On Fri, Oct 29, 2010 at 5:01 AM, Charles Forsyth <[email protected]>wrote:
> >What you are saying is that the problem could be something like: > > >-> Tclunk > >(do not wait for response) > >-> Topen (the file is exclusive) > > no, because what actually happens is closer to > A: Topen > ... > queue request to *another process* to send Tclunk > ... > A: Topen > > leading to either case 1 > A: Topen > B: Tclunk > A: Topen > > or case 2 > A: Topen > A: Topen > B: Tclunk > > depending on the scheduling of the two processes A and B > > introducing that other process introduces a new race, that simply did not > exist before, because > that other process didn't exist before. you always got case 1. > > and indeed, with the test i ran on the modified system usually it gets case > 1 > because of timing, but eventually a case 2 shows up and the second open > fails. > > Correct. Either ordering is reasonable and not-a-problem when dealing with a decent fileserver. There are certainly file servers and open options that force single-open, but this approach is not for them. -- vs
