/*
 * Copyright (c) 2017 Contributors as noted in the AUTHORS file
 *
 * This file is part of Solo5, a sandboxed execution environment.
 *
 * Permission to use, copy, modify, and/or distribute this software
 * for any purpose with or without fee is hereby granted, provided
 * that the above copyright notice and this permission notice appear
 * in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
 * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
 * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef MUEN_CHANNEL_H
#define MUEN_CHANNEL_H

#include <stdint.h>
#include <stdbool.h>

/*
 * Muen shared memory channels.
 *
 * Muen shared memory channels are an implementation of the SHMStream Version 2
 * IPC protocol (shmstream) as specified by 'SHMStream Version 2 IPC Interface'.
 */

#define SHMSTREAM20     0x487312b6b79a9b6dULL
#define MUCHANNEL_NULL_EPOCH    0

struct muchannel_header {
    uint64_t transport;
    uint64_t epoch;
    uint64_t protocol;
    uint64_t size;
    uint64_t elements;
    uint64_t __reserved;
    uint64_t wsc;
    uint64_t wc;
} __attribute__((packed, aligned(8)));

struct muchannel {
    struct muchannel_header hdr;
    char data[];
};

/*
 * Returns True if the channe is currently active.
 */
bool muen_channel_is_active(const struct muchannel * const channel);

#endif