| Subject: | Fetching fails with multiple requests to the same host. |
When an instance of Net-Async-HTTP is being used to issue several
requests to the same host, it fails. I'm using v5.8.8 built for x86_64-
linux-thread-multi on Linux 2.6.18-164.2.1.el5.028stab066.10 (CentOS
5.4).
Please consider the following sample code (a simple FastCGI script that
is supposed to fetch content from an uri and modify it in some way):
#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;
use Net::Async::FastCGI;
use IO::Async::Loop;
use Net::Async::HTTP;
use URI;
use Carp;
$SIG{ __DIE__ } = sub { Carp::confess( @_ ) };
my $loop = IO::Async::Loop->new();
my $http = Net::Async::HTTP->new();
my $fcgi = Net::Async::FastCGI->new(
on_request => sub {
my ( $fcgi, $r ) = @_;
$http->do_request(
uri => URI->new("http://test.com/test"),
on_response => sub {
my ($response) = @_;
$r->print_stdout("Status: 200 OK\r\n" .
"Content-type: text/html\r\n" . "\r\n");
$r->print_stdout("<pre>". Dumper $response);
$r->finish();
},
on_error => sub {
my ($message) = @_;
$r->print_stdout("Error: $message");
$r->finish();
}
)
}
);
$loop->add($fcgi);
$loop->add($http);
$fcgi->listen( service => 8888,
on_resolve_error => sub { print STDERR "Cannot resolve - $_[0]\n";
},
on_listen_error => sub { print STDERR "Cannot listen $_[0]\n"; },
);
$loop->loop_forever;
The above code works happily when called once. As soon as concurrent
requests are issues (i.e. ab -n 10 -c 2 uri), I'm getting the message
Can't call method "write" on an undefined value at
/usr/lib/perl5/site_perl/5.8.8/IO/Async/Protocol/Stream.pm line 200.
The backtrace follows:
Can't call method "write" on an undefined value at
/usr/lib/perl5/site_perl/5.8.8/IO/Async/Protocol/Stream.pm line 200.
at ./test.pl line 11
main::__ANON__('Can\'t call method "write" on an undefined value
at /usr/lib/...') called at
/usr/lib/perl5/site_perl/5.8.8/IO/Async/Protocol/Stream.pm line 200
IO::Async::Protocol::Stream::write('Net::Async::HTTP::Protocol=H
ASH(0x1e455650)', 'GET /test HTTP/1.1\x{d}\x{a}Host:
safein.us\x{d}\x{a}User-Agent: Perl + Net::...') called at
/usr/lib/perl5/site_perl/5.8.8/Net/Async/HTTP/Protocol.pm line 184
Net::Async::HTTP::Protocol::request('Net::Async::HTTP::Protocol=
HASH(0x1e455650)', 'request', 'HTTP::Request=HASH(0x1e4c9a10)',
'request_body', 'undef', 'on_header', 'CODE(0x1e4c96f0)', 'on_error',
'CODE(0x1e4c9600)', ...) called at
/usr/lib/perl5/site_perl/5.8.8/Net/Async/HTTP.pm line 503
Net::Async::HTTP::__ANON__('Net::Async::HTTP::Protocol=HASH(0x1e
455650)') called at /usr/lib/perl5/site_perl/5.8.8/Net/Async/HTTP.pm
line 166
Net::Async::HTTP::get_connection('Net::Async::HTTP=HASH(0x1e28ff
b0)', 'host', 'safein.us', 'port', 80, 'SSL', '', 'on_error',
'CODE(0x1e4c9600)', ...) called at
/usr/lib/perl5/site_perl/5.8.8/Net/Async/HTTP.pm line 510
Net::Async::HTTP::do_request('Net::Async::HTTP=HASH(0x1e28ffb0)'
, 'uri', 'URI::http=SCALAR(0x1e4551f0)', 'on_response',
'CODE(0x1e4c9520)', 'on_error', 'CODE(0x1e4c9600)') called at ./test.pl
line 40
main::__ANON__('Net::Async::FastCGI=HASH(0x1e290380)',
'Net::Async::FastCGI::Request=HASH(0x1e4bfd80)') called at
/usr/lib/perl5/site_perl/5.8.8/Net/Async/FastCGI.pm line 188
Net::Async::FastCGI::_request_ready('Net::Async::FastCGI=HASH(0x
1e290380)', 'Net::Async::FastCGI::Request=HASH(0x1e4bfd80)') called at
/usr/lib/perl5/site_perl/5.8.8/Net/Async/FastCGI/Request.pm line 146
Net::Async::FastCGI::Request::_ready_check('Net::Async::FastCGI:
:Request=HASH(0x1e4bfd80)') called at
/usr/lib/perl5/site_perl/5.8.8/Net/Async/FastCGI/Request.pm line 187
Net::Async::FastCGI::Request::incomingrecord_stdin('Net::Async::
FastCGI::Request=HASH(0x1e4bfd80)', 'HASH(0x1e2970a0)') called at
/usr/lib/perl5/site_perl/5.8.8/Net/Async/FastCGI/Request.pm line 131
Net::Async::FastCGI::Request::incomingrecord('Net::Async::FastCG
I::Request=HASH(0x1e4bfd80)', 'HASH(0x1e2970a0)') called at
/usr/lib/perl5/site_perl/5.8.8/Net/Async/FastCGI/ServerProtocol.pm line
84
Net::Async::FastCGI::ServerProtocol::on_record('Net::Async::Fast
CGI::ServerProtocol=HASH(0x1e461410)', 1, 'HASH(0x1e2970a0)') called at
/usr/lib/perl5/site_perl/5.8.8/Net/Async/FastCGI/Protocol.pm line 65
Net::Async::FastCGI::Protocol::on_read('Net::Async::FastCGI::Ser
verProtocol=HASH(0x1e461410)', 'SCALAR(0x1e455d20)', '') called at
/usr/lib/perl5/site_perl/5.8.8/IO/Async/Notifier.pm line 634
IO::Async::Notifier::invoke_event('Net::Async::FastCGI::ServerPr
otocol=HASH(0x1e461410)', 'on_read', 'SCALAR(0x1e455d20)', '') called at
/usr/lib/perl5/site_perl/5.8.8/IO/Async/Protocol/Stream.pm line 159
IO::Async::Protocol::Stream::__ANON__('undef',
'IO::Async::Stream=HASH(0x1e460fc0)', 'SCALAR(0x1e455d20)', '') called
at /usr/lib/perl5/site_perl/5.8.8/IO/Async/Notifier.pm line 634
IO::Async::Notifier::invoke_event('IO::Async::Stream=HASH(0x1e46
0fc0)', 'on_read', 'SCALAR(0x1e455d20)', '') called at
/usr/lib/perl5/site_perl/5.8.8/IO/Async/Stream.pm line 553
IO::Async::Stream::on_read_ready('undef') called at
/usr/lib/perl5/site_perl/5.8.8/IO/Async/Loop/Poll.pm line 146
IO::Async::Loop::Poll::post_poll('IO::Async::Loop::Poll=HASH(0x1
e28fe40)') called at
/usr/lib/perl5/site_perl/5.8.8/IO/Async/Loop/Poll.pm line 214
IO::Async::Loop::Poll::loop_once('IO::Async::Loop::Poll=HASH(0x1
e28fe40)', 'undef') called at
/usr/lib/perl5/site_perl/5.8.8/IO/Async/Loop.pm line 432
IO::Async::Loop::loop_forever('IO::Async::Loop::Poll=HASH(0x1e28
fe40)') called at ./test.pl
I'm looking into this myself, trying to reproduce with more recent perl
version, and will provide the patch if I'll be able to solve the issue,
but any help from the author or anyone else will be highly appreciated.
Thank you,
Greg.