Taking tilly's advice, I wrote the following code, which seems to avoid the segfault all together!

Much, much thanks to tilly. Let me know if there's anything wrong.

use strict;
use Carp;
use IO::Select;
use Storable qw/ nfreeze thaw /;

sub send
{
        my( $socket, $hash, $timeout ) = @_;

        return undef if( !_is_valid_socket( $socket ) );

        foreach my $key ( keys %{ $hash } ) {
                if( !exists $hash->{ lc $key } ) {
                        $hash->{ lc $key } = $hash->{ $key };
                        delete $hash->{ $key };
                }
        }
        my $select = IO::Select->new( $socket );

        my $data = nfreeze( $hash );

        my $message = sprintf(
                "Content-Length: %d\015\012" , length( $data )
        );
        $message .= "\015\012" . $data;

        my $sofar = 0;
        $timeout ||= 60;

        while( $sofar != length( $message ) ) {
                last if( !_is_valid_socket( $socket ) );
                last if( !$select->can_write( $timeout ) );

                my $bytes = syswrite(
                        $socket, $message, length($message) - $sofar, 
+$sofar
                );
                $sofar += $bytes;
        }

        if( $sofar != length( $message ) ){
                return 0;
        }

        return 1;
}

sub _is_valid_socket
{
        my $socket = shift;

        return undef if !$socket;
        if( ref( $socket ) eq 'IO::Socket::INET' ) {
                return undef if !$socket->opened;
                return undef if $socket->error;
        } else {
                return undef if !fileno( $socket );
        }

        return 1;
}

sub read
{
        my $socket = shift;
        my $timeout = shift;
        return undef if( !_is_valid_socket( $socket ) );

        my $buf = '';
        my $select = IO::Select->new( $socket );
        while( 1 ) {
                last if( !_is_valid_socket( $socket ) );
                last if( !$select->can_read( $timeout ) );

                my $read_bytes = sysread( $socket, $buf, 8192, length(
+ $buf ) );

                last unless $read_bytes;

                if( my $pos = index( $buf, "\015\012\015\012" ) ) {
                        my( $headers, $data ) = (
                                substr( $buf, 0, $pos ),
                                substr( $buf, $pos + 4 )
                        );
                        my %headers = ( $headers =~ m{^\s*([a-zA-Z0-9_
+-]+)\s*:\s
*([a-zA-Z0-9_-]+)\s*(?:\015\012)?$}msg );

                        foreach my $key( keys %headers ) {
                                $headers{ lc $key } = $headers{ $key }
+;
                        }

                        ## Now read Content-Length bytes from the stre
+am
                        my $sofar = length( $data );
                        my $toread = $headers{ 'content-length' };
                        while( $sofar != $toread ) {
                                last if( !_is_valid_socket( $socket ) 
+);
                                last if( !$select->can_read( $timeout 
+) );

                                $read_bytes = sysread( $socket, $data,
+ 8192, len
gth( $data ) );
                                last unless $read_bytes;
                                $sofar += $read_bytes;
                        }

                        if( $sofar != $toread ) {
                                return undef;
                        }
                        my $object = eval{ thaw( $data ) };
                        if( $@ ) {
                                return undef;
                        } else {
                                return $object;
                        }
                }
        }
}
[download]