new file mode 100644
--- /dev/null
+++ b/src/core/ngx_cycle.c
@@ -0,0 +1,767 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_event.h>
+
+
+static void ngx_clean_old_cycles(ngx_event_t *ev);
+
+
+volatile ngx_cycle_t  *ngx_cycle;
+ngx_array_t            ngx_old_cycles;
+
+static ngx_pool_t     *ngx_temp_pool;
+static ngx_event_t     ngx_cleaner_event;
+
+ngx_uint_t             ngx_test_config;
+
+#if (NGX_THREADS)
+ngx_tls_key_t          ngx_core_tls_key;
+#endif
+
+
+/* STUB NAME */
+static ngx_connection_t  dumb;
+/* STUB */
+
+#ifdef NGX_ERROR_LOG_PATH
+static ngx_str_t  error_log = ngx_string(NGX_ERROR_LOG_PATH);
+#else
+static ngx_str_t  error_log = ngx_null_string;
+#endif
+
+
+ngx_cycle_t *ngx_init_cycle(ngx_cycle_t *old_cycle)
+{
+    void               *rv;
+    ngx_uint_t          i, n, failed;
+    ngx_log_t          *log;
+    ngx_conf_t          conf;
+    ngx_pool_t         *pool;
+    ngx_cycle_t        *cycle, **old;
+    ngx_socket_t        fd;
+    ngx_list_part_t    *part;
+    ngx_open_file_t    *file;
+    ngx_listening_t    *ls, *nls;
+    ngx_core_module_t  *module;
+
+    log = old_cycle->log;
+
+    if (!(pool = ngx_create_pool(16 * 1024, log))) {
+        return NULL;
+    }
+    pool->log = log;
+
+    if (!(cycle = ngx_pcalloc(pool, sizeof(ngx_cycle_t)))) {
+        ngx_destroy_pool(pool);
+        return NULL;
+    }
+    cycle->pool = pool;
+    cycle->log = log;
+    cycle->old_cycle = old_cycle;
+    cycle->conf_file = old_cycle->conf_file;
+    cycle->root.len = sizeof(NGX_PREFIX) - 1;
+    cycle->root.data = (u_char *) NGX_PREFIX;
+
+
+    n = old_cycle->pathes.nelts ? old_cycle->pathes.nelts : 10;
+    if (!(cycle->pathes.elts = ngx_pcalloc(pool, n * sizeof(ngx_path_t *)))) {
+        ngx_destroy_pool(pool);
+        return NULL;
+    }
+    cycle->pathes.nelts = 0;
+    cycle->pathes.size = sizeof(ngx_path_t *);
+    cycle->pathes.nalloc = n;
+    cycle->pathes.pool = pool;
+
+
+    if (old_cycle->open_files.part.nelts) {
+        n = old_cycle->open_files.part.nelts;
+        for (part = old_cycle->open_files.part.next; part; part = part->next) {
+            n += part->nelts;
+        }
+
+    } else {
+        n = 20;
+    }
+
+    if (ngx_list_init(&cycle->open_files, pool, n, sizeof(ngx_open_file_t))
+                                                                  == NGX_ERROR)
+    {
+        ngx_destroy_pool(pool);
+        return NULL;
+    }
+
+
+    if (!(cycle->new_log = ngx_log_create_errlog(cycle, NULL))) {
+        ngx_destroy_pool(pool);
+        return NULL;
+    }
+
+    cycle->new_log->file->name = error_log;
+
+
+    n = old_cycle->listening.nelts ? old_cycle->listening.nelts : 10;
+    cycle->listening.elts = ngx_pcalloc(pool, n * sizeof(ngx_listening_t));
+    if (cycle->listening.elts == NULL) {
+        ngx_destroy_pool(pool);
+        return NULL;
+    }
+    cycle->listening.nelts = 0;
+    cycle->listening.size = sizeof(ngx_listening_t);
+    cycle->listening.nalloc = n;
+    cycle->listening.pool = pool;
+
+
+    cycle->conf_ctx = ngx_pcalloc(pool, ngx_max_module * sizeof(void *));
+    if (cycle->conf_ctx == NULL) {
+        ngx_destroy_pool(pool);
+        return NULL;
+    }
+
+
+    for (i = 0; ngx_modules[i]; i++) {
+        if (ngx_modules[i]->type != NGX_CORE_MODULE) {
+            continue;
+        }
+
+        module = ngx_modules[i]->ctx;
+
+        if (module->create_conf) {
+            rv = module->create_conf(cycle);
+            if (rv == NGX_CONF_ERROR) {
+                ngx_destroy_pool(pool);
+                return NULL;
+            }
+            cycle->conf_ctx[ngx_modules[i]->index] = rv;
+        }
+    }
+
+
+    ngx_memzero(&conf, sizeof(ngx_conf_t));
+    /* STUB: init array ? */
+    conf.args = ngx_create_array(pool, 10, sizeof(ngx_str_t));
+    if (conf.args == NULL) {
+        ngx_destroy_pool(pool);
+        return NULL;
+    }
+
+    conf.ctx = cycle->conf_ctx;
+    conf.cycle = cycle;
+    conf.pool = pool;
+    conf.log = log;
+    conf.module_type = NGX_CORE_MODULE;
+    conf.cmd_type = NGX_MAIN_CONF;
+
+
+    if (ngx_conf_parse(&conf, &cycle->conf_file) != NGX_CONF_OK) {
+        ngx_destroy_pool(pool);
+        return NULL;
+    }
+
+    if (ngx_test_config) {
+        ngx_log_error(NGX_LOG_INFO, log, 0,
+                      "the configuration file %s syntax is ok",
+                      cycle->conf_file.data);
+    }
+
+
+    for (i = 0; ngx_modules[i]; i++) {
+        if (ngx_modules[i]->type != NGX_CORE_MODULE) {
+            continue;
+        }
+
+        module = ngx_modules[i]->ctx;
+
+        if (module->init_conf) {
+            if (module->init_conf(cycle, cycle->conf_ctx[ngx_modules[i]->index])
+                                                              == NGX_CONF_ERROR)
+            {
+                ngx_destroy_pool(pool);
+                return NULL;
+            }
+        }
+    }
+
+
+    failed = 0;
+
+
+#if !(WIN32)
+    if (ngx_create_pidfile(cycle, old_cycle) == NGX_ERROR) {
+        failed = 1;
+    }
+#endif
+
+
+    if (!failed) {
+
+        part = &cycle->open_files.part;
+        file = part->elts;
+
+        for (i = 0; /* void */ ; i++) {
+
+            if (i >= part->nelts) {
+                if (part->next == NULL) {
+                    break;
+                }
+                part = part->next;
+                file = part->elts;
+                i = 0;
+            }
+
+            if (file[i].name.data == NULL) {
+                continue;
+            }
+
+            file[i].fd = ngx_open_file(file[i].name.data,
+                                       NGX_FILE_RDWR,
+                                       NGX_FILE_CREATE_OR_OPEN|NGX_FILE_APPEND);
+
+#if 0
+            log->log_level = NGX_LOG_DEBUG_ALL;
+#endif
+            ngx_log_debug3(NGX_LOG_DEBUG_CORE, log, 0,
+                           "log: %0X %d \"%s\"",
+                           &file[i], file[i].fd, file[i].name.data);
+
+            if (file[i].fd == NGX_INVALID_FILE) {
+                ngx_log_error(NGX_LOG_EMERG, log, ngx_errno,
+                              ngx_open_file_n " \"%s\" failed",
+                              file[i].name.data);
+                failed = 1;
+                break;
+            }
+
+#if (WIN32)
+            if (ngx_file_append_mode(file[i].fd) == NGX_ERROR) {
+                ngx_log_error(NGX_LOG_EMERG, log, ngx_errno,
+                              ngx_file_append_mode_n " \"%s\" failed",
+                              file[i].name.data);
+                failed = 1;
+                break;
+            }
+#else
+            if (fcntl(file[i].fd, F_SETFD, FD_CLOEXEC) == -1) {
+                ngx_log_error(NGX_LOG_EMERG, log, ngx_errno,
+                              "fcntl(FD_CLOEXEC) \"%s\" failed",
+                              file[i].name.data);
+                failed = 1;
+                break;
+            }
+#endif
+        }
+    }
+
+    cycle->log = cycle->new_log;
+    pool->log = cycle->new_log;
+
+    if (cycle->log->log_level == 0) {
+        cycle->log->log_level = NGX_LOG_ERR;
+    }
+
+    if (!failed) {
+        if (old_cycle->listening.nelts) {
+            ls = old_cycle->listening.elts;
+            for (i = 0; i < old_cycle->listening.nelts; i++) {
+                ls[i].remain = 0;
+            }
+
+            nls = cycle->listening.elts;
+            for (n = 0; n < cycle->listening.nelts; n++) {
+                for (i = 0; i < old_cycle->listening.nelts; i++) {
+                    if (ls[i].ignore) {
+                        continue;
+                    }
+
+                    if (ngx_memcmp(nls[n].sockaddr,
+                                   ls[i].sockaddr, ls[i].socklen) == 0)
+                    {
+                        fd = ls[i].fd;
+#if (WIN32)
+                        /*
+                         * Winsock assignes a socket number divisible by 4 so
+                         * to find a connection we divide a socket number by 4.
+                         */
+
+                        fd /= 4;
+#endif
+                        if (fd >= (ngx_socket_t) cycle->connection_n) {
+                            ngx_log_error(NGX_LOG_EMERG, log, 0,
+                                        "%d connections is not enough to hold "
+                                        "an open listening socket on %s, "
+                                        "required at least %d connections",
+                                        cycle->connection_n,
+                                        ls[i].addr_text.data, fd);
+                            failed = 1;
+                            break;
+                        }
+
+                        nls[n].fd = ls[i].fd;
+                        nls[i].remain = 1;
+                        ls[i].remain = 1;
+                        break;
+                    }
+                }
+
+                if (nls[n].fd == -1) {
+                    nls[n].new = 1;
+                }
+            }
+
+        } else {
+            ls = cycle->listening.elts;
+            for (i = 0; i < cycle->listening.nelts; i++) {
+                ls[i].new = 1;
+            }
+        }
+
+        if (!ngx_test_config && !failed) {
+            if (ngx_open_listening_sockets(cycle) == NGX_ERROR) {
+                failed = 1;
+            }
+        }
+    }
+
+    if (failed) {
+
+        /* rollback the new cycle configuration */
+
+        part = &cycle->open_files.part;
+        file = part->elts;
+
+        for (i = 0; /* void */ ; i++) {
+
+            if (i >= part->nelts) {
+                if (part->next == NULL) {
+                    break;
+                }
+                part = part->next;
+                file = part->elts;
+                i = 0;
+            }
+
+            if (file[i].fd == NGX_INVALID_FILE
+                || file[i].fd == ngx_stderr_fileno)
+            {
+                continue;
+            }
+
+            if (ngx_close_file(file[i].fd) == NGX_FILE_ERROR) {
+                ngx_log_error(NGX_LOG_EMERG, log, ngx_errno,
+                              ngx_close_file_n " \"%s\" failed",
+                              file[i].name.data);
+            }
+        }
+
+        if (ngx_test_config) {
+            ngx_destroy_pool(pool);
+            return NULL;
+        }
+
+        ls = cycle->listening.elts;
+        for (i = 0; i < cycle->listening.nelts; i++) {
+            if (ls[i].fd == -1 || !ls[i].new) {
+                continue;
+            }
+
+            if (ngx_close_socket(ls[i].fd) == -1) {
+                ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
+                              ngx_close_socket_n " %s failed",
+                              ls[i].addr_text.data);
+            }
+        }
+
+        ngx_destroy_pool(pool);
+        return NULL;
+    }
+
+
+    /* commit the new cycle configuration */
+
+#if !(WIN32)
+
+    if (!ngx_test_config && cycle->log->file->fd != STDERR_FILENO) {
+
+        ngx_log_debug3(NGX_LOG_DEBUG_CORE, log, 0,
+                       "dup2: %0X %d \"%s\"",
+                       cycle->log->file,
+                       cycle->log->file->fd, cycle->log->file->name.data);
+
+        if (dup2(cycle->log->file->fd, STDERR_FILENO) == NGX_ERROR) {
+            ngx_log_error(NGX_LOG_EMERG, log, ngx_errno,
+                          "dup2(STDERR) failed");
+            /* fatal */
+            exit(1);
+        }
+    }
+
+#endif
+
+    pool->log = cycle->log;
+
+    for (i = 0; ngx_modules[i]; i++) {
+        if (ngx_modules[i]->init_module) {
+            if (ngx_modules[i]->init_module(cycle) == NGX_ERROR) {
+                /* fatal */
+                exit(1);
+            }
+        }
+    }
+
+    /* close and delete stuff that lefts from an old cycle */
+
+    /* close the unneeded listening sockets */
+
+    ls = old_cycle->listening.elts;
+    for (i = 0; i < old_cycle->listening.nelts; i++) {
+        if (ls[i].remain) {
+            continue;
+        }
+
+        if (ngx_close_socket(ls[i].fd) == -1) {
+            ngx_log_error(NGX_LOG_EMERG, log, ngx_socket_errno,
+                          ngx_close_socket_n " %s failed",
+                          ls[i].addr_text.data);
+        }
+    }
+
+
+    /* close the unneeded open files */
+
+    part = &old_cycle->open_files.part;
+    file = part->elts;
+
+    for (i = 0; /* void */ ; i++) {
+
+        if (i >= part->nelts) {
+            if (part->next == NULL) {
+                break;
+            }
+            part = part->next;
+            file = part->elts;
+            i = 0;
+        }
+
+        if (file[i].fd == NGX_INVALID_FILE || file[i].fd == ngx_stderr_fileno) {
+            continue;
+        }
+
+        if (ngx_close_file(file[i].fd) == NGX_FILE_ERROR) {
+            ngx_log_error(NGX_LOG_EMERG, log, ngx_errno,
+                          ngx_close_file_n " \"%s\" failed",
+                          file[i].name.data);
+        }
+    }
+
+    if (old_cycle->connections == NULL) {
+        /* an old cycle is an init cycle */
+        ngx_destroy_pool(old_cycle->pool);
+        return cycle;
+    }
+
+    if (ngx_process == NGX_PROCESS_MASTER) {
+        ngx_destroy_pool(old_cycle->pool);
+        return cycle;
+    }
+
+    if (ngx_temp_pool == NULL) {
+        ngx_temp_pool = ngx_create_pool(128, cycle->log);
+        if (ngx_temp_pool == NULL) {
+            ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
+                          "can not create ngx_temp_pool");
+            exit(1);
+        }
+
+        n = 10;
+        ngx_old_cycles.elts = ngx_pcalloc(ngx_temp_pool,
+                                          n * sizeof(ngx_cycle_t *));
+        if (ngx_old_cycles.elts == NULL) {
+            exit(1);
+        }
+        ngx_old_cycles.nelts = 0;
+        ngx_old_cycles.size = sizeof(ngx_cycle_t *);
+        ngx_old_cycles.nalloc = n;
+        ngx_old_cycles.pool = ngx_temp_pool;
+
+        ngx_cleaner_event.event_handler = ngx_clean_old_cycles;
+        ngx_cleaner_event.log = cycle->log;
+        ngx_cleaner_event.data = &dumb;
+        dumb.fd = (ngx_socket_t) -1;
+    }
+
+    ngx_temp_pool->log = cycle->log;
+
+    old = ngx_push_array(&ngx_old_cycles);
+    if (old == NULL) {
+        exit(1);
+    }
+    *old = old_cycle;
+
+    if (!ngx_cleaner_event.timer_set) {
+        ngx_add_timer(&ngx_cleaner_event, 30000);
+        ngx_cleaner_event.timer_set = 1;
+    }
+
+    return cycle;
+}
+
+
+#if !(WIN32)
+
+ngx_int_t ngx_create_pidfile(ngx_cycle_t *cycle, ngx_cycle_t *old_cycle)
+{
+    ngx_uint_t        trunc;
+    size_t            len;
+    u_char           *name, pid[NGX_INT64_LEN + 1];
+    ngx_file_t        file;
+    ngx_core_conf_t  *ccf, *old_ccf;
+
+    if (!ngx_test_config && old_cycle && old_cycle->conf_ctx == NULL) {
+
+        /*
+         * do not create the pid file in the first ngx_init_cycle() call
+         * because we need to write the demonized process pid 
+         */
+
+        return NGX_OK;
+    }
+
+    ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
+
+    if (!ngx_test_config && old_cycle) {
+        old_ccf = (ngx_core_conf_t *) ngx_get_conf(old_cycle->conf_ctx,
+                                                   ngx_core_module);
+
+        if (ccf->pid.len == old_ccf->pid.len
+            && ngx_strcmp(ccf->pid.data, old_ccf->pid.data) == 0)
+        {
+
+            /* pid file name is the same */
+
+            return NGX_OK;
+        }
+    }
+
+    len = ngx_snprintf((char *) pid, NGX_INT64_LEN + 1, PID_T_FMT, ngx_pid);
+
+    ngx_memzero(&file, sizeof(ngx_file_t));
+    file.name = (ngx_inherited && getppid() > 1) ? ccf->newpid : ccf->pid;
+    file.log = cycle->log;
+
+    trunc = ngx_test_config ? 0: NGX_FILE_TRUNCATE;
+
+    file.fd = ngx_open_file(file.name.data, NGX_FILE_RDWR,
+                            NGX_FILE_CREATE_OR_OPEN|trunc);
+
+    if (file.fd == NGX_INVALID_FILE) {
+        ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
+                      ngx_open_file_n " \"%s\" failed", file.name.data);
+        return NGX_ERROR;
+    }
+
+    if (!ngx_test_config) {
+        if (ngx_write_file(&file, pid, len, 0) == NGX_ERROR) {
+            return NGX_ERROR;
+        }
+    }
+
+    if (ngx_close_file(file.fd) == NGX_FILE_ERROR) {
+        ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
+                      ngx_close_file_n " \"%s\" failed", file.name.data);
+    }
+
+    ngx_delete_pidfile(old_cycle);
+
+    return NGX_OK;
+}
+
+
+void ngx_delete_pidfile(ngx_cycle_t *cycle)
+{   
+    u_char           *name;
+    ngx_core_conf_t  *ccf;
+
+    if (cycle == NULL || cycle->conf_ctx == NULL) {
+        return;
+    }
+
+    ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
+
+    if (ngx_inherited && getppid() > 1) {
+        name = ccf->newpid.data;
+
+    } else { 
+        name = ccf->pid.data;
+    }
+
+    if (ngx_delete_file(name) == NGX_FILE_ERROR) {
+        ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
+                      ngx_delete_file_n " \"%s\" failed", name);
+    }
+}
+
+#endif
+
+
+void ngx_reopen_files(ngx_cycle_t *cycle, ngx_uid_t user)
+{
+    ngx_fd_t          fd;
+    ngx_uint_t        i;
+    ngx_list_part_t  *part;
+    ngx_open_file_t  *file;
+
+    part = &cycle->open_files.part;
+    file = part->elts;
+
+    for (i = 0; /* void */ ; i++) {
+
+        if (i >= part->nelts) {
+            if (part->next == NULL) {
+                break;
+            }
+            part = part->next;
+            i = 0;
+        }
+
+        if (file[i].name.data == NULL) {
+            continue;
+        }
+
+        fd = ngx_open_file(file[i].name.data, NGX_FILE_RDWR,
+                           NGX_FILE_CREATE_OR_OPEN|NGX_FILE_APPEND);
+
+        ngx_log_debug3(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
+                       "reopen file \"%s\", old:%d new:%d",
+                       file[i].name.data, file[i].fd, fd);
+
+        if (fd == NGX_INVALID_FILE) {
+            ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
+                          ngx_open_file_n " \"%s\" failed", file[i].name.data);
+            continue;
+        }
+
+#if (WIN32)
+        if (ngx_file_append_mode(fd) == NGX_ERROR) {
+            ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
+                          ngx_file_append_mode_n " \"%s\" failed",
+                          file[i].name.data);
+
+            if (ngx_close_file(fd) == NGX_FILE_ERROR) {
+                ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
+                              ngx_close_file_n " \"%s\" failed",
+                              file[i].name.data);
+            }
+
+            continue;
+        }
+#else
+        if (user != (ngx_uid_t) -1) {
+            if (chown((const char *) file[i].name.data, user, -1) == -1) {
+                ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
+                              "chown \"%s\" failed", file[i].name.data);
+
+                if (ngx_close_file(fd) == NGX_FILE_ERROR) {
+                    ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
+                                  ngx_close_file_n " \"%s\" failed",
+                                  file[i].name.data);
+                }
+            }
+        }
+
+        if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1) {
+            ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
+                          "fcntl(FD_CLOEXEC) \"%s\" failed",
+                          file[i].name.data);
+
+            if (ngx_close_file(fd) == NGX_FILE_ERROR) {
+                ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
+                              ngx_close_file_n " \"%s\" failed",
+                              file[i].name.data);
+            }
+
+            continue;
+        }
+#endif
+
+        if (ngx_close_file(file[i].fd) == NGX_FILE_ERROR) {
+            ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
+                          ngx_close_file_n " \"%s\" failed",
+                          file[i].name.data);
+        }
+
+        file[i].fd = fd;
+    }
+
+#if !(WIN32)
+
+    if (cycle->log->file->fd != STDERR_FILENO) {
+        if (dup2(cycle->log->file->fd, STDERR_FILENO) == -1) {
+            ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
+                          "dup2(STDERR) failed");
+        }
+    }
+
+#endif
+}
+
+
+static void ngx_clean_old_cycles(ngx_event_t *ev)
+{
+    ngx_uint_t     i, n, found, live;
+    ngx_log_t     *log;
+    ngx_cycle_t  **cycle;
+
+    log = ngx_cycle->log;
+    ngx_temp_pool->log = log;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_CORE, log, 0, "clean old cycles");
+
+    live = 0;
+
+    cycle = ngx_old_cycles.elts;
+    for (i = 0; i < ngx_old_cycles.nelts; i++) {
+
+        if (cycle[i] == NULL) {
+            continue;
+        }
+
+        found = 0;
+
+        for (n = 0; n < cycle[i]->connection_n; n++) {
+            if (cycle[i]->connections[n].fd != (ngx_socket_t) -1) {
+                found = 1;
+
+                ngx_log_debug1(NGX_LOG_DEBUG_CORE, log, 0, "live fd:%d", n);
+
+                break;
+            }
+        }
+
+        if (found) {
+            live = 1;
+            continue;
+        }
+
+        ngx_log_debug1(NGX_LOG_DEBUG_CORE, log, 0, "clean old cycle: %d", i);
+
+        ngx_destroy_pool(cycle[i]->pool);
+        cycle[i] = NULL;
+    }
+
+    ngx_log_debug1(NGX_LOG_DEBUG_CORE, log, 0, "old cycles status: %d", live);
+
+    if (live) {
+        ngx_add_timer(ev, 30000);
+
+    } else {
+        ngx_destroy_pool(ngx_temp_pool);
+        ngx_temp_pool = NULL;
+        ngx_old_cycles.nelts = 0;
+    }
+}