When I wanted this, I could not find what I was looking for on CPAN. It may have been there, I just didn't see it. For instance if you go browse for descriptions on CPAN you will find that File::Flock and File::BasicFlock just are more sophisticated versions of the flock() command. So they do not implement the semantics that I wanted. The File::Lock module looked closer, but it had only a very simple OO interface that was not fired by destruction.

In general all of the things I saw on CPAN were wrappers around the idea, "let us give better/more detailed ways to lock stuff" while I wanted, "Gimme an incredibly easy 'get a lock' semantic that I won't mess up on."

However KM pointed out to me that the system call to "touch" is not the best approach if the file does not exist. I should really either do that in Perl or else use File::Flock.

FWIW I use this for wrapping a lot of complex operations. For instance if I want a set of processes to go in order, I just have them start in order and attempt to grab a lock. They will not succeed until the previous process drops the lock. I can then combine this in some processes with a timeout_limit argument and send a page if it does not succeed...

In reply to RE (2): Simple Locking by tilly
in thread Simple Locking by tilly

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.