C++ Socket庫實(shí)現(xiàn)連接超時(shí)重試

在C++中，我們可以使用<sys/socket.h>和<netinet/in.h>庫來實(shí)現(xiàn)一個(gè)帶有超時(shí)重試功能的Socket客戶端。以下是一個(gè)簡單的示例，展示了如何實(shí)現(xiàn)連接超時(shí)重試功能：

#include <iostream>
#include <cstring>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <chrono>
#include <thread>

const int MAX_RETRIES = 5;
const int RETRY_DELAY = 2; // seconds
const std::string SERVER_IP = "127.0.0.1";
const int SERVER_PORT = 8080;

bool connect_with_retry(int retries) {
    int sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) {
        std::cerr << "Error creating socket" << std::endl;
        return false;
    }

    struct sockaddr_in server_addr;
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(SERVER_PORT);
    inet_pton(AF_INET, SERVER_IP.c_str(), &server_addr.sin_addr);

    for (int i = 0; i < retries; ++i) {
        if (connect(sockfd, (struct sockaddr*)&server_addr, sizeof(server_addr)) == 0) {
            std::cout << "Connected to server successfully" << std::endl;
            return true;
        } else {
            std::cerr << "Connection failed, retrying in " << RETRY_DELAY << " seconds..." << std::endl;
            std::this_thread::sleep_for(std::chrono::seconds(RETRY_DELAY));
        }
    }

    std::cerr << "Failed to connect to server after " << retries << " retries" << std::endl;
    close(sockfd);
    return false;
}

int main() {
    if (connect_with_retry(MAX_RETRIES)) {
        // Perform the rest of your communication here
        close(sockfd);
    } else {
        std::cerr << "Failed to connect to server" << std::endl;
    }

    return 0;
}

在這個(gè)示例中，我們定義了一個(gè)connect_with_retry函數(shù)，它嘗試連接到指定的服務(wù)器和端口。如果連接失敗，它將等待一段時(shí)間然后重試，直到達(dá)到最大重試次數(shù)。如果所有嘗試都失敗了，函數(shù)將返回false。

請注意，這個(gè)示例僅用于演示目的，實(shí)際應(yīng)用中可能需要根據(jù)具體需求進(jìn)行調(diào)整。例如，你可能需要設(shè)置不同的超時(shí)時(shí)間、重試次數(shù)限制以及錯(cuò)誤處理策略。