With the improvements made in CAM-4400, in case jobs cannot be submitted to the execution queue they are no longer executed by the acquiring thread but deferred for re-submission in the next acquisition cycle. This essentially means there is a context of acquired-not-yet-executed jobs shared between subsequent job acquisition cycles. However, between two cycles an engine may be unregistered or the job executor may be shut down. In such cases, the currently pending jobs are not unlocked, so when immediately restarting the job executor (or re-registering the engine), some jobs are only re-attempted when the lock expires.