Bug #47411 for File-Pid-Quick: use non-blocking flock

Sun Jun 28 05:13:46 2009 blue [...] thisisnotmyrealemail.com - Ticket created

Subject:

use non-blocking flock

use flag LOCK_NB with flock to avoid blocking or do something like mentioned in perlopentut. also, i think sysopen, instead of open, should be used before locking the file

Fri Feb 05 16:45:11 2010 chaos [...] cpan.org - Correspondence added 15 min

On Sun Jun 28 05:13:46 2009, blue wrote: Show quoted text

> use flag LOCK_NB with flock to avoid blocking or do something like > mentioned in perlopentut. > > also, i think sysopen, instead of open, should be used before locking > the file

There isn't any way to correctly integrate use of LOCK_NB. If finding an exclusive lock on the PID file is interpreted as meaning we should exit, there's then no way to implement the timeout value, since that requires reading the file. If we were going to just go ahead and read the file despite the lock, there's no point checking the lock in the first place; the reason we do is that the only time the file should be locked is because another process is literally in the middle of writing its content, which means its content is unreliable. Can you justify for me why you think sysopen should be used in preference to open?

Fri Feb 05 16:45:14 2010 The RT System itself - Status changed from 'new' to 'open'

Fri Feb 05 17:42:36 2010 chaos [...] cpan.org - Taken