1. A system for processing multiple tasks, the system comprising: a processing cluster that includes a plurality of processing units; at least one memory device coupled to the processing cluster, the at least one memory device storing a plurality of instruction entities; a scheduling means configured to schedule a set of one or more instruction entities belonging to an execution group on the processing cluster, the execution group comprising a set of instruction entities from the plurality of instruction entities; wherein a first unit of the plurality of processing units is designated by the scheduling means as a master processing unit and at least one of the set of one or more instruction entities is designated as a master instruction entity for execution on the master processing unit; wherein the master processing unit executes the at least one master instruction entity; wherein when the execution group contains one or more slave instruction entities, the scheduling means schedules execution of said one or more slave instruction entities on at least one processing unit of the processing cluster other than the first unit; and wherein the scheduling means terminates execution of the one or more slave instruction entities when a master instruction entity is executed on the processing cluster that is not a member of the execution group.