hurd/msgportdemux.c

   1 /* Demux messages sent on the signal port.
   2
   3 Copyright (C) 1991, 1992, 1994, 1995 Free Software Foundation, Inc.
   4 This file is part of the GNU C Library.
   5
   6 The GNU C Library is free software; you can redistribute it and/or
   7 modify it under the terms of the GNU Library General Public License as
   8 published by the Free Software Foundation; either version 2 of the
   9 License, or (at your option) any later version.
  10
  11 The GNU C Library is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 Library General Public License for more details.
  15
  16 You should have received a copy of the GNU Library General Public
  17 License along with the GNU C Library; see the file COPYING.LIB.  If
  18 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  19 Cambridge, MA 02139, USA.  */
  20
  21 #include <hurd.h>
  22 #include <hurd/signal.h>
  23 #include <stddef.h>
  24
  25 struct demux
  26   {
  27     struct demux *next;
  28     boolean_t (*demux) (mach_msg_header_t *inp,
  29                         mach_msg_header_t *outp);
  30   };
  31
  32 struct demux *_hurd_msgport_demuxers = NULL;
  33
  34 extern boolean_t __msg_server (mach_msg_header_t *inp,
  35                                mach_msg_header_t *outp);
  36
  37 static boolean_t
  38 msgport_server (mach_msg_header_t *inp,
  39                 mach_msg_header_t *outp)
  40 {
  41   extern boolean_t _S_msg_server (mach_msg_header_t *inp,
  42                                   mach_msg_header_t *outp);
  43   extern boolean_t _S_exc_server (mach_msg_header_t *inp,
  44                                   mach_msg_header_t *outp);
  45   struct demux *d;
  46
  47   for (d = _hurd_msgport_demuxers; d != NULL; d = d->next)
  48     if ((*d->demux) (inp, outp))
  49       return 1;
  50
  51   return (_S_exc_server (inp, outp) ||
  52           _S_msg_server (inp, outp));
  53 }
  54
  55 /* This is the code that the signal thread runs.  */
  56 void
  57 _hurd_msgport_receive (void)
  58 {
  59   /* Get our own sigstate cached so we never again have to take a lock to
  60      fetch it.  There is much code in hurdsig.c that operates with some
  61      sigstate lock held, which will deadlock with _hurd_thread_sigstate.  */
  62   (void) _hurd_self_sigstate ();
  63
  64   while (1)
  65     (void) __mach_msg_server (msgport_server, __vm_page_size, _hurd_msgport);
  66 }