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 (<a href="http://en.wikipedia.org/wiki/Inotify">http://en.wikipedia.org/wiki/Inotify</a>), but I&#39;m pretty sure that other OSes have similar interfaces. The &quot;modification time&quot; method seems really fragile and I probably not very efficient as well.<div>

<br></div><div>Best regards,</div><div>Krzysztof Skrzętnicki<br><br><div class="gmail_quote">On Thu, Dec 16, 2010 at 17:50, Arnaud Bailly <span dir="ltr">&lt;<a href="mailto:arnaud.oqube@gmail.com">arnaud.oqube@gmail.com</a>&gt;</span> wrote:<br>

<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">actually, IRL the code works as expected. Might it be possible that<br>
the speed of test execution is greater than the granularity of the<br>
system&#39;s modification timestamp?<br>
<div><div></div><div class="h5"><br>
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