registry.h

/*
 * Copyright (C) 2004 Philippe Gerum <rpm@xenomai.org>
 *
 * 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; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program 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 _COBALT_KERNEL_REGISTRY_H
#define _COBALT_KERNEL_REGISTRY_H

#include <cobalt/kernel/list.h>
#include <cobalt/kernel/synch.h>
#include <cobalt/kernel/vfile.h>

struct xnpnode;

struct xnobject {
        void *objaddr;
        const char *key;          /* !< Hash key. May be NULL if anonynous. */
        unsigned long cstamp;             /* !< Creation stamp. */
#ifdef CONFIG_XENO_OPT_VFILE
        struct xnpnode *pnode;  /* !< v-file information class. */
        union {
                struct {
                        struct xnvfile_rev_tag tag;
                        struct xnvfile_snapshot file;
                } vfsnap; /* !< virtual snapshot file. */
                struct xnvfile_regular vfreg; /* !< virtual regular file */
                struct xnvfile_link link;     /* !< virtual link. */
        } vfile_u;
        struct xnvfile *vfilp;
#endif /* CONFIG_XENO_OPT_VFILE */
        struct hlist_node hlink; /* !< Link in h-table */
        struct list_head link;
};

int xnregistry_init(void);

void xnregistry_cleanup(void);

#ifdef CONFIG_XENO_OPT_VFILE

#define XNOBJECT_PNODE_RESERVED1 ((struct xnvfile *)1)
#define XNOBJECT_PNODE_RESERVED2 ((struct xnvfile *)2)

struct xnptree {
        const char *dirname;
        /* hidden */
        int entries;
        struct xnvfile_directory vdir;
};

#define DEFINE_XNPTREE(__var, __name)           \
        struct xnptree __var = {                \
                .dirname = __name,              \
                .entries = 0,                   \
                .vdir = xnvfile_nodir,          \
        }

struct xnpnode_ops {
        int (*export)(struct xnobject *object, struct xnpnode *pnode);
        void (*unexport)(struct xnobject *object, struct xnpnode *pnode);
        void (*touch)(struct xnobject *object);
};

struct xnpnode {
        const char *dirname;
        struct xnptree *root;
        struct xnpnode_ops *ops;
        /* hidden */
        int entries;
        struct xnvfile_directory vdir;
};

struct xnpnode_snapshot {
        struct xnpnode node;
        struct xnvfile_snapshot_template vfile;
};

struct xnpnode_regular {
        struct xnpnode node;
        struct xnvfile_regular_template vfile;
};

struct xnpnode_link {
        struct xnpnode node;
        char *(*target)(void *obj);
};

#else /* !CONFIG_XENO_OPT_VFILE */

#define DEFINE_XNPTREE(__var, __name);

/* Placeholders. */

struct xnpnode {
        const char *dirname;
};

struct xnpnode_snapshot {
        struct xnpnode node;
};

struct xnpnode_regular {
        struct xnpnode node;
};

struct xnpnode_link {
        struct xnpnode node;
};

#endif /* !CONFIG_XENO_OPT_VFILE */

/* Public interface. */

extern struct xnobject *registry_obj_slots;

static inline struct xnobject *xnregistry_validate(xnhandle_t handle)
{
        struct xnobject *object;
        /*
         * Careful: a removed object which is still in flight to be
         * unexported carries a NULL objaddr, so we have to check this
         * as well.
         */
        handle = xnhandle_get_index(handle);
        if (likely(handle && handle < CONFIG_XENO_OPT_REGISTRY_NRSLOTS)) {
                object = &registry_obj_slots[handle];
                return object->objaddr ? object : NULL;
        }

        return NULL;
}

static inline const char *xnregistry_key(xnhandle_t handle)
{
        struct xnobject *object = xnregistry_validate(handle);
        return object ? object->key : NULL;
}

int xnregistry_enter(const char *key,
                     void *objaddr,
                     xnhandle_t *phandle,
                     struct xnpnode *pnode);

static inline int
xnregistry_enter_anon(void *objaddr, xnhandle_t *phandle)
{
        return xnregistry_enter(NULL, objaddr, phandle, NULL);
}

int xnregistry_bind(const char *key,
                    xnticks_t timeout,
                    int timeout_mode,
                    xnhandle_t *phandle);

int xnregistry_remove(xnhandle_t handle);

static inline
void *xnregistry_lookup(xnhandle_t handle,
                        unsigned long *cstamp_r)
{
        struct xnobject *object = xnregistry_validate(handle);

        if (object == NULL)
                return NULL;

        if (cstamp_r)
                *cstamp_r = object->cstamp;

        return object->objaddr;
}

int xnregistry_unlink(const char *key);

unsigned xnregistry_hash_size(void);

extern struct xnpnode_ops xnregistry_vfsnap_ops;

extern struct xnpnode_ops xnregistry_vlink_ops;

#endif /* !_COBALT_KERNEL_REGISTRY_H */