2020-11-08 20:21:29 -08:00

305 lines
10 KiB
C

/*
* Copyright (c) 2013-2014 Apple Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this
* file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
#ifndef _PTHREAD_QOS_H
#define _PTHREAD_QOS_H
#include <sys/cdefs.h>
#include <sys/_pthread/_pthread_attr_t.h> /* pthread_attr_t */
#include <sys/_pthread/_pthread_t.h> /* pthread_t */
#include <Availability.h>
#if __DARWIN_C_LEVEL >= __DARWIN_C_FULL
#include <sys/qos.h>
#ifndef KERNEL
#if __has_feature(assume_nonnull)
_Pragma("clang assume_nonnull begin")
#endif
__BEGIN_DECLS
/*!
* @function pthread_attr_set_qos_class_np
*
* @abstract
* Sets the QOS class and relative priority of a pthread attribute structure
* which may be used to specify the requested QOS class of newly created
* threads.
*
* @discussion
* The QOS class and relative priority represent an overall combination of
* system quality of service attributes on a thread.
*
* Subsequent calls to interfaces such as pthread_attr_setschedparam() that are
* incompatible or in conflict with the QOS class system will unset the QOS
* class requested with this interface and pthread_attr_get_qos_class_np() will
* return QOS_CLASS_UNSPECIFIED.
*
* @param __attr
* The pthread attribute structure to modify.
*
* @param __qos_class
* A QOS class value:
* - QOS_CLASS_USER_INTERACTIVE
* - QOS_CLASS_USER_INITIATED
* - QOS_CLASS_DEFAULT
* - QOS_CLASS_UTILITY
* - QOS_CLASS_BACKGROUND
* EINVAL will be returned if any other value is provided.
*
* @param __relative_priority
* A relative priority within the QOS class. This value is a negative offset
* from the maximum supported scheduler priority for the given class.
* EINVAL will be returned if the value is greater than zero or less than
* QOS_MIN_RELATIVE_PRIORITY.
*
* @return
* Zero if successful, otherwise an errno value.
*/
__API_AVAILABLE(macos(10.10), ios(8.0))
int
pthread_attr_set_qos_class_np(pthread_attr_t *__attr,
qos_class_t __qos_class, int __relative_priority);
/*!
* @function pthread_attr_get_qos_class_np
*
* @abstract
* Gets the QOS class and relative priority of a pthread attribute structure.
*
* @param __attr
* The pthread attribute structure to inspect.
*
* @param __qos_class
* On output, a QOS class value:
* - QOS_CLASS_USER_INTERACTIVE
* - QOS_CLASS_USER_INITIATED
* - QOS_CLASS_DEFAULT
* - QOS_CLASS_UTILITY
* - QOS_CLASS_BACKGROUND
* - QOS_CLASS_UNSPECIFIED
* This value may be NULL in which case no value is returned.
*
* @param __relative_priority
* On output, a relative priority offset within the QOS class.
* This value may be NULL in which case no value is returned.
*
* @return
* Zero if successful, otherwise an errno value.
*/
__API_AVAILABLE(macos(10.10), ios(8.0))
int
pthread_attr_get_qos_class_np(pthread_attr_t * __restrict __attr,
qos_class_t * _Nullable __restrict __qos_class,
int * _Nullable __restrict __relative_priority);
/*!
* @function pthread_set_qos_class_self_np
*
* @abstract
* Sets the requested QOS class and relative priority of the current thread.
*
* @discussion
* The QOS class and relative priority represent an overall combination of
* system quality of service attributes on a thread.
*
* Subsequent calls to interfaces such as pthread_setschedparam() that are
* incompatible or in conflict with the QOS class system will unset the QOS
* class requested with this interface and pthread_get_qos_class_np() will
* return QOS_CLASS_UNSPECIFIED thereafter. A thread so modified is permanently
* opted-out of the QOS class system and calls to this function to request a QOS
* class for such a thread will fail and return EPERM.
*
* @param __qos_class
* A QOS class value:
* - QOS_CLASS_USER_INTERACTIVE
* - QOS_CLASS_USER_INITIATED
* - QOS_CLASS_DEFAULT
* - QOS_CLASS_UTILITY
* - QOS_CLASS_BACKGROUND
* EINVAL will be returned if any other value is provided.
*
* @param __relative_priority
* A relative priority within the QOS class. This value is a negative offset
* from the maximum supported scheduler priority for the given class.
* EINVAL will be returned if the value is greater than zero or less than
* QOS_MIN_RELATIVE_PRIORITY.
*
* @return
* Zero if successful, otherwise an errno value.
*/
__API_AVAILABLE(macos(10.10), ios(8.0))
int
pthread_set_qos_class_self_np(qos_class_t __qos_class,
int __relative_priority);
/*!
* @function pthread_get_qos_class_np
*
* @abstract
* Gets the requested QOS class and relative priority of a thread.
*
* @param __pthread
* The target thread to inspect.
*
* @param __qos_class
* On output, a QOS class value:
* - QOS_CLASS_USER_INTERACTIVE
* - QOS_CLASS_USER_INITIATED
* - QOS_CLASS_DEFAULT
* - QOS_CLASS_UTILITY
* - QOS_CLASS_BACKGROUND
* - QOS_CLASS_UNSPECIFIED
* This value may be NULL in which case no value is returned.
*
* @param __relative_priority
* On output, a relative priority offset within the QOS class.
* This value may be NULL in which case no value is returned.
*
* @return
* Zero if successful, otherwise an errno value.
*/
__API_AVAILABLE(macos(10.10), ios(8.0))
int
pthread_get_qos_class_np(pthread_t __pthread,
qos_class_t * _Nullable __restrict __qos_class,
int * _Nullable __restrict __relative_priority);
/*!
* @typedef pthread_override_t
*
* @abstract
* An opaque object representing a QOS class override of a thread.
*
* @discussion
* A QOS class override of a target thread expresses that an item of pending
* work classified with a specific QOS class and relative priority depends on
* the completion of the work currently being executed by the thread (e.g. due
* to ordering requirements).
*
* While overrides are in effect, the target thread will execute at the maximum
* QOS class and relative priority of all overrides and of the QOS class
* requested by the thread itself.
*
* A QOS class override does not modify the target thread's requested QOS class
* value and the effect of an override is not visible to the qos_class_self()
* and pthread_get_qos_class_np() interfaces.
*/
typedef struct pthread_override_s* pthread_override_t;
/*!
* @function pthread_override_qos_class_start_np
*
* @abstract
* Starts a QOS class override of the specified target thread.
*
* @discussion
* Starting a QOS class override of the specified target thread expresses that
* an item of pending work classified with the specified QOS class and relative
* priority depends on the completion of the work currently being executed by
* the thread (e.g. due to ordering requirements).
*
* While overrides are in effect, the specified target thread will execute at
* the maximum QOS class and relative priority of all overrides and of the QOS
* class requested by the thread itself.
*
* Starting a QOS class override does not modify the target thread's requested
* QOS class value and the effect of an override is not visible to the
* qos_class_self() and pthread_get_qos_class_np() interfaces.
*
* The returned newly allocated override object is intended to be associated
* with the item of pending work in question. Once the dependency has been
* satisfied and enabled that work to begin executing, the QOS class override
* must be ended by passing the associated override object to
* pthread_override_qos_class_end_np(). Failure to do so will result in the
* associated resources to be leaked and the target thread to be permanently
* executed at an inappropriately elevated QOS class.
*
* @param __pthread
* The target thread to modify.
*
* @param __qos_class
* A QOS class value:
* - QOS_CLASS_USER_INTERACTIVE
* - QOS_CLASS_USER_INITIATED
* - QOS_CLASS_DEFAULT
* - QOS_CLASS_UTILITY
* - QOS_CLASS_BACKGROUND
* NULL will be returned if any other value is provided.
*
* @param __relative_priority
* A relative priority within the QOS class. This value is a negative offset
* from the maximum supported scheduler priority for the given class.
* NULL will be returned if the value is greater than zero or less than
* QOS_MIN_RELATIVE_PRIORITY.
*
* @return
* A newly allocated override object if successful, or NULL if the override
* could not be started.
*/
__API_AVAILABLE(macos(10.10), ios(8.0))
pthread_override_t
pthread_override_qos_class_start_np(pthread_t __pthread,
qos_class_t __qos_class, int __relative_priority);
/*!
* @function pthread_override_qos_class_end_np
*
* @abstract
* Ends a QOS class override.
*
* @discussion
* Passing an override object returned by pthread_override_qos_class_start_np()
* ends the QOS class override started by that call and deallocates all
* associated resources as well as the override object itself.
*
* The thread starting and the thread ending a QOS class override need not be
* identical. If the thread ending the override is the the target thread of the
* override itself, it should take care to elevate its requested QOS class
* appropriately with pthread_set_qos_class_self_np() before ending the
* override.
*
* @param __override
* An override object returned by pthread_override_qos_class_start_np().
*
* @return
* Zero if successful, otherwise an errno value.
*/
__API_AVAILABLE(macos(10.10), ios(8.0))
int
pthread_override_qos_class_end_np(pthread_override_t __override);
__END_DECLS
#if __has_feature(assume_nonnull)
_Pragma("clang assume_nonnull end")
#endif
#endif // KERNEL
#endif // __DARWIN_C_LEVEL >= __DARWIN_C_FULL
#endif // _PTHREAD_QOS_H