incubator-nuttx/sched/semaphore/sem_timeout.c

104 lines
3.5 KiB
C

/****************************************************************************
* sched/semaphore/sem_timeout.c
*
* Copyright (C) 2011, 2013-2015 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 <errno.h>
#include <nuttx/sched.h>
#include <nuttx/wdog.h>
#include <nuttx/irq.h>
#include "semaphore/semaphore.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxsem_timeout
*
* Description:
* This function is called if the timeout elapses before before a
* semaphore is acquired.
*
* Input Parameters:
* argc - The number of arguments (should be 1)
* pid - The task ID of the task to wakeup
*
* Returned Value:
* None
*
* Assumptions:
* - Called from the context of the timer interrupt handler.
*
****************************************************************************/
void nxsem_timeout(int argc, wdparm_t pid, ...)
{
FAR struct tcb_s *wtcb;
irqstate_t flags;
/* Disable interrupts to avoid race conditions */
flags = enter_critical_section();
/* Get the TCB associated with this PID. It is possible that
* task may no longer be active when this watchdog goes off.
*/
wtcb = nxsched_get_tcb((pid_t)pid);
/* It is also possible that an interrupt/context switch beat us to the
* punch and already changed the task's state.
*/
if (wtcb && wtcb->task_state == TSTATE_WAIT_SEM)
{
/* Cancel the semaphore wait */
nxsem_wait_irq(wtcb, ETIMEDOUT);
}
/* Interrupts may now be enabled. */
leave_critical_section(flags);
}