1ef904003e
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5725 42af7a65-404d-4744-a932-0658087f49c3
141 lines
4.8 KiB
C
141 lines
4.8 KiB
C
/****************************************************************************
|
|
* sched/sem_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 <semaphore.h>
|
|
#include <sched.h>
|
|
#include <queue.h>
|
|
|
|
#include "os_internal.h"
|
|
#include "sem_internal.h"
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Type Declarations
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Global Variables
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Variables
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: sem_unlink
|
|
*
|
|
* Description:
|
|
* This function removes the semaphore named by the input parameter 'name.'
|
|
* If the semaphore named by 'name' is currently referenced by other task,
|
|
* the sem_unlink() will have no effect on the state of the semaphore. If
|
|
* one or more processes have the semaphore open when sem_unlink() is
|
|
* called, destruction of the semaphore will be postponed until all
|
|
* references to the semaphore have been destroyed by calls of sem_close().
|
|
*
|
|
* Parameters:
|
|
* name - Semaphore name
|
|
*
|
|
* Return Value:
|
|
* 0 (OK), or -1 (ERROR) if unsuccessful.
|
|
*
|
|
* Assumptions:
|
|
*
|
|
****************************************************************************/
|
|
|
|
int sem_unlink(FAR const char *name)
|
|
{
|
|
FAR nsem_t *psem;
|
|
int ret = ERROR;
|
|
|
|
/* Verify the input values */
|
|
|
|
if (name)
|
|
{
|
|
sched_lock();
|
|
|
|
/* Find the named semaphore */
|
|
|
|
psem = sem_findnamed(name);
|
|
|
|
/* Check if the semaphore was found */
|
|
|
|
if (psem)
|
|
{
|
|
/* If the named semaphore was found and if there are no
|
|
* connects to it, then deallocate it
|
|
*/
|
|
|
|
if (!psem->nconnect)
|
|
{
|
|
dq_rem((FAR dq_entry_t*)psem, &g_nsems);
|
|
sched_kfree(psem);
|
|
}
|
|
|
|
/* If one or more process still has the semaphore open,
|
|
* then just mark it as unlinked. The unlinked semaphore will
|
|
* be deleted when the final process closes the semaphore.
|
|
*/
|
|
|
|
else
|
|
{
|
|
psem->unlinked = true;
|
|
}
|
|
ret = OK;
|
|
}
|
|
|
|
sched_unlock();
|
|
}
|
|
|
|
return ret;
|
|
}
|