Archipelago » qemu

/*

 * Generic FIFO component, implemented as a circular buffer.

 *

 * Copyright (c) 2012 Peter A. G. Crosthwaite

 *

 * This program 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.

 *

 * You should have received a copy of the GNU General Public License along

 * with this program; if not, see <http://www.gnu.org/licenses/>.

 */

#include "qemu-common.h"

#include "qemu/fifo8.h"

void fifo8_create(Fifo8 *fifo, uint32_t capacity)

{

    fifo->data = g_new(uint8_t, capacity);

    fifo->capacity = capacity;

    fifo->head = 0;

    fifo->num = 0;

}

void fifo8_destroy(Fifo8 *fifo)

{

    g_free(fifo->data);

}

void fifo8_push(Fifo8 *fifo, uint8_t data)

{

    if (fifo->num == fifo->capacity) {

        abort();

    }

    fifo->data[(fifo->head + fifo->num) % fifo->capacity] = data;

    fifo->num++;

}

uint8_t fifo8_pop(Fifo8 *fifo)

{

    uint8_t ret;

    if (fifo->num == 0) {

        abort();

    }

    ret = fifo->data[fifo->head++];

    fifo->head %= fifo->capacity;

    fifo->num--;

    return ret;

}

void fifo8_reset(Fifo8 *fifo)

{

    fifo->num = 0;

}

bool fifo8_is_empty(Fifo8 *fifo)

{

    return (fifo->num == 0);

}

bool fifo8_is_full(Fifo8 *fifo)

{

    return (fifo->num == fifo->capacity);

}

const VMStateDescription vmstate_fifo8 = {

    .name = "Fifo8",

    .version_id = 1,

    .minimum_version_id = 1,

    .minimum_version_id_old = 1,

    .fields      = (VMStateField[]) {

        VMSTATE_VBUFFER_UINT32(data, Fifo8, 1, NULL, 0, capacity),

        VMSTATE_UINT32(head, Fifo8),

        VMSTATE_UINT32(num, Fifo8),

        VMSTATE_END_OF_LIST()

    }

};