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=head1 NAME |
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Coro::LWP - make LWP non-blocking - as much as possible |
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=head1 SYNOPSIS |
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use Coro::LWP; # afterwards LWP should not block |
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=head1 DESCRIPTION |
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This module tries to make L<LWP|LWP> non-blocking with respect to other |
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coroutines as much as possible, and with whatever means it takes. |
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LWP really tries very hard to be blocking, so this module had to be very |
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invasive and must be loaded very early to take the proper effect. |
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Here is what it currently does (future versions of LWP might require |
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different tricks): |
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=over 4 |
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=item It loads Coro::Select, overwriting the perl C<select> builtin I<globally>. |
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This is necessary because LWP calls select quite often for timeouts and |
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who-knows-what. |
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Impact: everybody else uses this (slower) version of select, too. It should be quite |
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compatible to perls builtin select, though. |
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=item It overwrites Socket::inet_aton with Coro::Util::inet_aton. |
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This is necessary because LWP might try to resolve hostnames this way. |
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Impact: likely little, the two functions should be pretty equivalent. |
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=item It overwrites IO::Socket::INET::new with Coro::Socket::new |
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This is necessary because LWP does not always use select to see wether a |
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filehandle can be read/written without blocking. |
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Impact: Coro::Socket is not at all compatible to IO::Socket::INET. While |
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it duplicates some undocumented functionality required by LWP, it does not |
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have all the methods of IO::Socket::INET and might act quite differently |
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in practise. Every app that uses IO::Socket::INET now has to cope with |
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Coro::Socket. |
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=back |
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All this likely makes other libraries than just LWP not block, but thats |
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just a side effect you cannot rely on. |
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Increases parallelism is not supported by all libraries, some might cache |
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data globally. |
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=cut |
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package Coro::LWP; |
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use strict; |
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use Coro::Select; |
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use Coro::Util; |
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use Coro::Socket; |
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use Socket; |
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use IO::Socket::INET; |
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*Socket::inet_aton = \&Coro::Util::inet_aton; |
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*IO::Socket::INET::new = sub { |
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new Coro::Socket forward_class => @_; |
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}; |
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=cut |
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=head1 AUTHOR |
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Marc Lehmann <schmorp@schmorp.de> |
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http://home.schmorp.de/ |
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=cut |
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