This is xnu-4903.221.2. See this file in:
/*
 * Copyright (c) 2017 Apple, 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
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * 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_OSREFERENCE_LICENSE_HEADER_END@
 */

#ifndef _PTHREAD_WORKQUEUE_PRIVATE_H_
#define _PTHREAD_WORKQUEUE_PRIVATE_H_

#if XNU_KERNEL_PRIVATE && !defined(__PTHREAD_EXPOSE_INTERNALS__)
#define __PTHREAD_EXPOSE_INTERNALS__ 1
#endif // XNU_KERNEL_PRIVATE

#ifdef __PTHREAD_EXPOSE_INTERNALS__
/* workq_kernreturn commands */
#define WQOPS_THREAD_RETURN        0x04	/* parks the thread back into the kernel */
#define WQOPS_QUEUE_NEWSPISUPP     0x10	/* this is to check for newer SPI support */
#define WQOPS_QUEUE_REQTHREADS     0x20	/* request number of threads of a prio */
#define WQOPS_QUEUE_REQTHREADS2    0x30	/* request a number of threads in a given priority bucket */
#define WQOPS_THREAD_KEVENT_RETURN 0x40	/* parks the thread after delivering the passed kevent array */
#define WQOPS_SET_EVENT_MANAGER_PRIORITY 0x80	/* max() in the provided priority in the the priority of the event manager */
#define WQOPS_THREAD_WORKLOOP_RETURN 0x100	/* parks the thread after delivering the passed kevent array */
#define WQOPS_SHOULD_NARROW 0x200	/* checks whether we should narrow our concurrency */

/* flag values for upcall flags field, only 8 bits per struct threadlist */
#define WQ_FLAG_THREAD_PRIO_SCHED		0x00008000
#define WQ_FLAG_THREAD_PRIO_QOS			0x00004000
#define WQ_FLAG_THREAD_PRIO_MASK		0x00000fff

#define WQ_FLAG_THREAD_OVERCOMMIT		0x00010000  /* thread is with overcommit prio */
#define WQ_FLAG_THREAD_REUSE			0x00020000  /* thread is being reused */
#define WQ_FLAG_THREAD_NEWSPI			0x00040000  /* the call is with new SPIs */
#define WQ_FLAG_THREAD_KEVENT			0x00080000  /* thread is response to kevent req */
#define WQ_FLAG_THREAD_EVENT_MANAGER	0x00100000  /* event manager thread */
#define WQ_FLAG_THREAD_TSD_BASE_SET		0x00200000  /* tsd base has already been set */
#define WQ_FLAG_THREAD_WORKLOOP			0x00400000  /* workloop thread */
#define WQ_FLAG_THREAD_OUTSIDEQOS		0x00800000  /* thread qos changes should not be sent to kernel */

#define WQ_KEVENT_LIST_LEN  16 // WORKQ_KEVENT_EVENT_BUFFER_LEN
#define WQ_KEVENT_DATA_SIZE (32 * 1024)

/* kqueue_workloop_ctl commands */
#define KQ_WORKLOOP_CREATE				0x01
#define KQ_WORKLOOP_DESTROY				0x02

/* indicate which fields of kq_workloop_create params are valid */
#define KQ_WORKLOOP_CREATE_SCHED_PRI	0x01
#define KQ_WORKLOOP_CREATE_SCHED_POL	0x02
#define KQ_WORKLOOP_CREATE_CPU_PERCENT	0x04

struct kqueue_workloop_params {
	int kqwlp_version;
	int kqwlp_flags;
	uint64_t kqwlp_id;
	int kqwlp_sched_pri;
	int kqwlp_sched_pol;
	int kqwlp_cpu_percent;
	int kqwlp_cpu_refillms;
} __attribute__((packed));

_Static_assert(offsetof(struct kqueue_workloop_params, kqwlp_version) == 0,
		"kqwlp_version should be first");

int
__workq_open(void);

int
__workq_kernreturn(int op, void *arg2, int arg3, int arg4);

int
__kqueue_workloop_ctl(uintptr_t cmd, uint64_t options, void *addr, size_t sz);

/* SPI flags between WQ and workq_setup_thread in pthread.kext */
#define WQ_SETUP_FIRST_USE      1
#define WQ_SETUP_CLEAR_VOUCHER  2
// was  WQ_SETUP_SET_SCHED_CALL 4
#define WQ_SETUP_EXIT_THREAD    8

#endif // __PTHREAD_EXPOSE_INTERNALS__
#endif // _PTHREAD_WORKQUEUE_PRIVATE_H_