New process port exchange changed. READY message type introduced.

Application process start request DATA message from router to master.
Master notifies router via NEW_PORT message after worker process become ready.

src/nxt_port.c

@@ -11,13 +11,28 @@
 
 static void nxt_port_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg);
 
+static nxt_atomic_uint_t nxt_port_last_id;
+
+nxt_port_id_t
+nxt_port_get_next_id()
+{
+    return nxt_atomic_fetch_add(&nxt_port_last_id, 1);
+}
+
 
 void
-nxt_port_create(nxt_task_t *task, nxt_port_t *port,
+nxt_port_reset_next_id()
+{
+    nxt_port_last_id = 1;
+}
+
+
+void
+nxt_port_enable(nxt_task_t *task, nxt_port_t *port,
     nxt_port_handler_t *handlers)
 {
     port->pid = nxt_pid;
-    port->engine = task->thread->engine->id;
+    port->engine = task->thread->engine;
     port->handler = nxt_port_handler;
     port->data = handlers;
 
@@ -77,12 +92,13 @@ nxt_port_quit_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg)
 
 void
 nxt_port_send_new_port(nxt_task_t *task, nxt_runtime_t *rt,
-    nxt_port_t *new_port)
+    nxt_port_t *new_port, uint32_t stream)
 {
+    nxt_port_t     *port;
     nxt_process_t  *process;
 
-    nxt_debug(task, "new port %d for process %PI engine %uD",
-              new_port->pair[1], new_port->pid, new_port->engine);
+    nxt_debug(task, "new port %d for process %PI",
+              new_port->pair[1], new_port->pid);
 
     nxt_runtime_process_each(rt, process)
     {
@@ -90,15 +106,22 @@ nxt_port_send_new_port(nxt_task_t *task, nxt_runtime_t *rt,
             continue;
         }
 
-        (void) nxt_port_send_port(task, nxt_process_port_first(process),
-                                  new_port);
+        port = nxt_process_port_first(process);
+
+        if (port->type == NXT_PROCESS_MASTER ||
+            port->type == NXT_PROCESS_CONTROLLER ||
+            port->type == NXT_PROCESS_ROUTER) {
+
+            (void) nxt_port_send_port(task, port, new_port, stream);
+        }
     }
     nxt_runtime_process_loop;
 }
 
 
 nxt_int_t
-nxt_port_send_port(nxt_task_t *task, nxt_port_t *port, nxt_port_t *new_port)
+nxt_port_send_port(nxt_task_t *task, nxt_port_t *port, nxt_port_t *new_port,
+    uint32_t stream)
 {
     nxt_buf_t                *b;
     nxt_port_msg_new_port_t  *msg;
@@ -116,13 +139,12 @@ nxt_port_send_port(nxt_task_t *task, nxt_port_t *port, nxt_port_t *new_port)
 
     msg->id = new_port->id;
     msg->pid = new_port->pid;
-    msg->engine = new_port->engine;
     msg->max_size = port->max_size;
     msg->max_share = port->max_share;
     msg->type = new_port->type;
 
     return nxt_port_socket_write(task, port, NXT_PORT_MSG_NEW_PORT,
-                                 new_port->pair[1], 0, 0, b);
+                                 new_port->pair[1], stream, 0, b);
 }
 
 
@@ -140,12 +162,26 @@ nxt_port_new_port_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg)
     new_port_msg = (nxt_port_msg_new_port_t *) msg->buf->mem.pos;
     msg->buf->mem.pos = msg->buf->mem.free;
 
+    nxt_debug(task, "new port %d received for process %PI:%d",
+              msg->fd, new_port_msg->pid, new_port_msg->id);
+
+    port = nxt_runtime_port_find(rt, new_port_msg->pid, new_port_msg->id);
+    if (port != NULL) {
+        nxt_debug(task, "port %PI:%d already exists", new_port_msg->pid,
+              new_port_msg->id);
+
+        nxt_fd_close(msg->fd);
+        msg->fd = -1;
+        return;
+    }
+
     process = nxt_runtime_process_get(rt, new_port_msg->pid);
     if (nxt_slow_path(process == NULL)) {
         return;
     }
 
-    port = nxt_process_port_new(process);
+    port = nxt_process_port_new(rt, process, new_port_msg->id,
+                                new_port_msg->type);
     if (nxt_slow_path(port == NULL)) {
         return;
     }
@@ -157,16 +193,10 @@ nxt_port_new_port_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg)
 
     port->mem_pool = mp;
 
-    nxt_debug(task, "new port %d received for process %PI engine %uD",
-              msg->fd, new_port_msg->pid, new_port_msg->engine);
-
-    port->id = new_port_msg->id;
-    port->engine = new_port_msg->engine;
     port->pair[0] = -1;
     port->pair[1] = msg->fd;
     port->max_size = new_port_msg->max_size;
     port->max_share = new_port_msg->max_share;
-    port->type = new_port_msg->type;
 
     nxt_queue_init(&port->messages);
 
@@ -175,6 +205,37 @@ nxt_port_new_port_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg)
     nxt_runtime_port_add(rt, port);
 
     nxt_port_write_enable(task, port);
+
+    msg->new_port = port;
+}
+
+
+void
+nxt_port_ready_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg)
+{
+    nxt_port_t     *port;
+    nxt_process_t  *process;
+    nxt_runtime_t  *rt;
+
+    rt = task->thread->runtime;
+
+    process = nxt_runtime_process_get(rt, msg->port_msg.pid);
+    if (nxt_slow_path(process == NULL)) {
+        return;
+    }
+
+    process->ready = 1;
+
+    port = nxt_process_port_first(process);
+    if (nxt_slow_path(port == NULL)) {
+        return;
+    }
+
+    nxt_debug(task, "process %PI ready", msg->port_msg.pid);
+
+    if (nxt_runtime_is_master(rt)) {
+        nxt_port_send_new_port(task, rt, port, msg->port_msg.stream);
+    }
 }