You've commented out "seek" but you say using "sysseek" was a problem. "seek" will not work with syswrite, you must use sysseek. If you were using sysseek, how did it break things (i.e. compared to how they are broken without it)?

If you are going to sort the output anyway, one way of handling this might be to have each writer send output to it's own file, then concatenate/sort the files all at the same time at the end.

If you are writing output lines one at a time, you may be able to just open the file in append mode and write that way, without locks. I think this is OS/stdlib dependent so YMMV. UPDATE: Now that I think about it, this last suggestion just sounds bad. I forgot that I always use locks even in this case since there is no guarantee that the perl/OS/stdlib/whatever will support this in the future even on a machine I believe works this way today.

In reply to Re: What the flock!? Concurrency issues in file writing. by bluto
in thread What the flock!? Concurrency issues in file writing. by suaveant

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.