Linux C经典项目 webbench详解

Webbench是知名的网站压力测试工具，它模拟通过创建子进程，模拟浏览器去访问域名/IP地址，然后测试每秒钟相应请求数和每秒钟传输数据量

Webbench程序运行在linux平台下，下面介绍源代码编译安装过程。

yum install -y gcc ctags
wget http://www.ha97.com/code/webbench-1.5.tar.gz
tar zxvf webbench-1.5.tar.gz
cd webbench-1.5
make
make install

在终端种使用Webbench

webbench -c 10 -t 10 http://test.domain.com/phpinfo.php
webbench -c 并发数 -t 运行测试时间 URL

测试实验结果解释

速度：每秒钟响应请求数：444 pages/min，每秒钟传输数据量59377 bytes/sec.
返回数：73次返回成功，1次返回失败

 

Webbench源码剖析

命令行参数解析

命令行参数解析当然是linux下的经典做法，通过getopt_long库函数。这个函数需要配合一个全局变量使用

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}
};

标准的命令行输入如下

webbench -c 10 -t 10 http://test.domain.com/phpinfo.php
webbench -c 并发数 -t 运行测试时间 URL

输入命令行参数帮助如下

/* help 信息 */
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 <sec>          Run benchmark for <sec> seconds. Default 30.\n"
	"  -p|--proxy <server:port> Use proxy server for request.\n"
	"  -c|--clients <n>         Run <n> 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"
	);
};

 主函数中，命令行参数的解析逻辑如下：

    int opt = 0;
    int options_index = 0;
    char *tmp = NULL;

    /* 不带参数时直接输出 help 信息 */
    if(argc == 1)
    {
        usage();
        return 2;
    }

    /* getopt_long 为命令行解析的库函数，可通过 man 3 getopt_long 查看 */
    while((opt = getopt_long(argc,argv,"912Vfrt:p:c:?h",long_options,&options_index)) != EOF )
    {
        /* 如果有返回对应的命令行参数 */
        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;
        }
    }

    /* optind 被 getopt_long 设置为命令行参数中未读取的下一个元素下标值 */
    if(optind == argc)
    {
        fprintf(stderr,"webbench: Missing URL!\n");
        usage();
        return 2;
    }

    /* 不能指定客户端数和请求时间为 0 */
    if(clients == 0) clients = 1;
    if(benchtime == 0) benchtime = 60;

构造http请求报文

/* Copyright */
    fprintf(stderr,"Webbench - Simple Web Benchmark "PROGRAM_VERSION"\n"
	 "Copyright (c) Radim Kolar 1997-2004, GPL Open Source Software.\n"
     );

    /* 构造 HTTP 请求到 request 数组 */
    build_request(argv[optind]);

    /* 以下到函数结束为输出提示信息 */
    /* 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");

HTTP请求报文，采用字符串拼接形成

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

    /* 初始化 */
    bzero(host,MAXHOSTNAMELEN);
    bzero(request,REQUEST_SIZE);

    /* 判断应该使用的 HTTP 协议 */
    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;

    /*填写 method 方法 */
    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," ");

    /* URL 合法性判断 */
    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))
        {
            /* 只支持 HTTP 地址 */
            fprintf(stderr,"\nOnly HTTP protocol is directly supported, set --proxy for others.\n");
            exit(2);
        }

    /* 找到主机名开始的地方 */
    /* protocol/host delimiter */
    i = strstr(url,"://")-url+3;

    /* 必须以 / 结束*/
    /* 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,':') < index(url+i,'/'))
        {
            strncpy(host,url+i,strchr(url+i,':')-url-i);
            /* 端口 */
            bzero(tmp,10);
            strncpy(tmp,index(url+i,':')+1,strchr(url+i,'/')-index(url+i,':')-1);
            /* printf("tmp=%s\n",tmp); */
            /* 设置端口 */
            proxyport = atoi(tmp);
            if(proxyport==0) proxyport=80;

        } else {
            strncpy(host,url+i,strcspn(url+i,"/"));
        }
        // printf("Host=%s\n",host);

        strcat(request+strlen(request),url+i+strcspn(url+i,"/"));
    } else {
        // printf("ProxyHost=%s\nProxyPort=%d\n",proxyhost,proxyport);
        strcat(request,url);
    }

    if(http10 == 1)
        strcat(request," HTTP/1.0");
    else if (http10==2)
        strcat(request," HTTP/1.1");
    strcat(request,"\r\n");

    if(http10 > 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);
}

 压力测试

 

主进程创建子进程，子进程对服务器进行并发访问，把数据通过管道传给子进程，有三个数据

fprintf(f,"%d %d %d\n",speed,failed,bytes);

static int bench(void)
{
    int i,j,k;
    pid_t pid = 0;
    FILE *f;

    /* 作为测试地址是否合法 */
    /* 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);

    /* 建立管道 */
    /* 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();
     * */

    /* 派生子进程 */
    /* fork childs */
    for(i = 0;i < clients;i++)
    {
        pid = fork();
        if(pid <= (pid_t)0)
        {
            /* child process or error*/
            sleep(1); /* make childs faster */
            break; /* 子进程立刻跳出循环，要不就子进程继续 fork 了 */
        }
    }

    if( pid < (pid_t)0)
    {
        fprintf(stderr,"problems forking worker no. %d\n",i);
        perror("fork failed.");
        return 3;
    }

    if(pid == (pid_t)0)
    {
        /* 子进程发出实际请求 */
        /* I am a child */
        if(proxyhost == NULL)
            benchcore(host,proxyport,request);
        else
            benchcore(proxyhost,proxyport,request);

        /* 打开管道写 */
        /* write results to pipe */
        f = fdopen(mypipe[1],"w");
        if(f == NULL)
        {
            perror("open pipe for writing failed.");
            return 3;
        }

        /* fprintf(stderr,"Child - %d %d\n",speed,failed); */
        fprintf(f,"%d %d %d\n",speed,failed,bytes);
        fclose(f);

        return 0;

    } else {
        /* 父进程打开管道读 */
        f = fdopen(mypipe[0],"r");
        if(f == NULL)
        {
            perror("open pipe for reading failed.");
            return 3;
        }

        setvbuf(f,NULL,_IONBF,0);
        speed = 0; /* 传输速度 */
        failed = 0; /* 失败请求数 */
        bytes = 0; /* 传输字节数 */

        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); */
            /* 子进程是否读取完 */
            if(--clients == 0) break;
        }
        fclose(f);

        /* 结果计算 */
        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;
}

单个子进程访问服务器的逻辑

 

void benchcore(const char *host,const int port,const char *req)
{
    int rlen;
    char buf[1500];
    int s,i;
    struct sigaction sa;

    /*安装信号 */
    /* setup alarm signal handler */
    sa.sa_handler = alarm_handler;
    sa.sa_flags = 0;
    if(sigaction(SIGALRM,&sa,NULL))
        exit(3);

    /* 设置闹钟函数 */
    alarm(benchtime);

    rlen = strlen(req);

nexttry:
    while(1){
        /* 收到信号则 timerexpired = 1 */
        if(timerexpired)
        {
            if(failed > 0)
            {
                /* fprintf(stderr,"Correcting failed by signal\n"); */
                failed--;
            }
            return;
        }
        /* 建立 socket, 进行 HTTP 请求 */
        s = Socket(host,port);
        if(s < 0)
        {
            failed++;
            continue;
        }
        if(rlen!=write(s,req,rlen))
        {
            failed++;
            close(s);
            continue;
        }
        /* HTTP 0.9 的处理 */
        if(http10==0)
            /* 如果关闭不成功 */
            if(shutdown(s,1))
            {
                failed++;
                close(s);
                continue;
            }

        /* -f 选项时不读取服务器回复 */
        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++;
    }
}

 

来源：https://blog.csdn.net/wwxy1995/article/details/99305054