Re: Using flock() on files

You can't lock a file without having a filehandle that references that file;
File locks do not survive fork().

One possible solution to your problem would be to have a DBF file with a list of all files that are currently locked. The files themselves would not be locked via flock() but access to the DBF file would be gated through flock().
Advantage: locks will be maintained even if your server/client crashes and is then restarted;
Disadvantage: having all processes use the same file may create a bottleneck. To minimize the probability of this happening, make sure the DBF file is locked only when necessary.

Hope this helps.

--perlplexer

Comment on Re: Using flock() on files

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Re: Re: Using flock() on files by no_slogan (Deacon) on Apr 20, 2003 at 08:23 UTC
locks will be maintained even if your server/client crashes and is then restarted This is not necessarily an advantage. You need a way to break old, stale locks that might be left behind after a crash.	[reply]
Re: Re: Re: Using flock() on files by perlplexer (Hermit) on Apr 20, 2003 at 14:13 UTC
I view this as an advantage because I'd rather have the locks stay than have corrupt data. You can easily write a tool for cleaning up old locks; writing a tool for restoring corrupt data, however, may not even be possible depending on what kind of data you're dealing with. --perlplexer	[reply]