include/nucleus/pipe.h

/*
 * @note Copyright (C) 2001,2002,2003 Philippe Gerum.
 *
 * Xenomai is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA
 * 02139, USA; either version 2 of the License, or (at your option)
 * any later version.
 *
 * Xenomai 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
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#ifndef _XENO_NUCLEUS_PIPE_H
#define _XENO_NUCLEUS_PIPE_H

#define XNPIPE_NDEVS      CONFIG_XENO_OPT_PIPE_NRDEV
#define XNPIPE_DEV_MAJOR  150

#define XNPIPE_IOCTL_BASE     'p'
#define XNPIPEIOC_GET_NRDEV   _IOW(XNPIPE_IOCTL_BASE,0,int)
#define XNPIPEIOC_FLUSH       _IO(XNPIPE_IOCTL_BASE,1)
#define XNPIPEIOC_SETSIG      _IO(XNPIPE_IOCTL_BASE,2)

#define XNPIPE_NORMAL  0x0
#define XNPIPE_URGENT  0x1

#define XNPIPE_IFLUSH  0x1
#define XNPIPE_OFLUSH  0x2

#define XNPIPE_MINOR_AUTO  -1

#ifdef __KERNEL__

#include <nucleus/queue.h>
#include <nucleus/synch.h>
#include <nucleus/thread.h>
#include <linux/types.h>
#include <linux/poll.h>

#define XNPIPE_KERN_CONN         0x1
#define XNPIPE_USER_CONN         0x2
#define XNPIPE_USER_SIGIO        0x4
#define XNPIPE_USER_WREAD        0x8
#define XNPIPE_USER_WREAD_READY  0x10
#define XNPIPE_USER_WSYNC        0x20
#define XNPIPE_USER_WSYNC_READY  0x40

#define XNPIPE_USER_ALL_WAIT \
(XNPIPE_USER_WREAD|XNPIPE_USER_WSYNC)

#define XNPIPE_USER_ALL_READY \
(XNPIPE_USER_WREAD_READY|XNPIPE_USER_WSYNC_READY)

typedef struct xnpipe_mh {

        xnholder_t link;
        unsigned size;
        unsigned rdoff;

} xnpipe_mh_t;

static inline xnpipe_mh_t *link2mh(xnholder_t *ln)
{
        return ln ? container_of(ln, xnpipe_mh_t, link) : NULL;
}

typedef int xnpipe_io_handler (int minor,
                               struct xnpipe_mh *mh, int retval, void *cookie);

typedef int xnpipe_session_handler (int minor, void *cookie);

typedef void *xnpipe_alloc_handler (int minor, size_t size, void *cookie);

typedef struct xnpipe_state {

        xnholder_t slink;       /* Link on sleep queue */
        xnholder_t alink;       /* Link on async queue */
#define link2xnpipe(ln, fld)    container_of(ln, xnpipe_state_t, fld)

        xnqueue_t inq;          /* From user-space to kernel */
        xnqueue_t outq;         /* From kernel to user-space */
        xnpipe_io_handler *output_handler;
        xnpipe_io_handler *input_handler;
        xnpipe_alloc_handler *alloc_handler;
        xnsynch_t synchbase;
        void *cookie;

        /* Linux kernel part */
        xnflags_t status;
        struct fasync_struct *asyncq;
        wait_queue_head_t readq;        /* open/read/poll waiters */
        wait_queue_head_t syncq;        /* sync waiters */
        size_t ionrd;

} xnpipe_state_t;

extern xnpipe_state_t xnpipe_states[];

#define xnminor_from_state(s) (s - xnpipe_states)

#ifdef __cplusplus
extern "C" {
#endif                          /* __cplusplus */

int xnpipe_mount(void);

void xnpipe_umount(void);

/* Entry points of the kernel interface. */

void xnpipe_setup(xnpipe_session_handler *open_handler,
                  xnpipe_session_handler *close_handler);

int xnpipe_connect(int minor,
                   xnpipe_io_handler *output_handler,
                   xnpipe_io_handler *input_handler,
                   xnpipe_alloc_handler *alloc_handler, void *cookie);

int xnpipe_disconnect(int minor);

ssize_t xnpipe_send(int minor,
                    struct xnpipe_mh *mh, size_t size, int flags);

ssize_t xnpipe_mfixup(int minor, struct xnpipe_mh *mh, ssize_t size);

ssize_t xnpipe_recv(int minor,
                    struct xnpipe_mh **pmh, xnticks_t timeout);

int xnpipe_inquire(int minor);

int xnpipe_flush(int minor, int mode);

#ifdef __cplusplus
}
#endif /* __cplusplus */

static inline xnholder_t *xnpipe_m_link(xnpipe_mh_t *mh)
{
        return &mh->link;
}

static inline char *xnpipe_m_data(xnpipe_mh_t *mh)
{
        return (char *)(mh + 1);
}

#define xnpipe_m_size(mh) ((mh)->size)

#define xnpipe_m_rdoff(mh) ((mh)->rdoff)

#endif /* __KERNEL__ */

#endif /* !_XENO_NUCLEUS_PIPE_H */

---