Update tcpsendpacket.c

1 files changed, 22 insertions, 15 deletions

diff --git a/examples/network/tcpsendpacket.c b/examples/network/tcpsendpacket.c
index 75134c19a2..462de6000d 100644
--- a/examples/network/tcpsendpacket.c
+++ b/examples/network/tcpsendpacket.c
@@ -1,7 +1,7 @@
 #include <rtthread.h>
 
-#include <netdb.h>   /* Ϊ�˽�������������Ҫ����netdb.hͷ�ļ� */
-#include <sys/socket.h> /* ʹ��BSD socket����Ҫ����socket.hͷ�ļ� */
+#include <netdb.h>   /* 为了解析主机名，需要包含netdb.h头文件 */
+#include <sys/socket.h> /* 使用BSD socket，需要包含socket.h头文件 */
 
 void tcp_senddata(const char *url, int port, int length)
 {
@@ -10,45 +10,52 @@ void tcp_senddata(const char *url, int port, int length)
     struct sockaddr_in server_addr;
     rt_uint8_t *buffer_ptr;
 
-    /* ͨ��������ڲ���url���host��ַ��������������������������� */
+    /* 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） */
     host = gethostbyname(url);
-    /* ����һ��socket��������SOCKET_STREAM��TCP���� */
+    /* 创建一个socket，类型是SOCKET_STREAM，TCP类型 */
     if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1)
     {
-        /* ����socketʧ�� */
+        /* 创建socket失败 */
         rt_kprintf("Socket error\n");
         return;
     }
 
-    /* �����ڴ� */
+    /* 申请内存 */
     buffer_ptr = rt_malloc(length);
-    /* ���췢������ */
+    if(RT_NULL == buffer_ptr)
+    {
+        /* 申请内存失败 */
+        rt_kprintf("Not enough memory\n");
+        return;        
+    }
+    
+    /* 构造发送数据 */
     for (index = 0; index < length; index ++)
         buffer_ptr[index] = index & 0xff;
 
     timeout = 100;
-    /* ���÷��ͳ�ʱʱ��100ms */
+    /* 设置发送超时时间100ms */
     setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, &timeout, sizeof(timeout));
-    /* ��ʼ��Ԥ���ӵķ���˵�ַ */
+    /* 初始化预连接的服务端地址 */
     server_addr.sin_family = AF_INET;
     server_addr.sin_port = htons(port);
     server_addr.sin_addr = *((struct in_addr *)host->h_addr);
     rt_memset(&(server_addr.sin_zero), 0, sizeof(server_addr.sin_zero));
 
-    /* ���ӵ������ */
+    /* 连接到服务端 */
     err = connect(sock, (struct sockaddr *)&server_addr, sizeof(struct sockaddr));
     rt_kprintf("TCP thread connect error code: %d\n", err);
 
     while (1)
     {
-        /* �������ݵ�sock���� */
+        /* 发送数据到sock连接 */
         result = send(sock, buffer_ptr, length, MSG_DONTWAIT);
-        if (result < 0) //���ݷ��ʹ�����
+        if (result < 0) //数据发送错误处理
         {
             rt_kprintf("TCP thread send error: %d\n", result);
             closesocket(sock);
 
-            /* �ر����ӣ����´������� */
+            /* 关闭连接，重新创建连接 */
             rt_thread_delay(10);
 
             if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1)
@@ -59,7 +66,7 @@ void tcp_senddata(const char *url, int port, int length)
         }
         else if (result == 0)
         {
-            /* ��ӡsend��������ֵΪ0�ľ�����Ϣ */
+            /* 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");
         }
     }
@@ -67,7 +74,7 @@ void tcp_senddata(const char *url, int port, int length)
 
 #ifdef RT_USING_FINSH
 #include <finsh.h>
-/* ���tcpclient������finsh shell�� */
+/* 输出tcpclient函数到finsh shell中 */
 FINSH_FUNCTION_EXPORT(tcp_senddata, send a packet through tcp connection);
 #endif