예제 #1
0
pthread_t
pte_new (void)
{
  pthread_t t;
  pthread_t nil = NULL;
  pte_thread_t * tp;

  /*
   * If there's a reusable pthread_t then use it.
   */
  t = pte_threadReusePop ();

  if (NULL != t)
    {
      tp = (pte_thread_t *) t;
    }
  else
    {
      /* No reuse threads available */
      tp = (pte_thread_t *) calloc (1, sizeof(pte_thread_t));

      if (tp == NULL)
        {
          return nil;
        }

      /* ptHandle.p needs to point to it's parent pte_thread_t. */
      t = tp;
      tp->x = 0;
    }

  /* Set default state. */
  tp->sched_priority = pte_osThreadGetMinPriority();

  tp->detachState = PTHREAD_CREATE_JOINABLE;
  tp->cancelState = PTHREAD_CANCEL_ENABLE;
  tp->cancelType = PTHREAD_CANCEL_DEFERRED;
  tp->cancelLock = PTHREAD_MUTEX_INITIALIZER;
  tp->threadLock = PTHREAD_MUTEX_INITIALIZER;

  return t;

}
예제 #2
0
int pthread_create (pthread_t * tid,
                const pthread_attr_t * attr,
                void *(*start) (void *), void *arg)
/*
 * ------------------------------------------------------
 * DOCPUBLIC
 *      This function creates a thread running the start function,
 *      passing it the parameter value, 'arg'. The 'attr'
 *      argument specifies optional creation attributes.
 *      The identity of the new thread is returned
 *      via 'tid', which should not be NULL.
 *
 * PARAMETERS
 *      tid
 *              pointer to an instance of pthread_t
 *
 *      attr
 *              optional pointer to an instance of pthread_attr_t
 *
 *      start
 *              pointer to the starting routine for the new thread
 *
 *      arg
 *              optional parameter passed to 'start'
 *
 *
 * DESCRIPTION
 *      This function creates a thread running the start function,
 *      passing it the parameter value, 'arg'. The 'attr'
 *      argument specifies optional creation attributes.
 *      The identity of the new thread is returned
 *      via 'tid', which should not be the NULL pointer.
 *
 * RESULTS
 *              0               successfully created thread,
 *              EINVAL          attr invalid,
 *              EAGAIN          insufficient resources.
 *
 * ------------------------------------------------------
 */
{
   pthread_t thread;
   pte_thread_t * tp;
   int result = EAGAIN;
   int run = PTE_TRUE;
   ThreadParms *parms = NULL;
   long stackSize;
   int priority = 0;
   pthread_t self;
   pte_osResult osResult;
   register pthread_attr_t a = NULL;

   /*
    * Before doing anything, check that tid can be stored through
    * without invoking a memory protection error (segfault).
    * Make sure that the assignment below can't be optimised out by the compiler.
    * This is assured by conditionally assigning *tid again at the end.
    */

   if (attr != NULL)
      a = *attr;

   if ((thread = pte_new ()) == NULL)
      goto FAIL0;

   tp = (pte_thread_t *) thread;

   priority = tp->sched_priority;

   if ((parms = (ThreadParms *) malloc (sizeof (*parms))) == NULL)
      goto FAIL0;

   parms->tid   = thread;
   parms->start = start;
   parms->arg   = arg;

   if (a != NULL)
   {
      stackSize = a->stacksize;
      tp->detachState = a->detachstate;
      priority = a->param.sched_priority;

      if ( (priority > pte_osThreadGetMaxPriority()) ||
            (priority < pte_osThreadGetMinPriority()) )
      {
         result = EINVAL;
         goto FAIL0;
      }

      /* Everything else */

      /*
       * Thread priority must be set to a valid system level
       * without altering the value set by pthread_attr_setschedparam().
       */

      if (PTHREAD_INHERIT_SCHED == a->inheritsched)
      {
         /*
          * If the thread that called pthread_create() is an OS thread
          * then the inherited priority could be the result of a temporary
          * system adjustment. This is not the case for POSIX threads.
          */
         self = pthread_self ();
         priority = ((pte_thread_t *) self)->sched_priority;
      }


   }
   else
   {
      /*
       * Default stackSize
       */
      stackSize = PTHREAD_STACK_MIN;

   }

   tp->state = run ? PThreadStateInitial : PThreadStateSuspended;

   tp->keys  = NULL;

   /*
    * Threads must be started in suspended mode and resumed if necessary
    * after _beginthreadex returns us the handle. Otherwise we set up a
    * race condition between the creating and the created threads.
    * Note that we also retain a local copy of the handle for use
    * by us in case thread.p->threadH gets NULLed later but before we've
    * finished with it here.
    */
   result = pthread_mutex_lock (&tp->threadLock);

   if (result == 0)
   {
      /*
       * Must record the thread's sched_priority as given,
       * not as finally adjusted.
       */
      tp->sched_priority = priority;

      (void) pthread_mutex_unlock (&tp->threadLock);
   }

   osResult = pte_osThreadCreate(pte_threadStart,
         stackSize,
         priority,
         parms,
         &(tp->threadId));

   if (osResult == PTE_OS_OK)
   {
      pte_osThreadStart(tp->threadId);
      result = 0;
   }
   else
   {
      tp->threadId = 0;
      result = EAGAIN;
      goto FAIL0;
   }

   /*
    * Fall Through Intentionally
    */

   /*
    * ------------
    * Failure Code
    * ------------
    */

FAIL0:
   if (result != 0)
   {

      pte_threadDestroy (thread);
      tp = NULL;

      if (parms != NULL)
         free (parms);
   }
   else
   {
      if (tid != NULL)
         *tid = thread;
   }

   return (result);
}