ngx_event.c

来自「Nginx是一个高性能的HTTP和反向代理服务器」· C语言 代码 · 共 1,266 行 · 第 1/3 页

static ngx_int_t
ngx_event_module_init(ngx_cycle_t *cycle)
{
    void              ***cf;
    u_char              *shared;
    size_t               size, cl;
    ngx_shm_t            shm;
    ngx_core_conf_t     *ccf;
    ngx_event_conf_t    *ecf;

    cf = ngx_get_conf(cycle->conf_ctx, ngx_events_module);

    if (cf == NULL) {
        ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
                      "no \"events\" section in configuration");
        return NGX_ERROR;
    }

    ecf = (*cf)[ngx_event_core_module.ctx_index];

    if (!ngx_test_config) {
        ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0,
                      "using the \"%s\" event method", ecf->name);
    }

    ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);

    ngx_timer_resolution = ccf->timer_resolution;

#if !(NGX_WIN32)
    {
    ngx_int_t      limit;
    struct rlimit  rlmt;

    if (getrlimit(RLIMIT_NOFILE, &rlmt) == -1) {
        ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                      "getrlimit(RLIMIT_NOFILE) failed, ignored");

    } else {
        if (ecf->connections > (ngx_uint_t) rlmt.rlim_cur
            && (ccf->rlimit_nofile == NGX_CONF_UNSET
                || ecf->connections > (ngx_uint_t) ccf->rlimit_nofile))
        {
            limit = (ccf->rlimit_nofile == NGX_CONF_UNSET) ?
                         (ngx_int_t) rlmt.rlim_cur : ccf->rlimit_nofile;

            ngx_log_error(NGX_LOG_WARN, cycle->log, 0,
                          "%ui worker_connections are more than "
                          "open file resource limit: %i",
                          ecf->connections, limit);
        }
    }
    }
#endif /* !(NGX_WIN32) */


    if (ccf->master == 0) {
        return NGX_OK;
    }

    if (ngx_accept_mutex_ptr) {
        return NGX_OK;
    }


    /* cl should be equal or bigger than cache line size */

    cl = 128;

    size = cl            /* ngx_accept_mutex */
           + cl;         /* ngx_connection_counter */

#if (NGX_STAT_STUB)

    size += cl           /* ngx_stat_accepted */
           + cl          /* ngx_stat_handled */
           + cl          /* ngx_stat_requests */
           + cl          /* ngx_stat_active */
           + cl          /* ngx_stat_reading */
           + cl;         /* ngx_stat_writing */

#endif

    shm.size = size;
    shm.log = cycle->log;

    if (ngx_shm_alloc(&shm) != NGX_OK) {
        return NGX_ERROR;
    }

    shared = shm.addr;

    ngx_accept_mutex_ptr = (ngx_atomic_t *) shared;

    if (ngx_shmtx_create(&ngx_accept_mutex, shared, cycle->lock_file.data)
        != NGX_OK)
    {
        return NGX_ERROR;
    }

    ngx_connection_counter = (ngx_atomic_t *) (shared + 1 * cl);

#if (NGX_STAT_STUB)

    ngx_stat_accepted = (ngx_atomic_t *) (shared + 2 * cl);
    ngx_stat_handled = (ngx_atomic_t *) (shared + 3 * cl);
    ngx_stat_requests = (ngx_atomic_t *) (shared + 4 * cl);
    ngx_stat_active = (ngx_atomic_t *) (shared + 5 * cl);
    ngx_stat_reading = (ngx_atomic_t *) (shared + 6 * cl);
    ngx_stat_writing = (ngx_atomic_t *) (shared + 7 * cl);

#endif

    *ngx_connection_counter = 1;

    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
                   "counter: %p, %d",
                   ngx_connection_counter, *ngx_connection_counter);

    return NGX_OK;
}


#if !(NGX_WIN32)

void
ngx_timer_signal_handler(int signo)
{
    ngx_event_timer_alarm = 1;

    ngx_time_update(0, 0);

#if 1
    ngx_log_debug0(NGX_LOG_DEBUG_EVENT, ngx_cycle->log, 0, "timer signal");
#endif
}

#endif


static ngx_int_t
ngx_event_process_init(ngx_cycle_t *cycle)
{
    ngx_uint_t           m, i;
    ngx_event_t         *rev, *wev;
    ngx_listening_t     *ls;
    ngx_connection_t    *c, *next, *old;
    ngx_core_conf_t     *ccf;
    ngx_event_conf_t    *ecf;
    ngx_event_module_t  *module;

    ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
    ecf = ngx_event_get_conf(cycle->conf_ctx, ngx_event_core_module);

    if (ccf->master && ccf->worker_processes > 1 && ecf->accept_mutex) {
        ngx_use_accept_mutex = 1;
        ngx_accept_mutex_held = 0;
        ngx_accept_mutex_delay = ecf->accept_mutex_delay;

    } else {
        ngx_use_accept_mutex = 0;
    }

#if (NGX_THREADS)
    ngx_posted_events_mutex = ngx_mutex_init(cycle->log, 0);
    if (ngx_posted_events_mutex == NULL) {
        return NGX_ERROR;
    }
#endif

    if (ngx_event_timer_init(cycle->log) == NGX_ERROR) {
        return NGX_ERROR;
    }

    cycle->connection_n = ecf->connections;

    for (m = 0; ngx_modules[m]; m++) {
        if (ngx_modules[m]->type != NGX_EVENT_MODULE) {
            continue;
        }

        if (ngx_modules[m]->ctx_index == ecf->use) {
            module = ngx_modules[m]->ctx;
            if (module->actions.init(cycle, ngx_timer_resolution) == NGX_ERROR)
            {
                /* fatal */
                exit(2);
            }
            break;
        }
    }

#if !(NGX_WIN32)

    if (ngx_timer_resolution && !(ngx_event_flags & NGX_USE_TIMER_EVENT)) {
        struct sigaction  sa;
        struct itimerval  itv;

        ngx_memzero(&sa, sizeof(struct sigaction));
        sa.sa_handler = ngx_timer_signal_handler;
        sigemptyset(&sa.sa_mask);

        if (sigaction(SIGALRM, &sa, NULL) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "sigaction(SIGALRM) failed");
            return NGX_ERROR;
        }

        itv.it_interval.tv_sec = ngx_timer_resolution / 1000;
        itv.it_interval.tv_usec = (ngx_timer_resolution % 1000) * 1000;
        itv.it_value.tv_sec = ngx_timer_resolution / 1000;
        itv.it_value.tv_usec = (ngx_timer_resolution % 1000 ) * 1000;

        if (setitimer(ITIMER_REAL, &itv, NULL) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "setitimer() failed");
        }
    }

    if (ngx_event_flags & NGX_USE_FD_EVENT) {
        struct rlimit  rlmt;

        if (getrlimit(RLIMIT_NOFILE, &rlmt) == -1) {
            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
                          "getrlimit(RLIMIT_NOFILE) failed");
            return NGX_ERROR;
        }

        cycle->files_n = (ngx_uint_t) rlmt.rlim_cur;

        cycle->files = ngx_calloc(sizeof(ngx_connection_t *) * cycle->files_n,
                                  cycle->log);
        if (cycle->files == NULL) {
            return NGX_ERROR;
        }
    }

#endif

    cycle->connections = ngx_alloc(sizeof(ngx_connection_t) * ecf->connections,
                                   cycle->log);
    if (cycle->connections == NULL) {
        return NGX_ERROR;
    }

    c = cycle->connections;

    cycle->read_events = ngx_alloc(sizeof(ngx_event_t) * ecf->connections,
                                   cycle->log);
    if (cycle->read_events == NULL) {
        return NGX_ERROR;
    }

    rev = cycle->read_events;
    for (i = 0; i < cycle->connection_n; i++) {
        rev[i].closed = 1;
        rev[i].instance = 1;
#if (NGX_THREADS)
        rev[i].lock = &c[i].lock;
        rev[i].own_lock = &c[i].lock;
#endif
    }

    cycle->write_events = ngx_alloc(sizeof(ngx_event_t) * ecf->connections,
                                    cycle->log);
    if (cycle->write_events == NULL) {
        return NGX_ERROR;
    }

    wev = cycle->write_events;
    for (i = 0; i < cycle->connection_n; i++) {
        wev[i].closed = 1;
#if (NGX_THREADS)
        wev[i].lock = &c[i].lock;
        wev[i].own_lock = &c[i].lock;
#endif
    }

    i = cycle->connection_n;
    next = NULL;

    do {
        i--;

        c[i].data = next;
        c[i].read = &cycle->read_events[i];
        c[i].write = &cycle->write_events[i];
        c[i].fd = (ngx_socket_t) -1;

        next = &c[i];

#if (NGX_THREADS)
        c[i].lock = 0;
#endif
    } while (i);

    cycle->free_connections = next;
    cycle->free_connection_n = ecf->connections;

    /* for each listening socket */

    ls = cycle->listening.elts;
    for (i = 0; i < cycle->listening.nelts; i++) {

        c = ngx_get_connection(ls[i].fd, cycle->log);

        if (c == NULL) {
            return NGX_ERROR;
        }

        c->log = &ls[i].log;

        c->listening = &ls[i];
        ls[i].connection = c;

        rev = c->read;

        rev->log = c->log;
        rev->accept = 1;

#if (NGX_HAVE_DEFERRED_ACCEPT)
        rev->deferred_accept = ls[i].deferred_accept;
#endif

        if (!(ngx_event_flags & NGX_USE_IOCP_EVENT)) {
            if (ls[i].previous) {

                /*
                 * delete the old accept events that were bound to
                 * the old cycle read events array
                 */

                old = ls[i].previous->connection;

                if (ngx_del_event(old->read, NGX_READ_EVENT, NGX_CLOSE_EVENT)
                    == NGX_ERROR)
                {
                    return NGX_ERROR;
                }

                old->fd = (ngx_socket_t) -1;
            }
        }

#if (NGX_WIN32)

        if (ngx_event_flags & NGX_USE_IOCP_EVENT) {
            ngx_iocp_conf_t  *iocpcf;

            rev->handler = ngx_event_acceptex;

            if (ngx_add_event(rev, 0, NGX_IOCP_ACCEPT) == NGX_ERROR) {
                return NGX_ERROR;
            }

            ls[i].log.handler = ngx_acceptex_log_error;

            iocpcf = ngx_event_get_conf(cycle->conf_ctx, ngx_iocp_module);
            if (ngx_event_post_acceptex(&ls[i], iocpcf->post_acceptex)
                == NGX_ERROR)
            {
                return NGX_ERROR;
            }

        } else {
            rev->handler = ngx_event_accept;

            if (ngx_add_event(rev, NGX_READ_EVENT, 0) == NGX_ERROR) {
                return NGX_ERROR;
            }
        }

#else

        rev->handler = ngx_event_accept;

        if (ngx_use_accept_mutex) {
            continue;
        }

        if (ngx_event_flags & NGX_USE_RTSIG_EVENT) {
            if (ngx_add_conn(c) == NGX_ERROR) {
                return NGX_ERROR;
            }

        } else {
            if (ngx_add_event(rev, NGX_READ_EVENT, 0) == NGX_ERROR) {
                return NGX_ERROR;
            }
        }

#endif

    }

    return NGX_OK;
}


ngx_int_t
ngx_send_lowat(ngx_connection_t *c, size_t lowat)
{
    int  sndlowat;

#if (NGX_HAVE_LOWAT_EVENT)

    if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {
        c->write->available = lowat;
        return NGX_OK;
    }

#endif

    if (lowat == 0 || c->sndlowat) {
        return NGX_OK;
    }

    sndlowat = (int) lowat;

    if (setsockopt(c->fd, SOL_SOCKET, SO_SNDLOWAT,