使用C语言分别实现一下这两种方式-DPDK中文网

下面是使用 C 语言分别实现 TCP 客户端的阻塞式接收和非阻塞式接收的示例代码。

1. 阻塞式接收

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>

#define PORT 8080
#define BUFFER_SIZE 1024

int main() {
    int sock;
    struct sockaddr_in server_addr;
    char buffer[BUFFER_SIZE];

    // 创建 socket
    if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
        perror("Socket creation failed");
        exit(EXIT_FAILURE);
    }

    // 设置服务器地址
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(PORT);
    
    // 将IPv4地址从文本转换为二进制形式
    if (inet_pton(AF_INET, "127.0.0.1", &server_addr.sin_addr) <= 0) {
        perror("Invalid address / Address not supported");
        exit(EXIT_FAILURE);
    }

    // 与服务器连接
    if (connect(sock, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
        perror("Connection failed");
        exit(EXIT_FAILURE);
    }

    // 阻塞式接收数据
    while (1) {
        ssize_t bytes_received = recv(sock, buffer, BUFFER_SIZE - 1, 0);
        
        if (bytes_received < 0) {
            perror("Receive failed");
            break;
        } else if (bytes_received == 0) {
            printf("Server closed the connection.\n");
            break;
        }
        
        buffer[bytes_received] = '\0'; // null-terminate the string
        printf("Received: %s\n", buffer);
    }

    close(sock);
    return 0;
}

2. 非阻塞式接收

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <fcntl.h> // for fcntl()
#include <errno.h>

#define PORT 8080
#define BUFFER_SIZE 1024

int main() {
    int sock;
    struct sockaddr_in server_addr;
    
     char buffer[BUFFER_SIZE];

   // 创建 socket 
   if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) { 
      perror("Socket creation failed"); 
      exit(EXIT_FAILURE); 
   }
  
   // 设置服务器地址 
   memset(&server_addr, 0, sizeof(server_addr)); 
   server_addr.sin_family = AF_INET; 
   server_addr.sin_port = htons(PORT);

   // 将IPv4地址从文本转换为二进制形式 
   if(inet_pton(AF_INET,"127.0.0.1",&server_addr.sin_addr)<=0){  
      perror("Invalid address / Address not supported"); 
      exit(EXIT_FAILURE); 
   }
   
   // 与服务器连接 
   if(connect(sock,(struct sockaddr*)&server_addr,sizeof(server_addr))<0){  
       perror("Connection failed");  
       exit(EXIT_FAILURE);  
   }
   
   // 设置socket为非阻塞模式
   int flags = fcntl(sock, F_GETFL, 0);
   fcntl(sock, F_SETFL, flags | O_NONBLOCK);

   while (1) {     
       ssize_t bytes_received = recv(sock, buffer, BUFFER_SIZE - 1 ,MSG_DONTWAIT); 
        
       if (bytes_received > 0) {         
           buffer[bytes_received] = '\0';         
           printf("Received: %s\n", buffer);     
       } else if (bytes_received == -1 && errno != EAGAIN && errno != EWOULDBLOCK) {          
           perror("Receive failed");       
           break;      
       } 

       usleep(100000); // Sleep for a short duration to avoid busy waiting
   }

   close(sock);   
}