Github Webbench 源码分析+学习(待续)


前言:

Webbench 是一个古老而著名的网站压力测试工具,简单而实用。如果你不清楚你的网站能承受多大的压力,或者你想分析对比两个网站的性能,webbench 再好用不过了。

Gitbub 地址:https://github.com/cnnewjohn/webbench

1,linux编程学习:Makefile


记得以前linux程序都是直接g++编译的(好几行是一个命令,好low),看到这么长的Makefile简直懵逼了,下面逐句学习,见注释。另外如何Makefile进行GDB调试。
--》
  • *     :: 表示任意一个或多个字符
  • ?     :: 表示任意一个字符
  • [...] :: ex. [abcd] 表示a,b,c,d中任意一个字符, [^abcd]表示除a,b,c,d以外的字符, [0-9]表示 0~9中任意一个数字
  • ~     :: 表示用户的home目录
--》

查看C文件的依赖关系 : 

写 Makefile 的时候, 需要确定每个目标的依赖关系.

GNU提供一个机制可以查看C代码文件依赖那些文件, 这样我们在写 Makefile 目标的时候就不用打开C源码来看其依赖那些文件了.

比如, 下面命令显示内核源码中 virt/kvm/kvm_main.c 中的依赖关系

$ cd virt/kvm/
$ gcc -MM kvm_main.c 
kvm_main.o: kvm_main.c iodev.h coalesced_mmio.h async_pf.h   <-- 这句就可以加到 Makefile 中作为编译 kvm_main.o 的依赖关系

Makefile源代码:
CFLAGS?=	-Wall -ggdb -W -O
CC?=		gcc
LIBS?=
LDFLAGS?=
PREFIX?=	/usr/local
VERSION=1.5
TMPDIR=/tmp/webbench-$(VERSION)

all:   webbench tags

tags:  *.c
	-ctags *.c

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) 

clean:
	-rm -f *.o webbench *~ core *.core tags
	
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)



.PHONY: clean install all tar
代码很长,其实使用make命令之后,输出如下: 
    
 
   
cc -Wall -ggdb -W -O   -c -o webbench.o webbench.c
cc -Wall -ggdb -W -O  -o webbench webbench.o
ctags *.c
/bin/sh: 1: ctags: not found
make: [tags] Error 127 (ignored)
其实就是编译两个.c文件。至于其他的涉及到各种linux命令,下次再看。

2,网络编程和多线程编程学习。

主要函数:
alarm_handler 信号处理函数,时钟结束时进行调用。

usage 输出 webbench 命令用法

main 提供程序入口...

build_request 构造 HTTP 请求

bench 派生子进程,父子进程管道通信最后输出计算结果。

benchcore 每个子进程的实际发起请求函数。


主要流程:
说一下程序执行的主要流程:

1. 解析命令行参数,根据命令行指定参数设定变量,可以认为是初始化配置。

2.根据指定的配置构造 HTTP 请求报文格式。

3.开始执行 bench 函数,先进行一次 socket 连接建立与断开,测试是否可以正常访问。

4.建立管道,派生根据指定进程数派生子进程。

5.每个子进程调用 benchcore 函数,先通过 sigaction 安装信号,用 alarm 设置闹钟函数,接着不断建立 socket 进行通信,与服务器交互数据,直到收到信号结束访问测试。子进程将访问测试结果写进管道。

源代码:

/*
 * (C) Radim Kolar 1997-2004
 * This is free software, see GNU Public License version 2 for
 * details.
 *
 * Simple forking WWW Server benchmark:
 *
 * Usage:
 *   webbench --help
 *
 * Return codes:
 *    0 - sucess
 *    1 - benchmark failed (server is not on-line)
 *    2 - bad param
 *    3 - internal error, fork failed
 * 
 */ 
#include "socket.c"
#include 
#include 
#include 
#include 
#include 
#include 
#include 

/* values */
volatile int timerexpired=0;
int speed=0;
int failed=0;
int bytes=0;
/* globals */
int http10=1; /* 0 - http/0.9, 1 - http/1.0, 2 - http/1.1 */
/* Allow: GET, HEAD, OPTIONS, TRACE */
#define METHOD_GET 0
#define METHOD_HEAD 1
#define METHOD_OPTIONS 2
#define METHOD_TRACE 3
#define PROGRAM_VERSION "1.5"
int method=METHOD_GET;
int clients=1;
int force=0;
int force_reload=0;
int proxyport=80;
char *proxyhost=NULL;
int benchtime=30;
/* internal */
int mypipe[2];
char host[MAXHOSTNAMELEN];
#define REQUEST_SIZE 2048
char request[REQUEST_SIZE];

static const struct option long_options[]=
{
 {"force",no_argument,&force,1},
 {"reload",no_argument,&force_reload,1},
 {"time",required_argument,NULL,'t'},
 {"help",no_argument,NULL,'?'},
 {"http09",no_argument,NULL,'9'},
 {"http10",no_argument,NULL,'1'},
 {"http11",no_argument,NULL,'2'},
 {"get",no_argument,&method,METHOD_GET},
 {"head",no_argument,&method,METHOD_HEAD},
 {"options",no_argument,&method,METHOD_OPTIONS},
 {"trace",no_argument,&method,METHOD_TRACE},
 {"version",no_argument,NULL,'V'},
 {"proxy",required_argument,NULL,'p'},
 {"clients",required_argument,NULL,'c'},
 {NULL,0,NULL,0}
};

/* prototypes */
static void benchcore(const char* host,const int port, const char *request);
static int bench(void);
static void build_request(const char *url);

static void alarm_handler(int signal)
{
   timerexpired=1;
}	

static void usage(void)
{
   fprintf(stderr,
	"webbench [option]... URL\n"
	"  -f|--force               Don't wait for reply from server.\n"
	"  -r|--reload              Send reload request - Pragma: no-cache.\n"
	"  -t|--time           Run benchmark for  seconds. Default 30.\n"
	"  -p|--proxy  Use proxy server for request.\n"
	"  -c|--clients          Run  HTTP clients at once. Default one.\n"
	"  -9|--http09              Use HTTP/0.9 style requests.\n"
	"  -1|--http10              Use HTTP/1.0 protocol.\n"
	"  -2|--http11              Use HTTP/1.1 protocol.\n"
	"  --get                    Use GET request method.\n"
	"  --head                   Use HEAD request method.\n"
	"  --options                Use OPTIONS request method.\n"
	"  --trace                  Use TRACE request method.\n"
	"  -?|-h|--help             This information.\n"
	"  -V|--version             Display program version.\n"
	);
};
int main(int argc, char *argv[])
{
 int opt=0;
 int options_index=0;
 char *tmp=NULL;

 if(argc==1)
 {
	  usage();
          return 2;
 } 

 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"
	 );
 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");
 return bench();
}

void build_request(const char *url)
{
  char tmp[10];
  int i;

  bzero(host,MAXHOSTNAMELEN);
  bzero(request,REQUEST_SIZE);

  if(force_reload && proxyhost!=NULL && http10<1) http10=1;
  if(method==METHOD_HEAD && http10<1) http10=1;
  if(method==METHOD_OPTIONS && http10<2) http10=2;
  if(method==METHOD_TRACE && http10<2) http10=2;

  switch(method)
  {
	  default:
	  case METHOD_GET: strcpy(request,"GET");break;
	  case METHOD_HEAD: strcpy(request,"HEAD");break;
	  case METHOD_OPTIONS: strcpy(request,"OPTIONS");break;
	  case METHOD_TRACE: strcpy(request,"TRACE");break;
  }
		  
  strcat(request," ");

  if(NULL==strstr(url,"://"))
  {
	  fprintf(stderr, "\n%s: is not a valid URL.\n",url);
	  exit(2);
  }
  if(strlen(url)>1500)
  {
         fprintf(stderr,"URL is too long.\n");
	 exit(2);
  }
  if(proxyhost==NULL)
	   if (0!=strncasecmp("http://",url,7)) 
	   { fprintf(stderr,"\nOnly HTTP protocol is directly supported, set --proxy for others.\n");
             exit(2);
           }
  /* protocol/host delimiter */
  i=strstr(url,"://")-url+3;
  /* printf("%d\n",i); */

  if(strchr(url+i,'/')==NULL) {
                                fprintf(stderr,"\nInvalid URL syntax - hostname don't ends with '/'.\n");
                                exit(2);
                              }
  if(proxyhost==NULL)
  {
   /* get port from hostname */
   if(index(url+i,':')!=NULL &&
      index(url+i,':')0)
	  strcat(request,"User-Agent: WebBench "PROGRAM_VERSION"\r\n");
  if(proxyhost==NULL && http10>0)
  {
	  strcat(request,"Host: ");
	  strcat(request,host);
	  strcat(request,"\r\n");
  }
  if(force_reload && proxyhost!=NULL)
  {
	  strcat(request,"Pragma: no-cache\r\n");
  }
  if(http10>1)
	  strcat(request,"Connection: close\r\n");
  /* add empty line at end */
  if(http10>0) strcat(request,"\r\n"); 
  // printf("Req=%s\n",request);
}

/* vraci system rc error kod */
static int bench(void)
{
  int i,j,k;	
  pid_t pid=0;
  FILE *f;

  /* 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 */
  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;i0)
       {
          /* fprintf(stderr,"Correcting failed by signal\n"); */
          failed--;
       }
       return;
    }
    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
			       bytes+=i;
	    }
    }
    if(close(s)) {failed++;continue;}
    speed++;
 }
}

/* $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 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

int Socket(const char *host, int clientPort)
{
    int sock;
    unsigned long inaddr;
    struct sockaddr_in ad;
    struct hostent *hp;
    
    memset(&ad, 0, sizeof(ad));
    ad.sin_family = AF_INET;

    inaddr = inet_addr(host);
    if (inaddr != INADDR_NONE)
        memcpy(&ad.sin_addr, &inaddr, sizeof(inaddr));
    else
    {
        hp = gethostbyname(host);
        if (hp == NULL)
            return -1;
        memcpy(&ad.sin_addr, hp->h_addr, hp->h_length);
    }
    ad.sin_port = htons(clientPort);
    
    sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock < 0)
        return sock;
    if (connect(sock, (struct sockaddr *)&ad, sizeof(ad)) < 0)
        return -1;
    return sock;
}




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