glibc/hurd/ctty-input.c
1995-02-18 01:27:10 +00:00

78 lines
2.6 KiB
C

/* _hurd_ctty_input -- Do an input RPC and generate SIGTTIN 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 SIGTTIN or EIO as appropriate. */
error_t
_hurd_ctty_input (io_t port, io_t ctty, error_t (*rpc) (io_t))
{
error_t err;
do
{
err = (*rpc) (ctty != MACH_PORT_NULL ? ctty : port);
if (ctty != MACH_PORT_NULL && err == EBACKGROUND)
{
/* We are a background job and tried to read from the tty.
We should probably get a SIGTTIN signal. */
struct hurd_sigstate *ss;
if (_hurd_orphaned)
/* Our process group is orphaned. Don't stop; just fail. */
err = EIO;
else
{
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;
}