Hi Sebastian,
On Mar 19, 2010, at 12:53 PM, Sebastian Good wrote:
> Is there any work scheduled to allow parallel access to HDF5 files from a
> single process? The current implementation implements thread-safety by
> restricting access to one thread at a time, which is certainly safe, but
> restricts scalability of processes, like web or database servers, which may
> be serving many users at once. I understand it would likely be some fairly
> involved work to deal with cache coherence issues!
Yes, we are progressing down this path, although not terribly quickly.
At this point, we've contributed to the development of an open "portable
atomics" library (http://trac.mcs.anl.gov/projects/openpa) with the developers
at Argonne National Laboratory. We're a little side-tracked on other projects
right now, but I expect that we'll get back to working on this and improve the
concurrency of the HDF5 library. No timeline right now though... :-/
Quincey
>
> On Fri, Mar 19, 2010 at 12:31 PM, Werner Benger <[email protected]> wrote:
> Some time ago I made an experimental port for HDF5 threads using native
> Windows API calls, thus being independent of pthreads.
>
> It hasn't been thoroughly tested and involves some changes in the HDF source
> which might be out of sync with the latest version, but most changes had been
> in just one file. Also, I only implemented it for Windows 32 bit, but as it's
> native windows calls, it might just be the same for Windows 64.
>
> If you're interested in looking at it, could dig it out.
>
> Werner
>
>
>
> On Fri, 19 Mar 2010 11:51:13 -0500, Mitchell, Scott - IS
> <[email protected]> wrote:
>
> I implemented the thread safe version of HDF5 for Windows to get past some
> issues writing to HDF5 files from different threads. I hoped I didn't need to
> bother since each thread had exclusive access to one file, but testing proved
> otherwise.
>
> So the thread-safe option uses PThreads (32 bit). This code will shortly be
> moving to a 64 bit platform. A quick search didn't turn up a 64 bit variant.
> Is there a way to implement this in 64 bit?
>
>
> Scott
>
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> ___________________________________________________________________________
> Dr. Werner Benger Visualization Research
> Laboratory for Creative Arts and Technology (LCAT)
> Center for Computation & Technology at Louisiana State University (CCT/LSU)
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