NGINX EVENTS 机制

char *ngx_module_names[] = "ngx_http_upstream_module{
    "ngx_core_module",
    "ngx_errlog_module",
    "ngx_conf_module",
    "ngx_regex_module",
    "ngx_events_module",
    "ngx_event_core_module",
    "ngx_epoll_module",
    "ngx_http_module",
    "ngx_http_core_module",
    "ngx_http_log_module",
    ,
    "ngx_http_static_module",
    /* ... */
}";

ngx_int_t
ngx_preinit_modules(void)
{
    ngx_uint_t  i;

    for (i = 0; ngx_modules[i]; i++) {
        ngx_modules[i]->index = i;
        ngx_modules[i]->name = ngx_module_names[i];
    }

    ngx_modules_n = i;
    ngx_max_module = ngx_modules_n + NGX_MAX_DYNAMIC_MODULES;

    return NGX_OK;
}

ngx_int_t
ngx_cycle_modules(ngx_cycle_t *cycle)
{
    /*
     * create a list of modules to be used for this cycle,
     * copy static modules to it
     */

    cycle->modules = ngx_pcalloc(cycle->pool, (ngx_max_module + 1)
                                              * sizeof(ngx_module_t *));
    if (cycle->modules == NULL) {
        return NGX_ERROR;
    }

    ngx_memcpy(cycle->modules, ngx_modules,
               ngx_modules_n * sizeof(ngx_module_t *));

    cycle->modules_n = ngx_modules_n;

    return NGX_OK;
}

for (i = 0; cycle->modules[i]; i++) {
    if (cycle->modules[i]->type != NGX_CORE_MODULE) {
        continue;
    }

    module = cycle->modules[i]->ctx;

    if (module->create_conf) {
        rv = module->create_conf(cycle);
        if (rv == NULL) {
            ngx_destroy_pool(pool);
            return NULL;
        }
        cycle->conf_ctx[cycle->modules[i]->index] = rv;
    }
}

void
ngx_single_process_cycle(ngx_cycle_t *cycle)
{
    // ...
    for (i = 0; cycle->modules[i]; i++) {
        if (cycle->modules[i]->init_process) {
            if (cycle->modules[i]->init_process(cycle) == NGX_ERROR) {
                /* fatal */
                exit(2);
            }
        }
    }

    for ( ;; ) {
        ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "worker cycle");

        ngx_process_events_and_timers(cycle);
        // ...
    }
}

static void
ngx_worker_process_init(ngx_cycle_t *cycle, ngx_int_t worker)
{
    // ...
    for (i = 0; cycle->modules[i]; i++) {
        if (cycle->modules[i]->init_process) {
            if (cycle->modules[i]->init_process(cycle) == NGX_ERROR) {
                /* fatal */
                exit(2);
            }
        }
    }
    // ...
}

static void
ngx_worker_process_cycle(ngx_cycle_t *cycle, void *data)
{
    // ...
    ngx_int_t worker = (intptr_t) data;
    ngx_worker_process_init(cycle, worker);

    for ( ;; ) {
        // ...
        ngx_process_events_and_timers(cycle);
        // ...
    }
}

void
ngx_process_events_and_timers(ngx_cycle_t *cycle)
{
    if (ngx_use_accept_mutex) {
        // ...
    }

    (void) ngx_process_events(cycle, timer, flags);

    ngx_event_process_posted(cycle, &ngx_posted_accept_events);

    ngx_event_expire_timers();

    ngx_event_process_posted(cycle, &ngx_posted_events);
}

#define ngx_process_events   ngx_event_actions.process_events
#define ngx_done_events      ngx_event_actions.done

#define ngx_add_event        ngx_event_actions.add
#define ngx_del_event        ngx_event_actions.del
#define ngx_add_conn         ngx_event_actions.add_conn
#define ngx_del_conn         ngx_event_actions.del_conn

#define ngx_notify           ngx_event_actions.notify

#define ngx_add_timer        ngx_event_add_timer
#define ngx_del_timer        ngx_event_del_timer

static ngx_int_t
ngx_epoll_init(ngx_cycle_t *cycle, ngx_msec_t timer)
{
    ngx_epoll_conf_t  *epcf;

    epcf = ngx_event_get_conf(cycle->conf_ctx, ngx_epoll_module);

    if (nevents < epcf->events) {
        if (event_list) {
            ngx_free(event_list);
        }
        event_list = ngx_alloc(sizeof(struct epoll_event) * epcf->events,
                               cycle->log);
    }

    nevents = epcf->events;

    ngx_io = ngx_os_io;

    ngx_event_actions = ngx_epoll_module_ctx.actions;

    return NGX_OK;
}

ngx_conf_handler