Complete some error handling when send or receive function returns a value is zero.

examples/network/tcpclient.c

@@ -10,6 +10,7 @@ void tcpclient(const char* url, int port)
     char *recv_data;
     struct hostent *host;
     int sock, bytes_received;
+	int ret;
     struct sockaddr_in server_addr;
 
     /* 通过函数入口参数url获得host地址（如果是域名，会做域名解析） */
@@ -56,15 +57,19 @@ void tcpclient(const char* url, int port)
     {
         /* 从sock连接中接收最大BUFSZ - 1字节数据 */
         bytes_received = recv(sock, recv_data, BUFSZ - 1, 0);
-        if (bytes_received <= 0)
+        if (bytes_received < 0)
         {
             /* 接收失败，关闭这个连接 */
             lwip_close(sock);
-
+            rt_kprintf("\nreceived error,close the socket.\r\n");	
             /* 释放接收缓冲 */
             rt_free(recv_data);
             break;
-        }
+        }else if (bytes_received == 0)
+		{
+			/* 打印recv函数返回值为0的警告信息 */
+            rt_kprintf("\nReceived warning,recv function return 0.\r\n");						
+		}
 
         /* 有接收到数据，把末端清零 */
         recv_data[bytes_received] = '\0';
@@ -73,7 +78,7 @@ void tcpclient(const char* url, int port)
         {
             /* 如果是首字母是q或Q，关闭这个连接 */
             lwip_close(sock);
-
+            rt_kprintf("\n got a 'q' or 'Q',close the socket.\r\n");	
             /* 释放接收缓冲 */
             rt_free(recv_data);
             break;
@@ -85,7 +90,18 @@ void tcpclient(const char* url, int port)
         }
 
         /* 发送数据到sock连接 */
-        send(sock,send_data,strlen(send_data), 0);
+        ret = send(sock,send_data,strlen(send_data), 0);
+		if (ret < 0)
+        {
+            /* 接收失败，关闭这个连接 */
+            lwip_close(sock);
+            rt_kprintf("\nsend error,close the socket.\r\n");		
+            break;
+        }else if (ret == 0)
+		{
+			/* 打印send函数返回值为0的警告信息 */
+            rt_kprintf("\n Send warning,send function return 0.\r\n");						
+		}		
     }
 
     return;

examples/network/tcpsendpacket.c

@@ -51,6 +51,10 @@ void tcp_senddata(const char* url, int port, int length)
 				rt_kprintf("TCP Socket error:%d\n",sock);
 			err = connect(sock, (struct sockaddr *)&server_addr, sizeof(struct sockaddr));
 			rt_kprintf("TCP thread connect error code: %d\n", err);
+		}else if (result == 0)
+		{
+			/* 打印send函数返回值为0的警告信息 */
+            rt_kprintf("\n Send warning,send function return 0.\r\n");						
 		}	
 	}
 }

examples/network/tcpserver.c

@@ -9,6 +9,7 @@ void tcpserv(void* parameter)
    int sock, connected, bytes_received;
    struct sockaddr_in server_addr, client_addr;
    rt_bool_t stop = RT_FALSE; /* 停止标志 */
+   int ret;
 
    recv_data = rt_malloc(1024); /* 分配接收用的数据缓冲 */
    if (recv_data == RT_NULL)
@@ -72,16 +73,31 @@ void tcpserv(void* parameter)
        while (1)
        {
            /* 发送数据到connected socket */
-           send(connected, send_data, strlen(send_data), 0);
+           ret = send(connected, send_data, strlen(send_data), 0);
+		   if (ret < 0)
+		   {
+				/* 接收失败，关闭这个连接 */
+				lwip_close(sock);
+				rt_kprintf("\nsend error,close the socket.\r\n");		
+				break;
+		   }else if (ret == 0)
+		   {
+				/* 打印send函数返回值为0的警告信息 */
+				rt_kprintf("\n Send warning,send function return 0.\r\n");						
+		   }		
 		   
            /* 从connected socket中接收数据，接收buffer是1024大小，但并不一定能够收到1024大小的数据 */
            bytes_received = recv(connected,recv_data, 1024, 0);
-           if (bytes_received <= 0)
+           if (bytes_received < 0)
            {
                /* 接收失败，关闭这个connected socket */
                lwip_close(connected);
                break;
-           }
+           }else if (bytes_received == 0)
+		   {
+			   /* 打印recv函数返回值为0的警告信息 */
+			   rt_kprintf("\nReceived warning,recv function return 0.\r\n");						
+		   }
 
            /* 有接收到数据，把末端清零 */
            recv_data[bytes_received] = '\0';