with thread safe local statics

Change-Id: I6ba88ffc3b3489bfe4dce17c4297312dd9765f2e
Reviewed-on: https://gerrit.libreoffice.org/38594Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Tested-by: Noel Grandin <noel.grandin@collabora.co.uk>