cleanup class variable resources

lib/fluent/compat/call_super_mixin.rb

@@ -55,6 +55,15 @@ def before_shutdown
         end
       end
 
+      def stop
+        klass = self.class
+        @@_super_start.delete(klass)
+        @@_super_before_shutdown.delete(klass)
+        @@_super_shutdown.delete(klass)
+
+        super
+      end
+
       def shutdown
         super
         unless self.shutdown?

lib/fluent/plugin/buf_file.rb

@@ -50,6 +50,7 @@ def initialize
         @symlink_path = nil
         @multi_workers_available = false
         @additional_resume_path = nil
+        @buffer_path = nil
       end
 
       def configure(conf)
@@ -73,7 +74,8 @@ def configure(conf)
           raise ConfigError, "Other '#{type_using_this_path}' plugin already use same buffer path: type = #{type_of_owner}, buffer path = #{@path}"
         end
 
-        @@buffer_paths[@path] = type_of_owner
+        @buffer_path = @path
+        @@buffer_paths[@buffer_path] = type_of_owner
 
         specified_directory_exists = File.exist?(@path) && File.directory?(@path)
         unexisting_path_for_directory = !File.exist?(@path) && [email protected]?('.*')
@@ -122,6 +124,12 @@ def start
         super
       end
 
+      def stop
+        @@buffer_paths.delete(@buffer_path)
+
+        super
+      end
+
       def persistent?
         true
       end

lib/fluent/plugin/buf_file_single.rb

@@ -144,6 +144,12 @@ def start
         super
       end
 
+      def stop
+        @@buffer_paths.delete(@path)
+
+        super
+      end
+
       def persistent?
         true
       end

lib/fluent/plugin/in_tail.rb

@@ -204,6 +204,12 @@ def start
       timer_execute(:in_tail_refresh_watchers, @refresh_interval, &method(:refresh_watchers))
     end
 
+    def stop
+      @@pos_file_paths.delete(@pos_file)
+
+      super
+    end
+
     def shutdown
       # during shutdown phase, don't close io. It should be done in close after all threads are stopped. See close.
       stop_watchers(@tails.keys, immediate: true, remove_watcher: false)

lib/fluent/plugin_id.rb

@@ -76,5 +76,11 @@ def plugin_root_dir
       @_plugin_root_dir = dir.freeze
       dir
     end
+
+    def stop
+      @@configured_ids.delete(@id)
+
+      super
+    end
   end
 end