I remember that there was a good description in the Camel book (16: Signals - Timing out Slow Operations). Since Perl tries to recover from interrupted system calls, a eval/die-construct was necessary to handle this situation properly. A similar description can be found in the perlipc-doc after the second occurrence of longjmp.

You've probably done that, but if not then you should consider resetting the alarm after successful completion (alarm(0);).

Update: In the Camel book example, the alarm was cleared again after the eval-block to cope with a race condition when the signal occurred after a successful IO operation but before resetting the alarm within the same eval block. I am not sure if this is still an issue with modern kernels.

In reply to Re: Best way to timeout on a read by Perlbotics
in thread Best way to timeout on a read by pileofrogs

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.