api: fix INIT state stuck

Sometimes, instance could enter the queue initialization
while still in the orphan mode. This resulted in "lazy
start". But tarantool does not call `box.cfg {}` after
leaving orphan mode, so queue was stuck in the `INIT` state.

Now we wait for all orphan instances on the init stage of the queue.

Closes #226

Author: DerekBum

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Fixed
+
+- Stuck in `INIT` state if instance failed to leave `orphan` mode in time (#226).
+
 ## [1.3.3] - 2023-09-13
 
 ### Fixed

queue/init.lua

@@ -73,6 +73,20 @@ local function cfg_call_wrapper(cfg, ...)
     return wrapper_impl(...)
 end
 
+local function orphan_waiter()
+    local fiber = require('fiber')
+    local wait_for_orphan = fiber.new(function()
+        while true do
+            if box.info.status ~= 'orphan' then
+                break
+            end
+            fiber.sleep(0.1)
+        end
+    end)
+    wait_for_orphan:set_joinable(true)
+    wait_for_orphan:join()
+end
+
 local function wrap_box_cfg()
     if type(box.cfg) == 'function' then
         -- box.cfg before the first box.cfg call
@@ -97,6 +111,11 @@ function wrapper_impl(...)
         error(result[2])
     end
 
+    if box.info.ro_reason == 'orphan' then
+        -- Wait for the orphan instance.
+        orphan_waiter()
+    end
+
     if box.info.ro == false then
         local abstract = require 'queue.abstract'
         for name, val in pairs(abstract) do
@@ -121,6 +140,10 @@ end
 -- configured with read_only = false. Otherwise, a start is
 -- delayed until the instance will be configured with read_only = false.
 local function queue_init()
+    if rawget(box, 'space') ~= nil and box.info.ro_reason == 'orphan' then
+        -- Wait for the orphan instance.
+        orphan_waiter()
+    end
     if rawget(box, 'space') ~= nil and box.info.ro == false then
         -- The box was configured with read_only = false
         queue = require('queue.abstract')