[gdal-dev] NetCDF+HDF5 and threadsafety

[Even Rouault]

Le vendredi 05 février 2016 01:41:14, William Kyngesburye a écrit :
> On Feb 4, 2016, at 5:09 PM, Even Rouault <even.rouault at spatialys.com> wrote:
> > Le jeudi 04 février 2016 23:55:57, William Kyngesburye a écrit :
> >> I'm updating my HDF5 library and ran into a catch-22: I build my HDF5
> >> with threadsafety (threadsafe is good, right?), and NetCDF4 requires
> >> HDF5 with the high-level library.  At HDF5 1.8.12 I could do this
> >> combination, but HDF5 1.8.16 (I think it started with 1.8.13) says
> >> threadsafe and high-level options are not compatible.
> >> 
> >> Is threadsafety in HDF5 important for GDAL?
> > 
> > Hum, likely if people use the HDF5 driver in a multi-threaded context.
> > GDAL has explicit mutex around calls to the netCDF and HDF4 lib in the
> > netCDF and HDF4 drivers (since at least the versions of those lib I use
> > are not thread- safe), but not from the HDF5 driver. So if the HDF5 lib
> > is not re-entrant, there might be issues.
> > 
> > There's an optionnaly compiled app you can use to test threadsafety :
> > 
> > cd apps
> > make multireadtest
> > ./multireadtest -nlo [-oi number_of_iterations] file_to_test
> > 
> > Increase number_of_iterations so that it runs for a few seconds.
> 
> How do I trigger building that? 

Just like the above mentionned lines :-) After you've initially built GDAL 
from the top directory

-- 
Spatialys - Geospatial professional services
http://www.spatialys.com