在Linux环境下,C++可以通过多种方式实现进程间通信(IPC)。以下是一些常见的IPC机制:
管道(Pipes):
信号(Signals):
消息队列(Message Queues):
共享内存(Shared Memory):
信号量(Semaphores):
套接字(Sockets):
下面是使用这些IPC机制的一些基本示例:
#include <unistd.h>
#include <iostream>
int main() {
int pipefd[2];
char buffer[256];
// 创建管道
if (pipe(pipefd) == -1) {
perror("pipe");
return EXIT_FAILURE;
}
// 写入管道
const char* message = "Hello from pipe!";
write(pipefd[1], message, strlen(message) + 1);
// 从管道读取
read(pipefd[0], buffer, sizeof(buffer));
std::cout << "Message received: " << buffer << std::endl;
// 关闭管道
close(pipefd[0]);
close(pipefd[1]);
return EXIT_SUCCESS;
}
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <iostream>
int main() {
const char* fifo = "/tmp/myfifo";
// 创建命名管道
mkfifo(fifo, 0666);
// 打开命名管道进行写入
int fd = open(fifo, O_WRONLY);
if (fd == -1) {
perror("open");
return EXIT_FAILURE;
}
// 写入命名管道
const char* message = "Hello from FIFO!";
write(fd, message, strlen(message) + 1);
// 关闭命名管道
close(fd);
// 删除命名管道
unlink(fifo);
return EXIT_SUCCESS;
}
#include <sys/ipc.h>
#include <sys/shm.h>
#include <iostream>
#include <cstring>
int main() {
key_t key = ftok("shmfile", 65);
int shmid = shmget(key, 1024, 0666|IPC_CREAT);
char *str = (char*) shmat(shmid, (void*)0, 0);
strcpy(str, "Hello World");
std::cout << "String in shared memory: " << str << std::endl;
shmdt(str);
shmctl(shmid, IPC_RMID, NULL);
return 0;
}
#include <sys/ipc.h>
#include <sys/sem.h>
#include <iostream>
union semun {
int val;
struct semid_ds *buf;
unsigned short *array;
};
int main() {
key_t key = ftok("semfile", 65);
int semid = semget(key, 1, 0666|IPC_CREAT);
union semun arg;
arg.val = 1; // 初始化信号量为1
semctl(semid, 0, SETVAL, arg);
// 使用信号量进行同步操作
// ...
semctl(semid, 0, IPC_RMID);
return 0;
}
// 这里只给出一个简单的TCP套接字服务器示例
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <iostream>
#include <cstring>
int main() {
int server_fd, new_socket;
struct sockaddr_in address;
int opt = 1;
int addrlen = sizeof(address);
char buffer[1024] = {0};
// 创建套接字文件描述符
if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
perror("socket failed");
exit(EXIT_FAILURE);
}
// 绑定套接字到端口
address.sin_family = AF_INET;
address.sin_addr.s_addr = INADDR_ANY;
address.sin_port = htons(8080);
if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) {
perror("setsockopt");
exit(EXIT_FAILURE);
}
if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) {
perror("bind failed");
exit(EXIT_FAILURE);
}
if (listen(server_fd, 3) < 0) {
perror("listen");
exit(EXIT_FAILURE);
}
// 接受连接
if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t*)&addrlen)) < 0) {
perror("accept");
exit(EXIT_FAILURE);
}
// 读取数据
read(new_socket, buffer, 1024);
std::cout << "Message received: " << buffer << std::endl;
// 发送响应
send(new_socket, "Hello from server", 17, 0);
std::cout << "Hello message sent\n";
// 关闭套接字
close(new_socket);
close(server_fd);
return 0;
}
请注意,这些示例仅用于演示目的,实际应用中可能需要更复杂的错误检查和资源管理。在使用这些IPC机制时,还需要考虑同步和互斥的问题,以避免竞态条件和其他并发问题。