perrynzhou

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nginx 的worker_process

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nginx 的worker_process

nginx的配置worker_process

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[perrynzhou@perrynzhou-ubuntu ~/Debug/nginx-1.19.0/conf]$ cat nginx.conf 

#user  nobody;
worker_processes  1;

events {
    worker_connections  1024;
}


http {
    include       mime.types;
    default_type  application/octet-stream;
    sendfile        on;
    keepalive_timeout  65;


    server {
        listen       80;
        server_name  localhost;

        location / {
            root   html;
            index  index.html index.htm;
        }

        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }

}

nginx 如何配置worker_process呢?

nginx中通过static ngx_command_t ngx_core_commands[]数组表示配置文件以及配置文件中的回调函数
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{ ngx_string("worker_processes"),
   NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_TAKE1,
   ngx_set_worker_processes,
   0,
   0,
   NULL },
worker_process 通过回调函数ngx_set_worker_processes设置nginx的进程数
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static char *
ngx_set_worker_processes(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_str_t        *value;
    ngx_core_conf_t  *ccf;

    ccf = (ngx_core_conf_t *) conf;

    if (ccf->worker_processes != NGX_CONF_UNSET) {
        return "is duplicate";
    }

    value = (ngx_str_t *) cf->args->elts;

    if (ngx_strcmp(value[1].data, "auto") == 0) {
  		//如果在 conf/nginx.conf 中配置 worker_processes  auto;则会走这个逻辑
        ccf->worker_processes = ngx_ncpu;
        //ngx_cpu:会在 ngx_os_init 函数中初始化这个全局变量，ngx_ncpu = sysconf(_SC_NPROCESSORS_ONLN);获取CPU逻辑核
        return NGX_CONF_OK;
    }

    ccf->worker_processes = ngx_atoi(value[1].data, value[1].len);

    if (ccf->worker_processes == NGX_ERROR) {
        return "invalid value";
    }

    return NGX_CONF_OK;
}

nginx 如何启动一个或者多个 worker_process?

  • 调用关系链
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main->
		ngx_master_process_cycle->
			ngx_start_worker_processes
  • main:nginx入口函数
  • ngx_master_process_cycle:依据配置文件初始化worker_process和master process.同时提供nginx -h 列举出所有的命令操作实现，这里仅仅列举出来和master、worker进程相关的实现
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    void ngx_master_process_cycle(ngx_cycle_t *cycle)
    {
    		//fork进程作为master进程
    	   ngx_start_worker_processes(cycle, ccf->worker_processes,NGX_PROCESS_JUST_RESPAWN);
           
           //fork worker进程
           ngx_start_cache_manager_processes(cycle, 1);
    }
  • ngx_start_worker_processes:根据配置文件启动多个work_process.
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static void ngx_start_worker_processes(ngx_cycle_t *cycle, ngx_int_t n, ngx_int_t type)
{

    for (i = 0; i < n; i++) {
		//ngx_worker_process_cycle 是每个work进程执行的函数
        ngx_spawn_process(cycle, ngx_worker_process_cycle, (void *) (intptr_t) i, "worker process", type);
    }
}
static void ngx_worker_process_cycle(ngx_cycle_t *cycle, void *data)
{
    ngx_int_t worker = (intptr_t) data;

    ngx_uint_t         i;
    ngx_connection_t  *c;

    ngx_process = NGX_PROCESS_WORKER;
    ngx_worker_process_init(cycle, worker);
    ngx_setproctitle("worker process");
    //忽略了其他的代码
    for ( ;; ) {

        if (ngx_exiting) {

            c = cycle->connections;

            for (i = 0; i < cycle->connection_n; i++) {

                /* THREAD: lock */

                if (c[i].fd != -1 && c[i].idle) {
                    c[i].close = 1;
                    c[i].read->handler(c[i].read);
                }
            }
        }

}

ngx_pid_t ngx_spawn_process(ngx_cycle_t *cycle, ngx_spawn_proc_pt proc, void *data,char *name, ngx_int_t respawn)
{
	//
    pid = fork();

    switch (pid) {

    case -1:
        ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                      "fork() failed while spawning \"%s\"", name);
        ngx_close_channel(ngx_processes[s].channel, cycle->log);
        return NGX_INVALID_PID;

    case 0:
        ngx_pid = ngx_getpid();
        proc(cycle, data);
        break;

    default:
        break;
    }

}