glibc/hurd/ctty-output.c

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1995-02-18 01:27:10 +00:00
/* _hurd_ctty_output -- Do an output RPC and generate SIGTTOU if necessary.
Copyright (C) 1995 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <hurd.h>
#include <hurd/signal.h>
/* Call *RPC on PORT and/or CTTY. If a call on CTTY returns EBACKGROUND,
generate SIGTTOU if appropriate. */
error_t
_hurd_ctty_output (io_t port, io_t ctty, error_t (*rpc) (io_t))
{
error_t err;
struct hurd_sigstate *ss;
io_t ioport;
/* Don't use the ctty io port if we are blocking or ignoring SIGTTOU. */
if (ctty == MACH_PORT_NULL)
ioport = port;
else
{
ss = _hurd_self_sigstate ();
__spin_lock (&ss->lock);
if (__sigismember (&ss->blocked, SIGTTOU) ||
ss->actions[SIGTTOU].sa_handler == SIG_IGN)
ioport = port;
else
ioport = ctty;
__spin_unlock (&ss->lock);
}
do
{
err = (*rpc) (ioport);
if (ioport == ctty && err == EBACKGROUND)
{
if (_hurd_orphaned)
/* Our process group is orphaned, so we never generate a
signal; we just fail. */
err = EIO;
else
{
/* Send a SIGTTOU signal to our process group.
We must remember here not to clobber ERR, since
the loop condition below uses it to recall that
we should retry after a stop. */
__USEPORT (CTTYID, _hurd_sig_post (0, SIGTTOU, port));
/* XXX what to do if error here? */
/* At this point we should have just run the handler for
SIGTTOU or resumed after being stopped. Now this is
still a "system call", so check to see if we should
restart it. */
__spin_lock (&ss->lock);
if (!(ss->actions[SIGTTOU].sa_flags & SA_RESTART))
err = EINTR;
__spin_unlock (&ss->lock);
}
}
/* If the last RPC generated a SIGTTOU, loop to try it again. */
} while (err == EBACKGROUND);
return err;
}