1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2004 John Baldwin <jhb@FreeBSD.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 #ifndef _SYS_SLEEPQUEUE_H_ 32 #define _SYS_SLEEPQUEUE_H_ 33 34 /* 35 * Sleep queue interface. Sleep/wakeup, condition variables, and sx 36 * locks use a sleep queue for the queue of threads blocked on a sleep 37 * channel. 38 * 39 * A thread calls sleepq_lock() to lock the sleep queue chain associated 40 * with a given wait channel. A thread can then call call sleepq_add() to 41 * add themself onto a sleep queue and call one of the sleepq_wait() 42 * functions to actually go to sleep. If a thread needs to abort a sleep 43 * operation it should call sleepq_release() to unlock the associated sleep 44 * queue chain lock. If the thread also needs to remove itself from a queue 45 * it just enqueued itself on, it can use sleepq_remove() instead. 46 * 47 * If the thread only wishes to sleep for a limited amount of time, it can 48 * call sleepq_set_timeout() after sleepq_add() to setup a timeout. It 49 * should then use one of the sleepq_timedwait() functions to block. 50 * 51 * A thread is normally resumed from a sleep queue by either the 52 * sleepq_signal() or sleepq_broadcast() functions. Sleepq_signal() wakes 53 * the thread with the highest priority that is sleeping on the specified 54 * wait channel. Sleepq_broadcast() wakes all threads that are sleeping 55 * on the specified wait channel. A thread sleeping in an interruptible 56 * sleep can be interrupted by calling sleepq_abort(). A thread can also 57 * be removed from a specified sleep queue using the sleepq_remove() 58 * function. Note that the sleep queue chain must first be locked via 59 * sleepq_lock() before calling sleepq_abort(), sleepq_broadcast(), or 60 * sleepq_signal(). These routines each return a boolean that will be true 61 * if at least one swapped-out thread was resumed. In that case, the caller 62 * is responsible for waking up the swapper by calling kick_proc0() after 63 * releasing the sleep queue chain lock. 64 * 65 * Each thread allocates a sleep queue at thread creation via sleepq_alloc() 66 * and releases it at thread destruction via sleepq_free(). Note that 67 * a sleep queue is not tied to a specific thread and that the sleep queue 68 * released at thread destruction may not be the same sleep queue that the 69 * thread allocated when it was created. 70 * 71 * XXX: Some other parts of the kernel such as ithread sleeping may end up 72 * using this interface as well (death to TDI_IWAIT!) 73 */ 74 75 struct lock_object; 76 struct sleepqueue; 77 struct thread; 78 79 #ifdef _KERNEL 80 81 #define SLEEPQ_TYPE 0x0ff /* Mask of sleep queue types. */ 82 #define SLEEPQ_SLEEP 0x00 /* Used by sleep/wakeup. */ 83 #define SLEEPQ_CONDVAR 0x01 /* Used for a cv. */ 84 #define SLEEPQ_PAUSE 0x02 /* Used by pause. */ 85 #define SLEEPQ_SX 0x03 /* Used by an sx lock. */ 86 #define SLEEPQ_LK 0x04 /* Used by a lockmgr. */ 87 #define SLEEPQ_INTERRUPTIBLE 0x100 /* Sleep is interruptible. */ 88 89 void init_sleepqueues(void); 90 int sleepq_abort(struct thread *td, int intrval); 91 void sleepq_add(void *wchan, struct lock_object *lock, const char *wmesg, 92 int flags, int queue); 93 struct sleepqueue *sleepq_alloc(void); 94 int sleepq_broadcast(void *wchan, int flags, int pri, int queue); 95 void sleepq_chains_remove_matching(bool (*matches)(struct thread *)); 96 void sleepq_free(struct sleepqueue *sq); 97 void sleepq_lock(void *wchan); 98 struct sleepqueue *sleepq_lookup(void *wchan); 99 void sleepq_release(void *wchan); 100 void sleepq_remove(struct thread *td, void *wchan); 101 int sleepq_remove_matching(struct sleepqueue *sq, int queue, 102 bool (*matches)(struct thread *), int pri); 103 int sleepq_signal(void *wchan, int flags, int pri, int queue); 104 void sleepq_set_timeout_sbt(void *wchan, sbintime_t sbt, 105 sbintime_t pr, int flags); 106 #define sleepq_set_timeout(wchan, timo) \ 107 sleepq_set_timeout_sbt((wchan), tick_sbt * (timo), 0, C_HARDCLOCK) 108 u_int sleepq_sleepcnt(void *wchan, int queue); 109 int sleepq_timedwait(void *wchan, int pri); 110 int sleepq_timedwait_sig(void *wchan, int pri); 111 int sleepq_type(void *wchan); 112 void sleepq_wait(void *wchan, int pri); 113 int sleepq_wait_sig(void *wchan, int pri); 114 115 #ifdef STACK 116 struct sbuf; 117 int sleepq_sbuf_print_stacks(struct sbuf *sb, void *wchan, int queue, 118 int *count_stacks_printed); 119 #endif 120 121 #endif /* _KERNEL */ 122 #endif /* !_SYS_SLEEPQUEUE_H_ */ 123