On May 15, King, Jason said: >>A rather clever way to emulate locking is to use mkdir() and rmdir(). >> >>Although it requires you to create a lock file, it's atomic and safe. > >are you sure ? .. just because it constitutes one Perl statement doesn't >mean that it's atomic .. I suspect mkdir has several steps internally > >if you're sure then can you please provide references to the atomicity of >mkdir .. because it's a great find if it's truly atomic - many peopl believe >there to be no atomic file locking operation on Win9x machines Here are some references: http://www.davin.ottawa.on.ca/archive/modperl/2000-09/msg00683.phtml http://mail-index.netbsd.org/tech-security/1997/03/24/0010.html http://mail.gnu.org/pipermail/info-cvs/2000-December/011597.html They say that mkdir() is atomic ON A SERVER -- if you're on an NFS, all bets are off. The Perl Cookbook mentions the mkdir+rmdir locking scheme. I think that's a pretty safe bet. -- Jeff "japhy" Pinyan [EMAIL PROTECTED] http://www.pobox.com/~japhy/ Are you a Monk? http://www.perlmonks.com/ http://forums.perlguru.com/ Perl Programmer at RiskMetrics Group, Inc. http://www.riskmetrics.com/ Acacia Fraternity, Rensselaer Chapter. Brother #734
