/* Copyright (C) 1994-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C 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 2.1 of the License, or (at your option) any later version.

   The GNU C 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 the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <hurd.h>

#include <hurd/resource.h>

/* Set the priority of all processes specified by WHICH and WHO

   to PRIO.  Returns 0 on success, -1 on errors.  */

int

__setpriority (enum __priority_which which, id_t who, int prio)

{

  error_t err;

  error_t pidloser, priloser;

  unsigned int npids, ntasks, nwin, nperm, nacces;

  error_t setonepriority (pid_t pid, struct procinfo *pi)

    {

      task_t task;

      error_t piderr = __USEPORT (PROC, __proc_pid2task (port, pid, &task));

      if (piderr == EPERM)

	++nperm;

      if (piderr != ESRCH)

	{

	  ++npids;

	  if (piderr && piderr != EPERM)

	    pidloser = piderr;

	}

      if (! piderr)

	{

	  error_t prierr;

	  ++ntasks;

#ifdef POLICY_TIMESHARE_BASE_COUNT

	  {

	    /* XXX This assumes timeshare policy.  */

	    struct policy_timeshare_base base

	      = { NICE_TO_MACH_PRIORITY (prio) };

	    prierr = __task_policy (task, POLICY_TIMESHARE,

				    (policy_base_t) &base,

				    POLICY_TIMESHARE_BASE_COUNT,

				    0, 1);

	  }

#else

	  prierr = __task_priority (task, NICE_TO_MACH_PRIORITY (prio), 1);

#endif

	  __mach_port_deallocate (__mach_task_self (), task);

	  switch (prierr)

	    {

	    case KERN_FAILURE:

	      ++nacces;

	      break;

	    case KERN_SUCCESS:

	      ++nwin;

	      break;

	    case KERN_INVALID_ARGUMENT: /* Task died.  */

	      --npids;

	      --ntasks;

	      break;

	    default:

	      priloser = prierr;

	    }

	}

      return 0;

    }

  npids = ntasks = nwin = nperm = nacces = 0;

  pidloser = priloser = 0;

  err = _hurd_priority_which_map (which, who, setonepriority, 0);

  if (!err && npids == 0)

    /* No error, but no pids found.  */

    err = ESRCH;

  else if (nperm == npids)

    /* Got EPERM from proc_task2pid for every process.  */

    err = EPERM;

  else if (nacces == ntasks)

    /* Got KERN_FAILURE from task_priority for every task.  */

    err = EACCES;

  else if (nwin == 0)

    err = pidloser ?: priloser;

  return err ? __hurd_fail (err) : 0;

}

libc_hidden_def (__setpriority)

weak_alias (__setpriority, setpriority)