Controller: proper reconfiguration requests handling.

Now controller serializes all reconfiguration requests
and waits for result from router.

6 files changed, 153 insertions, 44 deletions

diff --git a/src/nxt_controller.c b/src/nxt_controller.c
index 85454550..4cf6ff95 100644
--- a/src/nxt_controller.c
+++ b/src/nxt_controller.c
@@ -20,8 +20,9 @@ typedef struct {
 typedef struct {
     nxt_http_request_parse_t  parser;
     size_t                    length;
-
     nxt_controller_conf_t     conf;
+    nxt_conn_t                *conn;
+    nxt_queue_link_t          link;
 } nxt_controller_request_t;
 
 
@@ -54,11 +55,14 @@ static nxt_int_t nxt_controller_request_content_length(void *ctx,
     nxt_http_field_t *field, nxt_log_t *log);
 
 static void nxt_controller_process_request(nxt_task_t *task,
-    nxt_conn_t *c, nxt_controller_request_t *r);
+    nxt_controller_request_t *req);
 static nxt_int_t nxt_controller_conf_apply(nxt_task_t *task,
+    nxt_controller_request_t *req);
+static void nxt_controller_process_waiting(nxt_task_t *task);
+static nxt_int_t nxt_controller_conf_pass(nxt_task_t *task,
     nxt_conf_value_t *conf);
-static nxt_int_t nxt_controller_response(nxt_task_t *task, nxt_conn_t *c,
-    nxt_controller_response_t *resp);
+static void nxt_controller_response(nxt_task_t *task,
+    nxt_controller_request_t *req, nxt_controller_response_t *resp);
 static nxt_buf_t *nxt_controller_response_body(nxt_controller_response_t *resp,
     nxt_mp_t *pool);
 
@@ -73,7 +77,9 @@ static nxt_http_fields_hash_entry_t  nxt_controller_request_fields[] = {
 static nxt_http_fields_hash_t  *nxt_controller_fields_hash;
 
 
-static nxt_controller_conf_t  nxt_controller_conf;
+static nxt_controller_conf_t     nxt_controller_conf;
+static nxt_queue_t               nxt_controller_waiting_requests;
+static nxt_controller_request_t  *nxt_controller_current_request;
 
 
 static const nxt_event_conn_state_t  nxt_controller_conn_read_state;
@@ -119,6 +125,8 @@ nxt_controller_start(nxt_task_t *task, nxt_runtime_t *rt)
     nxt_controller_conf.root = conf;
     nxt_controller_conf.pool = mp;
 
+    nxt_queue_init(&nxt_controller_waiting_requests);
+
     return NXT_OK;
 }
 
@@ -210,6 +218,8 @@ nxt_controller_conn_init(nxt_task_t *task, void *obj, void *data)
         return;
     }
 
+    r->conn = c;
+
     if (nxt_slow_path(nxt_http_parse_request_init(&r->parser, c->mem_pool)
                       != NXT_OK))
     {
@@ -307,7 +317,7 @@ nxt_controller_conn_read(nxt_task_t *task, void *obj, void *data)
                     r->length, preread);
 
     if (preread >= r->length) {
-        nxt_controller_process_request(task, c, r);
+        nxt_controller_process_request(task, r);
         return;
     }
 
@@ -399,7 +409,7 @@ nxt_controller_conn_body_read(nxt_task_t *task, void *obj, void *data)
               read, r->length);
 
     if (read >= r->length) {
-        nxt_controller_process_request(task, c, data);
+        nxt_controller_process_request(task, r);
         return;
     }
 
@@ -542,12 +552,12 @@ nxt_controller_request_content_length(void *ctx, nxt_http_field_t *field,
 
 
 static void
-nxt_controller_process_request(nxt_task_t *task, nxt_conn_t *c,
-    nxt_controller_request_t *req)
+nxt_controller_process_request(nxt_task_t *task, nxt_controller_request_t *req)
 {
     nxt_mp_t                   *mp;
     nxt_int_t                  rc;
     nxt_str_t                  path;
+    nxt_conn_t                 *c;
     nxt_uint_t                 status;
     nxt_buf_mem_t              *mbuf;
     nxt_conf_op_t              *ops;
@@ -556,6 +566,7 @@ nxt_controller_process_request(nxt_task_t *task, nxt_conn_t *c,
 
     static const nxt_str_t empty_obj = nxt_string("{}");
 
+    c = req->conn;
     path = req->parser.path;
 
     if (path.length > 1 && path.start[path.length - 1] == '/') {
@@ -631,21 +642,16 @@ nxt_controller_process_request(nxt_task_t *task, nxt_conn_t *c,
             goto done;
         }
 
-        if (nxt_slow_path(nxt_controller_conf_apply(task, value) != NXT_OK)) {
+        req->conf.root = value;
+        req->conf.pool = mp;
+
+        if (nxt_controller_conf_apply(task, req) != NXT_OK) {
             nxt_mp_destroy(mp);
             status = 500;
             goto done;
         }
 
-        nxt_mp_destroy(nxt_controller_conf.pool);
-
-        nxt_controller_conf.root = value;
-        nxt_controller_conf.pool = mp;
-
-        nxt_str_set(&resp.json, "{ \"success\": \"Updated.\" }");
-
-        status = 200;
-        goto done;
+        return;
     }
 
     if (nxt_str_eq(&req->parser.method, "DELETE", 6)) {
@@ -699,21 +705,16 @@ nxt_controller_process_request(nxt_task_t *task, nxt_conn_t *c,
             goto done;
         }
 
-        if (nxt_slow_path(nxt_controller_conf_apply(task, value) != NXT_OK)) {
+        req->conf.root = value;
+        req->conf.pool = mp;
+
+        if (nxt_controller_conf_apply(task, req) != NXT_OK) {
             nxt_mp_destroy(mp);
             status = 500;
             goto done;
         }
 
-        nxt_mp_destroy(nxt_controller_conf.pool);
-
-        nxt_controller_conf.root = value;
-        nxt_controller_conf.pool = mp;
-
-        nxt_str_set(&resp.json, "{ \"success\": \"Deleted.\" }");
-
-        status = 200;
-        goto done;
+        return;
     }
 
     status = 405;
@@ -746,14 +747,104 @@ done:
         break;
     }
 
-    if (nxt_controller_response(task, c, &resp) != NXT_OK) {
-        nxt_controller_conn_close(task, c, req);
+    nxt_controller_response(task, req, &resp);
+}
+
+
+static nxt_int_t
+nxt_controller_conf_apply(nxt_task_t *task, nxt_controller_request_t *req)
+{
+    nxt_int_t  rc;
+
+    if (nxt_controller_current_request != NULL) {
+        nxt_queue_insert_tail(&nxt_controller_waiting_requests, &req->link);
+        return NXT_OK;
+    }
+
+    rc = nxt_controller_conf_pass(task, req->conf.root);
+
+    if (nxt_slow_path(rc != NXT_OK)) {
+        return NXT_ERROR;
     }
+
+    nxt_controller_current_request = req;
+
+    return NXT_OK;
+}
+
+
+void
+nxt_port_controller_data_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg)
+{
+    size_t                     size, dump_size;
+    nxt_buf_t                  *b;
+    nxt_controller_request_t   *req;
+    nxt_controller_response_t  resp;
+
+    b = msg->buf;
+    size = b->mem.free - b->mem.pos;
+
+    dump_size = size > 300 ? 300 : size;
+
+    nxt_debug(task, "contoller data: %*s ...", dump_size, b->mem.pos);
+
+    nxt_memzero(&resp, sizeof(nxt_controller_response_t));
+
+    req = nxt_controller_current_request;
+    nxt_controller_current_request = NULL;
+
+    if (size == 2 && nxt_memcmp(b->mem.pos, "OK", 2) == 0) {
+
+        nxt_mp_destroy(nxt_controller_conf.pool);
+
+        nxt_controller_conf = req->conf;
+
+        nxt_str_set(&resp.status_line, "200 OK");
+        nxt_str_set(&resp.json, "{ \"success\": \"Reconfiguration done.\" }");
+
+    } else {
+        nxt_mp_destroy(req->conf.pool);
+
+        nxt_str_set(&resp.status_line, "500 Internal Server Error");
+        nxt_str_set(&resp.json,
+                    "{ \"error\": \"Failed to apply new configuration.\" }");
+    }
+
+    nxt_controller_response(task, req, &resp);
+
+    nxt_controller_process_waiting(task);
+}
+
+
+static void
+nxt_controller_process_waiting(nxt_task_t *task)
+{
+    nxt_controller_request_t   *req;
+    nxt_controller_response_t  resp;
+
+    nxt_queue_each(req, &nxt_controller_waiting_requests,
+                   nxt_controller_request_t, link)
+    {
+        nxt_queue_remove(&req->link);
+
+        if (nxt_fast_path(nxt_controller_conf_apply(task, req) == NXT_OK)) {
+            return;
+        }
+
+        nxt_mp_destroy(req->conf.pool);
+
+        nxt_str_set(&resp.status_line, "500 Internal Server Error");
+        nxt_str_set(&resp.json,
+                    "{ \"error\": \"Memory allocation failed.\" }");
+
+        nxt_controller_response(task, req, &resp);
+
+    } nxt_queue_loop;
 }
 
 
 static nxt_int_t
-nxt_controller_conf_apply(nxt_task_t *task, nxt_conf_value_t *conf)
+nxt_controller_conf_pass(nxt_task_t *task, nxt_conf_value_t *conf)
 {
     size_t         size;
     nxt_buf_t      *b;
@@ -776,24 +867,27 @@ nxt_controller_conf_apply(nxt_task_t *task, nxt_conf_value_t *conf)
 
     b->mem.free = nxt_conf_json_print(b->mem.free, conf, NULL);
 
-    (void) nxt_port_socket_write(task, port, NXT_PORT_MSG_DATA, -1, 0, 0, b);
-
-    return NXT_OK;
+    return nxt_port_socket_write(task, port, NXT_PORT_MSG_DATA, -1, 0, 0, b);
 }
 
 
-static nxt_int_t
-nxt_controller_response(nxt_task_t *task, nxt_conn_t *c,
+
+static void
+nxt_controller_response(nxt_task_t *task, nxt_controller_request_t *req,
     nxt_controller_response_t *resp)
 {
-    size_t     size;
-    nxt_buf_t  *b;
+    size_t      size;
+    nxt_buf_t   *b;
+    nxt_conn_t  *c;
+
+    c = req->conn;
 
     size = sizeof("HTTP/1.0 " "\r\n\r\n") - 1 + resp->status_line.length;
 
     b = nxt_buf_mem_alloc(c->mem_pool, size, 0);
     if (nxt_slow_path(b == NULL)) {
-        return NXT_ERROR;
+        nxt_controller_conn_close(task, c, req);
+        return;
     }
 
     b->mem.free = nxt_cpymem(b->mem.free, "HTTP/1.0 ", sizeof("HTTP/1.0 ") - 1);
@@ -805,15 +899,14 @@ nxt_controller_response(nxt_task_t *task, nxt_conn_t *c,
     b->next = nxt_controller_response_body(resp, c->mem_pool);
 
     if (nxt_slow_path(b->next == NULL)) {
-        return NXT_ERROR;
+        nxt_controller_conn_close(task, c, req);
+        return;
     }
 
     c->write = b;
     c->write_state = &nxt_controller_conn_write_state;
 
     nxt_conn_write(task->thread->engine, c);
-
-    return NXT_OK;
 }
 
 
diff --git a/src/nxt_master_process.c b/src/nxt_master_process.c
index c9617c9f..3b638389 100644
--- a/src/nxt_master_process.c
+++ b/src/nxt_master_process.c
@@ -145,7 +145,7 @@ nxt_master_start_controller_process(nxt_task_t *task, nxt_runtime_t *rt)
     init->start = nxt_controller_start;
     init->name = "controller process";
     init->user_cred = &rt->user_cred;
-    init->port_handlers = nxt_worker_process_port_handlers;
+    init->port_handlers = nxt_controller_process_port_handlers;
     init->signals = nxt_worker_process_signals;
     init->type = NXT_PROCESS_CONTROLLER;
 
diff --git a/src/nxt_master_process.h b/src/nxt_master_process.h
index 417c0aa5..6f7cc067 100644
--- a/src/nxt_master_process.h
+++ b/src/nxt_master_process.h
@@ -16,6 +16,7 @@ nxt_int_t nxt_controller_start(nxt_task_t *task, nxt_runtime_t *rt);
 nxt_int_t nxt_router_start(nxt_task_t *task, nxt_runtime_t *rt);
 
 
+extern nxt_port_handler_t  nxt_controller_process_port_handlers[];
 extern nxt_port_handler_t  nxt_worker_process_port_handlers[];
 extern nxt_port_handler_t  nxt_app_process_port_handlers[];
 extern nxt_port_handler_t  nxt_router_process_port_handlers[];
diff --git a/src/nxt_router.c b/src/nxt_router.c
index 28765deb..b54d1cf3 100644
--- a/src/nxt_router.c
+++ b/src/nxt_router.c
@@ -323,6 +323,8 @@ nxt_router_conf_send(nxt_task_t *task, nxt_router_temp_conf_t *tmcf,
         return;
     }
 
+    b->mem.free = nxt_cpymem(b->mem.free, start, size);
+
     b->parent = tmcf->mem_pool;
     b->completion_handler = nxt_router_conf_buf_completion;
 
diff --git a/src/nxt_runtime.h b/src/nxt_runtime.h
index 46e8e9d2..7cbd466a 100644
--- a/src/nxt_runtime.h
+++ b/src/nxt_runtime.h
@@ -132,6 +132,9 @@ nxt_port_t *nxt_runtime_port_first(nxt_runtime_t *rt,
 /* STUB */
 nxt_int_t nxt_runtime_controller_socket(nxt_task_t *task, nxt_runtime_t *rt);
 
+void nxt_port_controller_data_handler(nxt_task_t *task,
+    nxt_port_recv_msg_t *msg);
+
 nxt_str_t *nxt_current_directory(nxt_mp_t *mp);
 
 nxt_listen_socket_t *nxt_runtime_listen_socket_add(nxt_runtime_t *rt,
diff --git a/src/nxt_worker_process.c b/src/nxt_worker_process.c
index cdc1b1c5..86ee6408 100644
--- a/src/nxt_worker_process.c
+++ b/src/nxt_worker_process.c
@@ -22,6 +22,16 @@ static void nxt_worker_process_sigquit_handler(nxt_task_t *task, void *obj,
     void *data);
 
 
+nxt_port_handler_t  nxt_controller_process_port_handlers[] = {
+    nxt_worker_process_quit_handler,
+    nxt_port_new_port_handler,
+    nxt_port_change_log_file_handler,
+    nxt_port_mmap_handler,
+    nxt_port_controller_data_handler,
+    nxt_port_remove_pid_handler,
+};
+
+
 nxt_port_handler_t  nxt_worker_process_port_handlers[] = {
     nxt_worker_process_quit_handler,
     nxt_port_new_port_handler,