滑动窗口协议的模拟C++
时间: 2023-07-19 12:33:28 浏览: 70
好的,以下是一个简单的滑动窗口协议的模拟 C++ 代码:
```
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <ctime>
#define WINDOW_SIZE 4 // 滑动窗口大小
#define FRAME_SIZE 20 // 帧大小
using namespace std;
struct frame {
int seq_num; // 序列号
char data[FRAME_SIZE]; // 数据
};
int main() {
int i, j, k;
int ack_num, send_base, next_frame_to_send, frame_expected;
frame sending_window[WINDOW_SIZE], current_frame;
ack_num = send_base = next_frame_to_send = frame_expected = 0;
// 模拟发送端
for (i = 0; i < 8; i++) { // 发送 8 个帧
// 构造当前帧
current_frame.seq_num = next_frame_to_send;
for (j = 0; j < FRAME_SIZE; j++) {
current_frame.data[j] = 'a' + next_frame_to_send % 26;
}
cout << "发送帧 " << current_frame.seq_num << endl;
// 把当前帧放入发送窗口
sending_window[next_frame_to_send % WINDOW_SIZE] = current_frame;
next_frame_to_send++;
// 发送窗口已满,等待 ACK
if (next_frame_to_send == send_base + WINDOW_SIZE) {
cout << "发送窗口已满,等待 ACK..." << endl;
// 等待 ACK
while (ack_num < next_frame_to_send) {
cout << "等待 ACK " << ack_num << endl;
// 接收到 ACK
if (ack_num == frame_expected) {
cout << "接收到 ACK " << ack_num << endl;
send_base++;
frame_expected++;
}
ack_num++;
}
}
}
// 模拟接收端
srand(time(NULL));
for (k = 0; k < 8; k++) { // 接收 8 个帧
// 模拟丢失帧
if (rand() % 10 < 3) {
cout << "丢失帧 " << frame_expected << endl;
} else {
// 接收到正确的帧
cout << "接收到帧 " << frame_expected << endl;
ack_num = frame_expected;
// 发送 ACK
if (rand() % 10 >= 3) {
cout << "发送 ACK " << ack_num << endl;
frame_expected++;
}
}
}
return 0;
}
```
该代码与前面的 C 语言代码相似,不同之处在于使用了 C++ 的输入输出流和字符串处理函数。注意,该代码仅供参考,实际使用时应该根据具体需求进行修改和优化。