task_policy

Function - Set target task's default scheduling policy state.

SYNOPSIS

kern_return_t   task_policy
                (task_t                                    task,
                 policy_t                                policy,
                 policy_base_t                             base,
                 base                                base_count,
                 boolean_t                            set_limit,
                 boolean_t                       change_threads);

PARAMETERS

task

[in task send right] The port for the task whose scheduling attributes are to be set.

policy

[in scalar] Default policy. The values currently defined are POLICY_TIMESHARE, POLICY_RR (round robin) and POLICY_FIFO (firstin, first-out).

base

[pointer to in structure] Base scheduling policy data, policy_fifo_base, policy_rr_base or policy_timeshare_base.

base_count

[in scalar] The size of the buffer (in natural-sized units).

set_limit

[in scalar] True if the scheduling limits for the task should be restricted to allow no more service than specified by base.

change_threads

[in scalar] True if the attributes (and limits, if set_limit is true) of existing threads within the task should also be changed.

DESCRIPTION

The task_policy function sets the default scheduling attributes for task. These attributes are used when creating new threads. Changing the default attributes for a task does not affect the attributes of the contained threads unless change_threads is TRUE. At no time will a thread ever have scheduling attributes that exceed the thread's limits.

RETURN VALUES

KERN_INVALID_POLICY

The processor set does not currently enable policy.

KERN_POLICY_LIMIT

The specified scheduling attributes exceeds the thread's limits.

RELATED INFORMATION

Functions: thread_policy, thread_set_policy, task_set_policy, processor_set_policy_control.

Data Structures: policy_fifo_info, policy_rr_info, policy_timeshare_info.