Rohan Garg authored Aug 30, 2019 and Boris Brezillon committed Aug 30, 2019

Both the BO cache and the transient pool are shared across
context's. Protect access to these with mutexes.

Signed-off-by: Rohan Garg <rohan.garg@collabora.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>