zephyr/kernel/nanokernel/include/wait_q.h

118 lines
3.7 KiB
C

/* wait queue for multiple fibers on nanokernel objects */
/*
* Copyright (c) 2015 Wind River Systems, Inc.
*
* 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 Wind River Systems nor the names of its contributors
* may be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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.
*/
#ifndef _kernel_nanokernel_include_wait_q__h_
#define _kernel_nanokernel_include_wait_q__h_
#include <nano_private.h>
/* reset a wait queue, call during operation */
static inline void _nano_wait_q_reset(struct _nano_queue *wait_q)
{
wait_q->head = (void *)0;
wait_q->tail = (void *)&(wait_q->head);
}
/* initialize a wait queue: call only during object initialization */
static inline void _nano_wait_q_init(struct _nano_queue *wait_q)
{
_nano_wait_q_reset(wait_q);
}
/*
* Remove first fiber from a wait queue and put it on the ready queue, knowing
* that the wait queue is not empty.
*/
static inline
struct tcs *_nano_wait_q_remove_no_check(struct _nano_queue *wait_q)
{
struct tcs *tcs = wait_q->head;
if (wait_q->tail == wait_q->head) {
_nano_wait_q_reset(wait_q);
} else {
wait_q->head = tcs->link;
}
tcs->link = 0;
_nano_fiber_schedule(tcs);
return tcs;
}
/*
* Remove first fiber from a wait queue and put it on the ready queue.
* Abort and return NULL if the wait queue is empty.
*/
static inline struct tcs *_nano_wait_q_remove(struct _nano_queue *wait_q)
{
return wait_q->head ? _nano_wait_q_remove_no_check(wait_q) : NULL;
}
/* put current fiber on specified wait queue */
static inline void _nano_wait_q_put(struct _nano_queue *wait_q)
{
((struct tcs *)wait_q->tail)->link = _nanokernel.current;
wait_q->tail = _nanokernel.current;
}
#ifdef CONFIG_NANO_TIMEOUTS
static inline void _nano_timeout_remove_tcs_from_wait_q(struct tcs *tcs)
{
struct _nano_queue *wait_q = tcs->nano_timeout.wait_q;
if (wait_q->head == tcs) {
if (wait_q->tail == wait_q->head) {
_nano_wait_q_reset(wait_q);
} else {
wait_q->head = tcs->link;
}
} else {
struct tcs *prev = wait_q->head;
while (prev->link != tcs) {
prev = prev->link;
}
prev->link = tcs->link;
if (wait_q->tail == tcs) {
wait_q->tail = prev;
}
}
}
#include <timeout_q.h>
#else
#define _nano_timeout_tcs_init(tcs) do { } while ((0))
#define _nano_timeout_abort(tcs) do { } while ((0))
#define _nano_get_earliest_timeouts_deadline() ((uint32_t)TICKS_UNLIMITED)
#endif
#endif /* _kernel_nanokernel_include_wait_q__h_ */