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      1 /*
      2  * sched_setschedparam.c
      3  *
      4  * Description:
      5  * POSIX thread functions that deal with thread scheduling.
      6  *
      7  * --------------------------------------------------------------------------
      8  *
      9  *      Pthreads-win32 - POSIX Threads Library for Win32
     10  *      Copyright(C) 1998 John E. Bossom
     11  *      Copyright(C) 1999,2005 Pthreads-win32 contributors
     12  *
     13  *      Contact Email: rpj (at) callisto.canberra.edu.au
     14  *
     15  *      The current list of contributors is contained
     16  *      in the file CONTRIBUTORS included with the source
     17  *      code distribution. The list can also be seen at the
     18  *      following World Wide Web location:
     19  *      http://sources.redhat.com/pthreads-win32/contributors.html
     20  *
     21  *      This library is free software; you can redistribute it and/or
     22  *      modify it under the terms of the GNU Lesser General Public
     23  *      License as published by the Free Software Foundation; either
     24  *      version 2 of the License, or (at your option) any later version.
     25  *
     26  *      This library is distributed in the hope that it will be useful,
     27  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
     28  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     29  *      Lesser General Public License for more details.
     30  *
     31  *      You should have received a copy of the GNU Lesser General Public
     32  *      License along with this library in the file COPYING.LIB;
     33  *      if not, write to the Free Software Foundation, Inc.,
     34  *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
     35  */
     36 
     37 #include "pthread.h"
     38 #include "implement.h"
     39 #include "sched.h"
     40 
     41 int
     42 pthread_setschedparam (pthread_t thread, int policy,
     43 		       const struct sched_param *param)
     44 {
     45   int result;
     46 
     47   /* Validate the thread id. */
     48   result = pthread_kill (thread, 0);
     49   if (0 != result)
     50     {
     51       return result;
     52     }
     53 
     54   /* Validate the scheduling policy. */
     55   if (policy < SCHED_MIN || policy > SCHED_MAX)
     56     {
     57       return EINVAL;
     58     }
     59 
     60   /* Ensure the policy is SCHED_OTHER. */
     61   if (policy != SCHED_OTHER)
     62     {
     63       return ENOTSUP;
     64     }
     65 
     66   return (ptw32_setthreadpriority (thread, policy, param->sched_priority));
     67 }
     68 
     69 
     70 int
     71 ptw32_setthreadpriority (pthread_t thread, int policy, int priority)
     72 {
     73   int prio;
     74   ptw32_mcs_local_node_t threadLock;
     75   int result = 0;
     76   ptw32_thread_t * tp = (ptw32_thread_t *) thread.p;
     77 
     78   prio = priority;
     79 
     80   /* Validate priority level. */
     81   if (prio < sched_get_priority_min (policy) ||
     82       prio > sched_get_priority_max (policy))
     83     {
     84       return EINVAL;
     85     }
     86 
     87 #if (THREAD_PRIORITY_LOWEST > THREAD_PRIORITY_NORMAL)
     88 /* WinCE */
     89 #else
     90 /* Everything else */
     91 
     92   if (THREAD_PRIORITY_IDLE < prio && THREAD_PRIORITY_LOWEST > prio)
     93     {
     94       prio = THREAD_PRIORITY_LOWEST;
     95     }
     96   else if (THREAD_PRIORITY_TIME_CRITICAL > prio
     97 	   && THREAD_PRIORITY_HIGHEST < prio)
     98     {
     99       prio = THREAD_PRIORITY_HIGHEST;
    100     }
    101 
    102 #endif
    103 
    104   ptw32_mcs_lock_acquire (&tp->threadLock, &threadLock);
    105 
    106   /* If this fails, the current priority is unchanged. */
    107   if (0 == SetThreadPriority (tp->threadH, prio))
    108     {
    109       result = EINVAL;
    110     }
    111   else
    112     {
    113       /*
    114        * Must record the thread's sched_priority as given,
    115        * not as finally adjusted.
    116        */
    117       tp->sched_priority = priority;
    118     }
    119 
    120   ptw32_mcs_lock_release (&threadLock);
    121 
    122   return result;
    123 }
    124