The admission control algorithm used to negotiate a contract and create its corresponding server if accepted, is based on utilization tests in both implementations, although more elaborate algorithms could be used in the future, for example based on response time analysis. Both take into account the blocking effects of shared object synchronization. The utilization test in Shark is simpler but is restricted to deadlines equal to periods for the servers, while the utilization test in MaccccRTE OcccS allows deadlines smaller than or equal to the periods.