Using plain shared memory for configuration pass.

There is no restrictions on configration size and using segmented shared memory
only doubles memory usage because to parse configration on router side,
it needs to be 'plain' e. g. located in single continous memory buffer.

1 files changed, 38 insertions, 12 deletions

diff --git a/src/nxt_controller.c b/src/nxt_controller.c
index a61c127d..8c9d4c53 100644
--- a/src/nxt_controller.c
+++ b/src/nxt_controller.c
@@ -54,7 +54,7 @@ static nxt_int_t nxt_controller_conf_default(void);
 static void nxt_controller_conf_init_handler(nxt_task_t *task,
     nxt_port_recv_msg_t *msg, void *data);
 static void nxt_controller_flush_requests(nxt_task_t *task);
-static nxt_int_t nxt_controller_conf_send(nxt_task_t *task,
+static nxt_int_t nxt_controller_conf_send(nxt_task_t *task, nxt_mp_t *mp,
     nxt_conf_value_t *conf, nxt_port_rpc_handler_t handler, void *data);
 
 static void nxt_controller_conn_init(nxt_task_t *task, void *obj, void *data);
@@ -344,7 +344,7 @@ nxt_controller_send_current_conf(nxt_task_t *task)
     conf = nxt_controller_conf.root;
 
     if (conf != NULL) {
-        rc = nxt_controller_conf_send(task, conf,
+        rc = nxt_controller_conf_send(task, nxt_controller_conf.pool, conf,
                                       nxt_controller_conf_init_handler, NULL);
 
         if (nxt_fast_path(rc == NXT_OK)) {
@@ -497,11 +497,14 @@ nxt_controller_flush_requests(nxt_task_t *task)
 
 
 static nxt_int_t
-nxt_controller_conf_send(nxt_task_t *task, nxt_conf_value_t *conf,
+nxt_controller_conf_send(nxt_task_t *task, nxt_mp_t *mp, nxt_conf_value_t *conf,
     nxt_port_rpc_handler_t handler, void *data)
 {
+    void           *mem;
+    u_char         *end;
     size_t         size;
     uint32_t       stream;
+    nxt_fd_t       fd;
     nxt_int_t      rc;
     nxt_buf_t      *b;
     nxt_port_t     *router_port, *controller_port;
@@ -518,30 +521,53 @@ nxt_controller_conf_send(nxt_task_t *task, nxt_conf_value_t *conf,
 
     size = nxt_conf_json_length(conf, NULL);
 
-    b = nxt_port_mmap_get_buf(task, router_port, size);
+    b = nxt_buf_mem_alloc(mp, sizeof(size_t), 0);
     if (nxt_slow_path(b == NULL)) {
         return NXT_ERROR;
     }
 
-    b->mem.free = nxt_conf_json_print(b->mem.free, conf, NULL);
+    fd = nxt_shm_open(task, size);
+    if (nxt_slow_path(fd == -1)) {
+        return NXT_ERROR;
+    }
+
+    mem = nxt_mem_mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+    if (nxt_slow_path(mem == MAP_FAILED)) {
+        goto fail;
+    }
+
+    end = nxt_conf_json_print(mem, conf, NULL);
+
+    nxt_mem_munmap(mem, size);
+
+    size = end - (u_char *) mem;
+
+    b->mem.free = nxt_cpymem(b->mem.pos, &size, sizeof(size_t));
 
     stream = nxt_port_rpc_register_handler(task, controller_port,
                                            handler, handler,
                                            router_port->pid, data);
-
     if (nxt_slow_path(stream == 0)) {
-        return NXT_ERROR;
+        goto fail;
     }
 
-    rc = nxt_port_socket_write(task, router_port, NXT_PORT_MSG_DATA_LAST, -1,
-                               stream, controller_port->id, b);
+    rc = nxt_port_socket_write(task, router_port,
+                               NXT_PORT_MSG_DATA_LAST | NXT_PORT_MSG_CLOSE_FD,
+                               fd, stream, controller_port->id, b);
 
     if (nxt_slow_path(rc != NXT_OK)) {
         nxt_port_rpc_cancel(task, controller_port, stream);
-        return NXT_ERROR;
+
+        goto fail;
     }
 
     return NXT_OK;
+
+fail:
+
+    nxt_fd_close(fd);
+
+    return NXT_ERROR;
 }
 
 
@@ -1201,7 +1227,7 @@ nxt_controller_process_config(nxt_task_t *task, nxt_controller_request_t *req,
             goto alloc_fail;
         }
 
-        rc = nxt_controller_conf_send(task, value,
+        rc = nxt_controller_conf_send(task, mp, value,
                                       nxt_controller_conf_handler, req);
 
         if (nxt_slow_path(rc != NXT_OK)) {
@@ -1282,7 +1308,7 @@ nxt_controller_process_config(nxt_task_t *task, nxt_controller_request_t *req,
             goto alloc_fail;
         }
 
-        rc = nxt_controller_conf_send(task, value,
+        rc = nxt_controller_conf_send(task, mp, value,
                                       nxt_controller_conf_handler, req);
 
         if (nxt_slow_path(rc != NXT_OK)) {