C精选开源代码学习2 webbench
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C精选开源代码学习2 Web-Bench
一、 简介
Web-Bench 是一款优秀的 C语言开发的 性能压力测试工具，最多可以模拟3万个客户，主要返回每秒响应数和带宽。webbench是2004年的软件，已经有近二十年历史了。
二、下载源码
wget http://home.tiscali.cz/~cz210552/distfiles/webbench-1.5.tar.gz
tar -zxvf webbench-1.5.tar.gz
cd webbench-1.5
三、编译使用
make
make install
测试：
webbench -c 1000 -t 60 http://测试的网址
四、源码分析
源文件主要是
- webbench.c
- socket.c
1. make文件分析
CFLAGS?= -Wall -ggdb -W -O
CC?= gcc
LIBS?=
LDFLAGS?=
PREFIX?= /usr/local
VERSION=1.5
TMPDIR=/tmp/webbench-$(VERSION)
# 编译所有
all: webbench tags
# 更新所有目标
tags: *.c
-ctags *.c
# 安装
install: webbench
install -s webbench $(DESTDIR)$(PREFIX)/bin
install -m 644 webbench.1 $(DESTDIR)$(PREFIX)/man/man1
install -d $(DESTDIR)$(PREFIX)/share/doc/webbench
install -m 644 debian/copyright $(DESTDIR)$(PREFIX)/share/doc/webbench
install -m 644 debian/changelog $(DESTDIR)$(PREFIX)/share/doc/webbench
webbench: webbench.o Makefile
$(CC) $(CFLAGS) $(LDFLAGS) -o webbench webbench.o $(LIBS)
# 清理编译临时文件
clean:
-rm -f *.o webbench *~ core *.core tags
# 打包到/tmp/目录下
tar: clean
-debian/rules clean
rm -rf $(TMPDIR)
install -d $(TMPDIR)
cp -p Makefile webbench.c socket.c webbench.1 $(TMPDIR)
install -d $(TMPDIR)/debian
-cp -p debian/* $(TMPDIR)/debian
ln -sf debian/copyright $(TMPDIR)/COPYRIGHT
ln -sf debian/changelog $(TMPDIR)/ChangeLog
-cd $(TMPDIR) && cd .. && tar cozf webbench-$(VERSION).tar.gz webbench-$(VERSION)
webbench.o: webbench.c socket.c Makefile
.PHONY: clean install all tar
2. socket.c文件
/* $Id: socket.c 1.1 1995/01/01 07:11:14 cthuang Exp $
*
* This module has been modified by Radim Kolar for OS/2 emx
*/
/***********************************************************************
module: socket.c
program: popclient
SCCS ID: @(#)socket.c 1.5 4/1/94
programmer: Virginia Tech Computing Center
compiler: DEC RISC C compiler (Ultrix 4.1)
environment: DEC Ultrix 4.3
description: UNIX sockets code.
***********************************************************************/
#include <sys/types.h>
#include <sys/socket.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <sys/time.h>
#include <string.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
int Socket(const char *host, int clientPort)
{
int sock;
unsigned long inaddr;
// sockaddr_in 结构主要是存储主机、端口
struct sockaddr_in ad;
// hostent 记录主机的信息，包括主机名、别名、地址类型、地址长度和地址列表
struct hostent *hp;
//
memset(&ad, 0, sizeof(ad));
ad.sin_family = AF_INET;
inaddr = inet_addr(host);
// 不要是INADDR_NONE 的广播地址
if (inaddr != INADDR_NONE)
memcpy(&ad.sin_addr, &inaddr, sizeof(inaddr));
else
{
// 域名解析
hp = gethostbyname(host);
if (hp == NULL)
return -1;
memcpy(&ad.sin_addr, hp->h_addr, hp->h_length);
}
// htons 是将整型变量从主机字节顺序转变成网络字节顺序
ad.sin_port = htons(clientPort);
// 创建 socket
sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock < 0)
return sock;
// 建立连接
if (connect(sock, (struct sockaddr *)&ad, sizeof(ad)) < 0)
return -1;
return sock;
}
这个函数用来创建一个socket连接，参数是主机地址、端口号。
(1) 入口函数
入口函数最重要的事情就是解析命令行参数，给全局变量赋值，
int main(int argc, char *argv[]) {
int opt = 0;
int options_index = 0;
char *tmp = NULL;
if (argc == 1) {
usage();
return 2;
}
// 下面对参数进行处理，这里的getopt_long是GUN C提供的命令行参数处理函数。
while ((opt = getopt_long(argc, argv, "912Vfrt:p:c:?h", long_options, &options_index)) != EOF) {
switch (opt) {
case 0 :
break;
case 'f':
force = 1;
break;
case 'r':
force_reload = 1;
break;
case '9':
http10 = 0;
break;
case '1':
http10 = 1;
break;
case '2':
http10 = 2;
break;
case 'V':
printf(PROGRAM_VERSION"\\n");
exit(0);
case 't':
benchtime = atoi(optarg);
break;
case 'p':
/* proxy server parsing server:port */
tmp = strrchr(optarg, ':');
proxyhost = optarg;
if (tmp == NULL) {
break;
}
if (tmp == optarg) {
fprintf(stderr, "Error in option --proxy %s: Missing hostname.\\n", optarg);
return 2;
}
if (tmp == optarg + strlen(optarg) - 1) {
fprintf(stderr, "Error in option --proxy %s Port number is missing.\\n", optarg);
return 2;
}
*tmp = '\\0';
proxyport = atoi(tmp + 1);
break;
case ':':
case 'h':
case '?':
usage();
return 2;
break;
case 'c':
clients = atoi(optarg);
break;
}
}
if (optind == argc) {
fprintf(stderr, "webbench: Missing URL!\\n");
usage();
return 2;
}
if (clients == 0) clients = 1;
if (benchtime == 0) benchtime = 60;
/* Copyright */
fprintf(stderr, "Webbench - Simple Web Benchmark "PROGRAM_VERSION"\\n"
"Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.\\n"
);
// 调用函数创建请求
build_request(argv[optind]);
/* print bench info */
printf("\\nBenchmarking: ");
switch (method) {
case METHOD_GET:
default:
printf("GET");
break;
case METHOD_OPTIONS:
printf("OPTIONS");
break;
case METHOD_HEAD:
printf("HEAD");
break;
case METHOD_TRACE:
printf("TRACE");
break;
}
printf(" %s", argv[optind]);
switch (http10) {
case 0:
printf(" (using HTTP/0.9)");
break;
case 2:
printf(" (using HTTP/1.1)");
break;
}
printf("\\n");
if (clients == 1) printf("1 client");
else
printf("%d clients", clients);
printf(", running %d sec", benchtime);
if (force) printf(", early socket close");
if (proxyhost != NULL) printf(", via proxy server %s:%d", proxyhost, proxyport);
if (force_reload) printf(", forcing reload");
printf(".\\n");
// bench是请求的主函数
return bench();
}
(2) 全局变量
volatile int timerexpired=0;//判断压测时长是否已经到达设定的时间
int speed=0; //记录进程成功得到服务器响应的数量
int failed=0;//记录失败的数量（speed表示成功数，failed表示失败数）
int bytes=0;//记录进程成功读取的字节数
int http10=1;//http版本，0表示http0.9，1表示http1.0，2表示http1.1
int method=METHOD_GET; //请求方式，默认为GET，也支持HEAD、OPTIONS、TRACE
int clients=1;//并发数，默认只有1个进程发请求，通过-c参数设置
int force=0; //0不等待服务器返回数据（异步），1相反
int force_reload=0;//是否使用缓存，1表示不缓存，0表示可以缓存页面
int proxyport=80; //代理服务器的端口号
char *proxyhost=NULL; //代理服务器地址
int benchtime=30; //压测时间，默认30秒，通过-t参数设置
int mypipe[2]; //管道，父进程和子进程的通信用
char host[MAXHOSTNAMELEN]; //服务器端ip
char request[REQUEST_SIZE]; //所要发送的http请求
(3) bench函数
创建管道、子进程，对http请求测试。
static int bench(void) {
int i, j, k;
pid_t pid = 0;
FILE *f;
// 目标主机是否存在
/* check avaibility of target server */
i = Socket(proxyhost == NULL ? host : proxyhost, proxyport);
if (i < 0) {
fprintf(stderr, "\\nConnect to server failed. Aborting benchmark.\\n");
return 1;
}
close(i);
/* create pipe */
// pipe函数用于创建一个管道，以实现进程间的通信。
if (pipe(mypipe)) {
perror("pipe failed.");
return 3;
}
/* not needed, since we have alarm() in childrens */
/* wait 4 next system clock tick */
/*
cas=time(NULL);
while(time(NULL)==cas)
sched_yield();
*/
/* fork childs */
for (i = 0; i < clients; i++) {
// 复制进程
pid = fork();
if (pid <= (pid_t) 0) {
/* child process or error*/
sleep(1); /* make childs faster */
break;
}
}
if (pid < (pid_t) 0) {
fprintf(stderr, "problems forking worker no. %d\\n", i);
perror("fork failed.");
return 3;
}
if (pid == (pid_t) 0) {
/* I am a child */
// 子进程
if (proxyhost == NULL)
benchcore(host, proxyport, request);
else
benchcore(proxyhost, proxyport, request);
/* write results to pipe */
// 把结果写入管道
f = fdopen(mypipe[1], "w");
if (f == NULL) {
perror("open pipe for writing failed.");
return 3;
}
/* fprintf(stderr,"Child - %d %d\\n",speed,failed); */
// 写入管道
fprintf(f, "%d %d %d\\n", speed, failed, bytes);
fclose(f);
return 0;
} else {
// 打开父进程管道
f = fdopen(mypipe[0], "r");
if (f == NULL) {
perror("open pipe for reading failed.");
return 3;
}
setvbuf(f, NULL, _IONBF, 0);
speed = 0;
failed = 0;
bytes = 0;
while (1) {
pid = fscanf(f, "%d %d %d", &i, &j, &k);
if (pid < 2) {
fprintf(stderr, "Some of our childrens died.\\n");
break;
}
speed += i;
failed += j;
bytes += k;
/* fprintf(stderr,"*Knock* %d %d read=%d\\n",speed,failed,pid); */
if (--clients == 0) break;
}
fclose(f);
// 结果打印
printf("\\nSpeed=%d pages/min, %d bytes/sec.\\nRequests: %d susceed, %d failed.\\n",
(int) ((speed + failed) / (benchtime / 60.0f)),
(int) (bytes / (float) benchtime),
speed,
failed);
}
return i;
}
(4) 请求核心函数 benchcore
void benchcore(const char *host, const int port, const char *req) {
int rlen;
char buf[1500];
int s, i;
struct sigaction sa;
/* setup alarm signal handler */
sa.sa_handler = alarm_handler;
sa.sa_flags = 0;
// 检查或修改与指定信号相关联的处理动作
// SIGALARM 由setitimer触发的SIGALRM信号
if (sigaction(SIGALRM, &sa, NULL))
exit(3);
alarm(benchtime);
rlen = strlen(req);
nexttry:
while (1) {
if (timerexpired) {
if (failed > 0) {
/* fprintf(stderr,"Correcting failed by signal\\n"); */
failed--;
}
return;
}
// 创建连接
s = Socket(host, port);
if (s < 0) {
failed++;
continue;
}
if (rlen != write(s, req, rlen)) {
failed++;
close(s);
continue;
}
if (http10 == 0)
if (shutdown(s, 1)) {
failed++;
close(s);
continue;
}
if (force == 0) {
/* read all available data from socket */
while (1) {
if (timerexpired) break;
i = read(s, buf, 1500);
/* fprintf(stderr,"%d\\n",i); */
if (i < 0) {
failed++;
close(s);
goto nexttry;
} else if (i == 0) break;
else
// 读取字节数增加
bytes += i;
}
}
if (close(s)) {
failed++;
continue;
}
// http测试成功一次，speed加1
speed++;
}
}
(5) build_request
创建URL请求连接 ，请求创建好以后放到全局变量request中
/****************
创建URL请求连接
@url:url地址
创建好的请求放在全局变量request中
****************/
void build_request(const char *url)
{
char tmp[10];
int i;
//请求地址和请求连接清零
bzero(host,MAXHOSTNAMELEN);
bzero(request,REQUEST_SIZE)值得学习的C/C++开源框架（转）