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* Copyright (c) 2000-2017 Apple Computer, Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_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
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* may not be used to create, or enable the creation or redistribution of,
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*
* Please obtain a copy of the License at
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*
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#ifndef _PTHREAD_PRIORITY_PRIVATE_H_
#define _PTHREAD_PRIORITY_PRIVATE_H_
#if KERNEL
#define PTHREAD_EXPOSE_LAYOUT 1
#else
#include <TargetConditionals.h>
#if TARGET_OS_SIMULATOR
#define PTHREAD_EXPOSE_LAYOUT 0
#else
#define PTHREAD_EXPOSE_LAYOUT 1
#endif /* TARGET_OS_SIMULATOR */
#endif
/*!
* @typedef pthread_priority_t
*
* @abstract
* pthread_priority_t is an on opaque integer that is guaranteed to be ordered
* such that combations of QoS classes and relative priorities are ordered
* numerically, according to their combined priority.
*
* <b>xnu, pthread & libdispatch flags</b>
*
* @const _PTHREAD_PRIORITY_OVERCOMMIT_FLAG
* The thread this priority is applied to is overcommit (affects the workqueue
* creation policy for this priority).
*
* @const _PTHREAD_PRIORITY_COOPERATIVE_FLAG
* Used to convey that a thread is part of the cooperative pool. This is used
* both outgoing form kernel and incoming into kernel
*
* @const _PTHREAD_PRIORITY_THREAD_TYPE_MASK
* The set of bits that encode information about the thread type - whether it is
* overcommit, non-overcommit or cooperative
*
* @const _PTHREAD_PRIORITY_FALLBACK_FLAG
* Indicates that this priority is is used only when incoming events have no
* priority at all. It is merely used as a fallback (hence the name) instead of
* a floor.
*
* This is usually used with QOS_CLASS_DEFAULT and a 0 relative priority.
*
* @const _PTHREAD_PRIORITY_EVENT_MANAGER_FLAG
* The event manager flag indicates that this thread/request is for a event
* manager thread. There can only ever be one event manager thread at a time
* and it is brought up at the highest of all event manager priorities pthread
* knows about.
*
* @const _PTHREAD_PRIORITY_OVERRIDE_QOS_FLAG
* This flag indicates that the bits extracted using
* _PTHREAD_PRIORITY_QOS_CLASS_MASK represent { QoS override, req QoS } instead
* of just req QoS. This is only currently only used as input to the kernel as
* part of pthread_set_properties_self(). The override field here represents the
* dispatch workqueue override.
*
* @const _PTHREAD_PRIORITY_SCHED_PRI_FLAG
* @const _PTHREAD_PRIORITY_SCHED_PRI_MASK
* This flag indicates that the bits extracted using
* _PTHREAD_PRIORITY_SCHED_PRI_MASK represent a scheduler priority instead of
* a {qos, relative priority} pair.
*
* This flag is used by the pthread kext to indicate to libdispatch that the
* event manager queue priority is a scheduling priority and not a QoS. When
* the manager thread's priority is updated due to creation of pthread root
* queues, libdispatch passed a pthread_priority_t in to kernel with this flag
* to specify the new sched pri of manager. This flag is never used as an input
* by anything else and is why it can perform a double duty with
* _PTHREAD_PRIORITY_ROOTQUEUE_FLAG.
*
* @const _PTHREAD_PRIORITY_NEEDS_UNBIND_FLAG
* This flag is used for the priority of event delivery threads to indicate
* to libdispatch that this thread is bound to a kqueue.
*
* <b>dispatch only flags</b>
*
* @const _PTHREAD_PRIORITY_INHERIT_FLAG
* This flag is meaningful to libdispatch only and has no meaning for the
* kernel and/or pthread.
*
* @const _PTHREAD_PRIORITY_ROOTQUEUE_FLAG
* This flag is meaningful to libdispatch only and has no meaning for the
* kernel and/or pthread.
*
* @const _PTHREAD_PRIORITY_ENFORCE_FLAG
* This flag is used to indicate that this priority should be prefered for work
* submited asynchronously over the intrinsic priority of the queue/thread the
* work is submitted to.
*
*
* pthread_priority_t encoding - outgoing from kernel:
*
* Regular:
* flags req QoS class Rel pri
* |---------------------------------|--------------------|--------------------|
* 22 - 31 8-21 0-7
*
* With _PTHREAD_PRIORITY_SCHED_PRI_FLAG:
*
* flags unused sched priority
* |---------------------------------|----------|------------------------------|
* 22 - 31 16-21 0-15
*
* pthread_priority_t encoding - incoming to kernel via various syscalls:
*
* Regular:
*
* flags req QoS class Rel pri
* |---------------------------------|--------------------|--------------------|
* 22 - 31 8-21 0-7
*
* With _PTHREAD_PRIORITY_OVERRIDE_QOS_FLAG:
*
* flags QoS ovr QoS class Rel pri
* |---------------------------------|---------|----------|--------------------|
* 22 - 31 14-21 8-13 0-7
*
* With _PTHREAD_PRIORITY_SCHED_PRI_FLAG:
*
* flags unused sched priority
* |---------------------------------|----------|------------------------------|
* 22 - 31 16-21 0-15
*/
typedef unsigned long pthread_priority_t;
#define _PTHREAD_PRIORITY_OVERCOMMIT_FLAG 0x80000000u
#define _PTHREAD_PRIORITY_INHERIT_FLAG 0x40000000u /* dispatch only */
#define _PTHREAD_PRIORITY_ROOTQUEUE_FLAG 0x20000000u /* dispatch only */
#define _PTHREAD_PRIORITY_SCHED_PRI_FLAG 0x20000000u
#define _PTHREAD_PRIORITY_ENFORCE_FLAG 0x10000000u /* dispatch only */
#define _PTHREAD_PRIORITY_FALLBACK_FLAG 0x04000000u
#define _PTHREAD_PRIORITY_COOPERATIVE_FLAG 0x08000000u
#define _PTHREAD_PRIORITY_EVENT_MANAGER_FLAG 0x02000000u
#define _PTHREAD_PRIORITY_NEEDS_UNBIND_FLAG 0x01000000u
#define _PTHREAD_PRIORITY_DEFAULTQUEUE_FLAG _PTHREAD_PRIORITY_FALLBACK_FLAG // compat
#define _PTHREAD_PRIORITY_OVERRIDE_QOS_FLAG 0x00800000u
#define _PTHREAD_PRIORITY_THREAD_TYPE_MASK (_PTHREAD_PRIORITY_COOPERATIVE_FLAG | _PTHREAD_PRIORITY_OVERCOMMIT_FLAG)
#if PTHREAD_EXPOSE_LAYOUT || defined(__PTHREAD_EXPOSE_INTERNALS__)
// Masks for encoding of pthread priority
#define _PTHREAD_PRIORITY_FLAGS_MASK 0xff000000u
#define _PTHREAD_PRIORITY_SCHED_PRI_MASK 0x0000ffffu
#define _PTHREAD_PRIORITY_QOS_CLASS_MASK 0x003fff00u
#define _PTHREAD_PRIORITY_QOS_CLASS_SHIFT (8ull)
#define _PTHREAD_PRIORITY_VALID_QOS_CLASS_MASK 0x00003f00u
#define _PTHREAD_PRIORITY_VALID_OVERRIDE_QOS_MASK 0x003fc000u
#define _PTHREAD_PRIORITY_QOS_OVERRIDE_SHIFT (14ull)
#define _PTHREAD_PRIORITY_PRIORITY_MASK 0x000000ffu
#define _PTHREAD_PRIORITY_PRIORITY_SHIFT (0)
#endif /* PTHREAD_EXPOSE_LAYOUT */
#if PRIVATE
#if XNU_KERNEL_PRIVATE && !defined(__PTHREAD_EXPOSE_INTERNALS__)
#define __PTHREAD_EXPOSE_INTERNALS__ 1
#endif // XNU_KERNEL_PRIVATE
#ifdef __PTHREAD_EXPOSE_INTERNALS__
/*
* This exposes the encoding used for pthread_priority_t
* and is meant to be used by pthread and XNU only
*/
#include <mach/thread_policy.h> // THREAD_QOS_*
#include <stdbool.h>
// pthread_priority_t's type is unfortunately 64bits on LP64
// so we use this type for people who need to store it in structs
typedef unsigned int pthread_priority_compact_t;
__attribute__((always_inline, const))
static inline bool
_pthread_priority_has_qos(pthread_priority_t pp)
{
return (pp & (_PTHREAD_PRIORITY_SCHED_PRI_FLAG |
_PTHREAD_PRIORITY_EVENT_MANAGER_FLAG)) == 0 &&
(pp & _PTHREAD_PRIORITY_VALID_QOS_CLASS_MASK) != 0;
}
__attribute__((always_inline, const))
static inline bool
_pthread_priority_has_sched_pri(pthread_priority_t pp)
{
return pp & _PTHREAD_PRIORITY_SCHED_PRI_FLAG;
}
__attribute__((always_inline, const))
static inline bool
_pthread_priority_has_override_qos(pthread_priority_t pp)
{
return (pp & (_PTHREAD_PRIORITY_SCHED_PRI_FLAG |
_PTHREAD_PRIORITY_EVENT_MANAGER_FLAG)) == 0 &&
(pp & _PTHREAD_PRIORITY_OVERRIDE_QOS_FLAG) != 0 &&
(pp & _PTHREAD_PRIORITY_VALID_OVERRIDE_QOS_MASK) != 0;
}
__attribute__((always_inline, const))
static inline pthread_priority_compact_t
_pthread_priority_make_from_thread_qos(thread_qos_t qos, int relpri,
unsigned long flags)
{
pthread_priority_compact_t pp = (flags & _PTHREAD_PRIORITY_FLAGS_MASK);
if (qos && qos < THREAD_QOS_LAST) {
pp |= (1 << (_PTHREAD_PRIORITY_QOS_CLASS_SHIFT + qos - 1));
pp |= ((uint8_t)relpri - 1) & _PTHREAD_PRIORITY_PRIORITY_MASK;
}
return pp;
}
__attribute__((always_inline, const))
static inline pthread_priority_compact_t
_pthread_priority_make_from_sched_pri(int sched_pri, unsigned long flags)
{
pthread_priority_compact_t pp = (flags & _PTHREAD_PRIORITY_FLAGS_MASK);
pp |= _PTHREAD_PRIORITY_SCHED_PRI_FLAG;
pp |= (pthread_priority_compact_t) sched_pri;
return pp;
}
__attribute__((always_inline, const))
static inline pthread_priority_compact_t
_pthread_priority_make_from_thread_qos_and_override(thread_qos_t req_qos,
int relpri, thread_qos_t override_qos, unsigned long flags)
{
pthread_priority_compact_t pp;
pp = _pthread_priority_make_from_thread_qos(req_qos, relpri, flags);
if (override_qos && override_qos < THREAD_QOS_LAST) {
pp |= (1 << (_PTHREAD_PRIORITY_QOS_OVERRIDE_SHIFT + (override_qos - 1)));
pp |= _PTHREAD_PRIORITY_OVERRIDE_QOS_FLAG;
}
return pp;
}
__attribute__((always_inline, const))
static inline pthread_priority_compact_t
_pthread_event_manager_priority(void)
{
return _PTHREAD_PRIORITY_EVENT_MANAGER_FLAG;
}
__attribute__((always_inline, const))
static inline pthread_priority_compact_t
_pthread_unspecified_priority(void)
{
return _pthread_priority_make_from_thread_qos(THREAD_QOS_UNSPECIFIED, 0, 0);
}
__attribute__((always_inline, const))
static inline pthread_priority_compact_t
_pthread_default_priority(unsigned long flags)
{
return _pthread_priority_make_from_thread_qos(THREAD_QOS_LEGACY, 0, flags);
}
__attribute__((always_inline, const))
static inline thread_qos_t
_pthread_priority_thread_qos_fast(pthread_priority_t pp)
{
pp &= _PTHREAD_PRIORITY_VALID_QOS_CLASS_MASK;
pp >>= _PTHREAD_PRIORITY_QOS_CLASS_SHIFT;
return (thread_qos_t)__builtin_ffs((int)pp);
}
__attribute__((always_inline, const))
static inline thread_qos_t
_pthread_priority_thread_override_qos_fast(pthread_priority_t pp)
{
pp &= _PTHREAD_PRIORITY_VALID_OVERRIDE_QOS_MASK;
pp >>= _PTHREAD_PRIORITY_QOS_OVERRIDE_SHIFT;
return (thread_qos_t)__builtin_ffs((int)pp);
}
__attribute__((always_inline, const))
static inline int
_pthread_priority_sched_pri_fast(pthread_priority_t pp)
{
return pp & _PTHREAD_PRIORITY_SCHED_PRI_MASK;
}
__attribute__((always_inline, const))
static inline thread_qos_t
_pthread_priority_thread_qos(pthread_priority_t pp)
{
if (_pthread_priority_has_qos(pp)) {
return _pthread_priority_thread_qos_fast(pp);
}
return THREAD_QOS_UNSPECIFIED;
}
__attribute__((always_inline, const))
static inline thread_qos_t
_pthread_priority_thread_override_qos(pthread_priority_t pp)
{
if (_pthread_priority_has_override_qos(pp)) {
return _pthread_priority_thread_override_qos_fast(pp);
}
return THREAD_QOS_UNSPECIFIED;
}
__attribute__((always_inline, const))
static inline int
_pthread_priority_sched_pri(pthread_priority_t pp)
{
if (_pthread_priority_has_sched_pri(pp)) {
return _pthread_priority_sched_pri_fast(pp);
}
return 0;
}
__attribute__((always_inline, const))
static inline int
_pthread_priority_relpri(pthread_priority_t pp)
{
if (_pthread_priority_has_qos(pp)) {
pp &= _PTHREAD_PRIORITY_PRIORITY_MASK;
pp >>= _PTHREAD_PRIORITY_PRIORITY_SHIFT;
return (int8_t)pp + 1;
}
return 0;
}
__attribute__((always_inline, const))
static inline bool
_pthread_priority_is_overcommit(pthread_priority_t pp)
{
return pp & _PTHREAD_PRIORITY_OVERCOMMIT_FLAG;
}
__attribute__((always_inline, const))
static inline bool
_pthread_priority_is_cooperative(pthread_priority_t pp)
{
return pp & _PTHREAD_PRIORITY_COOPERATIVE_FLAG;
}
__attribute__((always_inline, const))
static inline bool
_pthread_priority_is_nonovercommit(pthread_priority_t pp)
{
return !_pthread_priority_is_cooperative(pp) && !_pthread_priority_is_overcommit(pp);
}
#if XNU_KERNEL_PRIVATE
// Interfaces only used by the kernel and not implemented in userspace.
/*
* Keep managerness, overcomitness and fallback, discard other flags.
* Normalize and validate QoS/relpri
*/
__attribute__((const))
pthread_priority_compact_t
_pthread_priority_normalize(pthread_priority_t pp);
/*
* Keep managerness, discard other flags.
* Normalize and validate QoS/relpri
*/
__attribute__((const))
pthread_priority_compact_t
_pthread_priority_normalize_for_ipc(pthread_priority_t pp);
/*
* Keep the flags from base_pp and return the priority with the maximum priority
* of base_pp and _pthread_priority_make_from_thread_qos(qos, 0, 0)
*/
__attribute__((const))
pthread_priority_compact_t
_pthread_priority_combine(pthread_priority_t base_pp, thread_qos_t qos);
#endif // XNU_KERNEL_PRIVATE
#endif // __PTHREAD_EXPOSE_INTERNALS__
#endif // PRIVATE
#endif // _PTHREAD_PRIORITY_PRIVATE_H_