nuttx/sched/pthread/pthread_getspecific.c
2014-08-08 14:21:48 -06:00

129 lines
4.6 KiB
C

/************************************************************************
* sched/pthread/pthread_getspecific.c
*
* Copyright (C) 2007, 2009, 2013 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 <sched.h>
#include <errno.h>
#include <assert.h>
#include <debug.h>
#include "os_internal.h"
#include "pthread/pthread.h"
/************************************************************************
* Definitions
************************************************************************/
/************************************************************************
* Private Type Declarations
************************************************************************/
/************************************************************************
* Global Variables
************************************************************************/
/************************************************************************
* Private Variables
************************************************************************/
/************************************************************************
* Private Functions
************************************************************************/
/************************************************************************
* Public Functions
************************************************************************/
/************************************************************************
* Name: pthread_getspecific
*
* Description:
* The pthread_getspecific() function returns the value currently
* bound to the specified key on behalf of the calling thread.
*
* The effect of calling pthread_getspecific() with with a key value
* not obtained from pthread_create() or after a key has been deleted
* with pthread_key_delete() is undefined.
*
* Parameters:
* key = The data key to get or set
*
* Return Value:
* The function pthread_getspecific() returns the thread-specific data
* associated with the given key. If no thread specific data is
* associated with the key, then the value NULL is returned.
*
* EINVAL - The key value is invalid.
*
* Assumptions:
*
* POSIX Compatibility:
* - Both calling pthread_setspecific() and pthread_getspecific()
* may be called from a thread-specific data destructor
* function.
*
************************************************************************/
FAR void *pthread_getspecific(pthread_key_t key)
{
#if CONFIG_NPTHREAD_KEYS > 0
FAR struct pthread_tcb_s *rtcb = (FAR struct pthread_tcb_s*)g_readytorun.head;
FAR struct task_group_s *group = rtcb->cmn.group;
FAR void *ret = NULL;
DEBUGASSERT(group &&
(rtcb->cmn.flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_PTHREAD);
/* Check if the key is valid. */
if (key < group->tg_nkeys)
{
/* Return the stored value. */
ret = rtcb->pthread_data[key];
}
return ret;
#else
return NULL;
#endif
}