Beefy Boxes and Bandwidth Generously Provided by pair Networks
Just another Perl shrine

Comment on

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

local %ENV doesn't remove the magic attached to %ENV, so changes to %ENV still affect every thread, so the race condition remains.

THREAD 1 THREAD 2 ---------------------------------- ------------------------------ +---- { T local %ENV; i -> Process's R_M remains undef m $ENV{REQUEST_METHOD} = 'GET'; e -> Process's R_M becomes GET | | { | local %ENV; v -> Process's R_M becomes undef $ENV{REQUEST_METHOD} = 'PUT'; -> Process's R_M becomes PUT print($ENV{REQUEST_METHOD}); -> Prints process's R_M (PUT) } -> Process's R_M restored to undef print($ENV{REQUEST_METHOD}); -> Prints process's R_M (undef +) } -> Process's R_M restored to u +ndef

That's why I suggested local *ENV instead. Then modifying %ENV doesn't change the processes environment.

Update: Added illustration of two race conditions.

In reply to Re^2: Populate CGI from HTTP::Request wo/ using %ENV ? by ikegami
in thread Populate CGI from HTTP::Request wo/ using %ENV ? by renodino

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?

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

    How do I use this? | Other CB clients
    Other Users?
    Others examining the Monastery: (6)
    As of 2015-01-27 06:43 GMT
    Find Nodes?
      Voting Booth?

      My top resolution in 2015 is:

      Results (197 votes), past polls