hurd/hurdpid.c

   1 /* Copyright (C) 1991-2020 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 <hurd.h>
  19 #include <lowlevellock.h>
  20
  21 pid_t _hurd_pid, _hurd_ppid, _hurd_pgrp;
  22 int _hurd_orphaned;
  23
  24 static void
  25 init_pids (void)
  26 {
  27   __USEPORT (PROC,
  28              ({
  29                __proc_getpids (port, &_hurd_pid, &_hurd_ppid, &_hurd_orphaned);
  30                __proc_getpgrp (port, _hurd_pid, &_hurd_pgrp);
  31              }));
  32
  33   (void) &init_pids;            /* Avoid "defined but not used" warning.  */
  34 }
  35
  36 text_set_element (_hurd_proc_subinit, init_pids);
  37 \f
  38 #include <hurd/msg_server.h>
  39 #include "set-hooks.h"
  40
  41 DEFINE_HOOK (_hurd_pgrp_changed_hook, (pid_t));
  42
  43 /* These let user threads synchronize with an operation which changes ids.  */
  44 unsigned int _hurd_pids_changed_stamp;
  45
  46 kern_return_t
  47 _S_msg_proc_newids (mach_port_t me,
  48                     task_t task,
  49                     pid_t ppid, pid_t pgrp, int orphaned)
  50 {
  51   int pgrp_changed;
  52
  53   if (task != __mach_task_self ())
  54     return EPERM;
  55
  56   __mach_port_deallocate (__mach_task_self (), task);
  57
  58   pgrp_changed = pgrp != _hurd_pgrp;
  59   _hurd_ppid = ppid;
  60   _hurd_pgrp = pgrp;
  61   _hurd_orphaned = orphaned;
  62
  63   if (pgrp_changed)
  64     /* Run things that want notification of a pgrp change.  */
  65     RUN_HOOK (_hurd_pgrp_changed_hook, (pgrp));
  66
  67   /* Notify any waiting user threads that the id change as been completed.  */
  68   ++_hurd_pids_changed_stamp;
  69   lll_wake (_hurd_pids_changed_stamp, GSYNC_BROADCAST);
  70
  71   return 0;
  72 }