fea73412a0
_sleep(9), wakeup(9), sleepqueue(9), et al do not dereference or modify the channel pointers provided in any way; they are merely used as intptrs into a dictionary structure to match waiters with wakers. Correctly annotate this such that _sleep() and wakeup() may be used on const pointers without invoking ugly patterns like __DECONST(). Plumb const through all of the underlying sleepqueue bits. No functional change. Reviewed by: rlibby Discussed with: kib, markj Differential Revision: https://reviews.freebsd.org/D22914
123 lines
5.6 KiB
C
123 lines
5.6 KiB
C
/*-
|
|
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
|
|
*
|
|
* Copyright (c) 2004 John Baldwin <jhb@FreeBSD.org>
|
|
*
|
|
* 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.
|
|
*
|
|
* 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.
|
|
*
|
|
* 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. */
|
|
#define SLEEPQ_UNFAIR 0x200 /* Unfair wakeup order. */
|
|
|
|
void init_sleepqueues(void);
|
|
int sleepq_abort(struct thread *td, int intrval);
|
|
void sleepq_add(const void *wchan, struct lock_object *lock,
|
|
const char *wmesg, int flags, int queue);
|
|
struct sleepqueue *sleepq_alloc(void);
|
|
int sleepq_broadcast(const void *wchan, int flags, int pri, int queue);
|
|
void sleepq_chains_remove_matching(bool (*matches)(struct thread *));
|
|
void sleepq_free(struct sleepqueue *sq);
|
|
void sleepq_lock(const void *wchan);
|
|
struct sleepqueue *sleepq_lookup(const void *wchan);
|
|
void sleepq_release(const void *wchan);
|
|
void sleepq_remove(struct thread *td, const void *wchan);
|
|
int sleepq_remove_matching(struct sleepqueue *sq, int queue,
|
|
bool (*matches)(struct thread *), int pri);
|
|
int sleepq_signal(const void *wchan, int flags, int pri, int queue);
|
|
void sleepq_set_timeout_sbt(const 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(const void *wchan, int queue);
|
|
int sleepq_timedwait(const void *wchan, int pri);
|
|
int sleepq_timedwait_sig(const void *wchan, int pri);
|
|
int sleepq_type(const void *wchan);
|
|
void sleepq_wait(const void *wchan, int pri);
|
|
int sleepq_wait_sig(const void *wchan, int pri);
|
|
|
|
#ifdef STACK
|
|
struct sbuf;
|
|
int sleepq_sbuf_print_stacks(struct sbuf *sb, const void *wchan, int queue,
|
|
int *count_stacks_printed);
|
|
#endif
|
|
|
|
#endif /* _KERNEL */
|
|
#endif /* !_SYS_SLEEPQUEUE_H_ */
|