but it still does not work

What doesn't work?

The timeout works fine. I changed 

my $scheme_pid = open (WORKER, "worker_program < $input |")

[download]
to 
my $scheme_pid = open (WORKER, "-|", $^X, '-e', '$|=1; for (1..100) { 
+print "%d\n", $_*$t; sleep(2) }')

[download]

and the timeout triggered. The log file contained only "0".

You'll need to fix the return 1, though. That will only return out of the eval, not out of the sub.

In reply to Re^4: Cannot catch ALRM signal for timeout by ikegami
in thread Cannot catch ALRM signal for timeout by Magice

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.