- using an isc_task to execute all rndc functions makes it relatively simple for them to acquire task exclusive mode when needed - control_recvmessage() has been separated into two functions, control_recvmessage() and control_respond(). the respond function can be called immediately from control_recvmessage() when processing a nonce, or it can be called after returning from the task event that ran the rndc command function.