A first request to execute a first task is received from a first module in a first address space and by a second module in a second address space. The first task is placed into a task queue for execution in the second address space. Pending responses not yet returned to the first module that are results of execution for other tasks in the second address space are extracted by the second module from a response queue. Requests for the other tasks were previously sent by the first module to the second module for execution in the second address space. The pending responses are compounded. The pending responses and a return value for acknowledgement the first request to execute the first task are combined, by the second module into a combined communication. The combined communication is transmitted by the second module to the first module in the first address space.