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| author | Laurent Bercot <ska-skaware@skarnet.org> | 2019-09-03 18:07:28 +0000 |
|---|---|---|
| committer | Laurent Bercot <ska-skaware@skarnet.org> | 2019-09-03 18:07:28 +0000 |
| commit | e69717d9e0cd107f461abff85f255be82d7bd69b (patch) | |
| tree | a1158470fe0ea9afea4fb95e974464ac61fe058e /doc/flags.html | |
| parent | 2aa26bce30a3a1d46979a011d85928dda927932c (diff) | |
| download | skalibs-e69717d9e0cd107f461abff85f255be82d7bd69b.tar.xz | |
Big wallclock/stopwatch refactor. It was long overdue.
* --enable-clock and --enable-monotonic are gone
* tain_sysclock() has been renamed tain_wallclock_read()
* tain_wallclock_read() reads from CLOCK_REALTIME (or gettimeofday())
* tain_clockmon[_init]() have been renamed to tain_stopwatch_[read|init]()
and now accept a monotonic clock name as an extra argument
* tain_now() points to the system (wall) clock by default
* tain_now_set_[stopwatch|wallclock]() can be used to switch
Now to make a pass on all skarnet.org programs and add a
tain_now_set_stopwatch() call everywhere needed... >.>
Diffstat (limited to 'doc/flags.html')
| -rw-r--r-- | doc/flags.html | 30 |
1 files changed, 0 insertions, 30 deletions
diff --git a/doc/flags.html b/doc/flags.html index c901b1c..b74d344 100644 --- a/doc/flags.html +++ b/doc/flags.html @@ -175,36 +175,6 @@ and <tt>settimeofday()</tt> interfaces will be used. This is the default, and it's usually safe. </p> -<a name="usemon"><h3> --enable-monotonic </h3></a> - -<p> - Unless you have an accurate hardware system clock <em>and</em> you set it -on a linear time scale such as TAI-10 instead of UTC (see above), it is -generally a bad idea to trust the system clock for precise time interval -measurements. Single Unix recommends the use of <tt>clock_gettime()</tt> -with the CLOCK_MONOTONIC option to do such measurements: a stopwatch, not -a wall clock. However: -</p> - -<ul> - <li> CLOCK_MONOTONIC is even less portable than CLOCK_REALTIME. </li> - <li> It's a bit tricky to emulate absolute time calculations based on -CLOCK_MONOTONIC. </li> -</ul> - -<p> - If <tt>--enable-monotonic</tt> is set, then the absolute time given by the -<tt>tain_now()</tt> call will be computed with CLOCK_MONOTONIC. This -will ensure precise time arithmetic but may drift away from the system -clock. -</p> - -<p> - Otherwise, <tt>tain_now()</tt> will -return a time based on the system clock, and not use CLOCK_MONOTONIC. -This is the default. -</p> - <a name="noipv6"><h3> --disable-ipv6 </h3></a> <p> |