relibc_pthreads-emb/pthread_setspecific.c

/*
 * pthread_setspecific.c
 *
 * Description:
 * POSIX thread functions which implement thread-specific data (TSD).
 *
 * --------------------------------------------------------------------------
 *
 *      Pthreads-embedded (PTE) - POSIX Threads Library for embedded systems
 *      Copyright(C) 2008 Jason Schmidlapp
 *
 *      Contact Email: [email protected]
 *
 *
 *      Based upon Pthreads-win32 - POSIX Threads Library for Win32
 *      Copyright(C) 1998 John E. Bossom
 *      Copyright(C) 1999,2005 Pthreads-win32 contributors
 *
 *      Contact Email: [email protected]
 *
 *      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 "pthread.h"
#include "implement.h"



int
pthread_setspecific (pthread_key_t key, const void *value)
/*
 * ------------------------------------------------------
 * DOCPUBLIC
 *      This function sets the value of the thread specific
 *      key in the calling thread.
 *
 * PARAMETERS
 *      key
 *              an instance of pthread_key_t
 *      value
 *              the value to set key to
 *
 *
 * DESCRIPTION
 *      This function sets the value of the thread specific
 *      key in the calling thread.
 *
 * RESULTS
 *              0               successfully set value
 *              EAGAIN          could not set value
 *              ENOENT          SERIOUS!!
 *
 * ------------------------------------------------------
 */
{
  pthread_t self;
  int result = 0;

  if (key != pte_selfThreadKey)
    {
      /*
       * Using pthread_self will implicitly create
       * an instance of pthread_t for the current
       * thread if one wasn't explicitly created
       */
      self = pthread_self ();
      if (self == NULL)
        {
          return ENOENT;
        }
    }
  else
    {
      /*
       * Resolve catch-22 of registering thread with selfThread
       * key
       */
      pte_thread_t * sp = (pte_thread_t *) pthread_getspecific (pte_selfThreadKey);

      if (sp == NULL)
        {
          if (value == NULL)
            {
              return ENOENT;
            }

          self = *((pthread_t *) value);
        }
      else
        {
          self = sp->ptHandle;
        }
    }

  result = 0;

  if (key != NULL)
    {
      if (self != NULL && key->destructor != NULL && value != NULL)
        {
          /*
           * Only require associations if we have to
           * call user destroy routine.
           * Don't need to locate an existing association
           * when setting data to NULL since the
           * data is stored with the operating system; not
           * on the association; setting assoc to NULL short
           * circuits the search.
           */
          ThreadKeyAssoc *assoc;

          if (pthread_mutex_lock(&(key->keyLock)) == 0)
            {
              pte_thread_t * sp = (pte_thread_t *) self;

              (void) pthread_mutex_lock(&(sp->threadLock));

              assoc = (ThreadKeyAssoc *) sp->keys;
              /*
               * Locate existing association
               */
              while (assoc != NULL)
                {
                  if (assoc->key == key)
                    {
                      /*
                       * Association already exists
                       */
                      break;
                    }
                  assoc = assoc->nextKey;
                }

              /*
               * create an association if not found
               */
              if (assoc == NULL)
                {
                  result = pte_tkAssocCreate (sp, key);
                }

              (void) pthread_mutex_unlock(&(sp->threadLock));
            }
          (void) pthread_mutex_unlock(&(key->keyLock));
        }

      if (result == 0)
        {
          if (pte_osTlsSetValue (key->key, (void *) value) != PTE_OS_OK)
            {
              result = EAGAIN;
            }

        }
    }

  return (result);
}				/* pthread_setspecific */