On Mon, Apr 30, 2012 at 10:50:50AM +1200, Michael Kerrisk (man-pages) wrote: > tags 540872 fixed-upstream > thanks > > Hi Josh! > > On Mon, Apr 30, 2012 at 7:15 AM, Josh Triplett <j...@joshtriplett.org> wrote: > > On Sun, Apr 29, 2012 at 10:40:48PM +1200, Michael Kerrisk (man-pages) wrote: > >> On Sun, Apr 29, 2012 at 10:21 AM, Simon Paillard <spaill...@debian.org> > >> wrote: > >> > tags + upstream > >> > thanks > >> > > >> > Hi, > >> > > >> > On Mon, Aug 10, 2009 at 11:30:34AM -0700, Josh Triplett wrote: > >> >> Package: manpages > >> >> Version: 3.22-1 > >> >> Severity: wishlist > >> >> > >> >> Developers of real-time programs (programs using real-time scheduling > >> >> and/or expecting low latency) sometimes see CLOCK_REALTIME and think > >> >> they want to use that, when they almost certainly don't. Please > >> >> consider adding some clarification that the "real-time" of > >> >> CLOCK_REALTIME refers to wall-clock time (as opposed to CPU or process > >> >> time, for instance) and that developers of real-time applications want > >> >> to use CLOCK_MONOTONIC. > >> > > >> > Michael Kerrisk improved clock_getres.2 in manpages 3.40: > >> > > >> > .B CLOCK_MONOTONIC > >> > Clock that cannot be set and represents monotonic time since > >> > some unspecified starting point. > >> > +This clock is not affected by discontinuous jumps in the system time > >> > +(e.g., if the system administrator manually changes the clock), > >> > +but is affected by the incremental adjustments performed by > >> > +.BR adjtime (2) > >> > +and NTP. > >> > > >> > Maybe one can add (please proofread my english): > >> > "This clock allow to precisely measuring time elapsed, for use in > >> > real-time programs." > >> > > >> > http://pubs.opengroup.org/onlinepubs/009604599/functions/clock_getres.html > >> > >> Simon, would that text not better apply to CLOCK_MONOTONIC_RAW? > > > > Probably, yes. > > > > Ideally, I'd also like to see something like this added to the > > description of CLOCK_REALTIME, to help avert a common trap people fall > > into: > > > > 'The "realtime" in the name CLOCK_REALTIME refers to wall-clock time, > > not to suitability for realtime (latency-sensitive) applications. Such > > applications generally want to use CLOCK_MONOTONIC or > > CLOCK_MONOTONIC_RAW.' > > How about doing this in a different way. Instead of pointing the > reader at CLOCK_MONOTONIC*, let's be more explicit about what > CLOCK_REALTIME is, so that it's evident to the designer of a realtime > application that they don't want this clock. > > [[ > .TP > .B CLOCK_REALTIME > System-wide clock that measures real (i.e., wall-clock) time. > Setting this clock requires appropriate privileges. > This clock is affected by discontinuous jumps in the system time > (e.g., if the system administrator manually changes the clock), > and by the incremental adjustments performed by > .BR adjtime (2) > and NTP. > ]]
Works for me. - Josh Triplett -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
