hdfview 2.11 locks SWMR files

[help at hdfgroup.org]

Hi Jan,

HDFView 2.11 is based on HDF5-1.8 with 32-bit object identifiers. SWMR is a new
feature in HDF5-1.10 (which has 64-bit object identifiers).

HDFView 3.0 (Beta) supports HDF5-1.10. However, even if you use it and select
"File->Open", it gets a lock on the file and it modifies it. We are working on
resolving this issue for the release version of HDFView 3.0 due out later this
year (after HDF5-1.10.2).

As a workaround, we believe you should be able to use HDFView 3.0 (Beta) to open 
the file if you select "File->Open Read-Only".

-Barbara

========================================================
Barbara Jones, The HDF Group Helpdesk, help at hdfgroup.org
Support Services:  https://www.hdfgroup.org/solutions/
========================================================

On Fri, 16 Feb 2018, Jan Kotanski wrote:

> Dear HDFView Maintainers,
>
> I've just accounted problems in reading SWMR files with hdfview 2.11 on debian stretch.
>
> The hdfview 2.11 not only cannot read the SWMR files but it breaks them, i.e. set a lock inside the files,
> and the files are no more readable.
>
> For example I create a file
>
>    http://www.desy.de/~jkotan/swmr/swmr.h5
>
> with:
>
>    http://www.desy.de/~jkotan/swmr/writer2dattr.py
>
> Normally, I can read it on stretch with:
>
>    http://www.desy.de/~jkotan/swmr/reader2d.py
>
>
> But after I run:
>
> jkotan at stretch-jk:~/sources/lavue/nxstest$ hdfview swmr.h5
>
> I get:
>
> jkotan at stretch-jk:~/sources/lavue/nxstest$ python reader2d.py
> Traceback (most recent call last):
>  File "reader2d.py", line 4, in <module>
>    f = h5py.File("swmr.h5", 'r', libver='latest', swmr=True)
>  File "/usr/lib/python2.7/dist-packages/h5py/_hl/files.py", line 271, in __init__
>    fid = make_fid(name, mode, userblock_size, fapl, swmr=swmr)
>  File "/usr/lib/python2.7/dist-packages/h5py/_hl/files.py", line 101, in make_fid
>    fid = h5f.open(name, flags, fapl=fapl)
>  File "h5py/_objects.pyx", line 54, in h5py._objects.with_phil.wrapper (/build/h5py-b1xqNM/h5py-2.7.0/h5py/_objects.c:2842)
>  File "h5py/_objects.pyx", line 55, in h5py._objects.with_phil.wrapper (/build/h5py-b1xqNM/h5py-2.7.0/h5py/_objects.c:2800)
>  File "h5py/h5f.pyx", line 78, in h5py.h5f.open (/build/h5py-b1xqNM/h5py-2.7.0/h5py/h5f.c:2127)
> IOError: Unable to open file (File is not already open for swmr writing)
>
>
> Thus, the hdfview breaks the file and the SWMR file is not more readable.
>
>
> Is it possible to provide backports for the hdfview package with the version which fix the above problem
>   (hope the newer version, e.g. 3.0.0 fix this problem)?
>
>
> Best regards,
> Jan
>

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