Hi Quincey thanks for the response, is this code available (AFAIK there's only 1.9.x development snapshots)? When is it planned to be released officially?
thanks again! Best -- dimitris 2011/1/20 Quincey Koziol <[email protected]> > Hi Dimitris, > > On Jan 20, 2011, at 8:05 AM, Dimitris Servis wrote: > > > Hi all, > > > > one of the major problems that I have in synchronizing reads and writes > with HDF5 files and locks is the update of metadata. Here' s some > pseudoflows that show the problem: > > > > Process 1: > > 1. Create file file.h5 > > 2. Start process 2 > > 3. Wait until file can be locked > > 4. Read /dataset > > > > Process 2: > > 1. Open file file.h5 > > 2. Get exclusive lock > > 3. Write /dataset > > 4. Unlock and close the file > > > > My locks work on the file handle returned by H5Fget_vfd_handle and always > lock the first byte. This is the only way I could find to synchronize > between threads and processes. this works fine so far, what I would like to > do now is this: Process 1 at step (4) will not read the dataset, because the > file handle in process 1 is opened before process B writes into the file. > What I would like to do is have a way to "refresh" the metadata. The ways to > do that are: > > > > 1. Close and reopen the file, but that will lose me the lock > > 2. Lock on an OS handle and then open the HDF5 handle. That will work on > Linux but not windows as the HDF5 handle will not be able to read. > > 3. Do it in a VFD driver but then locking/unlocking is not controlled by > the program. > > > > What I really would like to have is a function that simply forces the > metadata to be re-read from the same open file handle. Is there any such > function that is available for sharing? Otherwise I will try to write one. > > We have implemented this functionality for the 1.10 release. > > Quincey > > > _______________________________________________ > Hdf-forum is for HDF software users discussion. > [email protected] > http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org >
_______________________________________________ Hdf-forum is for HDF software users discussion. [email protected] http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org
