Re: [Haskell-cafe] Behaviour of System.Directory.getModificationTime
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 12/17/10 06:22 , Arnaud Bailly wrote: Thanks for your answers. I am a little bit surprised, I thought timestamps were on the milliseconds scale. POSIX timestamps are seconds. - -- brandon s. allbery [linux,solaris,freebsd,perl] allb...@kf8nh.com system administrator [openafs,heimdal,too many hats] allb...@ece.cmu.edu electrical and computer engineering, carnegie mellon university KF8NH -BEGIN PGP SIGNATURE- Version: GnuPG v2.0.10 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk0Ss28ACgkQIn7hlCsL25XpygCgziZm1KyO+dP00ACtIrfsueJg 0dQAoI6hNz3oSmiIO2kAiXtRmowWwAg1 =wAHu -END PGP SIGNATURE- ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Behaviour of System.Directory.getModificationTime
Thanks for your answers. I am a little bit surprised, I thought timestamps were on the milliseconds scale. @Krzysztof: Yes, you are right, an event-based interface is far superior to the basic polling approach I took. At present, a couple seconds granularity is fine with my use case so I don't care too much getting more precise notifications, but I'd rather be notified by the kernel than going through the hassle of polling it myself. I played a bit with inotify (through a Java binding) a year ago and found it a bit cumbersome to wield as one has to monitor explicitly all nodes in a tree. Maybe I am wrong. Moreover, I am not aware of a portable way of doing this. I would appreciate pointers and advices on these matters. Thanks again, arnaud 2010/12/16 Krzysztof Skrzętnicki gte...@gmail.com: If this is not a toy program I would really suggest using something that is builtin in the OS of choice. On Linux there is inotify (http://en.wikipedia.org/wiki/Inotify), but I'm pretty sure that other OSes have similar interfaces. The modification time method seems really fragile and I probably not very efficient as well. Best regards, Krzysztof Skrzętnicki On Thu, Dec 16, 2010 at 17:50, Arnaud Bailly arnaud.oq...@gmail.com wrote: actually, IRL the code works as expected. Might it be possible that the speed of test execution is greater than the granularity of the system's modification timestamp? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Behaviour of System.Directory.getModificationTime
actually, IRL the code works as expected. Might it be possible that the speed of test execution is greater than the granularity of the system's modification timestamp? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Behaviour of System.Directory.getModificationTime
Yes, modification times are reported in seconds, so you'll have to wait on average 0.5s for a file change to be visible via the modification date. Due to buffers and filesystem optimisations it might even take longer. On 16 December 2010 16:50, Arnaud Bailly arnaud.oq...@gmail.com wrote: actually, IRL the code works as expected. Might it be possible that the speed of test execution is greater than the granularity of the system's modification timestamp? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- Push the envelope. Watch it bend. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Behaviour of System.Directory.getModificationTime
If this is not a toy program I would really suggest using something that is builtin in the OS of choice. On Linux there is inotify ( http://en.wikipedia.org/wiki/Inotify), but I'm pretty sure that other OSes have similar interfaces. The modification time method seems really fragile and I probably not very efficient as well. Best regards, Krzysztof Skrzętnicki On Thu, Dec 16, 2010 at 17:50, Arnaud Bailly arnaud.oq...@gmail.com wrote: actually, IRL the code works as expected. Might it be possible that the speed of test execution is greater than the granularity of the system's modification timestamp? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
