op-challenger: Release agent resources once game is complete (#11820)

op-challenger/game/fault/player.go

@@ -64,6 +64,10 @@ type GameContract interface {
 	GetL1Head(ctx context.Context) (common.Hash, error)
 }
 
+var actNoop = func(ctx context.Context) error {
+	return nil
+}
+
 type resourceCreator func(ctx context.Context, logger log.Logger, gameDepth types.Depth, dir string) (types.TraceAccessor, error)
 
 func NewGamePlayer(
@@ -98,9 +102,7 @@ func NewGamePlayer(
 			prestateValidators: validators,
 			status:             status,
 			// Act function does nothing because the game is already complete
-			act: func(ctx context.Context) error {
-				return nil
-			},
+			act: actNoop,
 		}, nil
 	}
 
@@ -195,6 +197,10 @@ func (g *GamePlayer) ProgressGame(ctx context.Context) gameTypes.GameStatus {
 	}
 	g.logGameStatus(ctx, status)
 	g.status = status
+	if status != gameTypes.GameStatusInProgress {
+		// Release the agent as we will no longer need to act on this game.
+		g.act = actNoop
+	}
 	return status
 }
 

op-challenger/game/fault/player_test.go

@@ -90,6 +90,11 @@ func TestDoNotActOnCompleteGame(t *testing.T) {
 			fetched = game.ProgressGame(context.Background())
 			require.Equal(t, 1, gameState.callCount, "does not act after game is complete")
 			require.Equal(t, status, fetched)
+
+			// Should have replaced the act function with a noop so callCount doesn't update even when called directly
+			// This allows the agent resources to be GC'd
+			require.NoError(t, game.act(context.Background()))
+			require.Equal(t, 1, gameState.callCount)
 		})
 	}
 }