sysdeps/mach/hurd/setpriority.c

   1 /* Copyright (C) 1994,95,97,2000,02 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <hurd.h>
  20 #include <hurd/resource.h>
  21
  22 /* Set the priority of all processes specified by WHICH and WHO
  23    to PRIO.  Returns 0 on success, -1 on errors.  */
  24 int
  25 setpriority (enum __priority_which which, id_t who, int prio)
  26 {
  27   error_t err;
  28   error_t pidloser, priloser;
  29   unsigned int npids, ntasks, nwin, nperm, nacces;
  30
  31   error_t setonepriority (pid_t pid, struct procinfo *pi)
  32     {
  33       task_t task;
  34       error_t piderr = __USEPORT (PROC, __proc_pid2task (port, pid, &task));
  35       if (piderr == EPERM)
  36         ++nperm;
  37       if (piderr != ESRCH)
  38         {
  39           ++npids;
  40           if (piderr && piderr != EPERM)
  41             pidloser = piderr;
  42         }
  43       if (! piderr)
  44         {
  45           error_t prierr;
  46           ++ntasks;
  47 #ifdef POLICY_TIMESHARE_BASE_COUNT
  48           {
  49             /* XXX This assumes timeshare policy.  */
  50             struct policy_timeshare_base base
  51               = { NICE_TO_MACH_PRIORITY (prio) };
  52             prierr = __task_policy (task, POLICY_TIMESHARE,
  53                                     (policy_base_t) &base,
  54                                     POLICY_TIMESHARE_BASE_COUNT,
  55                                     0, 1);
  56           }
  57 #else
  58           prierr = __task_priority (task, NICE_TO_MACH_PRIORITY (prio), 1);
  59 #endif
  60           __mach_port_deallocate (__mach_task_self (), task);
  61           switch (prierr)
  62             {
  63             case KERN_FAILURE:
  64               ++nacces;
  65               break;
  66             case KERN_SUCCESS:
  67               ++nwin;
  68               break;
  69             case KERN_INVALID_ARGUMENT: /* Task died.  */
  70               --npids;
  71               --ntasks;
  72               break;
  73             default:
  74               priloser = prierr;
  75             }
  76         }
  77       return 0;
  78     }
  79
  80   npids = ntasks = nwin = nperm = nacces = 0;
  81   pidloser = priloser = 0;
  82   err = _hurd_priority_which_map (which, who, setonepriority, 0);
  83
  84   if (!err && npids == 0)
  85     /* No error, but no pids found.  */
  86     err = ESRCH;
  87   else if (nperm == npids)
  88     /* Got EPERM from proc_task2pid for every process.  */
  89     err = EPERM;
  90   else if (nacces == ntasks)
  91     /* Got KERN_FAILURE from task_priority for every task.  */
  92     err = EACCES;
  93   else if (nwin == 0)
  94     err = pidloser ?: priloser;
  95
  96   return err ? __hurd_fail (err) : 0;
  97 }
  98 libc_hidden_def (setpriority)