incubator-nuttx/libs/libc/pthread/pthread_getspecific.c

85 lines
2.9 KiB
C

/****************************************************************************
* libs/libc/pthread/pthread_getspecific.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 <pthread.h>
#include <assert.h>
#include <nuttx/tls.h>
#if defined(CONFIG_TLS_NELEM) && CONFIG_TLS_NELEM > 0
/****************************************************************************
* 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)
{
FAR struct tls_info_s *info;
FAR void *ret = NULL;
DEBUGASSERT(key >= 0 && key < CONFIG_TLS_NELEM);
if (key >= 0 && key < CONFIG_TLS_NELEM)
{
/* Get the TLS info structure from the current threads stack */
info = tls_get_info();
DEBUGASSERT(info != NULL);
/* Get the element value from the TLS info. */
ret = (FAR void *)info->tl_elem[key];
}
return ret;
}
#endif /* CONFIG_TLS_NELEM */