/****************************************************************************
* sched/pthread_keycreate.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 <sched.h>
#include <errno.h>
#include <debug.h>
#include "pthread_internal.h"
/****************************************************************************
* Definitions
****************************************************************************/
/****************************************************************************
* Private Type Declarations
****************************************************************************/
/****************************************************************************
* Global Variables
****************************************************************************/
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: pthread_key_create
*
* Description:
* This function creates a thread-specific data key visible to all threads
* in the system. Although the same key value may be used by different
* threads, the values bound to the key by pthread_setspecific() are
* maintained on a per-thread basis and persist for the life of the calling
* thread.
*
* Upon key creation, the value NULL will be associated with the new key
* in all active threads. Upon thread creation, the value NULL will be
* associated with all defined keys in the new thread.
*
* Parameters:
* key = A pointer to the key to create.
* destructor = An optional destructor() function that may be associated
* with each key that is invoked when a thread exits. However, this
* argument is ignored in the current implementation.
*
* Return Value:
* If successful, the pthread_key_create() function will store the newly
* created key value at *key and return zero (OK). Otherwise, an error
* number will bereturned to indicate the error:
*
* EAGAIN - The system lacked sufficient resources to create another
* thread-specific data key, or the system-imposed limit on the total
* number of keys pers process {PTHREAD_KEYS_MAX} has been exceeded
* ENONMEM - Insufficient memory exists to create the key.
*
* Assumptions:
*
* POSIX Compatibility:
* - The present implementation ignores the destructor argument.
*
****************************************************************************/
int pthread_key_create(FAR pthread_key_t *key, CODE void (*destructor)(void*))
{
#if CONFIG_NPTHREAD_KEYS > 0
int ret = EAGAIN;
/* Check if we have exceeded the system-defined number of keys. */
if (g_pthread_num_keys < PTHREAD_KEYS_MAX)
{
/* Return the key value */
*key = g_pthread_num_keys;
/* Increment the count of global keys. */
g_pthread_num_keys++;
/* Return success. */
ret = OK;
}
return ret;
#else
return ENOSYS;
#endif
}
