1  /* Copyright (C) 2002-2023 Free Software Foundation, Inc.
       2     This file is part of the GNU C Library.
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <errno.h>
      19  #include <string.h>
      20  #include "pthreadP.h"
      21  #include <lowlevellock.h>
      22  
      23  
      24  int
      25  __pthread_getschedparam (pthread_t threadid, int *policy,
      26  			 struct sched_param *param)
      27  {
      28    struct pthread *pd = (struct pthread *) threadid;
      29  
      30    /* Make sure the descriptor is valid.  */
      31    if (INVALID_TD_P (pd))
      32      /* Not a valid thread handle.  */
      33      return ESRCH;
      34  
      35    int result = 0;
      36  
      37    /* See CREATE THREAD NOTES in nptl/pthread_create.c.  */
      38    lll_lock (pd->lock, LLL_PRIVATE);
      39  
      40    /* The library is responsible for maintaining the values at all
      41       times.  If the user uses an interface other than
      42       pthread_setschedparam to modify the scheduler setting it is not
      43       the library's problem.  In case the descriptor's values have
      44       not yet been retrieved do it now.  */
      45    if ((pd->flags & ATTR_FLAG_SCHED_SET) == 0)
      46      {
      47        if (__sched_getparam (pd->tid, &pd->schedparam) != 0)
      48  	result = 1;
      49        else
      50  	pd->flags |= ATTR_FLAG_SCHED_SET;
      51      }
      52  
      53    if ((pd->flags & ATTR_FLAG_POLICY_SET) == 0)
      54      {
      55        pd->schedpolicy = __sched_getscheduler (pd->tid);
      56        if (pd->schedpolicy == -1)
      57  	result = 1;
      58        else
      59  	pd->flags |= ATTR_FLAG_POLICY_SET;
      60      }
      61  
      62    if (result == 0)
      63      {
      64        *policy = pd->schedpolicy;
      65        memcpy (param, &pd->schedparam, sizeof (struct sched_param));
      66      }
      67  
      68    lll_unlock (pd->lock, LLL_PRIVATE);
      69  
      70    return result;
      71  }
      72  libc_hidden_def (__pthread_getschedparam)
      73  strong_alias (__pthread_getschedparam, pthread_getschedparam)