Error KPEDBG_HDL_PUSH_FCPTRMAX : OCI thread - unsafety?

[giorgiomugnaini]

The oracle environment seems not to be thread safe by default. Sometimes when multiple concurrent sessions are created an error KPEDBG_HDL_PUSH_FCPTRMAX is raised.

This fact seems to be related witt the following: in

int OGROCISession::EstablishSession( const char *pszUserid, 
                                     const char *pszPassword,
                                     const char *pszDatabase )

the function OCIInitialize is called with flags: OCI_DEFAULT | OCI_OBJECT, without the OCI_THREADED flag.

Oracle Documentation tells:

" OCI_THREADED - threaded environment. In this mode, internal data structures not exposed to the user are protected from concurrent accesses by multiple threads."

Note on version 2.0

In version 2.0 the flag OCI_DEFAULT is employed. Again, without OCI_THREADED.

[Even Rouault]

Patch welcome

[Even Rouault]

Fixed per ​https://issues.qgis.org/issues/17311 / GDAL trunk ​https://trac.osgeo.org/gdal/changeset/40696 and GDAL 2.2 branche ​https://trac.osgeo.org/gdal/changeset/40697