| 1 |
=head1 NAME |
| 2 |
|
| 3 |
Coro::LWP - make LWP non-blocking - as much as possible |
| 4 |
|
| 5 |
=head1 SYNOPSIS |
| 6 |
|
| 7 |
use Coro::LWP; # afterwards LWP should not block |
| 8 |
|
| 9 |
=head1 DESCRIPTION |
| 10 |
|
| 11 |
This module tries to make L<LWP|LWP> non-blocking with respect to other |
| 12 |
coroutines as much as possible, and with whatever means it takes. |
| 13 |
|
| 14 |
LWP really tries very hard to be blocking, so this module had to be very |
| 15 |
invasive and must be loaded very early to take the proper effect. |
| 16 |
|
| 17 |
Here is what it currently does (future versions of LWP might require |
| 18 |
different tricks): |
| 19 |
|
| 20 |
=over 4 |
| 21 |
|
| 22 |
=item It loads Coro::Select, overwriting the perl C<select> builtin I<globally>. |
| 23 |
|
| 24 |
This is necessary because LWP calls select quite often for timeouts and |
| 25 |
who-knows-what. |
| 26 |
|
| 27 |
Impact: everybody else uses this (slower) version of select, too. It should be quite |
| 28 |
compatible to perls builtin select, though. |
| 29 |
|
| 30 |
=item It overwrites Socket::inet_aton with Coro::Util::inet_aton. |
| 31 |
|
| 32 |
This is necessary because LWP might (and does) try to resolve hostnames |
| 33 |
this way. |
| 34 |
|
| 35 |
Impact: likely little, the two functions should be pretty equivalent. |
| 36 |
|
| 37 |
=item It replaces the base class of Net::HTTP, Net::FTP, Net::NNTP. |
| 38 |
|
| 39 |
This is necessary because LWP does not always use select to see wether |
| 40 |
a filehandle can be read/written without blocking, so the base class |
| 41 |
C<IO::Socket::INET> needs to be replaced by C<Coro::Socket>. |
| 42 |
|
| 43 |
Impact: Coro::Socket is not at all compatible to IO::Socket::INET. While |
| 44 |
it duplicates some undocumented functionality required by LWP, it does not |
| 45 |
have all the methods of IO::Socket::INET and might act quite differently |
| 46 |
in practise. Also, protocols other than the above mentioned will still block, |
| 47 |
at least some of the time. |
| 48 |
|
| 49 |
=back |
| 50 |
|
| 51 |
All this likely makes other libraries than just LWP not block, but thats |
| 52 |
just a side effect you cannot rely on. |
| 53 |
|
| 54 |
Increases parallelism is not supported by all libraries, some might cache |
| 55 |
data globally. |
| 56 |
|
| 57 |
=cut |
| 58 |
|
| 59 |
package Coro::LWP; |
| 60 |
|
| 61 |
use strict; |
| 62 |
|
| 63 |
use Coro::Select; |
| 64 |
use Coro::Util; |
| 65 |
use Coro::Socket; |
| 66 |
|
| 67 |
use Socket; |
| 68 |
use IO::Socket::INET; |
| 69 |
|
| 70 |
use Net::HTTP; |
| 71 |
use Net::FTP; |
| 72 |
use Net::NNTP; |
| 73 |
|
| 74 |
our $VERSION = '0.9'; |
| 75 |
|
| 76 |
*Socket::inet_aton = \&Coro::Util::inet_aton; |
| 77 |
|
| 78 |
for (@Net::HTTP::ISA, @Net::FTP::ISA, @Net::NTTP::ISA) { |
| 79 |
$_ = Coro::LWP::Socket:: if $_ eq IO::Socket::INET::; |
| 80 |
} |
| 81 |
|
| 82 |
package Coro::LWP::Socket; |
| 83 |
|
| 84 |
use base Coro::Socket::; |
| 85 |
|
| 86 |
sub new { |
| 87 |
my $self = shift; |
| 88 |
|
| 89 |
$self->SUPER::new (@_, partial => 1) |
| 90 |
} |
| 91 |
|
| 92 |
1; |
| 93 |
|
| 94 |
=head1 AUTHOR |
| 95 |
|
| 96 |
Marc Lehmann <schmorp@schmorp.de> |
| 97 |
http://home.schmorp.de/ |
| 98 |
|
| 99 |
=cut |
| 100 |
|
| 101 |
|
