Re: Non-Blocking Semaphore

Have you tried using alarm()?

# untested with your particular situation, but should be a guide.
 eval {
        local $SIG{ALRM} = sub { die "lock\n" }; # NB: \n required
        alarm 5;
        flock(LOCK, LOCK_EX | LOCK_NB);
        alarm 0;
    };
    if ($@) {
        die unless $@ eq "lock\n";   
    } else {
        # keep going
    }
[download]

Cheers,
KM

Comment on Re: Non-Blocking Semaphore Download Code

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RE: Re: Non-Blocking Semaphore by maverick (Curate) on Aug 26, 2000 at 03:52 UTC
That would do the trick. But only if timing isn't critical as alarm isn't precise (like sleep) and if your timeout is always some number of whole seconds. /\/\averick	[reply]
RE (tilly) 3: Non-Blocking Semaphore by tilly (Archbishop) on Aug 26, 2000 at 09:59 UTC
Time::HiRes offers ualarm if you want and your OS has the command available. You can import their alarm as well. Yet another solution on systems which support SysV semantics (Linux does, Windows probably doesn't...) is to use IPC::Semaphore.	[reply]