new file mode 100644
--- /dev/null
+++ b/src/event/modules/ngx_select_module.c
@@ -0,0 +1,616 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_event.h>
+
+
+
+static ngx_int_t ngx_select_init(ngx_cycle_t *cycle);
+static void ngx_select_done(ngx_cycle_t *cycle);
+static ngx_int_t ngx_select_add_event(ngx_event_t *ev, int event, u_int flags);
+static ngx_int_t ngx_select_del_event(ngx_event_t *ev, int event, u_int flags);
+static ngx_int_t ngx_select_process_events(ngx_cycle_t *cycle);
+static char *ngx_select_init_conf(ngx_cycle_t *cycle, void *conf);
+
+
+static fd_set         master_read_fd_set;
+static fd_set         master_write_fd_set;
+static fd_set         work_read_fd_set;
+static fd_set         work_write_fd_set;
+
+#if (WIN32)
+static int            max_read;
+static int            max_write;
+#else
+static int            max_fd;
+#endif
+
+static ngx_uint_t     nevents;
+
+static ngx_event_t  **event_index;
+#if 0
+static ngx_event_t  **ready_index;
+#endif
+
+static ngx_event_t   *accept_events;
+
+
+static ngx_str_t    select_name = ngx_string("select");
+
+ngx_event_module_t  ngx_select_module_ctx = {
+    &select_name,
+    NULL,                                  /* create configuration */
+    ngx_select_init_conf,                  /* init configuration */
+
+    {
+        ngx_select_add_event,              /* add an event */
+        ngx_select_del_event,              /* delete an event */
+        ngx_select_add_event,              /* enable an event */
+        ngx_select_del_event,              /* disable an event */
+        NULL,                              /* add an connection */
+        NULL,                              /* delete an connection */
+        NULL,                              /* process the changes */
+        ngx_select_process_events,         /* process the events */
+        ngx_select_init,                   /* init the events */
+        ngx_select_done                    /* done the events */
+    }
+
+};
+
+ngx_module_t  ngx_select_module = {
+    NGX_MODULE,
+    &ngx_select_module_ctx,                /* module context */
+    NULL,                                  /* module directives */
+    NGX_EVENT_MODULE,                      /* module type */
+    NULL,                                  /* init module */
+    NULL                                   /* init process */
+};
+
+
+static ngx_int_t ngx_select_init(ngx_cycle_t *cycle)
+{
+    ngx_event_t  **index;
+
+    if (event_index == NULL) {
+        FD_ZERO(&master_read_fd_set);
+        FD_ZERO(&master_write_fd_set);
+        nevents = 0;
+    }
+
+    if (ngx_process == NGX_PROCESS_WORKER
+        || cycle->old_cycle == NULL
+        || cycle->old_cycle->connection_n < cycle->connection_n)
+    {
+        ngx_test_null(index,
+                      ngx_alloc(sizeof(ngx_event_t *) * 2 * cycle->connection_n,
+                                cycle->log),
+                      NGX_ERROR);
+
+        if (event_index) {
+            ngx_memcpy(index, event_index, sizeof(ngx_event_t *) * nevents);
+            ngx_free(event_index);
+        }
+        event_index = index;
+
+#if 0
+        if (ready_index) {
+            ngx_free(ready_index);
+        }
+        ngx_test_null(ready_index,
+                      ngx_alloc(sizeof(ngx_event_t *) * 2 * cycle->connection_n,
+                      cycle->log),
+                      NGX_ERROR);
+#endif
+    }
+
+    ngx_io = ngx_os_io;
+
+    ngx_event_actions = ngx_select_module_ctx.actions;
+
+    ngx_event_flags = NGX_USE_LEVEL_EVENT|NGX_USE_ONESHOT_EVENT;
+
+#if (WIN32)
+    max_read = max_write = 0;
+#else
+    max_fd = -1;
+#endif
+
+    return NGX_OK;
+}
+
+
+static void ngx_select_done(ngx_cycle_t *cycle)
+{
+    ngx_free(event_index);
+#if 0
+    ngx_free(ready_index);
+#endif
+
+    event_index = NULL;
+}
+
+
+static ngx_int_t ngx_select_add_event(ngx_event_t *ev, int event, u_int flags)
+{
+    ngx_connection_t  *c;
+
+    c = ev->data;
+
+    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
+                   "select add event fd:%d ev:%d", c->fd, event);
+
+    if (ev->index != NGX_INVALID_INDEX) {
+        ngx_log_error(NGX_LOG_ALERT, ev->log, 0,
+                      "select event fd:%d ev:%d is already set", c->fd, event);
+        return NGX_OK;
+    }
+
+#if (WIN32)
+
+    if ((event == NGX_READ_EVENT) && (max_read >= FD_SETSIZE)
+        || (event == NGX_WRITE_EVENT) && (max_write >= FD_SETSIZE))
+    {
+        ngx_log_error(NGX_LOG_ERR, ev->log, 0,
+                      "maximum number of descriptors "
+                      "supported by select() is %d", FD_SETSIZE);
+        return NGX_ERROR;
+    }
+
+    if (event == NGX_READ_EVENT) {
+        FD_SET(c->fd, &master_read_fd_set);
+        max_read++;
+
+    } else if (event == NGX_WRITE_EVENT) {
+        FD_SET(c->fd, &master_write_fd_set);
+        max_write++;
+    }
+
+#else
+
+    if (event == NGX_READ_EVENT) {
+        FD_SET(c->fd, &master_read_fd_set);
+
+    } else if (event == NGX_WRITE_EVENT) {
+        FD_SET(c->fd, &master_write_fd_set);
+    }
+
+    if (max_fd != -1 && max_fd < c->fd) {
+        max_fd = c->fd;
+    }
+
+#endif
+
+    ev->active = 1;
+    ev->oneshot = (u_char) ((flags & NGX_ONESHOT_EVENT) ? 1 : 0);
+
+    event_index[nevents] = ev;
+    ev->index = nevents;
+    nevents++;
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t ngx_select_del_event(ngx_event_t *ev, int event, u_int flags)
+{
+    ngx_connection_t  *c;
+
+    c = ev->data;
+
+    ev->active = 0;
+
+    if (ev->index == NGX_INVALID_INDEX) {
+        return NGX_OK;
+    }
+
+    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
+                   "select del event fd:%d ev:%d", c->fd, event);
+
+#if (WIN32)
+
+    if (event == NGX_READ_EVENT) {
+        FD_CLR(c->fd, &master_read_fd_set);
+        max_read--;
+
+    } else if (event == NGX_WRITE_EVENT) {
+        FD_CLR(c->fd, &master_write_fd_set);
+        max_write--;
+    }
+
+#else
+
+    if (event == NGX_READ_EVENT) {
+        FD_CLR(c->fd, &master_read_fd_set);
+
+    } else if (event == NGX_WRITE_EVENT) {
+        FD_CLR(c->fd, &master_write_fd_set);
+    }
+
+    if (max_fd == c->fd) {
+        max_fd = -1;
+    }
+
+#endif
+
+    if (ev->index < (u_int) --nevents) {
+        event_index[ev->index] = event_index[nevents];
+        event_index[ev->index]->index = ev->index;
+    }
+
+    ev->index = NGX_INVALID_INDEX;
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t ngx_select_process_events(ngx_cycle_t *cycle)
+{
+    int                       ready, nready;
+    ngx_uint_t                i, found, lock, expire;
+    ngx_err_t                 err;
+    ngx_msec_t                timer;
+    ngx_event_t              *ev;
+    ngx_connection_t         *c;
+    ngx_epoch_msec_t          delta;
+    struct timeval            tv, *tp;
+#if (HAVE_SELECT_CHANGE_TIMEOUT)
+    static ngx_epoch_msec_t   deltas = 0;
+#endif
+
+    for ( ;; ) {
+        timer = ngx_event_find_timer();
+
+        if (timer != 0) {
+            break;
+        }
+
+        ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
+                       "select expired timer");
+
+        ngx_event_expire_timers((ngx_msec_t)
+                                    (ngx_elapsed_msec - ngx_old_elapsed_msec));
+    }
+
+    ngx_old_elapsed_msec = ngx_elapsed_msec;
+
+    expire = 1;
+
+#if !(WIN32)
+
+    if (ngx_accept_mutex) {
+        if (ngx_accept_disabled > 0) {
+            ngx_accept_disabled--;
+
+        } else {
+            if (ngx_trylock_accept_mutex(cycle) == NGX_ERROR) {
+                return NGX_ERROR;
+            }
+
+            if (ngx_accept_mutex_held == 0
+                && (timer == NGX_TIMER_INFINITE
+                    || timer > ngx_accept_mutex_delay))
+            {
+                timer = ngx_accept_mutex_delay;
+                expire = 0;
+            }
+        }
+    }
+
+    if (max_fd == -1) {
+        for (i = 0; i < nevents; i++) {
+            c = event_index[i]->data;
+            if (max_fd < c->fd) {
+                max_fd = c->fd;
+            }
+        }
+
+        ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
+                       "change max_fd: %d", max_fd);
+    }
+
+#endif
+
+#if (NGX_DEBUG)
+    if (cycle->log->log_level & NGX_LOG_DEBUG_ALL) {
+        for (i = 0; i < nevents; i++) {
+            ev = event_index[i];
+            c = ev->data;
+            ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
+                           "select event: fd:%d wr:%d", c->fd, ev->write);
+        }
+
+#if !(WIN32)
+        ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
+                       "max_fd: %d", max_fd);
+#endif
+    }
+#endif
+
+    if (timer == NGX_TIMER_INFINITE) {
+        tp = NULL;
+        expire = 0;
+
+    } else {
+        tv.tv_sec = timer / 1000;
+        tv.tv_usec = (timer % 1000) * 1000;
+        tp = &tv;
+    }
+
+    ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
+                   "select timer: %d", timer);
+
+    work_read_fd_set = master_read_fd_set;
+    work_write_fd_set = master_write_fd_set;
+
+    ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
+                   "select read fd_set: %08X", *(int *) &work_read_fd_set);
+
+#if (WIN32)
+    ready = select(0, &work_read_fd_set, &work_write_fd_set, NULL, tp);
+#else
+    ready = select(max_fd + 1, &work_read_fd_set, &work_write_fd_set, NULL, tp);
+#endif
+
+    if (ready == -1) {
+        err = ngx_socket_errno;
+    } else {
+        err = 0;
+    }
+
+#if (HAVE_SELECT_CHANGE_TIMEOUT)
+
+    if (timer != NGX_TIMER_INFINITE) {
+        delta = timer - (tv.tv_sec * 1000 + tv.tv_usec / 1000);
+
+        /*
+         * learn the real time and update the cached time
+         * if the sum of the last deltas overcomes 1 second
+         */
+
+        deltas += delta;
+        if (deltas > 1000) {
+            ngx_gettimeofday(&tv);
+            ngx_time_update(tv.tv_sec);
+            deltas = tv.tv_usec / 1000;
+
+            ngx_elapsed_msec = (ngx_epoch_msec_t) tv.tv_sec * 1000
+                                          + tv.tv_usec / 1000 - ngx_start_msec;
+        } else {
+            ngx_elapsed_msec += delta;
+        }
+
+        ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
+                       "select timer: %d, delta: %d", timer, (int) delta);
+
+    } else {
+        delta = 0;
+        ngx_gettimeofday(&tv);
+        ngx_time_update(tv.tv_sec);
+
+        ngx_elapsed_msec = (ngx_epoch_msec_t) tv.tv_sec * 1000
+                                          + tv.tv_usec / 1000 - ngx_start_msec;
+
+        if (ready == 0) {
+            ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
+                          "select() returned no events without timeout");
+            ngx_accept_mutex_unlock();
+            return NGX_ERROR;
+        }
+    }
+
+#else /* !(HAVE_SELECT_CHANGE_TIMEOUT) */
+
+    ngx_gettimeofday(&tv);
+    ngx_time_update(tv.tv_sec);
+
+    delta = ngx_elapsed_msec;
+    ngx_elapsed_msec = (ngx_epoch_msec_t) tv.tv_sec * 1000
+                                          + tv.tv_usec / 1000 - ngx_start_msec;
+
+    if (timer != NGX_TIMER_INFINITE) {
+        delta = ngx_elapsed_msec - delta;
+
+        ngx_log_debug2(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
+                       "select timer: %d, delta: %d", timer, (int) delta);
+
+    } else {
+        if (ready == 0) {
+            ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
+                          "select() returned no events without timeout");
+            ngx_accept_mutex_unlock();
+            return NGX_ERROR;
+        }
+    }
+
+#endif /* HAVE_SELECT_CHANGE_TIMEOUT */
+
+    ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
+                   "select ready %d", ready);
+
+    if (err) {
+#if (WIN32)
+        ngx_log_error(NGX_LOG_ALERT, cycle->log, err, "select() failed");
+#else
+        ngx_log_error((err == NGX_EINTR) ? NGX_LOG_INFO : NGX_LOG_ALERT,
+                      cycle->log, err, "select() failed");
+#endif
+        ngx_accept_mutex_unlock();
+        return NGX_ERROR;
+    }
+
+
+    if (ngx_mutex_lock(ngx_posted_events_mutex) == NGX_ERROR) {
+        ngx_accept_mutex_unlock();
+        return NGX_ERROR;
+    }
+
+    lock = 1;
+    nready = 0;
+
+    for (i = 0; i < nevents; i++) {
+        ev = event_index[i];
+        c = ev->data;
+        found = 0;
+
+        if (ev->write) {
+            if (FD_ISSET(c->fd, &work_write_fd_set)) {
+                found = 1;
+                ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
+                               "select write %d", c->fd);
+            }
+
+        } else {
+            if (FD_ISSET(c->fd, &work_read_fd_set)) {
+                found = 1;
+                ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
+                               "select read %d", c->fd);
+            }
+        }
+
+        if (found) {
+            ev->ready = 1;
+
+            if (ev->oneshot) {
+                if (ev->timer_set) {
+                    ngx_del_timer(ev);
+                }
+
+                if (ev->write) {
+                    ngx_select_del_event(ev, NGX_WRITE_EVENT, 0);
+                } else {
+                    ngx_select_del_event(ev, NGX_READ_EVENT, 0);
+                }
+            }
+
+            if (ev->accept) {
+                ev->next = accept_events;
+                accept_events = ev;
+            } else {
+                ngx_post_event(ev);
+            }
+
+            nready++;
+
+#if 0
+            ready_index[nready++] = ev;
+#endif
+        }
+    }
+
+#if 0
+    for (i = 0; i < nready; i++) {
+        ev = ready_index[i];
+        ready--;
+
+        if (!ev->active) {
+            continue;
+        }
+
+        ev->ready = 1;
+
+        if (ev->oneshot) {
+            if (ev->timer_set) {
+                ngx_del_timer(ev);
+            }
+
+            if (ev->write) {
+                ngx_select_del_event(ev, NGX_WRITE_EVENT, 0);
+            } else {
+                ngx_select_del_event(ev, NGX_READ_EVENT, 0);
+            }
+        }
+
+        ev->event_handler(ev);
+    }
+#endif
+
+    ev = accept_events;
+
+    for ( ;; ) {
+
+        ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
+                      "accept event " PTR_FMT, ev);
+
+        if (ev == NULL) {
+            break;
+        }
+
+        ngx_mutex_unlock(ngx_posted_events_mutex);
+
+        ev->event_handler(ev);
+
+        if (ngx_accept_disabled > 0) {
+            lock = 0;
+            break;
+        }
+
+        ev = ev->next;
+
+        if (ev == NULL) {
+            lock = 0;
+            break;
+        }
+
+        if (ngx_mutex_lock(ngx_posted_events_mutex) == NGX_ERROR) {
+            ngx_accept_mutex_unlock();
+            return NGX_ERROR;
+        }
+    }
+
+    ngx_accept_mutex_unlock();
+    accept_events = NULL;
+
+    if (lock) {
+        ngx_mutex_unlock(ngx_posted_events_mutex);
+    }
+
+    if (ready != nready) {
+        ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "select ready != events");
+    }
+
+    if (expire && delta) {
+        ngx_event_expire_timers((ngx_msec_t) delta);
+    }
+
+    if (!ngx_threaded) {
+        ngx_event_process_posted(cycle);
+    }
+
+    return NGX_OK;
+}
+
+
+static char *ngx_select_init_conf(ngx_cycle_t *cycle, void *conf)
+{
+    ngx_event_conf_t  *ecf;
+
+    ecf = ngx_event_get_conf(cycle->conf_ctx, ngx_event_core_module);
+
+    if (ecf->use != ngx_select_module.ctx_index) {
+        return NGX_CONF_OK;
+    }
+
+    /* disable warning: the default FD_SETSIZE is 1024U in FreeBSD 5.x */
+
+#if !(WIN32)
+    if ((unsigned) ecf->connections > FD_SETSIZE) {
+        ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
+                      "the maximum number of files "
+                      "supported by select() is " ngx_value(FD_SETSIZE));
+        return NGX_CONF_ERROR;
+    }
+#endif
+
+#if (NGX_THREADS)
+    ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
+                  "select() is not supported in the threaded mode");
+    return NGX_CONF_ERROR;
+#else
+    return NGX_CONF_OK;
+#endif
+}