1 files changed, 64 insertions, 0 deletions
diff --git a/lib/gitlab/memory/watchdog/configuration.rb b/lib/gitlab/memory/watchdog/configuration.rb
new file mode 100644
index 00000000000..2d84b083f55
--- /dev/null
+++ b/lib/gitlab/memory/watchdog/configuration.rb
@@ -0,0 +1,64 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Memory
+    class Watchdog
+      class Configuration
+        class MonitorStack
+          def initialize
+            @monitors = []
+          end
+
+          def use(monitor_class, *args, **kwargs, &block)
+            remove(monitor_class)
+            @monitors.push(build_monitor_state(monitor_class, *args, **kwargs, &block))
+          end
+
+          def call_each
+            @monitors.each do |monitor|
+              yield monitor.call
+            end
+          end
+
+          private
+
+          def remove(monitor_class)
+            @monitors.delete_if { |monitor| monitor.monitor_class == monitor_class }
+          end
+
+          def build_monitor_state(monitor_class, *args, max_strikes:, **kwargs, &block)
+            monitor = build_monitor(monitor_class, *args, **kwargs, &block)
+
+            Gitlab::Memory::Watchdog::MonitorState.new(monitor, max_strikes: max_strikes)
+          end
+
+          def build_monitor(monitor_class, *args, **kwargs, &block)
+            monitor_class.new(*args, **kwargs, &block)
+          end
+        end
+
+        DEFAULT_SLEEP_TIME_SECONDS = 60
+
+        attr_reader :monitors
+        attr_writer :logger, :handler, :sleep_time_seconds
+
+        def initialize
+          @monitors = MonitorStack.new
+        end
+
+        def handler
+          @handler ||= NullHandler.instance
+        end
+
+        def logger
+          @logger ||= Gitlab::Logger.new($stdout)
+        end
+
+        # Used to control the frequency with which the watchdog will wake up and poll the GC.
+        def sleep_time_seconds
+          @sleep_time_seconds ||= DEFAULT_SLEEP_TIME_SECONDS
+        end
+      end
+    end
+  end
+end