线程间通信和进程间通信

线程间通信

#include <iostream>
#include <thread>
#include <queue>
#include <mutex>
#include <condition_variable>
#include <chrono>// 全局变量
std::queue<int> data_queue;
std::mutex mtx;
std::condition_variable cv_data; // 当队列有数据时，通知消费者
std::condition_variable cv_stop; // 当生产者停止时，通知消费者
bool stop = false;std::thread::id getCurrentThreadId() {return std::this_thread::get_id();
}// 生产者线程
void producer() {for (int i = 0; i < 10; ++i) {std::this_thread::sleep_for(std::chrono::milliseconds(100)); // 模拟耗时操作std::lock_guard<std::mutex> lock(mtx);data_queue.push(i);std::cout << "threadid:"<< getCurrentThreadId() << " Produced: " << i << std::endl;cv_data.notify_one(); // 通知消费者有新数据}// 通知消费者停止{std::lock_guard<std::mutex> lock(mtx);stop = true;}cv_stop.notify_one();
}// 消费者线程
void consumer() {while (true) {std::unique_lock<std::mutex> lock(mtx);// 等待数据或停止信号cv_data.wait(lock, []{ return !data_queue.empty() || stop; });if (stop && data_queue.empty()) {// 收到停止信号且队列为空，则退出break;}int value = data_queue.front();data_queue.pop();lock.unlock(); // 解锁以允许其他线程访问队列std::cout<< "threadid:"<< getCurrentThreadId() << " Consumed: " << value << std::endl;// 模拟处理数据的时间std::this_thread::sleep_for(std::chrono::milliseconds(200));}
}int main() {std::thread producer_thread(producer);std::thread consumer_thread(consumer);producer_thread.join();consumer_thread.join();std::cout << "All tasks completed." << std::endl;return 0;
}

进程间通信

使用POSIX命名管道（也称为FIFO）在Unix/Linux环境下实现进程间通信的简单示例

生产者

#include <iostream>
#include <fstream>
#include <cstring>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>// 封装函数，返回当前进程的PID
pid_t get_current_process_id() {return getpid();
}int main() {const char* fifo_name = "/tmp/my_fifo";// 创建FIFO，如果已存在则不创建mkfifo(fifo_name, 0666);// 打开FIFO以写入数据int fd = open(fifo_name, O_WRONLY);if (fd == -1) {perror("open");return 1;}const char* data = "Hello from producer!";ssize_t num_bytes = write(fd, data, strlen(data) + 1); // 包含字符串结束符'\0'if (num_bytes == -1) {perror("write");return 1;}close(fd);std::cout <<"Current process ID:"<< get_current_process_id() << "  Data written to FIFO." << std::endl;return 0;
}

消费者

#include <iostream>
#include <fstream>
#include <cstring>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
// 封装函数，返回当前进程的PID
pid_t get_current_process_id() {return getpid();
}int main() {const char* fifo_name = "/tmp/my_fifo";// 打开FIFO以读取数据int fd = open(fifo_name, O_RDONLY);if (fd == -1) {perror("open");return 1;}char buffer[256];ssize_t num_bytes = read(fd, buffer, sizeof(buffer) - 1); // 保留一个位置给'\0'if (num_bytes == -1) {perror("read");return 1;}buffer[num_bytes] = '\0'; // 添加字符串结束符close(fd);std::cout <<"Current process ID:"<< get_current_process_id()<< "  Data read from FIFO: " << buffer << std::endl;return 0;
}