nuttx/sched/pthread/pthread_getspecific.c

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/****************************************************************************
* sched/pthread/pthread_getspecific.c
*
* Copyright (C) 2007, 2009, 2013, 2018 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 "sched/sched.h"
#include "pthread/pthread.h"
/****************************************************************************
* 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 a key value
* not obtained from pthread_key_create() or after a key has been
* deleted with pthread_key_delete() is undefined.
*
* Input Parameters:
* key = The data key to get or set
*
* Returned 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.
*
* POSIX Compatibility:
* - Both 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 tcb_s *rtcb = this_task();
FAR struct task_group_s *group = rtcb->group;
FAR void *ret = NULL;
DEBUGASSERT(group != NULL && (unsigned)key < CONFIG_NPTHREAD_KEYS);
/* Check if the key is valid. */
if (key < CONFIG_NPTHREAD_KEYS && (group->tg_keyset & (1 << key)) != 0)
{
/* Return the stored value. */
ret = rtcb->pthread_data[key];
}
return ret;
#else
return NULL;
#endif
}