On Wed, Mar 30, 2011 at 10:22:36AM -0700, Johan Hake wrote: > On Wednesday March 30 2011 10:15:01 Niclas Jansson wrote: > > Johan Hake <johan.h...@gmail.com> writes: > > > On Wednesday March 30 2011 10:02:28 Niclas Jansson wrote: > > >> Johan Hake <johan.h...@gmail.com> writes: > > >> > On Tuesday March 29 2011 23:27:27 Anders Logg wrote: > > >> >> On Tue, Mar 29, 2011 at 11:10:17PM -0700, Johan Hake wrote: > > >> >> > What triggers the error? Is it writing and/or reading to/from file. > > >> >> > Is it assignment of data from within the read function in the > > >> >> > test? > > >> >> > > > >> >> > johan > > >> >> > > >> >> It's the next line following the read: > > >> >> std::string filename(p1["filename"]); > > >> > > > >> > It took some time to find the parameter unit test ;) > > >> > > > >> >> So something goes wrong for at least one of the processes when the > > >> >> parameters are read back from file. Here's what happens: > > >> >> > > >> >> 1. All processes create parameter set p0 > > >> >> > > >> >> 2. Process 0 writes p0 to file > > >> >> > > >> >> 3. Everyone waits (barrier) > > >> >> > > >> >> 4. All processes read from the file into p1 > > >> >> > > >> >> 5. All processes access parameters from p1 and compare to p0 > > >> > > > >> > I guess it is 4 that goes wrong. I have tried to google varieties of > > >> > "open shared file fstream". It looks like others have had the same > > >> > problem. > > >> > > > >> > Johan > > >> > > >> I don't think it's enough with a barrier. It doesn't guarantee that > > >> the data is flushed to the disk. > > > > > > But how could it work for some processes and not for others. Doesn't this > > > indicate that the file is properly created? > > > > > > Johan > > > > True... > > > > But, say that the file is flushed some time after the barrier. Maybe > > that is long enough for some of the processes to reach the "File f1" > > statement before the file is flushed. The others arrives a bit later > > and gets a valid file pointer. > > Ok, make sense. > > A flush at the end of each << call might not hurt anyway.
I tried a flush but it didn't help. -- Anders > Johan > > > Niclas > > > > >> An option is of course to use MPI I/O, but that would lead to a > > >> painful rewrite of most I/O routines... > > >> > > >> Niclas > > >> > > >> > > > >> > _______________________________________________ > > >> > Mailing list: https://launchpad.net/~dolfin > > >> > Post to : dolfin@lists.launchpad.net > > >> > Unsubscribe : https://launchpad.net/~dolfin > > >> > More help : https://help.launchpad.net/ListHelp > > > > _______________________________________________ > > Mailing list: https://launchpad.net/~dolfin > > Post to : dolfin@lists.launchpad.net > > Unsubscribe : https://launchpad.net/~dolfin > > More help : https://help.launchpad.net/ListHelp > > _______________________________________________ > Mailing list: https://launchpad.net/~dolfin > Post to : dolfin@lists.launchpad.net > Unsubscribe : https://launchpad.net/~dolfin > More help : https://help.launchpad.net/ListHelp _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : dolfin@lists.launchpad.net Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
