The master process has been renamed to the main process.

1 files changed, 1040 insertions, 0 deletions

diff --git a/src/nxt_main_process.c b/src/nxt_main_process.c
new file mode 100644
index 00000000..110867ca
--- /dev/null
+++ b/src/nxt_main_process.c
@@ -0,0 +1,1040 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ * Copyright (C) NGINX, Inc.
+ */
+
+#include <nxt_main.h>
+#include <nxt_runtime.h>
+#include <nxt_port.h>
+#include <nxt_main_process.h>
+#include <nxt_conf.h>
+#include <nxt_application.h>
+
+
+typedef struct {
+    nxt_socket_t        socket;
+    nxt_socket_error_t  error;
+    u_char              *start;
+    u_char              *end;
+} nxt_listening_socket_t;
+
+
+static nxt_int_t nxt_main_process_port_create(nxt_task_t *task,
+    nxt_runtime_t *rt);
+static void nxt_main_process_title(nxt_task_t *task);
+static nxt_int_t nxt_main_start_controller_process(nxt_task_t *task,
+    nxt_runtime_t *rt);
+static nxt_int_t nxt_main_start_router_process(nxt_task_t *task,
+    nxt_runtime_t *rt);
+static nxt_int_t nxt_main_start_discovery_process(nxt_task_t *task,
+    nxt_runtime_t *rt);
+static nxt_int_t nxt_main_start_worker_process(nxt_task_t *task,
+    nxt_runtime_t *rt, nxt_common_app_conf_t *app_conf, uint32_t stream);
+static nxt_int_t nxt_main_create_worker_process(nxt_task_t *task,
+    nxt_runtime_t *rt, nxt_process_init_t *init);
+static void nxt_main_process_sigterm_handler(nxt_task_t *task, void *obj,
+    void *data);
+static void nxt_main_process_sigquit_handler(nxt_task_t *task, void *obj,
+    void *data);
+static void nxt_main_process_sigusr1_handler(nxt_task_t *task, void *obj,
+    void *data);
+static void nxt_main_process_sigchld_handler(nxt_task_t *task, void *obj,
+    void *data);
+static void nxt_main_cleanup_worker_process(nxt_task_t *task, nxt_pid_t pid);
+static void nxt_main_port_socket_handler(nxt_task_t *task,
+    nxt_port_recv_msg_t *msg);
+static nxt_int_t nxt_main_listening_socket(nxt_sockaddr_t *sa,
+    nxt_listening_socket_t *ls);
+static void nxt_main_port_modules_handler(nxt_task_t *task,
+    nxt_port_recv_msg_t *msg);
+static int nxt_cdecl nxt_app_lang_compare(const void *v1, const void *v2);
+
+
+const nxt_sig_event_t  nxt_main_process_signals[] = {
+    nxt_event_signal(SIGINT,  nxt_main_process_sigterm_handler),
+    nxt_event_signal(SIGQUIT, nxt_main_process_sigquit_handler),
+    nxt_event_signal(SIGTERM, nxt_main_process_sigterm_handler),
+    nxt_event_signal(SIGCHLD, nxt_main_process_sigchld_handler),
+    nxt_event_signal(SIGUSR1, nxt_main_process_sigusr1_handler),
+    nxt_event_signal_end,
+};
+
+
+static nxt_bool_t  nxt_exiting;
+
+
+nxt_int_t
+nxt_main_process_start(nxt_thread_t *thr, nxt_task_t *task,
+    nxt_runtime_t *rt)
+{
+    rt->types |= (1U << NXT_PROCESS_MAIN);
+
+    if (nxt_main_process_port_create(task, rt) != NXT_OK) {
+        return NXT_ERROR;
+    }
+
+    nxt_main_process_title(task);
+
+    /*
+     * The dicsovery process will send a message processed by
+     * nxt_main_port_modules_handler() which starts the controller
+     * and router processes.
+     */
+    return nxt_main_start_discovery_process(task, rt);
+}
+
+
+static nxt_conf_map_t  nxt_common_app_conf[] = {
+    {
+        nxt_string("type"),
+        NXT_CONF_MAP_STR,
+        offsetof(nxt_common_app_conf_t, type),
+    },
+
+    {
+        nxt_string("user"),
+        NXT_CONF_MAP_STR,
+        offsetof(nxt_common_app_conf_t, user),
+    },
+
+    {
+        nxt_string("group"),
+        NXT_CONF_MAP_STR,
+        offsetof(nxt_common_app_conf_t, group),
+    },
+
+    {
+        nxt_string("workers"),
+        NXT_CONF_MAP_INT32,
+        offsetof(nxt_common_app_conf_t, workers),
+    },
+
+    {
+        nxt_string("path"),
+        NXT_CONF_MAP_STR,
+        offsetof(nxt_common_app_conf_t, u.python.path),
+    },
+
+    {
+        nxt_string("module"),
+        NXT_CONF_MAP_STR,
+        offsetof(nxt_common_app_conf_t, u.python.module),
+    },
+
+    {
+        nxt_string("root"),
+        NXT_CONF_MAP_STR,
+        offsetof(nxt_common_app_conf_t, u.php.root),
+    },
+
+    {
+        nxt_string("script"),
+        NXT_CONF_MAP_STR,
+        offsetof(nxt_common_app_conf_t, u.php.script),
+    },
+
+    {
+        nxt_string("index"),
+        NXT_CONF_MAP_STR,
+        offsetof(nxt_common_app_conf_t, u.php.index),
+    },
+
+    {
+        nxt_string("executable"),
+        NXT_CONF_MAP_STR,
+        offsetof(nxt_common_app_conf_t, u.go.executable),
+    },
+};
+
+
+static void
+nxt_port_main_data_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg)
+{
+    nxt_debug(task, "main data: %*s",
+              nxt_buf_mem_used_size(&msg->buf->mem), msg->buf->mem.pos);
+}
+
+
+static void
+nxt_port_main_start_worker_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg)
+{
+    u_char                 *start;
+    nxt_mp_t               *mp;
+    nxt_int_t              ret;
+    nxt_buf_t              *b;
+    nxt_conf_value_t       *conf;
+    nxt_common_app_conf_t  app_conf;
+
+    static nxt_str_t nobody = nxt_string("nobody");
+
+    b = msg->buf;
+
+    nxt_debug(task, "main start worker: %*s", b->mem.free - b->mem.pos,
+              b->mem.pos);
+
+    mp = nxt_mp_create(1024, 128, 256, 32);
+
+    nxt_memzero(&app_conf, sizeof(nxt_common_app_conf_t));
+
+    start = b->mem.pos;
+
+    app_conf.name.start = start;
+    app_conf.name.length = nxt_strlen(start);
+
+    start += app_conf.name.length + 1;
+
+    conf = nxt_conf_json_parse(mp, start, b->mem.free, NULL);
+
+    if (conf == NULL) {
+        nxt_log(task, NXT_LOG_CRIT, "configuration parsing error");
+        return;
+    }
+
+    app_conf.user = nobody;
+
+    ret = nxt_conf_map_object(mp, conf, nxt_common_app_conf,
+                              nxt_nitems(nxt_common_app_conf), &app_conf);
+    if (ret != NXT_OK) {
+        nxt_log(task, NXT_LOG_CRIT, "root map error");
+        return;
+    }
+
+    ret = nxt_main_start_worker_process(task, task->thread->runtime,
+                                        &app_conf, msg->port_msg.stream);
+
+    nxt_mp_destroy(mp);
+}
+
+
+static nxt_port_handler_t  nxt_main_process_port_handlers[] = {
+    NULL, /* NXT_PORT_MSG_QUIT         */
+    NULL, /* NXT_PORT_MSG_NEW_PORT     */
+    NULL, /* NXT_PORT_MSG_CHANGE_FILE  */
+    NULL, /* NXT_PORT_MSG_MMAP         */
+    nxt_port_main_data_handler,
+    NULL, /* NXT_PORT_MSG_REMOVE_PID   */
+    nxt_port_ready_handler,
+    nxt_port_main_start_worker_handler,
+    nxt_main_port_socket_handler,
+    nxt_main_port_modules_handler,
+    nxt_port_rpc_handler,
+    nxt_port_rpc_handler,
+};
+
+
+static nxt_int_t
+nxt_main_process_port_create(nxt_task_t *task, nxt_runtime_t *rt)
+{
+    nxt_int_t      ret;
+    nxt_port_t     *port;
+    nxt_process_t  *process;
+
+    process = nxt_runtime_process_get(rt, nxt_pid);
+    if (nxt_slow_path(process == NULL)) {
+        return NXT_ERROR;
+    }
+
+    port = nxt_port_new(task, 0, nxt_pid, NXT_PROCESS_MAIN);
+    if (nxt_slow_path(port == NULL)) {
+        return NXT_ERROR;
+    }
+
+    ret = nxt_port_socket_init(task, port, 0);
+    if (nxt_slow_path(ret != NXT_OK)) {
+        return ret;
+    }
+
+    nxt_process_port_add(task, process, port);
+
+    nxt_runtime_port_add(rt, port);
+
+    /*
+     * A main process port.  A write port is not closed
+     * since it should be inherited by worker processes.
+     */
+    nxt_port_enable(task, port, nxt_main_process_port_handlers);
+
+    process->ready = 1;
+
+    return NXT_OK;
+}
+
+
+static void
+nxt_main_process_title(nxt_task_t *task)
+{
+    u_char      *p, *end;
+    nxt_uint_t  i;
+    u_char      title[2048];
+
+    end = title + sizeof(title) - 1;
+
+    p = nxt_sprintf(title, end, "nginext: main [%s", nxt_process_argv[0]);
+
+    for (i = 1; nxt_process_argv[i] != NULL; i++) {
+        p = nxt_sprintf(p, end, " %s", nxt_process_argv[i]);
+    }
+
+    if (p < end) {
+        *p++ = ']';
+    }
+
+    *p = '\0';
+
+    nxt_process_title(task, "%s", title);
+}
+
+
+static nxt_int_t
+nxt_main_start_controller_process(nxt_task_t *task, nxt_runtime_t *rt)
+{
+    nxt_process_init_t  *init;
+
+    init = nxt_malloc(sizeof(nxt_process_init_t));
+    if (nxt_slow_path(init == NULL)) {
+        return NXT_ERROR;
+    }
+
+    init->start = nxt_controller_start;
+    init->name = "controller";
+    init->user_cred = &rt->user_cred;
+    init->port_handlers = nxt_controller_process_port_handlers;
+    init->signals = nxt_worker_process_signals;
+    init->type = NXT_PROCESS_CONTROLLER;
+    init->data = rt;
+    init->stream = 0;
+    init->restart = 1;
+
+    return nxt_main_create_worker_process(task, rt, init);
+}
+
+
+static nxt_int_t
+nxt_main_start_discovery_process(nxt_task_t *task, nxt_runtime_t *rt)
+{
+    nxt_process_init_t  *init;
+
+    init = nxt_malloc(sizeof(nxt_process_init_t));
+    if (nxt_slow_path(init == NULL)) {
+        return NXT_ERROR;
+    }
+
+    init->start = nxt_discovery_start;
+    init->name = "discovery";
+    init->user_cred = &rt->user_cred;
+    init->port_handlers = nxt_discovery_process_port_handlers;
+    init->signals = nxt_worker_process_signals;
+    init->type = NXT_PROCESS_DISCOVERY;
+    init->data = rt;
+    init->stream = 0;
+    init->restart = 0;
+
+    return nxt_main_create_worker_process(task, rt, init);
+}
+
+
+static nxt_int_t
+nxt_main_start_router_process(nxt_task_t *task, nxt_runtime_t *rt)
+{
+    nxt_process_init_t  *init;
+
+    init = nxt_malloc(sizeof(nxt_process_init_t));
+    if (nxt_slow_path(init == NULL)) {
+        return NXT_ERROR;
+    }
+
+    init->start = nxt_router_start;
+    init->name = "router";
+    init->user_cred = &rt->user_cred;
+    init->port_handlers = nxt_router_process_port_handlers;
+    init->signals = nxt_worker_process_signals;
+    init->type = NXT_PROCESS_ROUTER;
+    init->data = rt;
+    init->stream = 0;
+    init->restart = 1;
+
+    return nxt_main_create_worker_process(task, rt, init);
+}
+
+
+static nxt_int_t
+nxt_main_start_worker_process(nxt_task_t *task, nxt_runtime_t *rt,
+    nxt_common_app_conf_t *app_conf, uint32_t stream)
+{
+    char                *user, *group;
+    u_char              *title, *last, *end;
+    size_t              size;
+    nxt_process_init_t  *init;
+
+    size = sizeof(nxt_process_init_t)
+           + sizeof(nxt_user_cred_t)
+           + app_conf->user.length + 1
+           + app_conf->group.length + 1
+           + app_conf->name.length + sizeof("\"\" application");
+
+    init = nxt_malloc(size);
+    if (nxt_slow_path(init == NULL)) {
+        return NXT_ERROR;
+    }
+
+    init->user_cred = nxt_pointer_to(init, sizeof(nxt_process_init_t));
+    user = nxt_pointer_to(init->user_cred, sizeof(nxt_user_cred_t));
+
+    nxt_memcpy(user, app_conf->user.start, app_conf->user.length);
+    last = nxt_pointer_to(user, app_conf->user.length);
+    *last++ = '\0';
+
+    init->user_cred->user = user;
+
+    if (app_conf->group.start != NULL) {
+        group = (char *) last;
+
+        nxt_memcpy(group, app_conf->group.start, app_conf->group.length);
+        last = nxt_pointer_to(group, app_conf->group.length);
+        *last++ = '\0';
+
+    } else {
+        group = NULL;
+    }
+
+    if (nxt_user_cred_get(task, init->user_cred, group) != NXT_OK) {
+        return NXT_ERROR;
+    }
+
+    title = last;
+    end = title + app_conf->name.length + sizeof("\"\" application");
+
+    nxt_sprintf(title, end, "\"%V\" application%Z", &app_conf->name);
+
+    init->start = nxt_app_start;
+    init->name = (char *) title;
+    init->port_handlers = nxt_app_process_port_handlers;
+    init->signals = nxt_worker_process_signals;
+    init->type = NXT_PROCESS_WORKER;
+    init->data = app_conf;
+    init->stream = stream;
+    init->restart = 0;
+
+    return nxt_main_create_worker_process(task, rt, init);
+}
+
+
+static nxt_int_t
+nxt_main_create_worker_process(nxt_task_t *task, nxt_runtime_t *rt,
+    nxt_process_init_t *init)
+{
+    nxt_int_t      ret;
+    nxt_pid_t      pid;
+    nxt_port_t     *port;
+    nxt_process_t  *process;
+
+    /*
+     * TODO: remove process, init, ports from array on memory and fork failures.
+     */
+
+    process = nxt_runtime_process_new(rt);
+    if (nxt_slow_path(process == NULL)) {
+        return NXT_ERROR;
+    }
+
+    process->init = init;
+
+    port = nxt_port_new(task, 0, 0, init->type);
+    if (nxt_slow_path(port == NULL)) {
+        nxt_runtime_process_remove(rt, process);
+        return NXT_ERROR;
+    }
+
+    nxt_process_port_add(task, process, port);
+
+    ret = nxt_port_socket_init(task, port, 0);
+    if (nxt_slow_path(ret != NXT_OK)) {
+        nxt_mp_release(port->mem_pool, port);
+        return ret;
+    }
+
+    pid = nxt_process_create(task, process);
+
+    switch (pid) {
+
+    case -1:
+        return NXT_ERROR;
+
+    case 0:
+        /* A worker process, return to the event engine work queue loop. */
+        return NXT_AGAIN;
+
+    default:
+        /* The main process created a new process. */
+
+        nxt_port_read_close(port);
+        nxt_port_write_enable(task, port);
+
+        return NXT_OK;
+    }
+}
+
+
+void
+nxt_main_stop_worker_processes(nxt_task_t *task, nxt_runtime_t *rt)
+{
+    nxt_port_t     *port;
+    nxt_process_t  *process;
+
+    nxt_runtime_process_each(rt, process)
+    {
+        if (nxt_pid != process->pid) {
+            process->init = NULL;
+
+            nxt_process_port_each(process, port) {
+
+                (void) nxt_port_socket_write(task, port, NXT_PORT_MSG_QUIT,
+                                             -1, 0, 0, NULL);
+
+            } nxt_process_port_loop;
+        }
+    }
+    nxt_runtime_process_loop;
+}
+
+
+
+static void
+nxt_main_process_sigterm_handler(nxt_task_t *task, void *obj, void *data)
+{
+    nxt_debug(task, "sigterm handler signo:%d (%s)",
+              (int) (uintptr_t) obj, data);
+
+    /* TODO: fast exit. */
+
+    nxt_exiting = 1;
+
+    nxt_runtime_quit(task);
+}
+
+
+static void
+nxt_main_process_sigquit_handler(nxt_task_t *task, void *obj, void *data)
+{
+    nxt_debug(task, "sigquit handler signo:%d (%s)",
+              (int) (uintptr_t) obj, data);
+
+    /* TODO: graceful exit. */
+
+    nxt_exiting = 1;
+
+    nxt_runtime_quit(task);
+}
+
+
+static void
+nxt_main_process_sigusr1_handler(nxt_task_t *task, void *obj, void *data)
+{
+    nxt_mp_t        *mp;
+    nxt_int_t       ret;
+    nxt_uint_t      n;
+    nxt_file_t      *file, *new_file;
+    nxt_runtime_t   *rt;
+    nxt_array_t     *new_files;
+
+    nxt_log(task, NXT_LOG_NOTICE, "signal %d (%s) recevied, %s",
+            (int) (uintptr_t) obj, data, "log files rotation");
+
+    mp = nxt_mp_create(1024, 128, 256, 32);
+    if (mp == NULL) {
+        return;
+    }
+
+    rt = task->thread->runtime;
+
+    n = nxt_list_nelts(rt->log_files);
+
+    new_files = nxt_array_create(mp, n, sizeof(nxt_file_t));
+    if (new_files == NULL) {
+        nxt_mp_destroy(mp);
+        return;
+    }
+
+    nxt_list_each(file, rt->log_files) {
+
+        /* This allocation cannot fail. */
+        new_file = nxt_array_add(new_files);
+
+        new_file->name = file->name;
+        new_file->fd = NXT_FILE_INVALID;
+        new_file->log_level = NXT_LOG_CRIT;
+
+        ret = nxt_file_open(task, new_file, O_WRONLY | O_APPEND, O_CREAT,
+                            NXT_FILE_OWNER_ACCESS);
+
+        if (ret != NXT_OK) {
+            goto fail;
+        }
+
+    } nxt_list_loop;
+
+    new_file = new_files->elts;
+
+    ret = nxt_file_stderr(&new_file[0]);
+
+    if (ret == NXT_OK) {
+        n = 0;
+
+        nxt_list_each(file, rt->log_files) {
+
+            nxt_port_change_log_file(task, rt, n, new_file[n].fd);
+            /*
+             * The old log file descriptor must be closed at the moment
+             * when no other threads use it.  dup2() allows to use the
+             * old file descriptor for new log file.  This change is
+             * performed atomically in the kernel.
+             */
+            (void) nxt_file_redirect(file, new_file[n].fd);
+
+            n++;
+
+        } nxt_list_loop;
+
+        nxt_mp_destroy(mp);
+        return;
+   }
+
+fail:
+
+    new_file = new_files->elts;
+    n = new_files->nelts;
+
+    while (n != 0) {
+        if (new_file->fd != NXT_FILE_INVALID) {
+            nxt_file_close(task, new_file);
+        }
+
+        new_file++;
+        n--;
+    }
+
+    nxt_mp_destroy(mp);
+}
+
+
+static void
+nxt_main_process_sigchld_handler(nxt_task_t *task, void *obj, void *data)
+{
+    int                    status;
+    nxt_err_t              err;
+    nxt_pid_t              pid;
+
+    nxt_debug(task, "sigchld handler signo:%d (%s)",
+              (int) (uintptr_t) obj, data);
+
+    for ( ;; ) {
+        pid = waitpid(-1, &status, WNOHANG);
+
+        if (pid == -1) {
+
+            switch (err = nxt_errno) {
+
+            case NXT_ECHILD:
+                return;
+
+            case NXT_EINTR:
+                continue;
+
+            default:
+                nxt_log(task, NXT_LOG_CRIT, "waitpid() failed: %E", err);
+                return;
+            }
+        }
+
+        nxt_debug(task, "waitpid(): %PI", pid);
+
+        if (pid == 0) {
+            return;
+        }
+
+        if (WTERMSIG(status)) {
+#ifdef WCOREDUMP
+            nxt_log(task, NXT_LOG_CRIT, "process %PI exited on signal %d%s",
+                    pid, WTERMSIG(status),
+                    WCOREDUMP(status) ? " (core dumped)" : "");
+#else
+            nxt_log(task, NXT_LOG_CRIT, "process %PI exited on signal %d",
+                    pid, WTERMSIG(status));
+#endif
+
+        } else {
+            nxt_trace(task, "process %PI exited with code %d",
+                      pid, WEXITSTATUS(status));
+        }
+
+        nxt_main_cleanup_worker_process(task, pid);
+    }
+}
+
+
+static void
+nxt_main_cleanup_worker_process(nxt_task_t *task, nxt_pid_t pid)
+{
+    nxt_buf_t           *buf;
+    nxt_port_t          *port;
+    nxt_runtime_t       *rt;
+    nxt_process_t       *process;
+    nxt_process_init_t  *init;
+
+    rt = task->thread->runtime;
+
+    process = nxt_runtime_process_find(rt, pid);
+
+    if (process) {
+        init = process->init;
+
+        nxt_runtime_process_remove(rt, process);
+
+        if (!nxt_exiting) {
+            nxt_runtime_process_each(rt, process)
+            {
+                if (process->pid == nxt_pid ||
+                    process->pid == pid ||
+                    nxt_queue_is_empty(&process->ports)) {
+                    continue;
+                }
+
+                port = nxt_process_port_first(process);
+
+                buf = nxt_buf_mem_alloc(port->mem_pool, sizeof(pid), 0);
+                buf->mem.free = nxt_cpymem(buf->mem.free, &pid, sizeof(pid));
+
+                nxt_port_socket_write(task, port, NXT_PORT_MSG_REMOVE_PID,
+                                      -1, init->stream, 0, buf);
+            }
+            nxt_runtime_process_loop;
+        }
+
+        if (nxt_exiting) {
+
+            if (rt->nprocesses == 2) {
+                nxt_runtime_quit(task);
+            }
+
+        } else if (init != NULL) {
+            if (init->restart != 0) {
+                (void) nxt_main_create_worker_process(task, rt, init);
+
+            } else {
+                nxt_free(init);
+            }
+        }
+    }
+}
+
+
+static void
+nxt_main_port_socket_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg)
+{
+    size_t                  size;
+    nxt_int_t               ret;
+    nxt_buf_t               *b, *out;
+    nxt_port_t              *port;
+    nxt_sockaddr_t          *sa;
+    nxt_port_msg_type_t     type;
+    nxt_listening_socket_t  ls;
+    u_char                  message[2048];
+
+    b = msg->buf;
+    sa = (nxt_sockaddr_t *) b->mem.pos;
+
+    out = NULL;
+
+    ls.socket = -1;
+    ls.error = NXT_SOCKET_ERROR_SYSTEM;
+    ls.start = message;
+    ls.end = message + sizeof(message);
+
+    port = nxt_runtime_port_find(task->thread->runtime, msg->port_msg.pid,
+                                 msg->port_msg.reply_port);
+
+    nxt_debug(task, "listening socket \"%*s\"",
+              sa->length, nxt_sockaddr_start(sa));
+
+    ret = nxt_main_listening_socket(sa, &ls);
+
+    if (ret == NXT_OK) {
+        nxt_debug(task, "socket(\"%*s\"): %d",
+                  sa->length, nxt_sockaddr_start(sa), ls.socket);
+
+        type = NXT_PORT_MSG_RPC_READY_LAST | NXT_PORT_MSG_CLOSE_FD;
+
+    } else {
+        size = ls.end - ls.start;
+
+        nxt_log(task, NXT_LOG_CRIT, "%*s", size, ls.start);
+
+        out = nxt_buf_mem_alloc(port->mem_pool, size + 1, 0);
+        if (nxt_slow_path(out == NULL)) {
+            return;
+        }
+
+        *out->mem.free++ = (uint8_t) ls.error;
+
+        out->mem.free = nxt_cpymem(out->mem.free, ls.start, size);
+
+        type = NXT_PORT_MSG_RPC_ERROR;
+    }
+
+    nxt_port_socket_write(task, port, type, ls.socket, msg->port_msg.stream,
+                          0, out);
+}
+
+
+static nxt_int_t
+nxt_main_listening_socket(nxt_sockaddr_t *sa, nxt_listening_socket_t *ls)
+{
+    nxt_err_t         err;
+    nxt_socket_t      s;
+
+    const socklen_t   length = sizeof(int);
+    static const int  enable = 1;
+
+    s = socket(sa->u.sockaddr.sa_family, sa->type, 0);
+
+    if (nxt_slow_path(s == -1)) {
+        err = nxt_errno;
+
+#if (NXT_INET6)
+
+        if (err == EAFNOSUPPORT && sa->u.sockaddr.sa_family == AF_INET6) {
+            ls->error = NXT_SOCKET_ERROR_NOINET6;
+        }
+
+#endif
+
+        ls->end = nxt_sprintf(ls->start, ls->end,
+                              "socket(\\\"%*s\\\") failed %E",
+                              sa->length, nxt_sockaddr_start(sa), err);
+
+        return NXT_ERROR;
+    }
+
+    if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &enable, length) != 0) {
+        ls->end = nxt_sprintf(ls->start, ls->end,
+                              "setsockopt(\\\"%*s\\\", SO_REUSEADDR) failed %E",
+                              sa->length, nxt_sockaddr_start(sa), nxt_errno);
+        goto fail;
+    }
+
+#if (NXT_INET6)
+
+    if (sa->u.sockaddr.sa_family == AF_INET6) {
+
+        if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &enable, length) != 0) {
+            ls->end = nxt_sprintf(ls->start, ls->end,
+                               "setsockopt(\\\"%*s\\\", IPV6_V6ONLY) failed %E",
+                               sa->length, nxt_sockaddr_start(sa), nxt_errno);
+            goto fail;
+        }
+    }
+
+#endif
+
+    if (bind(s, &sa->u.sockaddr, sa->socklen) != 0) {
+        err = nxt_errno;
+
+#if (NXT_HAVE_UNIX_DOMAIN)
+
+        if (sa->u.sockaddr.sa_family == AF_UNIX) {
+            switch (err) {
+
+            case EACCES:
+                ls->error = NXT_SOCKET_ERROR_ACCESS;
+                break;
+
+            case ENOENT:
+            case ENOTDIR:
+                ls->error = NXT_SOCKET_ERROR_PATH;
+                break;
+            }
+
+            goto next;
+        }
+
+#endif
+
+        switch (err) {
+
+        case EACCES:
+            ls->error = NXT_SOCKET_ERROR_PORT;
+            break;
+
+        case EADDRINUSE:
+            ls->error = NXT_SOCKET_ERROR_INUSE;
+            break;
+
+        case EADDRNOTAVAIL:
+            ls->error = NXT_SOCKET_ERROR_NOADDR;
+            break;
+        }
+
+        ls->end = nxt_sprintf(ls->start, ls->end, "bind(\\\"%*s\\\") failed %E",
+                              sa->length, nxt_sockaddr_start(sa), err);
+        goto fail;
+    }
+
+#if (NXT_HAVE_UNIX_DOMAIN)
+
+next:
+
+    if (sa->u.sockaddr.sa_family == AF_UNIX) {
+        char     *filename;
+        mode_t   access;
+
+        filename = sa->u.sockaddr_un.sun_path;
+        access = (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
+
+        if (chmod(filename, access) != 0) {
+            ls->end = nxt_sprintf(ls->start, ls->end,
+                                  "chmod(\\\"%*s\\\") failed %E",
+                                  filename, nxt_errno);
+            goto fail;
+        }
+    }
+
+#endif
+
+    ls->socket = s;
+
+    return NXT_OK;
+
+fail:
+
+    (void) close(s);
+
+    return NXT_ERROR;
+}
+
+
+static nxt_conf_map_t  nxt_app_lang_module_map[] = {
+    {
+        nxt_string("type"),
+        NXT_CONF_MAP_STR_COPY,
+        offsetof(nxt_app_lang_module_t, type),
+    },
+
+    {
+        nxt_string("version"),
+        NXT_CONF_MAP_STR_COPY,
+        offsetof(nxt_app_lang_module_t, version),
+    },
+
+    {
+        nxt_string("file"),
+        NXT_CONF_MAP_CSTRZ,
+        offsetof(nxt_app_lang_module_t, file),
+    },
+};
+
+
+static void
+nxt_main_port_modules_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg)
+{
+    uint32_t               index;
+    nxt_mp_t               *mp;
+    nxt_int_t              ret;
+    nxt_buf_t              *b;
+    nxt_runtime_t          *rt;
+    nxt_conf_value_t       *conf, *root, *value;
+    nxt_app_lang_module_t  *lang;
+
+    static nxt_str_t   root_path = nxt_string("/");
+
+    rt = task->thread->runtime;
+
+    if (msg->port_msg.pid != rt->port_by_type[NXT_PROCESS_DISCOVERY]->pid) {
+        return;
+    }
+
+    b = msg->buf;
+
+    if (b == NULL) {
+        return;
+    }
+
+    nxt_debug(task, "application languages: \"%*s\"",
+              b->mem.free - b->mem.pos, b->mem.pos);
+
+    mp = nxt_mp_create(1024, 128, 256, 32);
+    if (mp == NULL) {
+        return;
+    }
+
+    conf = nxt_conf_json_parse(mp, b->mem.pos, b->mem.free, NULL);
+    if (conf == NULL) {
+        goto fail;
+    }
+
+    root = nxt_conf_get_path(conf, &root_path);
+    if (root == NULL) {
+        goto fail;
+    }
+
+    for (index = 0; /* void */ ; index++) {
+        value = nxt_conf_get_array_element(root, index);
+        if (value == NULL) {
+            break;
+        }
+
+        lang = nxt_array_add(rt->languages);
+        if (lang == NULL) {
+            goto fail;
+        }
+
+        lang->module = NULL;
+
+        ret = nxt_conf_map_object(rt->mem_pool, value, nxt_app_lang_module_map,
+                                  nxt_nitems(nxt_app_lang_module_map), lang);
+
+        if (ret != NXT_OK) {
+            goto fail;
+        }
+
+        nxt_debug(task, "lang %V %V \"%s\"",
+                  &lang->type, &lang->version, lang->file);
+    }
+
+    qsort(rt->languages->elts, rt->languages->nelts,
+          sizeof(nxt_app_lang_module_t), nxt_app_lang_compare);
+
+fail:
+
+    nxt_mp_destroy(mp);
+
+    ret = nxt_main_start_controller_process(task, rt);
+
+    if (ret == NXT_OK) {
+        (void) nxt_main_start_router_process(task, rt);
+    }
+}
+
+
+static int nxt_cdecl
+nxt_app_lang_compare(const void *v1, const void *v2)
+{
+    int                          n;
+    size_t                       length;
+    const nxt_app_lang_module_t  *lang1, *lang2;
+
+    lang1 = v1;
+    lang2 = v2;
+
+    length = nxt_min(lang1->version.length, lang2->version.length);
+
+    n = nxt_strncmp(lang1->version.start, lang2->version.start, length);
+
+    if (n == 0) {
+        n = lang1->version.length - lang2->version.length;
+    }
+
+    /* Negate result to move higher versions to the beginning. */
+
+    return -n;
+}