On Apr 4 19:51, Andrey Repin wrote: > If you mean the part about > > > BSD file locks created via flock are only propagated to the direct parent > > process, not to grand parents or sibling processes. The locks are only valid > > in the creating process, its parent process, and subsequently started child > > processes sharing the same file descriptor. > > then that's a showstopper. In short, it makes the function literally useless. > I can work around it in a given script, but... *sad panda*
The problem with BSD locks is that the way they are implemented requires a common shared datastructure in all child processes of a common ancestor process which opened the file. This isn't available in Cygwin. Implementing this is tricky and potentially costly so I only got around to implement this for the direct ancestor process. I'm open to suggestions or even patches to make this work in full. Have a look into Cygwin's flock.cc to see how locks are implemented. Feel free to discuss implementation details on the cygwin-developers ML. Note that the same restrictions don't apply to POSIX locks since they are working quite differently. > Why they aren't real locks? What's use for "advisory locks"? "I think I may > have a use for this file, but you are free to delete it, if you wish" ? Unix systems usually implement file locking advisory, not mandatory. Windows only implements mandatory locks which are incompatible in behaviour with POSIX as well as BSD locks. I guess you read that there's a way to use Windows mandatory locks, too. Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Maintainer cygwin AT cygwin DOT com Red Hat
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