sleepqueue.h revision 177085
1226048Sobrien/*- 2226048Sobrien * Copyright (c) 2004 John Baldwin <jhb@FreeBSD.org> 3226048Sobrien * All rights reserved. 4226048Sobrien * 5330569Sgordon * Redistribution and use in source and binary forms, with or without 6226048Sobrien * modification, are permitted provided that the following conditions 7226048Sobrien * are met: 8226048Sobrien * 1. Redistributions of source code must retain the above copyright 9226048Sobrien * notice, this list of conditions and the following disclaimer. 10226048Sobrien * 2. Redistributions in binary form must reproduce the above copyright 11226048Sobrien * notice, this list of conditions and the following disclaimer in the 12330569Sgordon * documentation and/or other materials provided with the distribution. 13330569Sgordon * 3. Neither the name of the author nor the names of any co-contributors 14330569Sgordon * may be used to endorse or promote products derived from this software 15226048Sobrien * without specific prior written permission. 16226048Sobrien * 17330569Sgordon * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18226048Sobrien * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19330569Sgordon * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20226048Sobrien * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21330569Sgordon * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22226048Sobrien * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23330569Sgordon * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24226048Sobrien * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25330569Sgordon * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26226048Sobrien * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27226048Sobrien * SUCH DAMAGE. 28226048Sobrien * 29330569Sgordon * $FreeBSD: head/sys/sys/sleepqueue.h 177085 2008-03-12 06:31:06Z jeff $ 30226048Sobrien */ 31 32#ifndef _SYS_SLEEPQUEUE_H_ 33#define _SYS_SLEEPQUEUE_H_ 34 35/* 36 * Sleep queue interface. Sleep/wakeup, condition variables, and sx 37 * locks use a sleep queue for the queue of threads blocked on a sleep 38 * channel. 39 * 40 * A thread calls sleepq_lock() to lock the sleep queue chain associated 41 * with a given wait channel. A thread can then call call sleepq_add() to 42 * add themself onto a sleep queue and call one of the sleepq_wait() 43 * functions to actually go to sleep. If a thread needs to abort a sleep 44 * operation it should call sleepq_release() to unlock the associated sleep 45 * queue chain lock. If the thread also needs to remove itself from a queue 46 * it just enqueued itself on, it can use sleepq_remove() instead. 47 * 48 * If the thread only wishes to sleep for a limited amount of time, it can 49 * call sleepq_set_timeout() after sleepq_add() to setup a timeout. It 50 * should then use one of the sleepq_timedwait() functions to block. 51 * 52 * If the thread wants to the sleep to be interruptible by signals, it can 53 * call sleepq_catch_signals() after sleepq_add(). It should then use 54 * one of the sleepq_wait_sig() functions to block. After the thread has 55 * been resumed, it should call sleepq_calc_signal_retval() to determine 56 * if it should return EINTR or ERESTART passing in the value returned from 57 * the earlier call to sleepq_catch_signals(). 58 * 59 * A thread is normally resumed from a sleep queue by either the 60 * sleepq_signal() or sleepq_broadcast() functions. Sleepq_signal() wakes 61 * the thread with the highest priority that is sleeping on the specified 62 * wait channel. Sleepq_broadcast() wakes all threads that are sleeping 63 * on the specified wait channel. A thread sleeping in an interruptible 64 * sleep can be interrupted by calling sleepq_abort(). A thread can also 65 * be removed from a specified sleep queue using the sleepq_remove() 66 * function. Note that the sleep queue chain must first be locked via 67 * sleepq_lock() when calling sleepq_signal() and sleepq_broadcast(). 68 * 69 * Each thread allocates a sleep queue at thread creation via sleepq_alloc() 70 * and releases it at thread destruction via sleepq_free(). Note that 71 * a sleep queue is not tied to a specific thread and that the sleep queue 72 * released at thread destruction may not be the same sleep queue that the 73 * thread allocated when it was created. 74 * 75 * XXX: Some other parts of the kernel such as ithread sleeping may end up 76 * using this interface as well (death to TDI_IWAIT!) 77 */ 78 79struct lock_object; 80struct sleepqueue; 81struct thread; 82 83#ifdef _KERNEL 84 85#define SLEEPQ_TYPE 0x0ff /* Mask of sleep queue types. */ 86#define SLEEPQ_SLEEP 0x00 /* Used by sleep/wakeup. */ 87#define SLEEPQ_CONDVAR 0x01 /* Used for a cv. */ 88#define SLEEPQ_PAUSE 0x02 /* Used by pause. */ 89#define SLEEPQ_SX 0x03 /* Used by an sx lock. */ 90#define SLEEPQ_INTERRUPTIBLE 0x100 /* Sleep is interruptible. */ 91 92void init_sleepqueues(void); 93void sleepq_abort(struct thread *td, int intrval); 94void sleepq_add(void *wchan, struct lock_object *lock, const char *wmesg, 95 int flags, int queue); 96struct sleepqueue *sleepq_alloc(void); 97void sleepq_broadcast(void *wchan, int flags, int pri, int queue); 98void sleepq_free(struct sleepqueue *sq); 99void sleepq_lock(void *wchan); 100struct sleepqueue *sleepq_lookup(void *wchan); 101void sleepq_release(void *wchan); 102void sleepq_remove(struct thread *td, void *wchan); 103void sleepq_signal(void *wchan, int flags, int pri, int queue); 104void sleepq_set_timeout(void *wchan, int timo); 105int sleepq_timedwait(void *wchan, int pri); 106int sleepq_timedwait_sig(void *wchan, int pri); 107void sleepq_wait(void *wchan, int pri); 108int sleepq_wait_sig(void *wchan, int pri); 109 110#endif /* _KERNEL */ 111#endif /* !_SYS_SLEEPQUEUE_H_ */ 112