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/* _hurd_ctty_output -- Do an output RPC and generate SIGTTOU if necessary.
Copyright (C) 1995-2021 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#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))
{
if (ctty == MACH_PORT_NULL)
return (*rpc) (port);
else
{
struct hurd_sigstate *ss = _hurd_self_sigstate ();
error_t err;
do
{
struct sigaction *actions;
/* Don't use the ctty io port if we are blocking or ignoring
SIGTTOU. We redo this check at the top of the loop in case
the signal handler changed the state. */
_hurd_sigstate_lock (ss);
actions = _hurd_sigstate_actions (ss);
if (__sigismember (&ss->blocked, SIGTTOU)
|| actions[SIGTTOU].sa_handler == SIG_IGN)
err = EIO;
else
err = 0;
_hurd_sigstate_unlock (ss);
if (err)
return (*rpc) (port);
err = (*rpc) (ctty);
if (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. */
_hurd_sigstate_lock (ss);
actions = _hurd_sigstate_actions (ss);
if (!(actions[SIGTTOU].sa_flags & SA_RESTART))
err = EINTR;
_hurd_sigstate_unlock (ss);
}
}
/* If the last RPC generated a SIGTTOU, loop to try it again. */
} while (err == EBACKGROUND);
return err;
}
}
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