new file mode 100644
--- /dev/null
+++ b/src/event/ngx_event_connect.c
@@ -0,0 +1,379 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_event.h>
+#include <ngx_event_connect.h>
+#include <nginx.h>
+
+
+/* AF_INET only */
+
+int ngx_event_connect_peer(ngx_peer_connection_t *pc)
+{
+    int                  rc;
+    ngx_uint_t           instance;
+    u_int                event;
+    time_t               now;
+    ngx_err_t            err;
+    ngx_peer_t          *peer;
+    ngx_socket_t         s;
+    ngx_event_t         *rev, *wev;
+    ngx_connection_t    *c;
+    ngx_event_conf_t    *ecf;
+    struct sockaddr_in   addr;
+
+    now = ngx_time();
+
+    /* ngx_lock_mutex(pc->peers->mutex); */
+
+    if (pc->peers->last_cached) {
+
+        /* cached connection */
+
+        c = pc->peers->cached[pc->peers->last_cached];
+        pc->peers->last_cached--;
+
+        /* ngx_unlock_mutex(pc->peers->mutex); */
+
+#if (NGX_THREADS)
+        c->read->lock = c->read->own_lock;
+        c->write->lock = c->write->own_lock;
+#endif
+
+        pc->connection = c;
+        pc->cached = 1;
+        return NGX_OK;
+    }
+
+    pc->cached = 0;
+    pc->connection = NULL;
+
+    if (pc->peers->number == 1) {
+        peer = &pc->peers->peers[0];
+
+    } else {
+
+        /* there are several peers */
+
+        if (pc->tries == pc->peers->number) {
+
+            /* it's a first try - get a current peer */
+
+            pc->cur_peer = pc->peers->current++;
+
+            if (pc->peers->current >= pc->peers->number) {
+                pc->peers->current = 0;
+            }
+        }
+
+        if (pc->peers->max_fails == 0) {
+            peer = &pc->peers->peers[pc->cur_peer];
+
+        } else {
+
+            /* the peers support a fault tolerance */
+
+            for ( ;; ) {
+                peer = &pc->peers->peers[pc->cur_peer];
+
+                if (peer->fails <= pc->peers->max_fails
+                    || (now - peer->accessed > pc->peers->fail_timeout))
+                {
+                    break;
+                }
+
+                pc->cur_peer++;
+
+                if (pc->cur_peer >= pc->peers->number) {
+                    pc->cur_peer = 0;
+                }
+
+                pc->tries--;
+
+                if (pc->tries == 0) {
+                    /* ngx_unlock_mutex(pc->peers->mutex); */
+
+                    return NGX_ERROR;
+                }
+            }
+        }
+    }
+
+    /* ngx_unlock_mutex(pc->peers->mutex); */
+
+
+    s = ngx_socket(AF_INET, SOCK_STREAM, IPPROTO_IP, 0);
+
+    if (s == -1) {
+        ngx_log_error(NGX_LOG_ALERT, pc->log, ngx_socket_errno,
+                      ngx_socket_n " failed");
+        return NGX_ERROR;
+    }
+
+
+    ecf = ngx_event_get_conf(ngx_cycle->conf_ctx, ngx_event_core_module);
+
+    /* disable warning: Win32 SOCKET is u_int while UNIX socket is int */
+
+    if ((ngx_uint_t) s >= ecf->connections) {
+
+        ngx_log_error(NGX_LOG_ALERT, pc->log, 0,
+                      "socket() returned socket #%d while only %d "
+                      "connections was configured, closing the socket",
+                      s, ecf->connections);
+
+        if (ngx_close_socket(s) == -1) {
+            ngx_log_error(NGX_LOG_ALERT, pc->log, ngx_socket_errno,
+                          ngx_close_socket_n "failed");
+        }
+
+        /* TODO: sleep for some time */
+
+        return NGX_ERROR;
+    }
+
+
+    if (pc->rcvbuf) {
+        if (setsockopt(s, SOL_SOCKET, SO_RCVBUF,
+                       (const void *) &pc->rcvbuf, sizeof(int)) == -1) {
+            ngx_log_error(NGX_LOG_ALERT, pc->log, ngx_socket_errno,
+                          "setsockopt(SO_RCVBUF) failed");
+
+            if (ngx_close_socket(s) == -1) {
+                ngx_log_error(NGX_LOG_ALERT, pc->log, ngx_socket_errno,
+                              ngx_close_socket_n " failed");
+            }
+
+            return NGX_ERROR;
+        }
+    }
+
+    if (ngx_nonblocking(s) == -1) {
+        ngx_log_error(NGX_LOG_ALERT, pc->log, ngx_socket_errno,
+                      ngx_nonblocking_n " failed");
+
+        if (ngx_close_socket(s) == -1) {
+            ngx_log_error(NGX_LOG_ALERT, pc->log, ngx_socket_errno,
+                          ngx_close_socket_n " failed");
+        }
+
+        return NGX_ERROR;
+    }
+
+#if (WIN32)
+    /*
+     * Winsock assignes a socket number divisible by 4
+     * so to find a connection we divide a socket number by 4.
+     */
+
+    if (s % 4) {
+        ngx_log_error(NGX_LOG_EMERG, pc->log, 0,
+                      ngx_socket_n
+                      " created socket %d, not divisible by 4", s);
+        exit(1);
+    }
+
+    c = &ngx_cycle->connections[s / 4];
+    rev = &ngx_cycle->read_events[s / 4];
+    wev = &ngx_cycle->write_events[s / 4];
+
+#else
+
+    c = &ngx_cycle->connections[s];
+    rev = &ngx_cycle->read_events[s];
+    wev = &ngx_cycle->write_events[s];
+
+#endif
+
+    instance = rev->instance;
+
+#if (NGX_THREADS)
+
+    if (*(&c->lock)) {
+        ngx_log_debug1(NGX_LOG_DEBUG_EVENT, pc->log, 0,
+                       "spinlock in connect, fd:%d", s);
+        ngx_spinlock(&c->lock, 1000);
+        ngx_unlock(&c->lock);
+    }
+
+#endif
+
+    ngx_memzero(c, sizeof(ngx_connection_t));
+    ngx_memzero(rev, sizeof(ngx_event_t));
+    ngx_memzero(wev, sizeof(ngx_event_t));
+
+    rev->instance = !instance;
+    wev->instance = !instance;
+
+    rev->index = NGX_INVALID_INDEX;
+    wev->index = NGX_INVALID_INDEX;
+
+    rev->data = c;
+    wev->data = c;
+
+    c->read = rev;
+    c->write = wev;
+    wev->write = 1;
+
+    c->log = pc->log;
+    rev->log = pc->log;
+    wev->log = pc->log;
+
+    c->fd = s;
+
+    c->log_error = pc->log_error;
+
+    pc->connection = c;
+
+    /*
+     * TODO: MT: - atomic increment (x86: lock xadd)
+     *             or protection by critical section or mutex
+     *
+     * TODO: MP: - allocated in a shared memory
+     *           - atomic increment (x86: lock xadd)
+     *             or protection by critical section or mutex
+     */
+
+    c->number = ngx_atomic_inc(ngx_connection_counter);
+
+#if (NGX_THREADS)
+    rev->lock = pc->lock;
+    wev->lock = pc->lock;
+    rev->own_lock = &c->lock;
+    wev->own_lock = &c->lock;
+#endif
+
+    if (ngx_add_conn) {
+        if (ngx_add_conn(c) == NGX_ERROR) {
+            return NGX_ERROR;
+        }
+    } 
+
+    ngx_memzero(&addr, sizeof(struct sockaddr_in));
+
+    addr.sin_family = AF_INET;
+    addr.sin_port = peer->port;
+    addr.sin_addr.s_addr = peer->addr;
+
+    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, pc->log, 0,
+                   "connect to %s, #%d", peer->addr_port_text.data, c->number);
+
+    rc = connect(s, (struct sockaddr *) &addr, sizeof(struct sockaddr_in));
+
+    if (rc == -1) {
+        err = ngx_socket_errno;
+
+        /* Winsock returns WSAEWOULDBLOCK (NGX_EAGAIN) */
+
+        if (err != NGX_EINPROGRESS && err != NGX_EAGAIN) {
+            ngx_connection_error(c, err, "connect() failed");
+
+            if (ngx_close_socket(s) == -1) {
+                ngx_log_error(NGX_LOG_ALERT, pc->log, ngx_socket_errno,
+                              ngx_close_socket_n " failed");
+            }
+
+            c->fd = (ngx_socket_t) -1;
+
+            return NGX_CONNECT_ERROR;
+        }
+    }
+
+    if (ngx_add_conn) {
+        if (rc == -1) {
+            /* NGX_EINPROGRESS */
+            return NGX_AGAIN;
+        }
+ 
+        ngx_log_debug0(NGX_LOG_DEBUG_EVENT, pc->log, 0, "connected");
+        return NGX_OK;
+    }
+
+    if (ngx_event_flags & NGX_USE_AIO_EVENT) {
+
+        /* aio, iocp */
+
+        if (ngx_blocking(s) == -1) {
+            ngx_log_error(NGX_LOG_ALERT, pc->log, ngx_socket_errno,
+                          ngx_blocking_n " failed");
+
+            if (ngx_close_socket(s) == -1) {
+                ngx_log_error(NGX_LOG_ALERT, pc->log, ngx_socket_errno,
+                              ngx_close_socket_n " failed");
+            }
+
+            return NGX_ERROR;
+        }
+
+        /*
+         * aio allows to post operation on non-connected socket
+         * at least in FreeBSD.
+         * NT does not support it.
+         * 
+         * TODO: check in Win32, etc. As workaround we can use NGX_ONESHOT_EVENT
+         */
+ 
+        rev->ready = 1;
+        wev->ready = 1;
+
+        return NGX_OK;
+    }
+
+    if (ngx_event_flags & NGX_USE_CLEAR_EVENT) {     /* kqueue */
+        event = NGX_CLEAR_EVENT;
+
+    } else {                                  /* select, poll, /dev/poll */
+        event = NGX_LEVEL_EVENT;
+    }
+
+    if (ngx_add_event(rev, NGX_READ_EVENT, event) != NGX_OK) {
+        return NGX_ERROR;
+    }
+
+    if (rc == -1) {
+
+        /* NGX_EINPROGRESS */
+
+        if (ngx_add_event(wev, NGX_WRITE_EVENT, event) != NGX_OK) {
+            return NGX_ERROR;
+        }
+
+        return NGX_AGAIN;
+    }
+
+    ngx_log_debug0(NGX_LOG_DEBUG_EVENT, pc->log, 0, "connected");
+
+    wev->ready = 1;
+
+    return NGX_OK;
+}
+
+
+void ngx_event_connect_peer_failed(ngx_peer_connection_t *pc)
+{
+    time_t  now;
+
+    now = ngx_time();
+
+    /* ngx_lock_mutex(pc->peers->mutex); */
+
+    pc->peers->peers[pc->cur_peer].fails++;
+    pc->peers->peers[pc->cur_peer].accessed = now;
+
+    /* ngx_unlock_mutex(pc->peers->mutex); */
+
+    pc->cur_peer++;
+
+    if (pc->cur_peer >= pc->peers->number) {
+        pc->cur_peer = 0;
+    }
+
+    pc->tries--;
+
+    return;
+}