1: /* _hurd_ctty_output -- Do an output RPC and generate SIGTTOU if necessary.
    2:    Copyright (C) 1995,97,99 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: 
   23: /* Call *RPC on PORT and/or CTTY.  If a call on CTTY returns EBACKGROUND,
   24:    generate SIGTTOU if appropriate.  */
   25: 
   26: error_t
   27: _hurd_ctty_output (io_t port, io_t ctty, error_t (*rpc) (io_t))
   28: {
   29:   if (ctty == MACH_PORT_NULL)
   30:     return (*rpc) (port);
   31:   else
   32:     {
   33:       struct hurd_sigstate *ss = _hurd_self_sigstate ();
   34:       error_t err;
   35: 
   36:       do
   37:         {
   38:           /* Don't use the ctty io port if we are blocking or ignoring
   39:              SIGTTOU.  We redo this check at the top of the loop in case
   40:              the signal handler changed the state.  */
   41:           __spin_lock (&ss->lock);
   42:           if (__sigismember (&ss->blocked, SIGTTOU) ||
   43:               ss->actions[SIGTTOU].sa_handler == SIG_IGN)
   44:             err = EIO;
   45:           else
   46:             err = 0;
   47:           __spin_unlock (&ss->lock);
   48: 
   49:           if (err)
   50:             return (*rpc) (port);
   51: 
   52:           err = (*rpc) (ctty);
   53:           if (err == EBACKGROUND)
   54:             {
   55:               if (_hurd_orphaned)
   56:                 /* Our process group is orphaned, so we never generate a
   57:                    signal; we just fail.  */
   58:                 err = EIO;
   59:               else
   60:                 {
   61:                   /* Send a SIGTTOU signal to our process group.
   62: 
   63:                      We must remember here not to clobber ERR, since
   64:                      the loop condition below uses it to recall that
   65:                   we should retry after a stop.  */
   66: 
   67:                   __USEPORT (CTTYID, _hurd_sig_post (0, SIGTTOU, port));
   68:                   /* XXX what to do if error here? */
   69: 
   70:                   /* At this point we should have just run the handler for
   71:                      SIGTTOU or resumed after being stopped.  Now this is
   72:                      still a "system call", so check to see if we should
   73:                   restart it.  */
   74:                   __spin_lock (&ss->lock);
   75:                   if (!(ss->actions[SIGTTOU].sa_flags & SA_RESTART))
   76:                     err = EINTR;
   77:                   __spin_unlock (&ss->lock);
   78:                 }
   79:             }
   80:           /* If the last RPC generated a SIGTTOU, loop to try it again.  */
   81:         } while (err == EBACKGROUND);
   82: 
   83:       return err;
   84:     }
   85: }