Dave Angel wrote: > On 07/11/2013 12:57 AM, Jason Friedman wrote: >> Other than using a database, what are my options for allowing two processes >> to edit the same file at the same time? When I say same time, I can accept >> delays. I considered lock files, but I cannot conceive of how I avoid race >> conditions. >> > > In general, no. That's what a database is for. > > Now, you presumably have some reason to avoid database, but in its stead > you have to specify some other limitations. To start with, what do you > mean by "the same time"? If each process can modify the entire file, > then there's no point in one process reading the file at all until it > has the lock. So the mechanism would be > 1) wait till you can acquire the lock > 2) open the file, read it, modify it, flush and close > 3) release the lock > > To come up with an appropriate lock, it'd be nice to start by specifying > the entire environment. Which Python, which OS? Are the two processes > on the same CPU, what's the file system, and is it locally mounted? > > > >
You can use a seperate server process to do file I/O, taking multiple inputs from clients. Like syslogd. -- http://mail.python.org/mailman/listinfo/python-list
