It seems that for this specific problem you should be able to use IO::Select ( which uses select ( the 3 or 4 arg version ) ). It would go a little something like this:

#!/usr/bin/perl -w
use strict;

use IO::Select;

my $timeout = '10'; # We'll wait for up to 10 seconds for input.
my @pslist;

    my $pid = open(my $shell, " ssh -2 $user\@ $peer ./pslist | ")
        || die "Remote process list gathering error:\n$!.\n";

    my $select = IO::Select->new($shell);

    my $handle;
    while($handle = $select->can_read($timeout)){
        chomp($_ = <$shell>);
        last unless $_;
        push(@pslist, $_);
    }
    close($shell);

    unless ($handle) {abort();}
     
    foreach (@service){
        # .. check the existence of a process
    }
[download]