...(set up socket)...
my $end = time + 15*60;
my $rin;
vec($rin, fileno($hSocket), 1) = 1;
while (1) {
    my $timeleft = $end - time;
    last if ($timeleft <= 0);
    my ($nfound, $t) = select(my $rout = $rin, undef, undef, $timeleft);
    last if ($nfound == 0); # either timeout or end of file
    # read from socket here
}