relibc_pthreads-emb/pte_tkAssocCreate.c

/*
 * pte_tkAssocCreate.c
 *
 * Description:
 * This translation unit implements routines which are private to
 * the implementation and may be used throughout it.
 *
 * --------------------------------------------------------------------------
 *
 *      Pthreads-embedded (PTE) - POSIX Threads Library for embedded systems
 *      Copyright(C) 2008 Jason Schmidlapp
 *
 *      Contact Email: jschmidlapp@users.sourceforge.net
 *
 *
 *      Based upon Pthreads-win32 - POSIX Threads Library for Win32
 *      Copyright(C) 1998 John E. Bossom
 *      Copyright(C) 1999,2005 Pthreads-win32 contributors
 *
 *      Contact Email: rpj@callisto.canberra.edu.au
 *
 *      The original list of contributors to the Pthreads-win32 project
 *      is contained in the file CONTRIBUTORS.ptw32 included with the
 *      source code distribution. The list can also be seen at the
 *      following World Wide Web location:
 *      http://sources.redhat.com/pthreads-win32/contributors.html
 *
 *      This library is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU Lesser General Public
 *      License as published by the Free Software Foundation; either
 *      version 2 of the License, or (at your option) any later version.
 *
 *      This library is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *      Lesser General Public License for more details.
 *
 *      You should have received a copy of the GNU Lesser General Public
 *      License along with this library in the file COPYING.LIB;
 *      if not, write to the Free Software Foundation, Inc.,
 *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */

#include <stdlib.h>

#include "pthread.h"
#include "implement.h"


int
pte_tkAssocCreate (pte_thread_t * sp, pthread_key_t key)
/*
 * -------------------------------------------------------------------
 * This routine creates an association that
 * is unique for the given (thread,key) combination.The association
 * is referenced by both the thread and the key.
 * This association allows us to determine what keys the
 * current thread references and what threads a given key
 * references.
 * See the detailed description
 * at the beginning of this file for further details.
 *
 * Notes:
 *      1)      New associations are pushed to the beginning of the
 *              chain so that the internal pte_selfThreadKey association
 *              is always last, thus allowing selfThreadExit to
 *              be implicitly called last by pthread_exit.
 *      2)
 *
 * Parameters:
 *              thread
 *                      current running thread.
 *              key
 *                      key on which to create an association.
 * Returns:
 *       0              - if successful,
 *       ENOMEM         - not enough memory to create assoc or other object
 *       EINVAL         - an internal error occurred
 *       ENOSYS         - an internal error occurred
 * -------------------------------------------------------------------
 */
{
  ThreadKeyAssoc *assoc;

  /*
   * Have to create an association and add it
   * to both the key and the thread.
   *
   * Both key->keyLock and thread->threadLock are locked on
   * entry to this routine.
   */
  assoc = (ThreadKeyAssoc *) calloc (1, sizeof (*assoc));

  if (assoc == NULL)
    {
      return ENOMEM;
    }

  assoc->thread = sp;
  assoc->key = key;

  /*
   * Register assoc with key
   */
  assoc->prevThread = NULL;
  assoc->nextThread = (ThreadKeyAssoc *) key->threads;
  if (assoc->nextThread != NULL)
    {
      assoc->nextThread->prevThread = assoc;
    }
  key->threads = (void *) assoc;

  /*
   * Register assoc with thread
   */
  assoc->prevKey = NULL;
  assoc->nextKey = (ThreadKeyAssoc *) sp->keys;
  if (assoc->nextKey != NULL)
    {
      assoc->nextKey->prevKey = assoc;
    }
  sp->keys = (void *) assoc;

  return (0);

}				/* pte_tkAssocCreate */