Unfortunately, gethostbyname is not reentrant.
(maybe a stupid question) Is there any particular reason why you cannot use
multiple processes instead?
Typed on a very small keyboard...
------------------------------
From: Jesper Persson <jesper.j.pers...@gmail.com>
Sent: 29/05/2013 07:17
To: libwww <libwww@perl.org>
Subject: is IO:Socket:INET thread safe?
Hi everybody,
I have a multithreaded program that monitors the content of web pages.
On a newly installed CentOS server I have seen strange behaviour where I
get 404 because http request is sent to a wrong ip address not maching the
domain that was requested.
I have inserted a print statement in IO:Socket:INET.pm in the procedure
_get_addr
to see what ip address the domain is translated to:
sub _get_addr {
my($sock,$addr_str, $multi) = @_;
my @addr;
if ($multi && $addr_str !~ /^\d+(?:\.\d+){3}$/) {
(undef, undef, undef, undef, @addr) = gethostbyname($addr_str);
} else {
my $h = inet_aton($addr_str);
push(@addr, $h) if defined $h;
}
open(FH, ">>/tmp/socket_get_addr.log");
print FH localtime().": addr_str: $addr_str, addr:
".inet_ntoa($addr[0])."\n";
close(FH);
@addr;
}
>From the log file:
Wed May 29 07:38:09 2013: addr_str: dk1.siteimprove.com, addr: 93.160.60.57
Wed May 29 07:38:09 2013: addr_str: siteimprove.dk, addr: 93.160.60.57
the ip address of siteimprove.dk is wrong and at the same second just
before a lookup of dk1.siteimprove.com gets the same ip address and that is
correct.
7 minutes later in the log file the siteimprove.dk domain is looked up
correctly:
Wed May 29 07:45:11 2013: addr_str: siteimprove.dk, addr: 93.160.60.87
Manually looking up the ip on then server gets the right ip address.
this entry is in the hosts file:
93.160.60.87 siteimprove.dk
CentOS release 6.3 (Final)
Summary of my perl5 (revision 5 version 10 subversion 1) configuration:
IO:Socket:INET version: $VERSION = "1.31";
Any help would be greatly appreciated.
Regards
Jesper Persson
