学步园

    gettimeofday的man说明：

#include <sys/time.h><br /> int gettimeofday(struct timeval *tv, struct timezone *tz);<br /> int settimeofday(const struct timeval *tv , const struct timezone *tz);<br /> 结构timeval的定义为：<br /> strut timeval {long tv_sec; /* 秒数 */long tv_usec; /* 微秒数 */}; 

    可以看出，使用这种方式计时，精度可达微秒，也就是10-6秒。进行计时的时候，我们需要前后调用两次gettimeofday，然后计算中间的差值：以下是写的一个小函数，客户端发送一个8K的数据给服务器，利用gettimeofday函数判断一次发送所需要的时间，也就是send()函数的一次调用时间。下面分别给出客户端和服务端的代码，客户端是可以链接TCP和UDP的客户端。中文注释有问题，我懒，不弄了，函数大家都能看得懂的。socket编程基础代码。

/*****************************************************<br /> FileName: client.c<br /> Description: Íø·¿Í»§¶Ë³ÌÐò£¬¿ÉÒÔÁ¬œÓtcpºÍudp·þÎñÆ÷<br /> Author: wanxiao<br /> *****************************************************/<br /> #include <stdio.h><br /> #include <stdlib.h><br /> #include <unistd.h><br /> #include <sys/types.h><br /> #include <sys/socket.h><br /> #include <netinet/in.h><br /> #include <string.h><br /> #include <sys/time.h><br /> #define MAXDATASIZE (1024*8)</p> <p> /*ŽòÓ¡ÃüÁîÐвÎÊýÓ÷š*/<br /> void useage()<br /> {<br /> printf("Command Error - ./filename [tcp] [ip_address] [port]/n");<br /> printf(" ./filename [udp] [ip_address] [port]/n");<br /> exit(1);<br /> }</p> <p> /*************************************************<br /> Function: tcpclient<br /> Description: tcp¿Í»§¶Ë£¬Á¬œÓ³É¹Šºó·¢ËÍÐÅÏ¢žøtcp·þÎñÆ÷<br /> Input: ·þÎñÆ÷ipµØÖ·ip_address £¬·þÎñÆ÷¶Ë¿Úport (¶ŒÊÇcharÐÍ)<br /> Output: ÎÞ<br /> Return: ³É¹Š·µ»Ø0£»Ê§°Ü·µ»Ø-1<br /> *************************************************/<br /> int tcpclient(char *ip_address ,char *port)<br /> {<br /> printf("ipaddress :%s/n port :%s/n",ip_address,port);</p> <p> struct sockaddr_in server; /*serverÌלÓ×ÖµØÖ·œá¹¹*/<br /> int sockfd;<br /> int ret;<br /> int i_port = atoi(port); /*×Ö·ûŽ®×ª»»ÕûÐÍ*/<br /> char msgbuf[MAXDATASIZE];<br /> struct timeval start;<br /> struct timeval end;<br /> struct timezone tz;</p> <p> /*socket*/<br /> sockfd = socket(AF_INET, SOCK_STREAM , 0);<br /> if(sockfd < 0)<br /> {<br /> perror("data stream socket create failed!/n");<br /> return -1;<br /> } </p> <p> server.sin_family = AF_INET; /*ipv4*/<br /> i_port = atoi(port);<br /> server.sin_port = htons(i_port); /*°ó¶š¶Ë¿Ú*/</p> <p> /*°ó¶šipµØÖ·*/<br /> ret = inet_pton(AF_INET, ip_address, &server.sin_addr.s_addr);<br /> if (ret <= 0)<br /> {<br /> printf("your ip address is unvalide!/n");<br /> useage();<br /> } </p> <p> /*connect*/<br /> ret = connect(sockfd,(struct sockaddr*) &server,sizeof(struct sockaddr_in));<br /> if(ret < 0)<br /> {<br /> perror("data connection is failed!/n");<br /> return -1;<br /> } </p> <p> printf("connect to server successfully!/n");<br /> while(1)<br /> {<br /> memset(msgbuf, 0, sizeof(msgbuf));<br /> /*send message to server*/<br /> gettimeofday(&start, &tz);<br /> ret = send(sockfd, msgbuf, sizeof(msgbuf), 0);<br /> gettimeofday(&end, &tz);<br /> if(ret == -1)<br /> {<br /> perror("send error");<br /> return -1;<br /> }<br /> printf("The time between 'send' = %d u_secs/n",end.tv_usec-start.tv_usec);<br /> //printf("send message sucessfully!/n");<br /> }<br /> }</p> <p> /*************************************************<br /> Function: udpclient<br /> Description: udp¿Í»§¶Ë£¬Á¬œÓ³É¹Šºó·¢ËÍÐÅÏ¢žøudp·þÎñÆ÷<br /> Input: ·þÎñÆ÷ipµØÖ·ip_address £¬·þÎñÆ÷¶Ë¿Úport (¶ŒÊÇcharÐÍ)<br /> Output: ÎÞ<br /> Return: ³É¹Š·µ»Ø0£»Ê§°Ü·µ»Ø-1<br /> *************************************************/<br /> int udpclient(char *ip_address ,char *port)<br /> {<br /> struct sockaddr_in server, client;<br /> int clientfd;<br /> int ret;<br /> int server_port = atoi(port); /*×Ö·ûŽ®×ªÕûÐÍ*/<br /> int client_port = 50000;<br /> char msgbuf[]="This is a message from udp client/n";</p> <p> server.sin_family = AF_INET;<br /> server.sin_port = htons(server_port);<br /> ret = inet_pton(AF_INET, ip_address, &server.sin_addr.s_addr);<br /> if (ret <= 0)<br /> {<br /> printf("your ip address is unvalide!/n");<br /> useage();<br /> } </p> <p> client.sin_family = AF_INET;<br /> client.sin_port = htons(client_port);<br /> client.sin_addr.s_addr = INADDR_ANY;</p> <p> /*socket*/<br /> clientfd = socket(AF_INET ,SOCK_DGRAM ,0);<br /> if ( -1 == clientfd )<br /> {<br /> printf("create socket failed/n");<br /> return -1;<br /> }</p> <p> /*bind*/<br /> ret = bind(clientfd, (struct sockaddr *)&client, sizeof(client));<br /> if ( -1 == ret)<br /> {<br /> printf("bind failed /n");<br /> return -1;<br /> }</p> <p> printf("connect to server sucessfully!/n");</p> <p> /*send message to server*/<br /> ret = sendto(clientfd, msgbuf, sizeof(msgbuf), 0, (struct sockaddr*)&server, sizeof(server));<br /> if(ret == -1)<br /> {<br /> perror("send to server");<br /> return -1;<br /> }</p> <p> printf("send message sucessfully/n");</p> <p> }</p> <p> int main(int argc ,char **argv)<br /> {<br /> /*ÅжÏÃüÁîÐвÎÊý*/<br /> if(argc != 4)<br /> {<br /> useage();<br /> }</p> <p> /*²ÎÊý1Ϊtcp£¬µ÷ÓÃtcpclient*/<br /> if(strcmp(argv[1],"tcp") == 0)<br /> {<br /> tcpclient(argv[2] ,argv[3]);<br /> }</p> <p> /*²ÎÊý1Ϊudp£¬µ÷ÓÃudpclient*/<br /> else if(strcmp(argv[1],"udp") == 0)<br /> {<br /> udpclient(argv[2] ,argv[3]);<br /> }<br /> else<br /> {<br /> useage();<br /> exit(1);<br /> }<br /> return 0;<br /> }

/*****************************************************<br /> FileName: client.c<br /> Description: tcp·þÎñ¶Ë£¬œÓÊÜ¿Í»§¶ËÇëÇ󲢎ðÓŠÊÕµœµÄ×Ö·ûŽ®<br /> Author: wanxiao<br /> Date: 2010-07-24<br /> *****************************************************/<br /> #include<stdio.h><br /> #include<stdlib.h><br /> #include<errno.h><br /> #include<string.h><br /> #include<sys/types.h><br /> #include<sys/socket.h><br /> #include<unistd.h><br /> #include<netinet/in.h><br /> #define MAXCONN 10 /*listenº¯ÊýŒàÌý×îŽóÁ¬œÓÊý*/<br /> #define MAXDATASIZE 1024*10 /*»º³åÇøŽóС*/<br /> int main(int argc, char **argv)<br /> {<br /> if (argc != 2)<br /> {<br /> printf("Command Error -- filename [server port]/n");<br /> return -1;<br /> }</p> <p> struct sockaddr_in server_sockaddr; /*Ö÷»úœá¹¹*/<br /> struct sockaddr_in client_sockaddr; /*¿Í»§¶Ëœá¹¹*/<br /> int addrlen = sizeof(struct sockaddr_in); /*µØÖ·œá¹¹×ÖœÚÊý*/<br /> int recvbytes;<br /> int sockfd;<br /> int new_sockfd;<br /> char buf[MAXDATASIZE];<br /> /*socket*/<br /> if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1)<br /> {<br /> perror("socket");<br /> exit(1);<br /> }<br /> printf("socket success!, socket id = %d/n", sockfd);<br /> server_sockaddr.sin_family = AF_INET;<br /> server_sockaddr.sin_port = htons(atoi(argv[1]));<br /> server_sockaddr.sin_addr.s_addr = INADDR_ANY; /*ÈÎÒâµØÖ·*/<br /> /*bind*/<br /> if(bind(sockfd, (struct sockaddr*)&server_sockaddr, sizeof(struct sockaddr)) == -1)<br /> {<br /> perror("bind");<br /> exit(1);<br /> }<br /> printf("bind success!/n");<br /> /*listen*/<br /> if(listen(sockfd, MAXCONN) == -1)<br /> {<br /> perror("listen");<br /> exit(1);<br /> }<br /> printf("listening.../n");<br /> /*accept*/<br /> if((new_sockfd = accept(sockfd, (struct sockaddr*)&client_sockaddr, &addrlen)) == -1)<br /> {<br /> perror("accept");<br /> exit(1);<br /> }</p> <p> while(1)<br /> {<br /> memset(buf, 0, sizeof(buf));<br /> /*recvœÓÊÜ¿Í»§¶ËµÄÐÅÏ¢*/<br /> if((recvbytes = recv(new_sockfd, buf, MAXDATASIZE, 0)) == -1)<br /> {<br /> perror("recv");<br /> exit(1);<br /> }<br /> printf("received data size :%d/n", recvbytes);<br /> }<br /> close(sockfd);<br /> return 0;<br /> }<br />

send文件可以打印出来每次时间，微妙级的精确计时工具，但是还有一个问题就是最后一次时间的输出实际上是第二个gettimeofday的调用后时间，这样实际上多加了一次gettimeofday的时间，应该是不够精准的，后续继续思考吧。希望看到的高人们给与指点……   ^_^!!