glibc/hurd/ctty-input.c

80 lines
2.5 KiB
C

/* _hurd_ctty_input -- Do an input RPC and generate SIGTTIN if necessary.
Copyright (C) 1995-2018 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
<http://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 SIGTTIN or EIO as appropriate. */
error_t
_hurd_ctty_input (io_t port, io_t ctty, error_t (*rpc) (io_t))
{
error_t err;
if (ctty == MACH_PORT_NULL)
return (*rpc) (port);
do
{
err = (*rpc) (ctty);
if (err == EBACKGROUND)
{
/* We are a background job and tried to read from the tty.
We should probably get a SIGTTIN signal. */
if (_hurd_orphaned)
/* Our process group is orphaned. Don't stop; just fail. */
err = EIO;
else
{
struct hurd_sigstate *ss = _hurd_self_sigstate ();
__spin_lock (&ss->lock);
if (__sigismember (&ss->blocked, SIGTTIN) ||
ss->actions[SIGTTIN].sa_handler == SIG_IGN)
/* We are blocking or ignoring SIGTTIN. Just fail. */
err = EIO;
__spin_unlock (&ss->lock);
if (err == EBACKGROUND)
{
/* Send a SIGTTIN 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, SIGTTIN, port));
/* XXX what to do if error here? */
/* At this point we should have just run the handler for
SIGTTIN 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[SIGTTIN].sa_flags & SA_RESTART))
err = EINTR;
__spin_unlock (&ss->lock);
}
}
}
/* If the last RPC generated a SIGTTIN, loop to try it again. */
} while (err == EBACKGROUND);
return err;
}