timeout problem in IO::Socket

[p5pRT]

Migrated from rt.perl.org#2167 (status was 'resolved')

Searchable as RT2167$

[p5pRT]

From wilfredm@inet.kpn.com

Created by wmollenvanger@yahoo.com

The LWP library I'm using had problems with defined timeouts so I traced
it
back to IO​::Socket​::connect​:

sub connect {
  @​_ == 2 || @​_ == 3 or croak 'usage​: $fh->connect(NAME) or
$fh->connect(PORT, ADDR)';
  my $fh = shift;
  my $addr = @​_ == 1 ? shift : sockaddr_in(@​_);
  my $timeout = ${*$fh}{'io_socket_timeout'};
  local($SIG{ALRM}) = $timeout ? sub { undef $fh; }
  : $SIG{ALRM} || 'DEFAULT';

  eval {
  croak 'connect​: Bad address'
  if(@​_ == 2 && !defined $_[1]);

  if($timeout) {
  defined $Config{d_alarm} && defined alarm($timeout) or
  $timeout = 0;
  }

  my $ok = connect($fh, $addr);

  alarm(0)
  if($timeout);

  croak "connect​: timeout"
  unless defined $fh;

  undef $fh unless $ok;
  };

  $fh;
}

Shouldn't the line were the signal handler is defined read​:

local($SIG{ALRM}) = $timeout ? sub { undef $fh; die; }
  : $SIG{ALRM} || 'DEFAULT';

otherwise it will 'never' timeout on the connect() call.

Regards,

Wilfred.

Perl Info

Site configuration information for perl 5.00503:

Configured by root at Mon Aug 30 23:08:56 EDT 1999.

Summary of my perl5 (5.0 patchlevel 5 subversion 3) configuration:
  Platform:
    osname=linux, osvers=2.2.5-22smp, archname=i386-linux
    uname='linux porky.devel.redhat.com 2.2.5-22smp #1 smp wed jun 2
09:11:51 edt 1999 i686 unknown '
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=undef useperlio=undef d_sfio=undef
  Compiler:
    cc='cc', optimize='-O2', gccversion=egcs-2.91.66 19990314/Linux
(egcs-1.1.2
release)
    cppflags='-Dbool=char -DHAS_BOOL -I/usr/local/include'
    ccflags ='-Dbool=char -DHAS_BOOL -I/usr/local/include'
    stdchar='char', d_stdstdio=undef, usevfork=false
    intsize=4, longsize=4, ptrsize=4, doublesize=8
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
    alignbytes=4, usemymalloc=n, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lnsl -ldl -lm -lc -lposix -lcrypt
    libc=, so=so, useshrplib=false, libperl=libperl.a
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-rdynamic'

    cccdlflags='-fpic', lddlflags='-shared -L/usr/local/lib'

Locally applied patches:



@INC for perl 5.00503:
    /usr/lib/perl5/5.00503/i386-linux
    /usr/lib/perl5/5.00503
    /usr/lib/perl5/site_perl/5.005/i386-linux
    /usr/lib/perl5/site_perl/5.005
    .


Environment for perl 5.00503:
    HOME=/export/home/wilfredm
    LANG=en_US
    LANGUAGE (unset)
    LC_ALL=en_US
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)

PATH=/usr/bin:/bin:/usr/X11R6/bin:/usr/local/bin:/opt/bin:/usr/X11R6/bin:/export/home/wilfredm/bin:/usr/local/ssh/bin:

    PERL_BADLANG (unset)
    SHELL=/bin/bash

[p5pRT]

From @gisle

Wilfred Mollenvanger <wilfredm@​inet.kpn.com> writes​:

-----------------------------------------------------------------
[Please enter your report here]
The LWP library I'm using had problems with defined timeouts so I traced
it back to IO​::Socket​::connect​:

sub connect {
@​_ == 2 || @​_ == 3 or croak 'usage​: $fh->connect(NAME) or
$fh->connect(PORT, ADDR)';
my $fh = shift;
my $addr = @​_ == 1 ? shift : sockaddr_in(@​_);
my $timeout = ${*$fh}{'io_socket_timeout'};
local($SIG{ALRM}) = $timeout ? sub { undef $fh; }
: $SIG{ALRM} || 'DEFAULT';

 eval \{
    croak 'connect​: Bad address'
        if\(@​\_ == 2 && \!defined $\_\[1\]\);

    if\($timeout\) \{
        defined $Config\{d\_alarm\} && defined alarm\($timeout\) or
            $timeout = 0;
    \}

    my $ok = connect\($fh\, $addr\);

    alarm\(0\)
        if\($timeout\);

    croak "connect​: timeout"
        unless defined $fh;

    undef $fh unless $ok;
\};

$fh;

}

Shouldn't the line were the signal handler is defined read​:

local($SIG{ALRM}) = $timeout ? sub { undef $fh; die; }
: $SIG{ALRM} || 'DEFAULT';

otherwise it will 'never' timeout on the connect() call.

The latest version of IO​::Socket, which is bundled with perl5.5.650
(perl's latest development release) will use non-blocking connect
instead of alarm. You can can achieve the same with perl5.005_03 by
installing IO-1.20 from CPAN.

I don't know if perl5.005_04 if/when it comes out will try to upgrade
the IO modules, but I doubt it.

Regards,
Gisle

[hell288]

Duplicate of #23815