incubator-nuttx/sched/timer/timer_release.c

137 lines
4.0 KiB
C

/****************************************************************************
* sched/timer/timer_release.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <queue.h>
#include <errno.h>
#include <nuttx/irq.h>
#include <nuttx/kmalloc.h>
#include "timer/timer.h"
#ifndef CONFIG_DISABLE_POSIX_TIMERS
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: timer_free
*
* Description:
* Remove the timer from the allocated timer list and free it or return it
* to the free list (depending on whether or not the timer is one of the
* preallocated timers)
*
****************************************************************************/
static inline void timer_free(struct posix_timer_s *timer)
{
irqstate_t flags;
/* Remove the timer from the allocated list */
flags = enter_critical_section();
sq_rem((FAR sq_entry_t *)timer, (FAR sq_queue_t *)&g_alloctimers);
/* Return it to the free list if it is one of the preallocated timers */
#if CONFIG_PREALLOC_TIMERS > 0
if ((timer->pt_flags & PT_FLAGS_PREALLOCATED) != 0)
{
sq_addlast((FAR sq_entry_t *)timer, (FAR sq_queue_t *)&g_freetimers);
leave_critical_section(flags);
}
else
#endif
{
/* Otherwise, return it to the heap */
leave_critical_section(flags);
kmm_free(timer);
}
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: timer_release
*
* Description:
* timer_release implements the heart of timer_delete. It is private to
* the OS internals and differs only in that return value of 1 means that
* the timer was not actually deleted.
*
* Input Parameters:
* timer - The per-thread timer, previously created by the call to
* timer_create(), to be deleted.
*
* Returned Value:
* If the call succeeds, timer_release() will return 0 (OK) or 1 (meaning
* that the timer is still valid). Otherwise, the function will return a
* negated errno value:
*
* -EINVAL - The timer specified timerid is not valid.
*
****************************************************************************/
int timer_release(FAR struct posix_timer_s *timer)
{
/* Some sanity checks */
if (timer == NULL)
{
return -EINVAL;
}
/* Release one reference to timer. Don't delete the timer until the count
* would decrement to zero.
*/
if (timer->pt_crefs > 1)
{
timer->pt_crefs--;
return 1;
}
/* Cancel the underlying watchdog instance */
wd_cancel(&timer->pt_wdog);
/* Cancel any pending notification */
nxsig_cancel_notification(&timer->pt_work);
/* Release the timer structure */
timer_free(timer);
return OK;
}
#endif /* CONFIG_DISABLE_POSIX_TIMERS */