px4-firmware/nuttx/sched/mq_unlink.c

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/************************************************************************
* sched.mq_unlink.c
*
* Copyright (C) 2007, 2009 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 <stdbool.h>
#include <mqueue.h>
#include <sched.h>
#include "os_internal.h"
#include "mq_internal.h"
/************************************************************************
* Pre-processor Definitions
************************************************************************/
/************************************************************************
* Private Type Declarations
************************************************************************/
/************************************************************************
* Global Variables
************************************************************************/
/************************************************************************
* Private Variables
************************************************************************/
/************************************************************************
* Private Functions
************************************************************************/
/************************************************************************
* Public Functions
************************************************************************/
/************************************************************************
* Name: mq_unlink
*
* Description:
* This function removes the message queue named by "mq_name." If one
* or more tasks have the message queue open when mq_unlink() is called,
* removal of the message queue is postponed until all references to the
* message queue have been closed.
*
* Parameters:
* mq_name - Name of the message queue
*
* Return Value:
* None
*
* Assumptions:
*
************************************************************************/
int mq_unlink(const char *mq_name)
{
FAR msgq_t *msgq;
irqstate_t saved_state;
int ret = ERROR;
/* Verify the input values */
if (mq_name)
{
sched_lock();
/* Find the named message queue */
msgq = mq_findnamed(mq_name);
if (msgq)
{
/* If it is no longer connected, then we can just
* discard the message queue now.
*/
if (!msgq->nconnect)
{
/* Remove the message queue from the list of all
* message queues
*/
saved_state = irqsave();
(void)sq_rem((FAR sq_entry_t*)msgq, &g_msgqueues);
irqrestore(saved_state);
/* Then deallocate it (and any messages left in it) */
mq_msgqfree(msgq);
}
/* If the message queue is still connected to a message descriptor,
* then mark it for deletion when the last message descriptor is
* closed
*/
else
{
msgq->unlinked = true;
}
ret = OK;
}
sched_unlock();
}
return ret;
}