int
pthread_setschedparam (pthread_t thread, int policy,
		       const struct sched_param *param)
{
  int result;

  
  result = pthread_kill (thread, 0);
  if (0 != result)
    {
      return result;
    }

  
  if (policy < SCHED_MIN || policy > SCHED_MAX)
    {
      return EINVAL;
    }

  
  if (policy != SCHED_OTHER)
    {
      return ENOTSUP;
    }

  return (ptw32_setthreadpriority (thread, policy, param->sched_priority));
}
int
pthread_setschedparam (pthread_t thread, int policy,
		       const struct sched_param *param)
{
  int result;

  /* Validate the thread id. */
  result = pthread_kill (thread, 0);
  if (0 != result)
    {
      return result;
    }

  /* Validate the scheduling policy. */
  if (policy < SCHED_MIN || policy > SCHED_MAX)
    {
      return EINVAL;
    }

  /* Ensure the policy is SCHED_OTHER. */
  if (policy != SCHED_OTHER)
    {
      return ENOTSUP;
    }

  return (ptw32_setthreadpriority (thread, policy, param->sched_priority));
}
Beispiel #3
0
int
pthread_create (pthread_t * tid,
                const pthread_attr_t * attr,
                void *(PTW32_CDECL *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 = { 0 };		// init to shut up MSVC2013: warning C4701 : potentially uninitialized local variable 'thread' used
    ptw32_thread_t * tp;
    ptw32_thread_t * sp;
    register pthread_attr_t a;
    HANDLE threadH = 0;
    int result = EAGAIN;
    int run = PTW32_TRUE;
    ThreadParms *parms = NULL;
    unsigned int stackSize;
    int priority;

    /*
     * 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.
     */
    tid->x = 0;

    if (NULL == (sp = (ptw32_thread_t *)pthread_self().p))
    {
        goto FAIL0;
    }

    if (attr != NULL)
    {
        a = *attr;
    }
    else
    {
        a = NULL;
    }

    thread = ptw32_new();
    if (thread.p == NULL)
    {
        goto FAIL0;
    }

    tp = (ptw32_thread_t *) thread.p;

    priority = tp->sched_priority;

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

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

    /*
     * Threads inherit their initial sigmask and CPU affinity from their creator thread.
     */
#if defined(HAVE_SIGSET_T)
    tp->sigmask = sp->sigmask;
#endif
#if defined(HAVE_CPU_AFFINITY)
    tp->cpuset = sp->cpuset;
#endif

    if (a != NULL)
    {
#if defined(HAVE_CPU_AFFINITY)
        cpu_set_t none;
        cpu_set_t attr_cpuset;
        ((_sched_cpu_set_vector_*)&attr_cpuset)->_cpuset = a->cpuset;

        CPU_ZERO(&none);
        if (! CPU_EQUAL(&attr_cpuset, &none))
        {
            tp->cpuset = a->cpuset;
        }
#endif
        stackSize = (unsigned int)a->stacksize;
        tp->detachState = a->detachstate;
        priority = a->param.sched_priority;
        if (a->thrname != NULL)
            tp->name = _strdup(a->thrname);

#if (THREAD_PRIORITY_LOWEST > THREAD_PRIORITY_NORMAL)
        /* WinCE */
#else
        /* Everything else */

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

        /*
         * PTHREAD_EXPLICIT_SCHED is the default because Win32 threads
         * don't inherit their creator's priority. They are started with
         * THREAD_PRIORITY_NORMAL (win32 value). The result of not supplying
         * an 'attr' arg to pthread_create() is equivalent to defaulting to
         * PTHREAD_EXPLICIT_SCHED and priority THREAD_PRIORITY_NORMAL.
         */
        if (PTHREAD_INHERIT_SCHED == a->inheritsched)
        {
            /*
             * If the thread that called pthread_create() is a Win32 thread
             * then the inherited priority could be the result of a temporary
             * system adjustment. This is not the case for POSIX threads.
             */
            priority = sp->sched_priority;
        }

#endif

    }
    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.
     */

#if ! defined (PTW32_CONFIG_MINGW) || defined (__MSVCRT__) || defined (__DMC__)

    tp->threadH =
        threadH =
            (HANDLE) _beginthreadex ((void *) NULL,	/* No security info             */
                                     stackSize,		/* default stack size   */
                                     ptw32_threadStart,
                                     parms,
                                     (unsigned)
                                     CREATE_SUSPENDED,
                                     (unsigned *) &(tp->thread));

    if (threadH != 0)
    {
        if (a != NULL)
        {
            (void) ptw32_setthreadpriority (thread, SCHED_OTHER, priority);
        }

#if defined(HAVE_CPU_AFFINITY)

        SetThreadAffinityMask(tp->threadH, tp->cpuset);

#endif

        if (run)
        {
            ResumeThread (threadH);
        }
    }

#else

    {
        ptw32_mcs_local_node_t stateLock;

        /*
         * This lock will force pthread_threadStart() to wait until we have
         * the thread handle and have set the priority.
         */
        ptw32_mcs_lock_acquire(&tp->stateLock, &stateLock);

        tp->threadH =
            threadH =
                (HANDLE) _beginthread (ptw32_threadStart, stackSize,	/* default stack size   */
                                       parms);

        /*
         * Make the return code match _beginthreadex's.
         */
        if (threadH == (HANDLE) - 1L)
        {
            tp->threadH = threadH = 0;
        }
        else
        {
            if (!run)
            {
                /*
                 * beginthread does not allow for create flags, so we do it now.
                 * Note that beginthread itself creates the thread in SUSPENDED
                 * mode, and then calls ResumeThread to start it.
                 */
                SuspendThread (threadH);
            }

            if (a != NULL)
            {
                (void) ptw32_setthreadpriority (thread, SCHED_OTHER, priority);
            }

#if defined(HAVE_CPU_AFFINITY)

            SetThreadAffinityMask(tp->threadH, tp->cpuset);

#endif

        }

        ptw32_mcs_lock_release (&stateLock);
    }
#endif

    result = (threadH != 0) ? 0 : EAGAIN;

    /*
     * Fall Through Intentionally
     */

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

FAIL0:
    if (result != 0)
    {
        ptw32_threadDestroy (thread);
        tp = NULL;

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

#if defined(_UWIN)
    if (result == 0)
        pthread_count++;
#endif
    return (result);
}				/* pthread_create */