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[REBOL] Re: Concurrent access to data file

From: coussement:c:itc:mil:be at: 20-Feb-2001 10:37

> i solved this problem with poem access on my site by > creating new read and write functions that "lock" the > file while it's being read from or written to. > the lock is just a temporary file that is removed as > soon as the read or write is finished. the lock exists > only as long as it takes to grab the data out of the > file or write to the file ... so the lock does not > exists the whole time the script is running, just for > about a fraction of a second, if that. > read locks are time stamped so there may be multiples > of them, this is because a read lock only prevents > writing, not reading. a write lock is just a single > file that prevents other processes from writing to or > reading from the file. > > the read and write functions recheck for the lock > file's existence about every 100th of a second. the > read function only checks for a write lock while the > write function checks for a read or write lock. > > i'd share the functions with you, but i wrote them > in perl. should be very easy to do in rebol.
[Thanks Erin for answering. I think the solution you propose here is the one I presented when initiating this thread. It's a -relative- safe one (see thread for discussion about it) but will give poor performences when 40 to 80 PC's you want to dump their data together ... Thanks anyway ;-) Best Regards, chr== ]