incubator-nuttx/sched/task/task_recover.c

/****************************************************************************
 * sched/task/task_recover.c
 *
 *   Copyright (C) 2013-2014 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 <nuttx/arch.h>
#include <nuttx/wdog.h>
#include <nuttx/sched.h>

#include "mqueue/mqueue.h"
#include "task/task.h"

/****************************************************************************
 * Definitions
 ****************************************************************************/

/****************************************************************************
 * Private Type Declarations
 ****************************************************************************/

/****************************************************************************
 * Global Variables
 ****************************************************************************/

/****************************************************************************
 * Private Variables
 ****************************************************************************/

/****************************************************************************
 * Private Function Prototypes
 ****************************************************************************/

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: task_recover
 *
 * Description:
 *   This function is called when a task is deleted via task_deleted or
 *   via pthread_cancel. I checks if the task was waiting for a message
 *   queue event and adjusts counts appropriately.
 *
 * Inputs:
 *   tcb - The TCB of the terminated task or thread
 *
 * Return Value:
 *   None.
 *
 * Assumptions:
 *   This function is called from task deletion logic in a safe context.
 *
 ****************************************************************************/

void task_recover(FAR struct tcb_s *tcb)
{
  irqstate_t flags;

  /* The task is being deleted.  If it is waiting for any timed event, then
   * tcb->waitdog will be non-NULL.  Cancel the watchdog now so that no
   * events occur after the watchdog expires.  Obviously there are lots of
   * race conditions here so this will most certainly have to be revisited in
   * the future.
   */

  flags = irqsave();
  if (tcb->waitdog)
    {
      (void)wd_cancel(tcb->waitdog);
      (void)wd_delete(tcb->waitdog);
      tcb->waitdog = NULL;
    }

  irqrestore(flags);

  /* Handle cases where the thread was waiting for a message queue event */

#ifndef CONFIG_DISABLE_MQUEUE
  mq_recover(tcb);
#endif
}