incubator-nuttx/sched/pthread/pthread_setcancelstate.c

145 lines
4.7 KiB
C

/****************************************************************************
* sched/pthread/pthread_setcancelstate.c
*
* Copyright (C) 2007, 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 <pthread.h>
#include <errno.h>
#include "task/task.h"
#include "sched/sched.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: pthread_setcancelstate
*
* Description:
* The pthread_setcancelstate() function atomically both sets the calling
* thread's cancelability state to the indicated state and returns the
* previous cancelability state at the location referenced by oldstate.
* Legal values for state are PTHREAD_CANCEL_ENABLE and
* PTHREAD_CANCEL_DISABLE.
*
* The cancelability state and type of any newly created threads,
* including the thread in which main() was first invoked, are
* PTHREAD_CANCEL_ENABLE and PTHREAD_CANCEL_DEFERRED respectively.
*
****************************************************************************/
int pthread_setcancelstate(int state, FAR int *oldstate)
{
FAR struct tcb_s *tcb = this_task();
int ret = OK;
/* Suppress context changes for a bit so that the flags are stable. (the
* flags should not change in interrupt handling).
*/
sched_lock();
/* Return the current state if so requrested */
if (oldstate)
{
if ((tcb->flags & TCB_FLAG_NONCANCELABLE) != 0)
{
*oldstate = PTHREAD_CANCEL_DISABLE;
}
else
{
*oldstate = PTHREAD_CANCEL_ENABLE;
}
}
/* Set the new cancellation state */
if (state == PTHREAD_CANCEL_ENABLE)
{
/* Clear the non-cancelable flag */
tcb->flags &= ~TCB_FLAG_NONCANCELABLE;
/* Check if a cancellation was pending */
if ((tcb->flags & TCB_FLAG_CANCEL_PENDING) != 0)
{
#ifdef CONFIG_CANCELLATION_POINTS
/* If we are using deferred cancellation? */
if ((tcb->flags & TCB_FLAG_CANCEL_DEFERRED) != 0)
{
/* Yes.. If we are within a cancellation point, then
* notify of the cancellation.
*/
if (tcb->cpcount > 0)
{
notify_cancellation(tcb);
}
}
else
#endif
{
/* No.. We are using asynchronous cancellation. If the
* cancellation was pending in this case, then just exit.
*/
tcb->flags &= ~TCB_FLAG_CANCEL_PENDING;
pthread_exit(PTHREAD_CANCELED);
}
}
}
else if (state == PTHREAD_CANCEL_DISABLE)
{
/* Set the non-cancelable state */
tcb->flags |= TCB_FLAG_NONCANCELABLE;
}
else
{
ret = EINVAL;
}
sched_unlock();
return ret;
}