sleepqueue.h revision 201879
1226048Sobrien/*- 2133359Sobrien * Copyright (c) 2004 John Baldwin <jhb@FreeBSD.org> 3284778Sdelphij * All rights reserved. 4186690Sobrien * 5133359Sobrien * Redistribution and use in source and binary forms, with or without 6186690Sobrien * modification, are permitted provided that the following conditions 7169962Sobrien * are met: 8226048Sobrien * 1. Redistributions of source code must retain the above copyright 9284778Sdelphij * notice, this list of conditions and the following disclaimer. 10284778Sdelphij * 2. Redistributions in binary form must reproduce the above copyright 11284778Sdelphij * notice, this list of conditions and the following disclaimer in the 12169962Sobrien * documentation and/or other materials provided with the distribution. 13284778Sdelphij * 3. Neither the name of the author nor the names of any co-contributors 14284778Sdelphij * may be used to endorse or promote products derived from this software 15284778Sdelphij * without specific prior written permission. 16284778Sdelphij * 17284778Sdelphij * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18284778Sdelphij * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19284778Sdelphij * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20159764Sobrien * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21186690Sobrien * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22186690Sobrien * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23186690Sobrien * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24169942Sobrien * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25186690Sobrien * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26186690Sobrien * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27186690Sobrien * SUCH DAMAGE. 28186690Sobrien * 29186690Sobrien * $FreeBSD: head/sys/sys/sleepqueue.h 201879 2010-01-09 01:46:38Z attilio $ 30226048Sobrien */ 31226048Sobrien 32226048Sobrien#ifndef _SYS_SLEEPQUEUE_H_ 33267843Sdelphij#define _SYS_SLEEPQUEUE_H_ 34267843Sdelphij 35267843Sdelphij/* 36267843Sdelphij * Sleep queue interface. Sleep/wakeup, condition variables, and sx 37267843Sdelphij * 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() before calling sleepq_abort(), sleepq_broadcast(), or 68 * sleepq_signal(). These routines each return a boolean that will be true 69 * if at least one swapped-out thread was resumed. In that case, the caller 70 * is responsible for waking up the swapper by calling kick_proc0() after 71 * releasing the sleep queeu chain lock. 72 * 73 * Each thread allocates a sleep queue at thread creation via sleepq_alloc() 74 * and releases it at thread destruction via sleepq_free(). Note that 75 * a sleep queue is not tied to a specific thread and that the sleep queue 76 * released at thread destruction may not be the same sleep queue that the 77 * thread allocated when it was created. 78 * 79 * XXX: Some other parts of the kernel such as ithread sleeping may end up 80 * using this interface as well (death to TDI_IWAIT!) 81 */ 82 83struct lock_object; 84struct sleepqueue; 85struct thread; 86 87#ifdef _KERNEL 88 89#define SLEEPQ_TYPE 0x0ff /* Mask of sleep queue types. */ 90#define SLEEPQ_SLEEP 0x00 /* Used by sleep/wakeup. */ 91#define SLEEPQ_CONDVAR 0x01 /* Used for a cv. */ 92#define SLEEPQ_PAUSE 0x02 /* Used by pause. */ 93#define SLEEPQ_SX 0x03 /* Used by an sx lock. */ 94#define SLEEPQ_LK 0x04 /* Used by a lockmgr. */ 95#define SLEEPQ_INTERRUPTIBLE 0x100 /* Sleep is interruptible. */ 96#define SLEEPQ_STOP_ON_BDRY 0x200 /* Stop sleeping thread on 97 user mode boundary */ 98 99void init_sleepqueues(void); 100int sleepq_abort(struct thread *td, int intrval); 101void sleepq_add(void *wchan, struct lock_object *lock, const char *wmesg, 102 int flags, int queue); 103struct sleepqueue *sleepq_alloc(void); 104int sleepq_broadcast(void *wchan, int flags, int pri, int queue); 105void sleepq_free(struct sleepqueue *sq); 106void sleepq_lock(void *wchan); 107struct sleepqueue *sleepq_lookup(void *wchan); 108void sleepq_release(void *wchan); 109void sleepq_remove(struct thread *td, void *wchan); 110int sleepq_signal(void *wchan, int flags, int pri, int queue); 111void sleepq_set_timeout(void *wchan, int timo); 112u_int sleepq_sleepcnt(void *wchan, int queue); 113int sleepq_timedwait(void *wchan, int pri); 114int sleepq_timedwait_sig(void *wchan, int pri); 115int sleepq_type(void *wchan); 116void sleepq_wait(void *wchan, int pri); 117int sleepq_wait_sig(void *wchan, int pri); 118 119#endif /* _KERNEL */ 120#endif /* !_SYS_SLEEPQUEUE_H_ */ 121