/********************************************************************************
* timer_release.c
*
* Copyright (C) 2008 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.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.
* 3. Neither the name NuttX 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 OWNER 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.
*
********************************************************************************/
/********************************************************************************
* Included Files
********************************************************************************/
#include <nuttx/config.h>
#include <queue.h>
#include <errno.h>
#include <nuttx/kmalloc.h>
#include "timer_internal.h"
#ifndef CONFIG_DISABLE_POSIX_TIMERS
/********************************************************************************
* Definitions
********************************************************************************/
/********************************************************************************
* Private Data
********************************************************************************/
/********************************************************************************
* Public Data
********************************************************************************/
/********************************************************************************
* 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 = irqsave();
sq_rem((FAR sq_entry_t*)timer, (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);
irqrestore(flags);
}
else
#endif
{
/* Otherwise, return it to the heap */
irqrestore(flags);
sched_free(timer);
}
}
/********************************************************************************
* Public Functions
********************************************************************************/
/********************************************************************************
* Name: timer_release
*
* Description:
* timer_release implements the heart of timer_delete. It is private to the
* the OS internals and differs only in that return value of 1 means that the
* timer was not actually deleted.
*
* Parameters:
* timer - The per-thread timer, previously created by the call to
* timer_create(), to be deleted.
*
* Return 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:
*
* -EINVAL - The timer specified timerid is not valid.
*
********************************************************************************/
int timer_release(FAR struct posix_timer_s *timer)
{
/* Some sanity checks */
if (!timer)
{
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;
}
/* Free the underlying watchdog instance (the timer will be canceled by the
* watchdog logic before it is actually deleted)
*/
(void)wd_delete(timer->pt_wdog);
/* Release the timer structure */
timer_free(timer);
return OK;
}
#endif /* CONFIG_DISABLE_POSIX_TIMERS */
