1  /* Copyright (C) 1994-2023 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 <limits.h>
      19  #include <hurd.h>
      20  #include <hurd/resource.h>
      21  
      22  /* Return the highest priority of any process specified by WHICH and WHO
      23     (see <sys/resource.h>); if WHO is zero, the current process, process group,
      24     or user (as specified by WHO) is used.  A lower priority number means higher
      25     priority.  Priorities range from PRIO_MIN to PRIO_MAX.  */
      26  int
      27  __getpriority (enum __priority_which which, id_t who)
      28  {
      29    error_t err, onerr;
      30    int maxpri = INT_MIN;
      31    struct procinfo *pip;		/* Just for sizeof.  */
      32    int pibuf[sizeof *pip + 2 * sizeof (pip->threadinfos[0])], *pi = pibuf;
      33    mach_msg_type_number_t pisize = sizeof pibuf / sizeof pibuf[0];
      34  
      35    error_t getonepriority (pid_t pid, struct procinfo *pip)
      36      {
      37        if (pip)
      38  	onerr = 0;
      39        else
      40  	{
      41  	  int *oldpi = pi;
      42  	  mach_msg_type_number_t oldpisize = pisize;
      43  	  char *tw = 0;
      44  	  mach_msg_type_number_t twsz = 0;
      45  	  int flags = PI_FETCH_TASKINFO;
      46  	  onerr = __USEPORT (PROC, __proc_getprocinfo (port, pid, &flags,
      47  						       &pi, &pisize,
      48  						       &tw, &twsz));
      49  	  if (twsz)
      50  	    __vm_deallocate (__mach_task_self (), (vm_address_t) tw, twsz);
      51  	  if (pi != oldpi && oldpi != pibuf)
      52  	    /* Old buffer from last call was not reused; free it.  */
      53  	    __vm_deallocate (__mach_task_self (),
      54  			     (vm_address_t) oldpi, oldpisize * sizeof pi[0]);
      55  	  pip = (struct procinfo *) pi;
      56  	}
      57  #ifdef TASK_SCHED_TIMESHARE_INFO
      58        if (!onerr && pip->timeshare_base_info.base_priority > maxpri)
      59  	maxpri = pip->timeshare_base_info.base_priority;
      60  #else
      61        if (!onerr && pip->taskinfo.base_priority > maxpri)
      62  	maxpri = pip->taskinfo.base_priority;
      63  #endif
      64        return 0;
      65      }
      66  
      67    onerr = 0;
      68    err = _hurd_priority_which_map (which, who,
      69  				  getonepriority, PI_FETCH_TASKINFO);
      70  
      71    if (pi != pibuf)
      72      __vm_deallocate (__mach_task_self (),
      73  		     (vm_address_t) pi, pisize * sizeof pi[0]);
      74  
      75    if (!err && maxpri == INT_MIN)
      76      /* No error, but no pids found.  */
      77      err = onerr ?: ESRCH;
      78  
      79    if (err)
      80      return __hurd_fail (err);
      81  
      82    return MACH_PRIORITY_TO_NICE (maxpri);
      83  }
      84  libc_hidden_def (__getpriority)
      85  weak_alias (__getpriority, getpriority)