caught; |
|
|
|
|
|
/* Ignore signals, but don't ignore the children. When wait3 |
|
|
@@ -89,7 +106,13 @@ resuse_end (pid, resp) |
|
|
return 0; |
|
|
} |
|
|
|
|
|
+#if HAVE_CLOCK_GETTIME |
|
|
+ clock_gettime(CLOCK_MONOTONIC, &res); |
|
|
+ resp->elapsed.tv_sec = res.tv_sec; |
|
|
+ resp->elapsed.tv_usec = res.tv_nsec / 1000; |
|
|
+#else |
|
|
gettimeofday (&resp->elapsed, (struct timezone *) 0); |
|
|
+#endif |
|
|
#else /* !HAVE_WAIT3 */ |
|
|
long value; |
|
|
struct tms tms; |
|
|
-- |
|
|
2.13.6 |
|
|
|
|
|
|
