linux send 阻塞

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>

int main() {
    int socket_fd = socket(AF_INET, SOCK_STREAM, 0);
    if (socket_fd < 0) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    // 设置非阻塞模式
    int flags = fcntl(socket_fd, F_GETFL, 0);
    fcntl(socket_fd, F_SETFL, flags | O_NONBLOCK);

    struct sockaddr_in server_addr;
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(8080);
    server_addr.sin_addr.s_addr = inet_addr("127.0.0.1");

    if (connect(socket_fd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
        perror("connect");
        exit(EXIT_FAILURE);
    }

    const char *message = "Hello, World!";
    ssize_t bytes_sent;
    while ((bytes_sent = send(socket_fd, message, strlen(message), 0)) < 0) {
        if (errno == EAGAIN || errno == EWOULDBLOCK) {
            printf("Send buffer is full, retrying...\n");
            usleep(1000); // 等待1ms后重试
            continue;
        } else {
            perror("send");
            exit(EXIT_FAILURE);
        }
    }

    printf("Sent %zd bytes\n", bytes_sent);
    close(socket_fd);
    return 0;
}