/* 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 <limits.h>

#include <hurd.h>

#include <hurd/resource.h>

/* Return the highest priority of any process specified by WHICH and WHO

   (see <sys/resource.h>); if WHO is zero, the current process, process group,

   or user (as specified by WHO) is used.  A lower priority number means higher

   priority.  Priorities range from PRIO_MIN to PRIO_MAX.  */

int

__getpriority (enum __priority_which which, id_t who)

{

  error_t err, onerr;

  int maxpri = INT_MIN;

  struct procinfo *pip;		/* Just for sizeof.  */

  int pibuf[sizeof *pip + 2 * sizeof (pip->threadinfos[0])], *pi = pibuf;

  size_t pisize = sizeof pibuf / sizeof pibuf[0];

  error_t getonepriority (pid_t pid, struct procinfo *pip)

    {

      if (pip)

	onerr = 0;

      else

	{

	  int *oldpi = pi;

	  size_t oldpisize = pisize;

	  char *tw = 0;

	  size_t twsz = 0;

	  int flags = PI_FETCH_TASKINFO;

	  onerr = __USEPORT (PROC, __proc_getprocinfo (port, pid, &flags,

						       &pi, &pisize,

						       &tw, &twsz));

	  if (twsz)

	    __vm_deallocate (__mach_task_self (), (vm_address_t) tw, twsz);

	  if (pi != oldpi && oldpi != pibuf)

	    /* Old buffer from last call was not reused; free it.  */

	    __vm_deallocate (__mach_task_self (),

			     (vm_address_t) oldpi, oldpisize * sizeof pi[0]);

	  pip = (struct procinfo *) pi;

	}

#ifdef TASK_SCHED_TIMESHARE_INFO

      if (!onerr && pip->timeshare_base_info.base_priority > maxpri)

	maxpri = pip->timeshare_base_info.base_priority;

#else

      if (!onerr && pip->taskinfo.base_priority > maxpri)

	maxpri = pip->taskinfo.base_priority;

#endif

      return 0;

    }

  onerr = 0;

  err = _hurd_priority_which_map (which, who,

				  getonepriority, PI_FETCH_TASKINFO);

  if (pi != pibuf)

    __vm_deallocate (__mach_task_self (),

		     (vm_address_t) pi, pisize * sizeof pi[0]);

  if (!err && maxpri == INT_MIN)

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

    err = onerr ?: ESRCH;

  if (err)

    return __hurd_fail (err);

  return MACH_PRIORITY_TO_NICE (maxpri);

}

libc_hidden_def (__getpriority)

weak_alias (__getpriority, getpriority)