sleepqueue.h revision 247783
11541Srgrimes/*- 21541Srgrimes * Copyright (c) 2004 John Baldwin <jhb@FreeBSD.org> 31541Srgrimes * All rights reserved. 41541Srgrimes * 51541Srgrimes * Redistribution and use in source and binary forms, with or without 61541Srgrimes * modification, are permitted provided that the following conditions 71541Srgrimes * are met: 81541Srgrimes * 1. Redistributions of source code must retain the above copyright 91541Srgrimes * notice, this list of conditions and the following disclaimer. 101541Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111541Srgrimes * notice, this list of conditions and the following disclaimer in the 121541Srgrimes * documentation and/or other materials provided with the distribution. 131541Srgrimes * 3. Neither the name of the author nor the names of any co-contributors 141541Srgrimes * may be used to endorse or promote products derived from this software 151541Srgrimes * without specific prior written permission. 161541Srgrimes * 171541Srgrimes * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 181541Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 191541Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 201541Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 211541Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 221541Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 231541Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 241541Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 251541Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 261541Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 271541Srgrimes * SUCH DAMAGE. 281541Srgrimes * 291541Srgrimes * $FreeBSD: head/sys/sys/sleepqueue.h 247783 2013-03-04 11:51:46Z davide $ 301541Srgrimes */ 311541Srgrimes 321541Srgrimes#ifndef _SYS_SLEEPQUEUE_H_ 331541Srgrimes#define _SYS_SLEEPQUEUE_H_ 341541Srgrimes 351541Srgrimes/* 361541Srgrimes * Sleep queue interface. Sleep/wakeup, condition variables, and sx 371541Srgrimes * locks use a sleep queue for the queue of threads blocked on a sleep 381541Srgrimes * channel. 391541Srgrimes * 401541Srgrimes * A thread calls sleepq_lock() to lock the sleep queue chain associated 411541Srgrimes * with a given wait channel. A thread can then call call sleepq_add() to 421541Srgrimes * add themself onto a sleep queue and call one of the sleepq_wait() 431541Srgrimes * functions to actually go to sleep. If a thread needs to abort a sleep 441541Srgrimes * operation it should call sleepq_release() to unlock the associated sleep 451541Srgrimes * queue chain lock. If the thread also needs to remove itself from a queue 461541Srgrimes * it just enqueued itself on, it can use sleepq_remove() instead. 471541Srgrimes * 481541Srgrimes * If the thread only wishes to sleep for a limited amount of time, it can 491541Srgrimes * call sleepq_set_timeout() after sleepq_add() to setup a timeout. It 501541Srgrimes * should then use one of the sleepq_timedwait() functions to block. 511541Srgrimes * 521541Srgrimes * If the thread wants the sleep to be interruptible by signals, it can 531541Srgrimes * call sleepq_catch_signals() after sleepq_add(). It should then use 541541Srgrimes * one of the sleepq_wait_sig() functions to block. After the thread has 551541Srgrimes * been resumed, it should call sleepq_calc_signal_retval() to determine 561541Srgrimes * if it should return EINTR or ERESTART passing in the value returned from 571541Srgrimes * the earlier call to sleepq_catch_signals(). 581541Srgrimes * 591541Srgrimes * A thread is normally resumed from a sleep queue by either the 601541Srgrimes * sleepq_signal() or sleepq_broadcast() functions. Sleepq_signal() wakes 611541Srgrimes * the thread with the highest priority that is sleeping on the specified 621541Srgrimes * wait channel. Sleepq_broadcast() wakes all threads that are sleeping 631541Srgrimes * on the specified wait channel. A thread sleeping in an interruptible 641541Srgrimes * sleep can be interrupted by calling sleepq_abort(). A thread can also 651541Srgrimes * be removed from a specified sleep queue using the sleepq_remove() 661541Srgrimes * function. Note that the sleep queue chain must first be locked via 671541Srgrimes * sleepq_lock() before calling sleepq_abort(), sleepq_broadcast(), or 681541Srgrimes * sleepq_signal(). These routines each return a boolean that will be true 691541Srgrimes * if at least one swapped-out thread was resumed. In that case, the caller 701541Srgrimes * is responsible for waking up the swapper by calling kick_proc0() after 711541Srgrimes * releasing the sleep queue chain lock. 721541Srgrimes * 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_sbt(void *wchan, sbintime_t sbt, 112 sbintime_t pr, int flags); 113#define sleepq_set_timeout(wchan, timo) \ 114 sleepq_set_timeout_sbt((wchan), (tick_sbt * (timo)), 0, C_HARDCLOCK) 115u_int sleepq_sleepcnt(void *wchan, int queue); 116int sleepq_timedwait(void *wchan, int pri); 117int sleepq_timedwait_sig(void *wchan, int pri); 118int sleepq_type(void *wchan); 119void sleepq_wait(void *wchan, int pri); 120int sleepq_wait_sig(void *wchan, int pri); 121 122#endif /* _KERNEL */ 123#endif /* !_SYS_SLEEPQUEUE_H_ */ 124