使用环形队列实现串口收发
时间: 2023-12-27 10:03:50 浏览: 38
在串口通信中,使用环形队列可以很好地处理收发数据的缓存和流控。
环形队列是一种特殊的队列,它的存储空间是环形的,即队列的尾部指向队列的开头,可以循环利用队列的存储空间。在串口通信中,可以将收到的数据放入队列中,然后再从队列中取出数据发送出去。
以下是使用环形队列实现串口收发的示例代码:
```c++
#include <iostream>
#include <windows.h>
#define QUEUE_SIZE 1024
class CircularQueue {
public:
CircularQueue() {
head_ = 0;
tail_ = 0;
size_ = QUEUE_SIZE;
buffer_ = new char[size_];
}
~CircularQueue() {
delete[] buffer_;
}
bool is_empty() const {
return head_ == tail_;
}
bool is_full() const {
return (tail_ + 1) % size_ == head_;
}
int size() const {
return (tail_ - head_ + size_) % size_;
}
bool push(char data) {
if (is_full()) {
return false;
} else {
buffer_[tail_] = data;
tail_ = (tail_ + 1) % size_;
return true;
}
}
bool pop(char& data) {
if (is_empty()) {
return false;
} else {
data = buffer_[head_];
head_ = (head_ + 1) % size_;
return true;
}
}
private:
char* buffer_;
int head_;
int tail_;
int size_;
};
int main() {
HANDLE hcom = CreateFile("COM1", GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);
if (hcom == INVALID_HANDLE_VALUE) {
std::cerr << "failed to open COM1\n";
return 1;
}
DCB dcb = { 0 };
dcb.DCBlength = sizeof(DCB);
if (!GetCommState(hcom, &dcb)) {
std::cerr << "failed to get comm state\n";
CloseHandle(hcom);
return 1;
}
dcb.BaudRate = 9600;
dcb.ByteSize = 8;
dcb.Parity = NOPARITY;
dcb.StopBits = ONESTOPBIT;
if (!SetCommState(hcom, &dcb)) {
std::cerr << "failed to set comm state\n";
CloseHandle(hcom);
return 1;
}
COMMTIMEOUTS timeouts = { 0 };
timeouts.ReadIntervalTimeout = MAXDWORD;
timeouts.ReadTotalTimeoutMultiplier = MAXDWORD;
timeouts.ReadTotalTimeoutConstant = 1000;
timeouts.WriteTotalTimeoutMultiplier = 0;
timeouts.WriteTotalTimeoutConstant = 1000;
if (!SetCommTimeouts(hcom, &timeouts)) {
std::cerr << "failed to set comm timeouts\n";
CloseHandle(hcom);
return 1;
}
CircularQueue queue;
while (true) {
char buf[1024];
DWORD nread = 0;
if (ReadFile(hcom, buf, sizeof(buf), &nread, NULL)) {
for (DWORD i = 0; i < nread; i++) {
if (!queue.push(buf[i])) {
std::cerr << "queue full\n";
}
}
} else {
std::cerr << "read error\n";
}
char data;
while (queue.pop(data)) {
DWORD nwrite = 0;
if (!WriteFile(hcom, &data, 1, &nwrite, NULL)) {
std::cerr << "write error\n";
}
}
}
CloseHandle(hcom);
return 0;
}
```
该代码使用 Windows API 实现串口通信,使用 CircularQueue 类实现环形队列。在主循环中,不断从串口读取数据,并将数据放入环形队列中;同时,从环形队列中读取数据,并将数据发送到串口中。
需要注意的是,在实际应用中,可能需要更加完善的错误处理和流控机制,以确保数据的正确传输。