1 /* 2 * Copyright (c) 2004 John Baldwin <jhb@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the author nor the names of any co-contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $FreeBSD$ 30 */ 31 32 #ifndef _SYS_SLEEPQUEUE_H_ 33 #define _SYS_SLEEPQUEUE_H_ 34 35 /* 36 * Sleep queue interface. Sleep/wakeup and condition variables use a sleep 37 * queue for the queue of threads blocked on a sleep channel. 38 * 39 * A thread calls sleepq_lookup() to look up the proper sleep queue in the 40 * hash table that is associated with a specified wait channel. This 41 * function returns a pointer to the queue and locks the associated sleep 42 * queue chain. A thread calls sleepq_add() to add themself onto a sleep 43 * queue and calls one of the sleepq_wait() functions to actually go to 44 * sleep. If a thread needs to abort a sleep operation it should call 45 * sleepq_release() to unlock the associated sleep queue chain lock. If 46 * the thread also needs to remove itself from a queue it just enqueued 47 * itself on, it can use sleepq_remove(). 48 * 49 * If the thread only wishes to sleep for a limited amount of time, it can 50 * call sleepq_set_timeout() after sleepq_add() to setup a timeout. It 51 * should then use one of the sleepq_timedwait() functions to block. 52 * 53 * If the thread wants to the sleep to be interruptible by signals, it can 54 * call sleepq_catch_signals() after sleepq_add(). It should then use 55 * one of the sleepq_wait_sig() functions to block. After the thread has 56 * been resumed, it should call sleepq_calc_signal_retval() to determine 57 * if it should return EINTR or ERESTART passing in the value returned from 58 * the earlier call to sleepq_catch_signals(). 59 * 60 * A thread is normally resumed from a sleep queue by either the 61 * sleepq_signal() or sleepq_broadcast() functions. Sleepq_signal() wakes 62 * the thread with the highest priority that is sleeping on the specified 63 * wait channel. Sleepq_broadcast() wakes all threads that are sleeping 64 * on the specified wait channel. A thread sleeping in an interruptible 65 * sleep can be interrupted by calling sleepq_abort(). A thread can also 66 * be removed from a specified sleep queue using the sleepq_remove() 67 * function. 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 79 struct mtx; 80 struct sleepqueue; 81 struct thread; 82 83 #ifdef _KERNEL 84 85 #define SLEEPQ_TYPE 0x0ff /* Mask of sleep queue types. */ 86 #define SLEEPQ_MSLEEP 0x00 /* Used by msleep/wakeup. */ 87 #define SLEEPQ_CONDVAR 0x01 /* Used for a cv. */ 88 #define SLEEPQ_INTERRUPTIBLE 0x100 /* Sleep is interruptible. */ 89 90 void init_sleepqueues(void); 91 void sleepq_abort(struct thread *td); 92 void sleepq_add(struct sleepqueue *, void *, struct mtx *, const char *, 93 int); 94 struct sleepqueue *sleepq_alloc(void); 95 void sleepq_broadcast(void *, int, int); 96 int sleepq_calc_signal_retval(int sig); 97 int sleepq_catch_signals(void *wchan); 98 void sleepq_free(struct sleepqueue *); 99 struct sleepqueue *sleepq_lookup(void *); 100 void sleepq_release(void *); 101 void sleepq_remove(struct thread *, void *); 102 void sleepq_signal(void *, int, int); 103 void sleepq_set_timeout(void *wchan, int timo); 104 int sleepq_timedwait(void *wchan); 105 int sleepq_timedwait_sig(void *wchan, int signal_caught); 106 void sleepq_wait(void *); 107 int sleepq_wait_sig(void *wchan); 108 109 #endif /* _KERNEL */ 110 #endif /* !_SYS_SLEEPQUEUE_H_ */ 111