1  /* Demux messages sent on the signal port.
       2     Copyright (C) 1991-2023 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, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <hurd.h>
      20  #include <hurd/signal.h>
      21  #include <stddef.h>
      22  
      23  static boolean_t
      24  msgport_server (mach_msg_header_t *inp,
      25  		mach_msg_header_t *outp)
      26  {
      27    extern boolean_t _S_msg_server (mach_msg_header_t *inp,
      28  				  mach_msg_header_t *outp);
      29    extern boolean_t _S_exc_server (mach_msg_header_t *inp,
      30  				  mach_msg_header_t *outp);
      31  
      32    return (_S_exc_server (inp, outp)
      33  	  || _S_msg_server (inp, outp));
      34  }
      35  
      36  /* This is the code that the signal thread runs.  */
      37  void *
      38  _hurd_msgport_receive (void *arg)
      39  {
      40    /* Get our own sigstate cached so we never again have to take a lock to
      41       fetch it.  There is much code in hurdsig.c that operates with some
      42       sigstate lock held, which will deadlock with _hurd_thread_sigstate.
      43  
      44       Furthermore, in the pthread case this is the convenient spot
      45       to initialize _hurd_msgport_thread (see hurdsig.c:_hurdsig_init).  */
      46  
      47    _hurd_msgport_thread = _hurd_self_sigstate ()->thread;
      48  
      49    while (1)
      50      (void) __mach_msg_server (msgport_server, __vm_page_size, _hurd_msgport);
      51  }