1: /* Demux messages sent on the signal port.
    2:    Copyright (C) 1991,92,94,95,97,99 Free Software Foundation, Inc.
    3:    This file is part of the GNU C Library.
    4: 
    5:    The GNU C Library is free software; you can redistribute it and/or
    6:    modify it under the terms of the GNU Lesser General Public
    7:    License as published by the Free Software Foundation; either
    8:    version 2.1 of the License, or (at your option) any later version.
    9: 
   10:    The GNU C Library is distributed in the hope that it will be useful,
   11:    but WITHOUT ANY WARRANTY; without even the implied warranty of
   12:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   13:    Lesser General Public License for more details.
   14: 
   15:    You should have received a copy of the GNU Lesser General Public
   16:    License along with the GNU C Library; if not, write to the Free
   17:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   18:    02111-1307 USA.  */
   19: 
   20: #include <hurd.h>
   21: #include <hurd/signal.h>
   22: #include <stddef.h>
   23: 
   24: struct demux
   25:   {
   26:     struct demux *next;
   27:     boolean_t (*demux) (mach_msg_header_t *inp,
   28:                         mach_msg_header_t *outp);
   29:   };
   30: 
   31: struct demux *_hurd_msgport_demuxers = NULL;
   32: 
   33: extern boolean_t __msg_server (mach_msg_header_t *inp,
   34:                                mach_msg_header_t *outp);
   35: 
   36: static boolean_t
   37: msgport_server (mach_msg_header_t *inp,
   38:                 mach_msg_header_t *outp)
   39: {
   40:   extern boolean_t _S_msg_server (mach_msg_header_t *inp,
   41:                                   mach_msg_header_t *outp);
   42:   extern boolean_t _S_exc_server (mach_msg_header_t *inp,
   43:                                   mach_msg_header_t *outp);
   44:   struct demux *d;
   45: 
   46:   for (d = _hurd_msgport_demuxers; d != NULL; d = d->next)
   47:     if ((*d->demux) (inp, outp))
   48:       return 1;
   49: 
   50:   return (_S_exc_server (inp, outp) ||
   51:           _S_msg_server (inp, outp));
   52: }
   53: 
   54: /* This is the code that the signal thread runs.  */
   55: void
   56: _hurd_msgport_receive (void)
   57: {
   58:   /* Get our own sigstate cached so we never again have to take a lock to
   59:      fetch it.  There is much code in hurdsig.c that operates with some
   60:      sigstate lock held, which will deadlock with _hurd_thread_sigstate.
   61: 
   62:      Furthermore, in the cthreads case this is the convenient spot
   63:      to initialize _hurd_msgport_thread (see hurdsig.c:_hurdsig_init).  */
   64: 
   65:   _hurd_msgport_thread = _hurd_self_sigstate ()->thread;
   66: 
   67:   while (1)
   68:     (void) __mach_msg_server (msgport_server, __vm_page_size, _hurd_msgport);
   69: }