global_define.c

#include "global_define.h"
#include "multi_task.h"

/**
 * 初始化数据缓冲区
 * @param {structFIFO} *fifo
 * @param {int} size
 * @param {unsignedchar} *buf
 * @return {*}
 */
void fifo8_init(struct FIFO8 *fifo, int size, unsigned char *buf, struct TASK *task) {
    fifo->size = size;
    fifo->buf = buf;
    fifo->free = size;
    fifo->read = 0;
    fifo->write = 0;
    fifo->flags = 0;
    fifo->task = task;
    return;
}

#define FLAGS_OVERRUN 0x0001

/**
 * 写缓冲
 * @param {structFIFO8} *fifo 缓冲区结构体
 * @param {unsignedchar} data 要写的缓冲区数据
 * @return {*}
 */
int fifo8_put(struct FIFO8 *fifo, unsigned char data) {
    if (fifo == 0) return -1;

    if (fifo->free == 0) {
        fifo->flags |= FLAGS_OVERRUN;
        return -1;
    }
    fifo->buf[fifo->write] = data;
    fifo->write++;
    if (fifo->write >= fifo->size) {  //写指针满则从头部开始覆盖
        fifo->write = 0;
    }
    fifo->free--;
    //若一个进程的消息队列绑定了该进程，那么向消息队列中存放信息的时候就会唤醒该进程
    if (fifo->task != 0) {
        if (fifo->task->flags != 2) {
            task_run(fifo->task, -1, 0);
        }
    }
    return OK;
}

/**
 * 读缓冲
 * @param {structFIFO8} *fifo 缓冲区结构体
 * @return {*}
 */
int fifo8_get(struct FIFO8 *fifo) {
    int data;
    if (fifo->free == fifo->size) {
        return -1;
    }
    data = fifo->buf[fifo->read];
    fifo->read++;
    if (fifo->read >= fifo->size) {  //写指针满则从头部开始覆盖
        fifo->read = 0;
    }
    fifo->free++;
    return data;
}

/**
 * 判断缓冲区状态
 * @param {structFIFO8} *fifo
 * @return {*}
 */
int fifo8_status(struct FIFO8 *fifo) {
    return fifo->size - fifo->free;
}