nginxをよむ

ソースコードリーディングが何ぼのもんじゃい

core/nginx.c

  if (ngx_process == NGX_PROCESS_SINGLE) {
        ngx_single_process_cycle(cycle);

    } else {
        ngx_master_process_cycle(cycle);
    }

os/ngx_process_cycle.c

 ngx_start_worker_processes(cycle, ccf->worker_processes,
                               NGX_PROCESS_RESPAWN);
    ngx_start_cache_manager_processes(cycle, 0);

//後ろの方にはシグナルとかrestartの処理が書いてあった

static void
ngx_start_worker_processes(ngx_cycle_t *cycle, ngx_int_t n, ngx_int_t type)
{
 ngx_spawn_process(cycle,ngx_worker_process_cycle,(void *) (intptr_t) i, "worker process", type);

}

os/unix/ngx_process.c

 ngx_pid_t
  ngx_spawn_process(ngx_cycle_t *cycle, ngx_spawn_proc_pt proc, void *data,
      char *name, ngx_int_t respawn){

//省略

    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;
    }

//省略

}

procが関数として呼び出されている
procの型はngx_spawn_proc_pt（なんだこりゃ

os/unix/ngx_process.h

typedef void (*ngx_spawn_proc_pt) (ngx_cycle_t *cycle, void *data);

ngx_spawn_proc_ptは上記二つの引数をとる関数の型

呼び出し元を見るとos/unix/ngx_process_cycle.cのngx_worker_process_cycle

os/unix/ngx_process_cycle.c


static void
ngx_worker_process_cycle(ngx_cycle_t *cycle, void *data)
{
//~
 ngx_process_events_and_timers(cycle);
//~
}

./event/ngx_event.c:194

void
ngx_process_events_and_timers(ngx_cycle_t *cycle){
//~
  (void) ngx_process_events(cycle, timer, flags);
//~
}

./event/ngx_event.h:408

#define ngx_process_events   ngx_event_actions.process_events

わった

検索結果

[root@hote src]# grep -rne ngx_event_actions ./
./event/modules/ngx_win32_select_module.c:106:    ngx_event_actions = ngx_select_module_ctx.actions;
./event/modules/ngx_devpoll_module.c:186:    ngx_event_actions = ngx_devpoll_module_ctx.actions;
./event/modules/ngx_epoll_module.c:368:    ngx_event_actions = ngx_epoll_module_ctx.actions;
./event/modules/ngx_eventport_module.c:279:    ngx_event_actions = ngx_eventport_module_ctx.actions;
./event/modules/ngx_kqueue_module.c:224:    ngx_event_actions = ngx_kqueue_module_ctx.actions;
./event/modules/ngx_poll_module.c:96:    ngx_event_actions = ngx_poll_module_ctx.actions;
./event/modules/ngx_select_module.c:105:    ngx_event_actions = ngx_select_module_ctx.actions;
./event/ngx_event.c:44:ngx_event_actions_t   ngx_event_actions;

環境と方式によって違うメソッドを実行している

/event/modules/ngx_eventport_module.c:279

static ngx_int_t
ngx_epoll_init(ngx_cycle_t *cycle, ngx_msec_t timer)
{
//~
ngx_event_actions = ngx_epoll_module_ctx.actions;
//~
}

/event/ngx_event.c

static char *
ngx_event_core_init_conf(ngx_cycle_t *cycle, void *conf)
{
    ngx_event_conf_t  *ecf = conf;

#if (NGX_HAVE_EPOLL) && !(NGX_TEST_BUILD_EPOLL)
    int                  fd;
#endif
    ngx_int_t            i;
    ngx_module_t        *module;
    ngx_event_module_t  *event_module;

    module = NULL;

#if (NGX_HAVE_EPOLL) && !(NGX_TEST_BUILD_EPOLL)

    fd = epoll_create(100);

    if (fd != -1) {
        (void) close(fd);
        module = &ngx_epoll_module;

    } else if (ngx_errno != NGX_ENOSYS) {
        module = &ngx_epoll_module;
    }
}
|||<
切り替えをしているのはこの部分
（パラメータで切り替えるのになぜマクロ？）
（気力が失せた）


module_epoll
>||
ngx_event_module_t  ngx_epoll_module_ctx = {
    &epoll_name,
    ngx_epoll_create_conf,               /* create configuration */
    ngx_epoll_init_conf,                 /* init configuration */

    {
        ngx_epoll_add_event,             /* add an event */
        ngx_epoll_del_event,             /* delete an event */
        ngx_epoll_add_event,             /* enable an event */
        ngx_epoll_del_event,             /* disable an event */
        ngx_epoll_add_connection,        /* add an connection */
        ngx_epoll_del_connection,        /* delete an connection */
#if (NGX_HAVE_EVENTFD)
        ngx_epoll_notify,                /* trigger a notify */
#else
        NULL,                            /* trigger a notify */
#endif
        ngx_epoll_process_events,        /* process the events */
        ngx_epoll_init,                  /* init the events */
        ngx_epoll_done,                  /* done the events */
    }
};

このうちのactionsに対応する部分を実行している

events.h

typedef struct {
    ngx_str_t              *name;

    void                 *(*create_conf)(ngx_cycle_t *cycle);
    char                 *(*init_conf)(ngx_cycle_t *cycle, void *conf);

    ngx_event_actions_t     actions;
} ngx_event_module_t;

actionsに相当するのは関数のリストであるぞ

このリストの中でメインループなのはprocess_events
なかでepoll掘って完了したイベントごとに何かしている感じ