/*- * Copyright (c) 2004 John Baldwin * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the author nor the names of any co-contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $FreeBSD$ */ #ifndef _SYS_SLEEPQUEUE_H_ #define _SYS_SLEEPQUEUE_H_ /* * Sleep queue interface. Sleep/wakeup, condition variables, and sx * locks use a sleep queue for the queue of threads blocked on a sleep * channel. * * A thread calls sleepq_lock() to lock the sleep queue chain associated * with a given wait channel. A thread can then call call sleepq_add() to * add themself onto a sleep queue and call one of the sleepq_wait() * functions to actually go to sleep. If a thread needs to abort a sleep * operation it should call sleepq_release() to unlock the associated sleep * queue chain lock. If the thread also needs to remove itself from a queue * it just enqueued itself on, it can use sleepq_remove() instead. * * If the thread only wishes to sleep for a limited amount of time, it can * call sleepq_set_timeout() after sleepq_add() to setup a timeout. It * should then use one of the sleepq_timedwait() functions to block. * * If the thread wants the sleep to be interruptible by signals, it can * call sleepq_catch_signals() after sleepq_add(). It should then use * one of the sleepq_wait_sig() functions to block. After the thread has * been resumed, it should call sleepq_calc_signal_retval() to determine * if it should return EINTR or ERESTART passing in the value returned from * the earlier call to sleepq_catch_signals(). * * A thread is normally resumed from a sleep queue by either the * sleepq_signal() or sleepq_broadcast() functions. Sleepq_signal() wakes * the thread with the highest priority that is sleeping on the specified * wait channel. Sleepq_broadcast() wakes all threads that are sleeping * on the specified wait channel. A thread sleeping in an interruptible * sleep can be interrupted by calling sleepq_abort(). A thread can also * be removed from a specified sleep queue using the sleepq_remove() * function. Note that the sleep queue chain must first be locked via * sleepq_lock() before calling sleepq_abort(), sleepq_broadcast(), or * sleepq_signal(). These routines each return a boolean that will be true * if at least one swapped-out thread was resumed. In that case, the caller * is responsible for waking up the swapper by calling kick_proc0() after * releasing the sleep queue chain lock. * * Each thread allocates a sleep queue at thread creation via sleepq_alloc() * and releases it at thread destruction via sleepq_free(). Note that * a sleep queue is not tied to a specific thread and that the sleep queue * released at thread destruction may not be the same sleep queue that the * thread allocated when it was created. * * XXX: Some other parts of the kernel such as ithread sleeping may end up * using this interface as well (death to TDI_IWAIT!) */ struct lock_object; struct sleepqueue; struct thread; #ifdef _KERNEL #define SLEEPQ_TYPE 0x0ff /* Mask of sleep queue types. */ #define SLEEPQ_SLEEP 0x00 /* Used by sleep/wakeup. */ #define SLEEPQ_CONDVAR 0x01 /* Used for a cv. */ #define SLEEPQ_PAUSE 0x02 /* Used by pause. */ #define SLEEPQ_SX 0x03 /* Used by an sx lock. */ #define SLEEPQ_LK 0x04 /* Used by a lockmgr. */ #define SLEEPQ_INTERRUPTIBLE 0x100 /* Sleep is interruptible. */ void init_sleepqueues(void); int sleepq_abort(struct thread *td, int intrval); void sleepq_add(void *wchan, struct lock_object *lock, const char *wmesg, int flags, int queue); struct sleepqueue *sleepq_alloc(void); int sleepq_broadcast(void *wchan, int flags, int pri, int queue); void sleepq_free(struct sleepqueue *sq); void sleepq_lock(void *wchan); struct sleepqueue *sleepq_lookup(void *wchan); void sleepq_release(void *wchan); void sleepq_remove(struct thread *td, void *wchan); int sleepq_signal(void *wchan, int flags, int pri, int queue); void sleepq_set_timeout_sbt(void *wchan, sbintime_t sbt, sbintime_t pr, int flags); #define sleepq_set_timeout(wchan, timo) \ sleepq_set_timeout_sbt((wchan), tick_sbt * (timo), 0, C_HARDCLOCK) u_int sleepq_sleepcnt(void *wchan, int queue); int sleepq_timedwait(void *wchan, int pri); int sleepq_timedwait_sig(void *wchan, int pri); int sleepq_type(void *wchan); void sleepq_wait(void *wchan, int pri); int sleepq_wait_sig(void *wchan, int pri); #endif /* _KERNEL */ #endif /* !_SYS_SLEEPQUEUE_H_ */