In some cases there is a need to fire bb events into multiple
python threads so locking is needed (writing to a fd/socket).
Adding a helper functions for disable/enable by request to avoid
overhead.
[YOCTO #10330]
(Bitbake rev: a583dc0b296415ec904c081c4de96ceef46732a8)
Signed-off-by: Aníbal Limón <anibal.limon@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>