Nginx 工作进程运行示意图

(旧存档丢了, 只剩下一张图 ⊙﹏⊙)

nginx 工作进程运行示意图:

void
ngx_process_events_and_timers(ngx_cycle_t *cycle)
{
    ngx_uint_t  flags;
    ngx_msec_t  timer, delta;

if (ngx_timer_resolution) {
        timer = NGX_TIMER_INFINITE;
        flags = 0;

} else {
        timer = ngx_event_find_timer();
        flags = NGX_UPDATE_TIME;

}
    // accept 互斥锁相关逻辑
    if (ngx_use_accept_mutex) {
        if (ngx_accept_disabled > 0) {
            ngx_accept_disabled--;

} else {
            if (ngx_trylock_accept_mutex(cycle) == NGX_ERROR) {
                return;
            }

if (ngx_accept_mutex_held) {
                flags |= NGX_POST_EVENTS;

} else {
                if (timer == NGX_TIMER_INFINITE
                    || timer > ngx_accept_mutex_delay)
                {
                    timer = ngx_accept_mutex_delay;
                }
            }
        }
    }

delta = ngx_current_msec;

// epoll wait 等待socket 读写等事件发生
    (void) ngx_process_events(cycle, timer, flags);

delta = ngx_current_msec - delta;

ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "timer delta: %M", delta);

// 优先处理 accept 事件
    ngx_event_process_posted(cycle, &ngx_posted_accept_events);

if (ngx_accept_mutex_held) {
        ngx_shmtx_unlock(&ngx_accept_mutex);
    }

// 处理定时器超时事件
        if (delta) {
        ngx_event_expire_timers();
    }

// 最后处理普通I/O等事件
    ngx_event_process_posted(cycle, &ngx_posted_events);
}

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

ngx_process = NGX_PROCESS_WORKER;
    ngx_worker = worker;

ngx_worker_process_init(cycle, worker);

ngx_setproctitle("worker process");

for ( ;; ) {

if (ngx_exiting) {
            ngx_event_cancel_timers();

if (ngx_event_timer_rbtree.root == ngx_event_timer_rbtree.sentinel)
            {
                ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "exiting");

ngx_worker_process_exit(cycle);
            }
        }

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

// 工作进程主要处理逻辑
        ngx_process_events_and_timers(cycle);

// 信号处理，重启退出等逻辑
        if (ngx_terminate) {
            ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "exiting");

ngx_worker_process_exit(cycle);
        }

if (ngx_quit) {
            ngx_quit = 0;
            ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0,
                          "gracefully shutting down");
            ngx_setproctitle("worker process is shutting down");

if (!ngx_exiting) {
                ngx_exiting = 1;
                ngx_close_listening_sockets(cycle);
                ngx_close_idle_connections(cycle);
            }
        }

if (ngx_reopen) {
            ngx_reopen = 0;
            ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reopening logs");
            ngx_reopen_files(cycle, -1);
        }
    }

转载请注明出处，谢谢。。