/************************************************************
* pthread_keycreate.c
*
* Copyright (C) 2007 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 Gregory Nutt 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 <sys/types.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
************************************************************/
/************************************************************
* Function: 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 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 be
* returned 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(pthread_key_t *key, void (*destructor)(void*))
{
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;
}
