nuttx/fs/mqueue/mq_close.c

/****************************************************************************
 *  fs/mqueue/mq_close.c
 *
 * 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.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <sched.h>
#include <mqueue.h>
#include <assert.h>
#include <debug.h>

#include <nuttx/kmalloc.h>
#include <nuttx/sched.h>
#include <nuttx/mqueue.h>

#include "inode/inode.h"
#include "mqueue/mqueue.h"

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

/****************************************************************************
 * Name: nxmq_close
 *
 * Description:
 *   This is an internal OS interface.  It is functionally equivalent to
 *   mq_close() except that:
 *
 *   - It is not a cancellation point, and
 *   - It does not modify the errno value.
 *
 *  See comments with mq_close() for a more complete description of the
 *  behavior of this function
 *
 * Input Parameters:
 *   mqdes - Message queue descriptor.
 *
 * Returned Value:
 *   This is an internal OS interface and should not be used by applications.
 *   It follows the NuttX internal error return policy:  Zero (OK) is
 *   returned on success. A negated errno value is returned on failure.
 *
 ****************************************************************************/

int nxmq_close(mqd_t mqdes)
{
  return nx_close(mqdes);
}

/****************************************************************************
 * Name: mq_close
 *
 * Description:
 *   This function is used to indicate that the calling task is finished
 *   with the specified message queue mqdes.  The mq_close() deallocates
 *   any system resources allocated by the system for use by this task for
 *   its message queue.
 *
 *   If the calling task has attached a notification to the message queue
 *   via this mqdes, this attachment will be removed and the message queue
 *   is available for another process to attach a notification.
 *
 * Input Parameters:
 *   mqdes - Message queue descriptor.
 *
 * Returned Value:
 *   0 (OK) if the message queue is closed successfully,
 *   otherwise, -1 (ERROR).
 *
 * Assumptions:
 * - The behavior of a task that is blocked on either a [nx]mq_send() or
 *   [nx]mq_receive() is undefined when mq_close() is called.
 * - The results of using this message queue descriptor after a successful
 *   return from mq_close() is undefined.
 *
 ****************************************************************************/

int mq_close(mqd_t mqdes)
{
  return close(mqdes);
}