hurd/hurdpid.c

   1 /* Copyright (C) 1991-2022 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 #include "set-hooks.h"
  21
  22 pid_t _hurd_pid, _hurd_ppid, _hurd_pgrp;
  23 int _hurd_orphaned;
  24
  25 static void attribute_used_retain
  26 init_pids (void)
  27 {
  28   __USEPORT (PROC,
  29              ({
  30                __proc_getpids (port, &_hurd_pid, &_hurd_ppid, &_hurd_orphaned);
  31                __proc_getpgrp (port, _hurd_pid, &_hurd_pgrp);
  32              }));
  33 }
  34
  35 SET_RELHOOK (_hurd_proc_subinit, init_pids);
  36 \f
  37 #include <hurd/msg_server.h>
  38 #include "set-hooks.h"
  39
  40 DEFINE_HOOK (_hurd_pgrp_changed_hook, (pid_t));
  41
  42 /* These let user threads synchronize with an operation which changes ids.  */
  43 unsigned int _hurd_pids_changed_stamp;
  44
  45 kern_return_t
  46 _S_msg_proc_newids (mach_port_t me,
  47                     task_t task,
  48                     pid_t ppid, pid_t pgrp, int orphaned)
  49 {
  50   int pgrp_changed;
  51
  52   if (task != __mach_task_self ())
  53     return EPERM;
  54
  55   __mach_port_deallocate (__mach_task_self (), task);
  56
  57   pgrp_changed = pgrp != _hurd_pgrp;
  58   _hurd_ppid = ppid;
  59   _hurd_pgrp = pgrp;
  60   _hurd_orphaned = orphaned;
  61
  62   if (pgrp_changed)
  63     /* Run things that want notification of a pgrp change.  */
  64     RUN_HOOK (_hurd_pgrp_changed_hook, (pgrp));
  65
  66   /* Notify any waiting user threads that the id change as been completed.  */
  67   ++_hurd_pids_changed_stamp;
  68   lll_wake (_hurd_pids_changed_stamp, GSYNC_BROADCAST);
  69
  70   return 0;
  71 }