FWIW I've been mucking around with my own sort of smart handle and a C++ api that wraps the C api without introducing much of any uncertainty - such as thread safety. HDF5 kinda plays nasty with the RAII concept since basically any c api function in HDF5 is allowed to set an exception... and destruction usually don't like that. The approach is really just facility C++ policies on the C api - and aiming for C++11/14 only. I also intend to have user pluggable uniform composition of compound types too, based on some previous work I've done - so static_arrays and things like dense Eigen::Matrix work as they should, where possible. Other people have played with this concept in various places... I just intend to good job of it here.
Anyway the existing C++ api has caused me many headaches/bugs from it's implementation so use it with care. I don't know if I'd advocate using c-only to it's implementation out right, but it has surprised me in every program I've written with it to date. And again when I've updated library versions... The issue you will certainly have if you are not careful with the C++ api as is - is that each object wrapper has it's own internal (C++ object only) reference count - and a) the calls for inc/dec are in all the inherited methods, not the base, and b) this doesn't sync up with the internal c library's reference count and c) it's not atomic! That was definitely not a good idea, at least since things got multithreaded, but I suspect in most any case. I suppose you could get some weirdness from exceptions but those are the prime factors that come to mind. -Jason On Tue, Nov 8, 2016 at 1:13 PM, Samer Afach <[email protected]> wrote: > Actually I use the C-API on my C++ program (I avoid foreign wrappers when > I can). I invented a solution to get rid of having to close handles > manually. I created a SmartHandle class that can be constructed like this: > > SmartHandle<hid_t,std::function<herr_t(hid_t)>> > attribHandler(H5Aopen(obj_id,attribName.c_str(),H5P_DEFAULT), [](hid_t f) > { return H5Aclose(f); }); > > Now this is a template function that takes 2 parameters, the first one is > the handle type, and the second one is an std::function that will do the > closing for you. And then all you have to do is get this to run at the > destructor of the class, and this will close the handle automatically when > it goes out of scope. There's an example on the full implementation of this > on Stackoverflow. > > This can be made even fancier, but this suffices for my purposes. Also you > could use std::unique_ptr for the same purpose, but then you have to make > another wrapper for the handle to use the deleter of std::unique_ptr. > > Cheers, > Samer Afach > > > On 08.11.2016 6:20 PM, Elvis Stansvik wrote: > > Den 8 nov. 2016 4:50 em skrev "Samer Afach" <[email protected]>: > > > > Hi all: > > > > The fact that HDF5 is not thread-safe is horrible actually and should be > fixed some time. The current model is more compatible with the 90s > computing models, not the current one. Actually I learned that HDF5 is not > thread-safe the hard way, and it ruined many of my plans for the use of the > library. I don't like/trust having build options that make my program > works, and I believe more in separating source writing from building, which > is why I decided I'm not going to use the --enable-threadsafe option, and > decided to use my own locks with std::thread (or boost::thread if you don't > use C++11). I just wrapped every H5 call with a > std::unique_lock<std::mutex>, and that solved the problem. For me this > wasn't a big change, because I use C++ classes and templates and > compile-time objects and I have a class with all the H5 functions I needed, > which were not too many. It took me like an hour to fix my program, and > it's working now. > > > > Just wanted to share my experience. > > And yes, I also think requiring certain build options is a little iffy. > But in my case, the deployment platform is Ubuntu, where HDF5 is built with > this option. So if I were to be prudent and do my own locking even when > using the C API, I would pay for double locking on my main (so far only) > target platform. > > Elvis > > > > > Cheers, > > Samer Afach > > > > > > On 08.11.2016 4:02 PM, Elvis Stansvik wrote: > >> > >> 2016-11-08 15:46 GMT+01:00 Elvis Stansvik <[email protected] > >: > >>> > >>> 2016-09-23 7:55 GMT+02:00 Elvis Stansvik <[email protected] > >: > >>>> > >>>> 2016-09-22 21:27 GMT+02:00 Werner Benger <[email protected]>: > >>>> > On 22.09.2016 20:34, Elvis Stansvik wrote: > >>>> > > >>>> >> 2016-09-22 20:25 GMT+02:00 Werner Benger <[email protected]>: > >>>> >>> > >>>> >>> There was some recent discussion that only the C API of HDF5 is > >>>> >>> threadsafe, > >>>> >>> but not the C++ layer on top of it. To be safe you should > probably keep > >>>> >>> at > >>>> >>> the C API. > >>>> >> > >>>> >> Aha. Thanks for the heads up Werner. > >>>> >> > >>>> >> The FAQ has this to say: > >>>> >> > >>>> >> "By default, you cannot build either Parallel HDF5 with C++ or > >>>> >> Parallel HDF5 with the thread-safe feature. You will receive a > >>>> >> configure error if you try either of these combinations." > >>>> >> > >>>> >> But it does not say that C++ with the thread-safe is unsupported > (when > >>>> >> using serial HDF5). Maybe the FAQ should be updated? > >>>> >> > >>>> >> This is quite unfortunate since our app is C++ and the C++ API is > so > >>>> >> much more convenient, but I guess I'll port our code to the C API > >>>> >> (it's not that much code). > >>>> > > >>>> > What you probably could do as well is to have your own lock with > one global > >>>> > mutex around each call to the C++ API. HDF5 itself allows only one > running > >>>> > thread internally as well and just puts such a lock inside the API, > so it > >>>> > would come to the same. > >>>> > >>>> This is what I ended up doing, so thanks a lot for the suggestion. > >>>> > >>>> It was much easier than I thought because, since I was using Qt > >>>> anyway, I could just create a global QMutex, and then create a > >>>> QMutexLocker (RAII-style mutex locker) on the stack in each function > >>>> (just two of them) where I use HDF5. > >>>> > >>>> This sort of coarse locking is OK for me since overwhelming majority > >>>> of time is spent in a HDF5 H5::DataSpace::read(..) call (I'm reading > >>>> big compressed data). The other HDF5 calls are very quick by > >>>> comparison. > >>> > >>> > >>> Just a final question about this. The FAQ states that the threadsafe > guarantee does not extent to the high-level API. > >>> > >>> I just want to confirm that this is really the case: Is the threadsafe > guarantee only for the low-level C API? > >>> > >>> The reason I'm asking is that I'm now considering porting my HDF5 > usage from C++ to C, to avoid having to do the manual locking myself, and > the high-level API looked quite convenient for what I want to do. But if > it's really not threadsafe, I'll stick to the regular C API. > >> > >> > >> Nevermind, I found a very definitive answer in the 1.8.16 release > notes, where the --enable-threadsafe --enable-hl combination was marked as > unsupported in the build system: > >> > >> - The thread-safety + high-level library combination has been marked > >> as "unsupported" in the Autotools > >> > >> The global lock used by the thread-safety feature has never been > >> raised to the high-level library level, making it possible that > >> the library state could change if a context switch were to occur > in > >> a high-level library call. Because of this, the combination of > >> thread-safety and high-level library is officially unsupported by > >> The HDF Group. > >> > >> In the past, although this combination has never been supported, > this > >> was not enforced by the build systems. These changes will cause an > >> Autotools configure step to fail if --enable-threadsafe and > >> --enable-hl are combined unless additional options are specified. > >> Since the high-level library is built by default, this means that > >> these extra configuration options will need to be used any time > >> --enable-threadsafe is selected. > >> > >> To build with --enable-threadsafe, either: > >> > >> 1) Use --disable-hl to disable the high-level library > (recommended) > >> > >> 2) Use --enable-unsupported to build the high-level library with > >> the thread-safety feature. > >> > >> So I'll stick to the low-level C API. > >> > >> Elvis > >> > >>> > >>> Thanks in advance, > >>> Elvis > >>> > >>>> > >>>> > >>>> Elvis > >>>> > >>>> > > >>>> > Werner > >>>> > > >>>> > > >>>> > > >>>> >> So far we haven't had any problems under Ubuntu (where the package > is > >>>> >> built with --enable-threadsafe --enable-unsupported), but I guess > >>>> >> we've just been lucky. > >>>> >> > >>>> >> Elvis > >>>> >> > >>>> >>> Cheers, > >>>> >>> > >>>> >>> Werner > >>>> >>> > >>>> >>> > >>>> >>> > >>>> >>> On 22.09.2016 20:15, Elvis Stansvik wrote: > >>>> >>>> > >>>> >>>> 2016-09-22 19:58 GMT+02:00 Scot Breitenfeld < > [email protected]>: > >>>> >>>>> > >>>> >>>>> Yes it is still the case that you cannot enable C++ or Fortran > (or the > >>>> >>>>> High Level APIs) when threadsafe is enabled. > —enable-unsupported can > >>>> >>>>> override this behavior. > >>>> >>>> > >>>> >>>> Aha, so that's why I had to enable that option :) > >>>> >>>> > >>>> >>>> I see now that this is what the Ubuntu package does. I'll ask > the Arch > >>>> >>>> package maintainer if he's willing to do the same. > >>>> >>>> > >>>> >>>> I've confirmed now that I don't have any problems with my > program if I > >>>> >>>> re-built the Arch package with --enable-threadsafe > >>>> >>>> --enable-unsupported. > >>>> >>>> > >>>> >>>> Thanks for the info! > >>>> >>>> > >>>> >>>> Elvis > >>>> >>>> > >>>> >>>>> Scot > >>>> >>>>> > >>>> >>>>> > >>>> >>>>>> On Sep 22, 2016, at 12:36 PM, Elvis Stansvik > >>>> >>>>>> <[email protected]> wrote: > >>>> >>>>>> > >>>> >>>>>> 2016-09-22 19:23 GMT+02:00 Elvis Stansvik > >>>> >>>>>> <[email protected]>: > >>>> >>>>>>> > >>>> >>>>>>> 2016-09-22 19:17 GMT+02:00 Dana Robinson < > [email protected]>: > >>>> >>>>>>>> > >>>> >>>>>>>> Hi Elvis, > >>>> >>>>>>>> > >>>> >>>>>>>> Did you build your HDF5 library with thread-safety enabled > >>>> >>>>>>>> (--enable-threadsafe w/ configure)? > >>>> >>>>>>> > >>>> >>>>>>> Hi Dana, and thanks for the quick reply. I think we just > e-mailed > >>>> >>>>>>> past > >>>> >>>>>>> each other (see my previous mail). > >>>> >>>>>>> > >>>> >>>>>>> I wrongly called it --thread-safe in that mail, but it was > >>>> >>>>>>> --enable-threadsafe I was referring to. But yes, I'm pretty > sure this > >>>> >>>>>>> is the problem. > >>>> >>>>>>> > >>>> >>>>>>> I'm rebuilding the Arch package now with --enable-threadsafe. > >>>> >>>>>> > >>>> >>>>>> I spoke a little too soon. I now found this bug filed against > the Arch > >>>> >>>>>> package: > >>>> >>>>>> > >>>> >>>>>> https://bugs.archlinux.org/task/33805 > >>>> >>>>>> > >>>> >>>>>> The reporter asked the package maintainer to add > --enable-threadsafe, > >>>> >>>>>> but the package maintainer closed the bug saying that > >>>> >>>>>> --enable-threadsafe is not compatible with the Fortran build > (in Arch, > >>>> >>>>>> the C++ and Fortran APIs are bundled into one package > >>>> >>>>>> hdf5-cpp-fortran). > >>>> >>>>>> > >>>> >>>>>> Anyone know if that is still the case? If so I can't open a bug > >>>> >>>>>> against the package again asking for --enable-threadsafe to be > added. > >>>> >>>>>> But I could open a bug asking the package to be split I guess. > >>>> >>>>>> > >>>> >>>>>> Elvis > >>>> >>>>>> > >>>> >>>>>>> Elvis > >>>> >>>>>>> > >>>> >>>>>>>> Dana Robinson > >>>> >>>>>>>> Software Engineer > >>>> >>>>>>>> The HDF Group > >>>> >>>>>>>> > >>>> >>>>>>>> Get Outlook for Android > >>>> >>>>>>>> > >>>> >>>>>>>> From: Elvis Stansvik > >>>> >>>>>>>> Sent: Thursday, September 22, 12:43 > >>>> >>>>>>>> Subject: [Hdf-forum] Simply using the library from separate > threads > >>>> >>>>>>>> (C++ > >>>> >>>>>>>> API) > >>>> >>>>>>>> To: HDF Users Discussion List > >>>> >>>>>>>> > >>>> >>>>>>>> Hi all, I'm using the C++ API to read HDF5 files from > separate > >>>> >>>>>>>> threads > >>>> >>>>>>>> (no > >>>> >>>>>>>> writing). None of my threads read the same file, but they do > execute > >>>> >>>>>>>> simultaneously. The reason I'm using threading is not to > speed > >>>> >>>>>>>> things > >>>> >>>>>>>> up or > >>>> >>>>>>>> get better throughput, but simply to not block the UI (it's > Qt > >>>> >>>>>>>> application) > >>>> >>>>>>>> while reading. So this is not about "Parallel HDF5" or > anything, > >>>> >>>>>>>> just > >>>> >>>>>>>> simply > >>>> >>>>>>>> using the serial library "from scratch" from multiple > threads. This > >>>> >>>>>>>> has been > >>>> >>>>>>>> working fine when testing on Ubuntu 16.04 (our target OS), > which has > >>>> >>>>>>>> HDF5 > >>>> >>>>>>>> 1.8.16. I recently tested on my personal Arch Linux machine > though, > >>>> >>>>>>>> which > >>>> >>>>>>>> has HDF5 1.10.0, and got this segmentation fault: (gdb) bt #0 > >>>> >>>>>>>> 0x00007ffff67c57d9 in H5SL_search () from > /usr/lib/libhdf5.so.100 #1 > >>>> >>>>>>>> 0x00007ffff678dd19 in H5P_copy_plist () from > /usr/lib/libhdf5.so.100 > >>>> >>>>>>>> #2 > >>>> >>>>>>>> 0x00007ffff66a7fc0 in H5F_new () from > /usr/lib/libhdf5.so.100 #3 > >>>> >>>>>>>> 0x00007ffff66a8f55 in H5F_open () from > /usr/lib/libhdf5.so.100 #4 > >>>> >>>>>>>> 0x00007ffff66a155d in H5Fopen () from > /usr/lib/libhdf5.so.100 #5 > >>>> >>>>>>>> 0x00007ffff6b79546 in H5::H5File::p_get_file(char const*, > unsigned > >>>> >>>>>>>> int, > >>>> >>>>>>>> H5::FileCreatPropList const&, H5::FileAccPropList const&) () > from > >>>> >>>>>>>> /usr/lib/libhdf5_cpp.so.100 #6 0x00007ffff6b79750 in > >>>> >>>>>>>> H5::H5File::H5File(char > >>>> >>>>>>>> const*, unsigned int, H5::FileCreatPropList const&, > >>>> >>>>>>>> H5::FileAccPropList > >>>> >>>>>>>> const&) () from /usr/lib/libhdf5_cpp.so.100 #7 > 0x000000000041f00e in > >>>> >>>>>>>> HDF5ImageReader::RequestInformation (this=0x7fffbc002de0, > >>>> >>>>>>>> request=0x7fffbc010da0, inputVector=0x0, > >>>> >>>>>>>> outputVector=0x7fffbc0039d0) > >>>> >>>>>>>> at > >>>> >>>>>>>> > >>>> >>>>>>>> > >>>> >>>>>>>> /home/estan/Projekt/orexplore/dev/src/insight/src/model/ > HDF5ImageReader.cpp:91 > >>>> >>>>>>>> #8 0x00007fffee8200d0 in > >>>> >>>>>>>> vtkExecutive::CallAlgorithm(vtkInformation*, > >>>> >>>>>>>> int, > >>>> >>>>>>>> vtkInformationVector**, vtkInformationVector*) () from > >>>> >>>>>>>> /usr/lib/libvtkCommonExecutionModel.so.1 #9 > 0x00007fffee837fa9 in > >>>> >>>>>>>> > >>>> >>>>>>>> vtkStreamingDemandDrivenPipeline::ExecuteInformation( > vtkInformation*, > >>>> >>>>>>>> vtkInformationVector**, vtkInformationVector*) () from > >>>> >>>>>>>> /usr/lib/libvtkCommonExecutionModel.so.1 #10 > 0x00007fffee81ce05 in > >>>> >>>>>>>> vtkDemandDrivenPipeline::ProcessRequest(vtkInformation*, > >>>> >>>>>>>> vtkInformationVector**, vtkInformationVector*) () from > >>>> >>>>>>>> /usr/lib/libvtkCommonExecutionModel.so.1 #11 > 0x00007fffee835c55 in > >>>> >>>>>>>> vtkStreamingDemandDrivenPipeline::ProcessRequest( > vtkInformation*, > >>>> >>>>>>>> vtkInformationVector**, vtkInformationVector*) () from > >>>> >>>>>>>> /usr/lib/libvtkCommonExecutionModel.so.1 #12 > 0x00007fffee816e1a in > >>>> >>>>>>>> vtkCompositeDataPipeline::ForwardUpstream(vtkInformation*) > () from > >>>> >>>>>>>> /usr/lib/libvtkCommonExecutionModel.so.1 #13 > 0x00007fffee81ccb5 in > >>>> >>>>>>>> vtkDemandDrivenPipeline::ProcessRequest(vtkInformation*, > >>>> >>>>>>>> vtkInformationVector**, vtkInformationVector*) () from > >>>> >>>>>>>> /usr/lib/libvtkCommonExecutionModel.so.1 #14 > 0x00007fffee835c55 in > >>>> >>>>>>>> vtkStreamingDemandDrivenPipeline::ProcessRequest( > vtkInformation*, > >>>> >>>>>>>> vtkInformationVector**, vtkInformationVector*) () from > >>>> >>>>>>>> /usr/lib/libvtkCommonExecutionModel.so.1 #15 > 0x00007fffee816e1a in > >>>> >>>>>>>> vtkCompositeDataPipeline::ForwardUpstream(vtkInformation*) > () from > >>>> >>>>>>>> /usr/lib/libvtkCommonExecutionModel.so.1 #16 > 0x00007fffee81ccb5 in > >>>> >>>>>>>> vtkDemandDrivenPipeline::ProcessRequest(vtkInformation*, > >>>> >>>>>>>> vtkInformationVector**, vtkInformationVector*) () from > >>>> >>>>>>>> /usr/lib/libvtkCommonExecutionModel.so.1 #17 > 0x00007fffee835c55 in > >>>> >>>>>>>> vtkStreamingDemandDrivenPipeline::ProcessRequest( > vtkInformation*, > >>>> >>>>>>>> vtkInformationVector**, vtkInformationVector*) () from > >>>> >>>>>>>> /usr/lib/libvtkCommonExecutionModel.so.1 #18 > 0x00007fffee816e1a in > >>>> >>>>>>>> vtkCompositeDataPipeline::ForwardUpstream(vtkInformation*) > () from > >>>> >>>>>>>> /usr/lib/libvtkCommonExecutionModel.so.1 #19 > 0x00007fffee81ccb5 in > >>>> >>>>>>>> vtkDemandDrivenPipeline::ProcessRequest(vtkInformation*, > >>>> >>>>>>>> vtkInformationVector**, vtkInformationVector*) () from > >>>> >>>>>>>> /usr/lib/libvtkCommonExecutionModel.so.1 #20 > 0x00007fffee835c55 in > >>>> >>>>>>>> vtkStreamingDemandDrivenPipeline::ProcessRequest( > vtkInformation*, > >>>> >>>>>>>> vtkInformationVector**, vtkInformationVector*) () from > >>>> >>>>>>>> /usr/lib/libvtkCommonExecutionModel.so.1 #21 > 0x00007fffee836482 in > >>>> >>>>>>>> vtkStreamingDemandDrivenPipeline::Update(int) () from > >>>> >>>>>>>> /usr/lib/libvtkCommonExecutionModel.so.1 #22 > 0x00007ffff1289a76 in > >>>> >>>>>>>> vtkAbstractVolumeMapper::GetBounds() () from > >>>> >>>>>>>> /usr/lib/libvtkRenderingCore.so.1 #23 0x00007ffff13459f9 in > >>>> >>>>>>>> vtkVolume::GetBounds() () from /usr/lib/libvtkRenderingCore.so.1 > #24 > >>>> >>>>>>>> 0x000000000043f235 in createVolume (image=..., from=0, > >>>> >>>>>>>> to=2.7803999378532183, opacityFunction=..., > colorFunction=...) at > >>>> >>>>>>>> > >>>> >>>>>>>> > >>>> >>>>>>>> /home/estan/Projekt/orexplore/dev/src/insight/src/view/Pipeline.cpp:123 > #25 > >>>> >>>>>>>> 0x00000000004295c4 in CreateVolume::operator() > (this=0x829248, > >>>> >>>>>>>> image=...) at > >>>> >>>>>>>> /home/estan/Projekt/orexplore/dev/src/insight/src/view/ > Pipeline.h:45 > >>>> >>>>>>>> #26 > >>>> >>>>>>>> 0x000000000042bc7a in > >>>> >>>>>>>> QtConcurrent::MappedEachKernel::const_iterator, > >>>> >>>>>>>> CreateVolume>::runIteration (this=0x829210, it=..., > >>>> >>>>>>>> result=0x7fffbc002da8) > >>>> >>>>>>>> at /usr/include/qt/QtConcurrent/qtconcurrentmapkernel.h:176 > #27 > >>>> >>>>>>>> 0x000000000042bd5d in > >>>> >>>>>>>> QtConcurrent::MappedEachKernel::const_iterator, > >>>> >>>>>>>> CreateVolume>::runIterations (this=0x829210, > >>>> >>>>>>>> sequenceBeginIterator=..., > >>>> >>>>>>>> begin=1, end=2, results=0x7fffbc002da8) at > >>>> >>>>>>>> /usr/include/qt/QtConcurrent/qtconcurrentmapkernel.h:186 #28 > >>>> >>>>>>>> 0x000000000042c4e1 in QtConcurrent::IterateKernel:: > const_iterator, > >>>> >>>>>>>> vtkSmartPointer >::forThreadFunction (this=0x829210) at > >>>> >>>>>>>> /usr/include/qt/QtConcurrent/qtconcurrentiteratekernel.h:256 > #29 > >>>> >>>>>>>> 0x000000000042bedc in QtConcurrent::IterateKernel:: > const_iterator, > >>>> >>>>>>>> vtkSmartPointer >::threadFunction (this=0x829210) at > >>>> >>>>>>>> /usr/include/qt/QtConcurrent/qtconcurrentiteratekernel.h:218 > #30 > >>>> >>>>>>>> 0x00007ffff7bd5cfd in QtConcurrent::ThreadEngineBase::run() > () from > >>>> >>>>>>>> /usr/lib/libQt5Concurrent.so.5 #31 0x00007ffff489a01f in ?? > () from > >>>> >>>>>>>> /usr/lib/libQt5Core.so.5 #32 0x00007ffff489dd78 in ?? () from > >>>> >>>>>>>> /usr/lib/libQt5Core.so.5 #33 0x00007fffeb3f5454 in > start_thread () > >>>> >>>>>>>> from > >>>> >>>>>>>> /usr/lib/libpthread.so.0 #34 0x00007fffec5f07df in clone () > from > >>>> >>>>>>>> /usr/lib/libc.so.6 (gdb) Before I start digging into what is > >>>> >>>>>>>> happening > >>>> >>>>>>>> here > >>>> >>>>>>>> I'd just like to ask: Do I have to do something special when > using > >>>> >>>>>>>> the > >>>> >>>>>>>> HDF5 > >>>> >>>>>>>> library from two different threads? I'm not reading the same > files > >>>> >>>>>>>> or > >>>> >>>>>>>> anything, it's simply two completely separate usages of the > library > >>>> >>>>>>>> in > >>>> >>>>>>>> threads that run in parallel. Does the library have any > global > >>>> >>>>>>>> structures or > >>>> >>>>>>>> something that must be initialized before spawning any > threads that > >>>> >>>>>>>> use it? > >>>> >>>>>>>> The reason I'm a little worried is that perhaps I've just > been lucky > >>>> >>>>>>>> when > >>>> >>>>>>>> running under Ubuntu / HDF5 1.8.16. My usage in each thread > >>>> >>>>>>>> basically > >>>> >>>>>>>> looks > >>>> >>>>>>>> like: 1) Create a H5::H5File 2) Open a dataset using > >>>> >>>>>>>> file.openDataset > >>>> >>>>>>>> 3) Get > >>>> >>>>>>>> the dataspace for the dataset and select a hyperslab 4) > Create a > >>>> >>>>>>>> memory > >>>> >>>>>>>> dataspace 5) Perform a single read(..) operation from the > dataset > >>>> >>>>>>>> dataspace > >>>> >>>>>>>> to the memory dataspace And it's always different files that > the > >>>> >>>>>>>> threads > >>>> >>>>>>>> work with. Is there some step 0 I'm missing? Thanks in > advance for > >>>> >>>>>>>> any > >>>> >>>>>>>> advice. Elvis ______________________________ > _________________ > >>>> >>>>>>>> Hdf-forum is > >>>> >>>>>>>> for HDF software users discussion. > [email protected] > >>>> >>>>>>>> > >>>> >>>>>>>> > >>>> >>>>>>>> http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_ > lists.hdfgroup.org > >>>> >>>>>>>> Twitter: https://twitter.com/hdf5 > >>>> >>>>>>>> > >>>> >>>>>>>> > >>>> >>>>>>>> _______________________________________________ > >>>> >>>>>>>> Hdf-forum is for HDF software users discussion. > >>>> >>>>>>>> [email protected] > >>>> >>>>>>>> > >>>> >>>>>>>> > >>>> >>>>>>>> http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_ > lists.hdfgroup.org > >>>> >>>>>>>> Twitter: https://twitter.com/hdf5 > >>>> >>>>>> > >>>> >>>>>> _______________________________________________ > >>>> >>>>>> Hdf-forum is for HDF software users discussion. > >>>> >>>>>> [email protected] > >>>> >>>>>> > >>>> >>>>>> http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_ > lists.hdfgroup.org > >>>> >>>>>> Twitter: https://twitter.com/hdf5 > >>>> >>>>> > >>>> >>>>> _______________________________________________ > >>>> >>>>> Hdf-forum is for HDF software users discussion. > >>>> >>>>> [email protected] > >>>> >>>>> http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_ > lists.hdfgroup.org > >>>> >>>>> Twitter: https://twitter.com/hdf5 > >>>> >>>> > >>>> >>>> _______________________________________________ > >>>> >>>> Hdf-forum is for HDF software users discussion. > >>>> >>>> [email protected] > >>>> >>>> http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_ > lists.hdfgroup.org > >>>> >>>> Twitter: https://twitter.com/hdf5 > >>>> >>> > >>>> >>> > >>>> >>> -- > >>>> >>> > >>>> >>> ____________________________________________________________ > _______________ > >>>> >>> Dr. Werner Benger Visualization Research > >>>> >>> Center for Computation & Technology at Louisiana State University > >>>> >>> (CCT/LSU) > >>>> >>> 2019 Digital Media Center, Baton Rouge, Louisiana 70803 > >>>> >>> Tel.: +1 225 578 4809 Fax.: +1 225 > 578-5362 > >>>> >>> > >>>> >>> > >>>> >>> > >>>> >>> _______________________________________________ > >>>> >>> Hdf-forum is for HDF software users discussion. > >>>> >>> [email protected] > >>>> >>> http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_ > lists.hdfgroup.org > >>>> >>> Twitter: https://twitter.com/hdf5 > >>>> >> > >>>> >> _______________________________________________ > >>>> >> Hdf-forum is for HDF software users discussion. > >>>> >> [email protected] > >>>> >> http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_ > lists.hdfgroup.org > >>>> >> Twitter: https://twitter.com/hdf5 > >>>> > > >>>> > > >>>> > -- > >>>> > ____________________________________________________________ > _______________ > >>>> > Dr. Werner Benger Visualization Research > >>>> > Center for Computation & Technology at Louisiana State University > (CCT/LSU) > >>>> > 2019 Digital Media Center, Baton Rouge, Louisiana 70803 > >>>> > Tel.: +1 225 578 4809 Fax.: +1 225 578-5362 > >>>> > > >>>> > > >>>> > _______________________________________________ > >>>> > Hdf-forum is for HDF software users discussion. > >>>> > [email protected] > >>>> > http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_ > lists.hdfgroup.org > >>>> > Twitter: https://twitter.com/hdf5 > >>> > >>> > >> > >> > >> > >> _______________________________________________ Hdf-forum is for HDF > software users discussion. [email protected] > http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org > Twitter: https://twitter.com/hdf5 > > > > > > > > _______________________________________________ > > Hdf-forum is for HDF software users discussion. > > [email protected] > > http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org > > Twitter: https://twitter.com/hdf5 > > > _______________________________________________ > Hdf-forum is for HDF software users > [email protected]http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org > Twitter: https://twitter.com/hdf5 > > > > _______________________________________________ > Hdf-forum is for HDF software users discussion. > [email protected] > http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org > Twitter: https://twitter.com/hdf5 >
_______________________________________________ Hdf-forum is for HDF software users discussion. [email protected] http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org Twitter: https://twitter.com/hdf5
