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1c79356b 1/*
91447636 2 * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
1c79356b 3 *
2d21ac55 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b 5 *
2d21ac55
A
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
8f6c56a5 14 *
2d21ac55
A
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
8f6c56a5
A
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
2d21ac55
A
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
8f6c56a5 25 *
2d21ac55 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
1c79356b 27 */
1c79356b 28
91447636 29#ifdef KERNEL_PRIVATE
9bccf70c 30
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31#ifndef _KERN_WAIT_QUEUE_H_
32#define _KERN_WAIT_QUEUE_H_
9bccf70c 33
91447636 34#include <mach/mach_types.h>
1c79356b 35#include <mach/sync_policy.h>
0b4e3aa0 36#include <mach/kern_return.h> /* for kern_return_t */
1c79356b 37
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38#include <kern/kern_types.h> /* for wait_queue_t */
39
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40#include <sys/cdefs.h>
41
42#ifdef MACH_KERNEL_PRIVATE
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43
44#include <kern/lock.h>
45#include <kern/queue.h>
91447636 46#include <machine/cpu_number.h>
9bccf70c 47
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48/*
49 * wait_queue_t
50 * This is the definition of the common event wait queue
51 * that the scheduler APIs understand. It is used
52 * internally by the gerneralized event waiting mechanism
53 * (assert_wait), and also for items that maintain their
54 * own wait queues (such as ports and semaphores).
55 *
56 * It is not published to other kernel components. They
57 * can create wait queues by calling wait_queue_alloc.
58 *
59 * NOTE: Hardware locks are used to protect event wait
60 * queues since interrupt code is free to post events to
61 * them.
62 */
63typedef struct wait_queue {
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64 unsigned int /* flags */
65 /* boolean_t */ wq_type:16, /* only public field */
66 wq_fifo:1, /* fifo wakeup policy? */
67 wq_isprepost:1, /* is waitq preposted? set only */
68 :0; /* force to long boundary */
1c79356b 69 hw_lock_data_t wq_interlock; /* interlock */
9bccf70c 70 queue_head_t wq_queue; /* queue of elements */
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71} WaitQueue;
72
73/*
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74 * wait_queue_set_t
75 * This is the common definition for a set wait queue.
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76 * These can be linked as members/elements of multiple regular
77 * wait queues. They have an additional set of linkages to
78 * identify the linkage structures that point to them.
79 */
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80typedef struct wait_queue_set {
81 WaitQueue wqs_wait_queue; /* our wait queue */
82 queue_head_t wqs_setlinks; /* links from set perspective */
0b4e3aa0 83 unsigned int wqs_refcount; /* refcount for preposting */
9bccf70c 84} WaitQueueSet;
1c79356b 85
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86#define wqs_type wqs_wait_queue.wq_type
87#define wqs_fifo wqs_wait_queue.wq_fifo
88#define wqs_isprepost wqs_wait_queue.wq_isprepost
89#define wqs_queue wqs_wait_queue.wq_queue
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90
91/*
92 * wait_queue_element_t
93 * This structure describes the elements on an event wait
94 * queue. It is the common first fields in a thread shuttle
95 * and wait_queue_link_t. In that way, a wait queue can
96 * consist of both thread shuttle elements and links off of
9bccf70c 97 * to other (set) wait queues.
1c79356b 98 *
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99 * WARNING: These fields correspond to fields in the thread
100 * shuttle (run queue links and run queue pointer). Any change in
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101 * the layout here will have to be matched with a change there.
102 */
103typedef struct wait_queue_element {
104 queue_chain_t wqe_links; /* link of elements on this queue */
9bccf70c 105 void * wqe_type; /* Identifies link vs. thread */
1c79356b 106 wait_queue_t wqe_queue; /* queue this element is on */
9bccf70c 107} WaitQueueElement;
1c79356b 108
9bccf70c 109typedef WaitQueueElement *wait_queue_element_t;
0b4e3aa0 110
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111/*
112 * wait_queue_link_t
9bccf70c 113 * Specialized wait queue element type for linking set
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114 * event waits queues onto a wait queue. In this way, an event
115 * can be constructed so that any thread waiting on any number
116 * of associated wait queues can handle the event, while letting
117 * the thread only be linked on the single wait queue it blocked on.
118 *
119 * One use: ports in multiple portsets. Each thread is queued up
120 * on the portset that it specifically blocked on during a receive
121 * operation. Each port's event queue links in all the portset
122 * event queues of which it is a member. An IPC event post associated
123 * with that port may wake up any thread from any of those portsets,
124 * or one that was waiting locally on the port itself.
125 */
2d21ac55 126typedef struct _wait_queue_link {
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127 WaitQueueElement wql_element; /* element on master */
128 queue_chain_t wql_setlinks; /* element on set */
129 wait_queue_set_t wql_setqueue; /* set queue */
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130} WaitQueueLink;
131
1c79356b 132#define wql_links wql_element.wqe_links
9bccf70c 133#define wql_type wql_element.wqe_type
1c79356b 134#define wql_queue wql_element.wqe_queue
0b4e3aa0 135
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136#define _WAIT_QUEUE_inited 0xf1d0
137#define _WAIT_QUEUE_SET_inited 0xf1d1
0b4e3aa0 138
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139#define wait_queue_is_queue(wq) \
140 ((wq)->wq_type == _WAIT_QUEUE_inited)
1c79356b 141
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142#define wait_queue_is_set(wqs) \
143 ((wqs)->wqs_type == _WAIT_QUEUE_SET_inited)
1c79356b 144
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145#define wait_queue_is_valid(wq) \
146 (((wq)->wq_type & ~1) == _WAIT_QUEUE_inited)
1c79356b 147
9bccf70c 148#define wait_queue_empty(wq) (queue_empty(&(wq)->wq_queue))
2d21ac55 149
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150#define wait_queue_held(wq) (hw_lock_held(&(wq)->wq_interlock))
151#define wait_queue_lock_try(wq) (hw_lock_try(&(wq)->wq_interlock))
1c79356b 152
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153/* For x86, the hardware timeout is in TSC units. */
154#if defined(i386)
155#define hwLockTimeOut LockTimeOutTSC
156#else
157#define hwLockTimeOut LockTimeOut
158#endif
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159/*
160 * Double the standard lock timeout, because wait queues tend
161 * to iterate over a number of threads - locking each. If there is
162 * a problem with a thread lock, it normally times out at the wait
163 * queue level first, hiding the real problem.
164 */
1c79356b 165
0c530ab8 166static inline void wait_queue_lock(wait_queue_t wq) {
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167 if (!hw_lock_to(&(wq)->wq_interlock, hwLockTimeOut * 2))
168 panic("wait queue deadlock - wq=%p, cpu=%d\n", wq, cpu_number(
169));
0c530ab8 170}
2d21ac55 171
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172static inline void wait_queue_unlock(wait_queue_t wq) {
173 assert(wait_queue_held(wq));
174#if defined(__i386__)
2d21ac55 175 /* DRK: On certain x86 systems, this spinlock is susceptible to
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176 * lock starvation. Hence use an unlock variant which performs
177 * a cacheline flush to minimize cache affinity on acquisition.
178 */
179 i386_lock_unlock_with_flush(&(wq)->wq_interlock);
180#else
2d21ac55 181 hw_lock_unlock(&(wq)->wq_interlock);
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182#endif
183}
1c79356b 184
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185#define wqs_lock(wqs) wait_queue_lock(&(wqs)->wqs_wait_queue)
186#define wqs_unlock(wqs) wait_queue_unlock(&(wqs)->wqs_wait_queue)
187#define wqs_lock_try(wqs) wait_queue__try_lock(&(wqs)->wqs_wait_queue)
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188
189#define wait_queue_assert_possible(thread) \
190 ((thread)->wait_queue == WAIT_QUEUE_NULL)
191
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192/******** Decomposed interfaces (to build higher level constructs) ***********/
193
1c79356b 194/* assert intent to wait on a locked wait queue */
9bccf70c 195__private_extern__ wait_result_t wait_queue_assert_wait64_locked(
1c79356b 196 wait_queue_t wait_queue,
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197 event64_t wait_event,
198 wait_interrupt_t interruptible,
91447636 199 uint64_t deadline,
55e303ae 200 thread_t thread);
1c79356b 201
2d21ac55 202/* pull a thread from its wait queue */
9bccf70c 203__private_extern__ void wait_queue_pull_thread_locked(
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204 wait_queue_t wait_queue,
205 thread_t thread,
206 boolean_t unlock);
207
208/* wakeup all threads waiting for a particular event on locked queue */
9bccf70c 209__private_extern__ kern_return_t wait_queue_wakeup64_all_locked(
1c79356b 210 wait_queue_t wait_queue,
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211 event64_t wake_event,
212 wait_result_t result,
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213 boolean_t unlock);
214
215/* wakeup one thread waiting for a particular event on locked queue */
9bccf70c 216__private_extern__ kern_return_t wait_queue_wakeup64_one_locked(
1c79356b 217 wait_queue_t wait_queue,
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218 event64_t wake_event,
219 wait_result_t result,
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220 boolean_t unlock);
221
1c79356b 222/* return identity of a thread awakened for a particular <wait_queue,event> */
9bccf70c 223__private_extern__ thread_t wait_queue_wakeup64_identity_locked(
1c79356b 224 wait_queue_t wait_queue,
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225 event64_t wake_event,
226 wait_result_t result,
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227 boolean_t unlock);
228
229/* wakeup thread iff its still waiting for a particular event on locked queue */
9bccf70c 230__private_extern__ kern_return_t wait_queue_wakeup64_thread_locked(
1c79356b 231 wait_queue_t wait_queue,
9bccf70c 232 event64_t wake_event,
1c79356b 233 thread_t thread,
9bccf70c 234 wait_result_t result,
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235 boolean_t unlock);
236
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237#endif /* MACH_KERNEL_PRIVATE */
238
239__BEGIN_DECLS
1c79356b 240
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241/******** Semi-Public interfaces (not a part of a higher construct) ************/
242
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243extern unsigned int wait_queue_set_size(void);
244extern unsigned int wait_queue_link_size(void);
245
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246extern kern_return_t wait_queue_init(
247 wait_queue_t wait_queue,
248 int policy);
249
250extern wait_queue_set_t wait_queue_set_alloc(
251 int policy);
252
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253extern kern_return_t wait_queue_set_init(
254 wait_queue_set_t set_queue,
255 int policy);
256
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257extern kern_return_t wait_queue_set_free(
258 wait_queue_set_t set_queue);
259
260extern wait_queue_link_t wait_queue_link_alloc(
261 int policy);
262
263extern kern_return_t wait_queue_link_free(
264 wait_queue_link_t link_element);
265
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266extern kern_return_t wait_queue_link(
267 wait_queue_t wait_queue,
268 wait_queue_set_t set_queue);
9bccf70c 269
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270extern kern_return_t wait_queue_link_noalloc(
271 wait_queue_t wait_queue,
272 wait_queue_set_t set_queue,
273 wait_queue_link_t link);
1c79356b 274
91447636 275extern boolean_t wait_queue_member(
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276 wait_queue_t wait_queue,
277 wait_queue_set_t set_queue);
278
279extern kern_return_t wait_queue_unlink(
280 wait_queue_t wait_queue,
281 wait_queue_set_t set_queue);
282
283extern kern_return_t wait_queue_unlink_all(
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284 wait_queue_t wait_queue);
285
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286extern kern_return_t wait_queue_unlinkall_nofree(
287 wait_queue_t wait_queue);
288
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289extern kern_return_t wait_queue_set_unlink_all(
290 wait_queue_set_t set_queue);
291
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292/* legacy API */
293kern_return_t wait_queue_sub_init(
294 wait_queue_set_t set_queue,
295 int policy);
296
297kern_return_t wait_queue_sub_clearrefs(
298 wait_queue_set_t wq_set);
299
300extern kern_return_t wait_subqueue_unlink_all(
301 wait_queue_set_t set_queue);
302
303extern wait_queue_t wait_queue_alloc(
304 int policy);
305
306extern kern_return_t wait_queue_free(
307 wait_queue_t wait_queue);
308
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309/* assert intent to wait on <wait_queue,event64> pair */
310extern wait_result_t wait_queue_assert_wait64(
311 wait_queue_t wait_queue,
312 event64_t wait_event,
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313 wait_interrupt_t interruptible,
314 uint64_t deadline);
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315
316/* wakeup the most appropriate thread waiting on <wait_queue,event64> pair */
317extern kern_return_t wait_queue_wakeup64_one(
318 wait_queue_t wait_queue,
319 event64_t wake_event,
320 wait_result_t result);
321
322/* wakeup all the threads waiting on <wait_queue,event64> pair */
323extern kern_return_t wait_queue_wakeup64_all(
324 wait_queue_t wait_queue,
325 event64_t wake_event,
326 wait_result_t result);
327
328/* wakeup a specified thread waiting iff waiting on <wait_queue,event64> pair */
329extern kern_return_t wait_queue_wakeup64_thread(
330 wait_queue_t wait_queue,
331 event64_t wake_event,
332 thread_t thread,
333 wait_result_t result);
334
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335/*
336 * Compatibility Wait Queue APIs based on pointer events instead of 64bit
337 * integer events.
338 */
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339
340/* assert intent to wait on <wait_queue,event> pair */
9bccf70c 341extern wait_result_t wait_queue_assert_wait(
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342 wait_queue_t wait_queue,
343 event_t wait_event,
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344 wait_interrupt_t interruptible,
345 uint64_t deadline);
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346
347/* wakeup the most appropriate thread waiting on <wait_queue,event> pair */
9bccf70c 348extern kern_return_t wait_queue_wakeup_one(
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349 wait_queue_t wait_queue,
350 event_t wake_event,
9bccf70c 351 wait_result_t result);
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352
353/* wakeup all the threads waiting on <wait_queue,event> pair */
9bccf70c 354extern kern_return_t wait_queue_wakeup_all(
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355 wait_queue_t wait_queue,
356 event_t wake_event,
9bccf70c 357 wait_result_t result);
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358
359/* wakeup a specified thread waiting iff waiting on <wait_queue,event> pair */
9bccf70c 360extern kern_return_t wait_queue_wakeup_thread(
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361 wait_queue_t wait_queue,
362 event_t wake_event,
363 thread_t thread,
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364 wait_result_t result);
365
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366__END_DECLS
367
368#endif /* _KERN_WAIT_QUEUE_H_ */
1c79356b 369
91447636 370#endif /* KERNEL_PRIVATE */