Beefy Boxes and Bandwidth Generously Provided by pair Networks
Problems? Is your data what you think it is?
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??

The memory cleanup on perl's exit, is a whole other type of cleanup I'm afraid. Perl allocates a bunch of memory from the OS, but the problem is in how it uses this memory itself. The memory is returned to the OS at perl exit offcourse.

Doing the same kind of cleanup without exiting perl would probably not be a trivial change to perl. Just an example of a problem you'd encounter would be how to handle the special global variables that are linked to the perl parameters from the shebang (#!) line...

A bigger problem though, would be that cleaning up all of the memory would mean all modules would have to be reloaded too, and the module loading and initialisation is often even slower then the perl interpreter loading...

As a perl module can change variables in *any* namespace, so we can't just clear the part of the namespace it's using, and keep it loaded. There is just no proper way to 'reset' a running perl to initial state. The 'flow' of compilation can change, because of the existence of stuff like BEGIN blocks, so the line between compilation time and runtime can get blurry. This makes resetting perls internal state even harder...

It's for these reasons that mod_perl has the complexity is has, and that the programmer needs to be aware of the persistent behaviour some variables may exhibit. There's just no way around it I'm afraid... Not without removing a ton of functionality from perl itself, which in turn would break half the modules out there that people are using.

It's a hard subject to explain without getting into deep technical detail, but I hope I've hinted in the right direction...


In reply to Re^3: More than mod_cgi less than mod_perl. by Gilimanjaro
in thread More than mod_cgi less than mod_perl. by techcode

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!
  • 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, 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, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • Outside of code tags, you may need to use entities for some characters:
            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.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others perusing the Monastery: (9)
    As of 2014-07-25 23:16 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      My favorite superfluous repetitious redundant duplicative phrase is:









      Results (175 votes), past polls