Function - Set target thread's scheduling policy state.
kern_return_t   thread_policy
                (thread_act_t                            thread,
                 policy_t                                policy,
                 policy_base_t                             base,
                 base                                base_count,
                 boolean_t                            set_limit);
The thread_policy function sets the scheduling policy to be applied to thread. policy must be a scheduling policy currently "enabled" for the thread's assigned processor set.
Functions: processor_set_policy_control, thread_set_policy, task_policy, task_set_policy.
Data Structures: policy_fifo_info, policy_rr_info, policy_timeshare_info.