c语言四个线程同时向一个串口发送数据,然后等待串口回复
时间: 2023-09-23 19:03:49 浏览: 138
实现四个线程同时向一个串口发送数据,并等待串口的回复,可以采用多线程和消息队列的方式。下面是一个简单的实现示例:
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <pthread.h>
#include <unistd.h>
#include "SerialPort.h"
#define MAX_MSG_LEN 1024
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
struct Msg {
int id;
char data[MAX_MSG_LEN];
};
struct ThreadArgs {
int id;
char* data;
SerialPort* port;
};
bool running = true;
pthread_t threads[4];
pthread_t recvThread;
SerialPort* port;
void* sendThread(void* arg) {
struct ThreadArgs* threadArgs = (struct ThreadArgs*)arg;
int id = threadArgs->id;
char* data = threadArgs->data;
SerialPort* port = threadArgs->port;
while (running) {
// 发送数据
printf("Thread %d sending data: %s\n", id, data);
port->write(data);
// 等待回复
pthread_mutex_lock(&mutex);
pthread_cond_wait(&cond, &mutex);
pthread_mutex_unlock(&mutex);
}
return NULL;
}
void* recvThreadFunc(void* arg) {
while (running) {
// 读取数据
char buff[MAX_MSG_LEN];
int n = port->read(buff, MAX_MSG_LEN);
if (n > 0) {
printf("Received data: %s\n", buff);
// 发送信号通知等待的线程
pthread_cond_signal(&cond);
}
}
return NULL;
}
int main() {
// 打开串口
port = new SerialPort("/dev/ttyUSB0", 9600);
port->open();
// 创建发送线程
struct ThreadArgs threadArgs[4];
char* data[4] = { "Thread1", "Thread2", "Thread3", "Thread4" };
for (int i = 0; i < 4; i++) {
threadArgs[i].id = i + 1;
threadArgs[i].data = data[i];
threadArgs[i].port = port;
pthread_create(&threads[i], NULL, sendThread, &threadArgs[i]);
}
// 创建接收线程
pthread_create(&recvThread, NULL, recvThreadFunc, NULL);
// 等待所有线程退出
for (int i = 0; i < 4; i++) {
pthread_join(threads[i], NULL);
}
pthread_join(recvThread, NULL);
// 关闭串口
port->close();
delete port;
return 0;
}
```
在上面的示例代码中,我们创建了四个发送线程和一个接收线程。每个发送线程都会向串口发送一个字符串,并等待串口的回复。接收线程不断地从串口读取数据,并判断是否有数据到达。如果有数据到达,则发送一个条件变量通知等待的线程。
需要注意的是,为了避免竞争和死锁,我们在等待串口回复时需要使用条件变量来进行同步。当串口接收到数据时,只有一个等待的线程能够被唤醒,其他线程会继续等待。