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/* File descriptors.
Copyright (C) 1993, 1994, 1995, 1996, 1997 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., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#ifndef _HURD_FD_H
#define _HURD_FD_H 1
#include <features.h>
#include <hurd/hurd_types.h>
#include <hurd/port.h>
/* Structure representing a file descriptor. */
struct hurd_fd
{
struct hurd_port port; /* io server port. */
int flags; /* fcntl flags; locked by port.lock. */
/* Normal port to the ctty. When `port' is our ctty, this is a port to
the same io object but which never returns EBACKGROUND; when not,
this is nil. */
struct hurd_port ctty;
};
/* Current file descriptor table. */
extern int _hurd_dtablesize;
extern struct hurd_fd **_hurd_dtable;
extern struct mutex _hurd_dtable_lock; /* Locks those two variables. */
#include <hurd/signal.h>
#include <lock-intern.h>
#ifndef _EXTERN_INLINE
#define _EXTERN_INLINE extern __inline
#endif
/* Returns the descriptor cell for FD. If FD is invalid or unused, return
NULL. The cell is unlocked; when ready to use it, lock it and check for
it being unused. */
_EXTERN_INLINE struct hurd_fd *
_hurd_fd_get (int fd)
{
struct hurd_fd *descriptor;
__mutex_lock (&_hurd_dtable_lock);
if (fd < 0 || fd >= _hurd_dtablesize)
descriptor = NULL;
else
{
struct hurd_fd *cell = _hurd_dtable[fd];
if (cell == NULL)
/* No descriptor allocated at this index. */
descriptor = NULL;
else
{
__spin_lock (&cell->port.lock);
if (cell->port.port == MACH_PORT_NULL)
/* The descriptor at this index has no port in it.
This happens if it existed before but was closed. */
descriptor = NULL;
else
descriptor = cell;
__spin_unlock (&cell->port.lock);
}
}
__mutex_unlock (&_hurd_dtable_lock);
return descriptor;
}
/* Evaluate EXPR with the variable `descriptor' bound to a pointer to the
file descriptor structure for FD. */
#define HURD_FD_USE(fd, expr) \
({ struct hurd_fd *descriptor = _hurd_fd_get (fd); \
descriptor == NULL ? EBADF : (expr); })
/* Evaluate EXPR with the variable `port' bound to the port to FD, and
`ctty' bound to the ctty port. */
#define HURD_DPORT_USE(fd, expr) \
HURD_FD_USE ((fd), HURD_FD_PORT_USE (descriptor, (expr)))
/* Likewise, but FD is a pointer to the file descriptor structure. */
#define HURD_FD_PORT_USE(fd, expr) \
({ error_t __result; \
struct hurd_fd *const __d = (fd); \
struct hurd_userlink __ulink, __ctty_ulink; \
io_t port, ctty; \
void *crit = _hurd_critical_section_lock (); \
__spin_lock (&__d->port.lock); \
if (__d->port.port == MACH_PORT_NULL) \
{ \
__spin_unlock (&__d->port.lock); \
_hurd_critical_section_unlock (crit); \
__result = EBADF; \
} \
else \
{ \
ctty = _hurd_port_get (&__d->ctty, &__ctty_ulink); \
port = _hurd_port_locked_get (&__d->port, &__ulink); \
_hurd_critical_section_unlock (crit); \
__result = (expr); \
_hurd_port_free (&__d->port, &__ulink, port); \
if (ctty != MACH_PORT_NULL) \
_hurd_port_free (&__d->ctty, &__ctty_ulink, ctty); \
} \
__result; })
#include <errno.h>
/* Check if ERR should generate a signal.
Returns the signal to take, or zero if none. */
_EXTERN_INLINE error_t
_hurd_fd_error_signal (error_t err)
{
switch (err)
{
case EMACH_SEND_INVALID_DEST:
case EMIG_SERVER_DIED:
/* The server has disappeared! */
return SIGLOST;
case EPIPE:
return SIGPIPE;
default:
/* Having a default case avoids -Wenum-switch warnings. */
return 0;
}
}
/* Handle an error from an RPC on a file descriptor's port. You should
always use this function to handle errors from RPCs made on file
descriptor ports. Some errors are translated into signals. */
_EXTERN_INLINE error_t
_hurd_fd_error (int fd, error_t err)
{
int signo = _hurd_fd_error_signal (err);
if (signo)
{
const struct hurd_signal_detail detail
= { code: fd, error: err, exc: 0 };
_hurd_raise_signal (NULL, signo, &detail);
}
return err;
}
/* Handle error code ERR from an RPC on file descriptor FD's port.
Set `errno' to the appropriate error code, and always return -1. */
_EXTERN_INLINE int
__hurd_dfail (int fd, error_t err)
{
errno = _hurd_fd_error (fd, err);
return -1;
}
/* Set up *FD to have PORT its server port, doing appropriate ctty magic.
Does no locking or unlocking. */
extern void _hurd_port2fd (struct hurd_fd *fd, io_t port, int flags);
/* Allocate a new file descriptor and install PORT in it (doing any
appropriate ctty magic); consumes a user reference on PORT. FLAGS are
as for `open'; only O_IGNORE_CTTY is meaningful, but all are saved.
If the descriptor table is full, set errno, and return -1.
If DEALLOC is nonzero, deallocate PORT first. */
extern int _hurd_intern_fd (io_t port, int flags, int dealloc);
/* Allocate a new file descriptor in the table and return it, locked. The
new descriptor number will be no less than FIRST_FD. If the table is
full, set errno to EMFILE and return NULL. If FIRST_FD is negative or
bigger than the size of the table, set errno to EINVAL and return NULL. */
extern struct hurd_fd *_hurd_alloc_fd (int *fd_ptr, int first_fd);
/* Allocate a new file descriptor structure and initialize its port cells
with PORT and CTTY. (This does not affect the descriptor table.) */
extern struct hurd_fd *_hurd_new_fd (io_t port, io_t ctty);
/* Close a file descriptor, making it available for future reallocation. */
extern error_t _hurd_fd_close (struct hurd_fd *fd);
/* Read and write data from a file descriptor; just like `read' and `write'.
If successful, stores the amount actually read or written in *NBYTES. */
extern error_t _hurd_fd_read (struct hurd_fd *fd, void *buf, size_t *nbytes);
extern error_t _hurd_fd_write (struct hurd_fd *fd,
const void *buf, size_t *nbytes);
/* Call *RPC on PORT and/or CTTY; if a call on CTTY returns EBACKGROUND,
generate SIGTTIN/SIGTTOU or EIO as appropriate. */
extern error_t _hurd_ctty_input (io_t port, io_t ctty, error_t (*rpc) (io_t));
extern error_t _hurd_ctty_output (io_t port, io_t ctty, error_t (*rpc) (io_t));
#endif /* hurd/fd.h */
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