incubator-nuttx/include/nuttx/cancelpt.h

163 lines
5.7 KiB
C

/****************************************************************************
* include/nuttx/cancelpt.h
* Definitions related to cancellation points
*
* 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.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_CANCELPT_H
#define __INCLUDE_NUTTX_CANCELPT_H
/****************************************************************************
* Cancellation Points.
*
* Cancellation points shall occur when a thread is executing the following
* functions:
*
* accept() mq_timedsend() putpmsg() sigtimedwait()
* aio_suspend() msgrcv() pwrite() sigwait()
* clock_nanosleep() msgsnd() read() sigwaitinfo()
* close() msync() readv() sleep()
* connect() nanosleep() recv() system()
* creat() open() recvfrom() tcdrain()
* fcntl() pause() recvmsg() usleep()
* fdatasync() poll() select() wait()
* fsync() pread() sem_timedwait() waitid()
* getmsg() pselect() sem_wait() waitpid()
* getpmsg() pthread_cond_timedwait() send() write()
* lockf() pthread_cond_wait() sendmsg() writev()
* mq_receive() pthread_join() sendto()
* mq_send() pthread_testcancel() sigpause()
* mq_timedreceive() putmsg() sigsuspend()
*
* Each of the above function must call enter_cancellation_point() on entry
* in order to establish the cancellation point and
* leave_cancellation_point() on exit. These functions are described below.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdbool.h>
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Name: enter_cancellation_point
*
* Description:
* Called at the beginning of the cancellation point to establish the
* cancellation point. This function does the following:
*
* 1. If deferred cancellation does not apply to this thread, nothing is
* done, otherwise, it
* 2. Sets state information in the caller's TCB and increments a nesting
* count.
* 3. If this is the outermost nesting level, it checks if there is a
* pending cancellation and, if so, calls either exit() or
* pthread_exit(), depending upon the type of the thread.
*
* Input Parameters:
* None
*
* Returned Value:
* true is returned if a cancellation is pending but cannot be performed
* now due to the nesting level.
*
****************************************************************************/
#ifdef CONFIG_CANCELLATION_POINTS
bool enter_cancellation_point(void);
#else
# define enter_cancellation_point() false
#endif
/****************************************************************************
* Name: leave_cancellation_point
*
* Description:
* Called at the end of the cancellation point. This function does the
* following:
*
* 1. If deferred cancellation does not apply to this thread, nothing is
* done, otherwise, it
* 2. Clears state information in the caller's TCB and decrements a
* nesting count.
* 3. If this is the outermost nesting level, it checks if there is a
* pending cancellation and, if so, calls either exit() or
* pthread_exit(), depending upon the type of the thread.
*
* Input Parameters:
* None
*
* Returned Value:
* None
*
****************************************************************************/
#ifdef CONFIG_CANCELLATION_POINTS
void leave_cancellation_point(void);
#else
# define leave_cancellation_point()
#endif
/****************************************************************************
* Name: check_cancellation_point
*
* Description:
* Returns true if:
*
* 1. Deferred cancellation does applies to this thread,
* 2. We are within a cancellation point (i.e., the nesting level in the
* TCB is greater than zero).
*
* Input Parameters:
* None
*
* Returned Value:
* true is returned if a cancellation is pending but cannot be performed
* now due to the nesting level.
*
****************************************************************************/
#ifdef CONFIG_CANCELLATION_POINTS
bool check_cancellation_point(void);
#else
# define check_cancellation_point() false
#endif
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* __INCLUDE_NUTTX_CANCELPT_H */