in_tail: Make closing io handler be done in closing phase

And add consideration for concurrent execution.

Signed-off-by: Daijiro Fukuda <[email protected]>

lib/fluent/plugin/in_tail.rb

@@ -269,7 +269,13 @@ def shutdown
       # during shutdown phase, don't close io. It should be done in close after all threads are stopped. See close.
       stop_watchers(existence_path, immediate: true, remove_watcher: false)
       @tails_rotate_wait.keys.each do |tw|
-        detach_watcher(tw, @tails_rotate_wait[tw][:ino])
+        # Note: Be careful about duplicate execution with the timer side.
+        # (There is no harm in duplicate execution, but need to be careful about nil exception, etc)
+        v = @tails_rotate_wait[tw]
+        next unless v
+        ino, timer = v.values
+        timer.detach rescue nil
+        detach_watcher(tw, ino, false)
       end
       @pf_file.close if @pf_file
 
@@ -279,6 +285,7 @@ def shutdown
     def close
       super
       # close file handles after all threads stopped (in #close of thread plugin helper)
+      # It may be because we need to wait IOHanlder.ready_to_shutdown()
       close_watcher_handles
     end
 
@@ -520,6 +527,9 @@ def close_watcher_handles
           tw.close
         end
       end
+      @tails_rotate_wait.keys.each do |tw|
+        tw.close
+      end
     end
 
     # refresh_watchers calls @tails.keys so we don't use stop_watcher -> start_watcher sequence for safety.