001/*
002 * Copyright (C) 2013 The Guava Authors
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
005 * in compliance with the License. You may obtain a copy of the License at
006 *
007 * http://www.apache.org/licenses/LICENSE-2.0
008 *
009 * Unless required by applicable law or agreed to in writing, software distributed under the License
010 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
011 * or implied. See the License for the specific language governing permissions and limitations under
012 * the License.
013 */
014
015package com.google.common.util.concurrent;
016
017import com.google.common.annotations.GwtCompatible;
018
019/**
020 * Static utility methods pertaining to the {@link Runnable} interface.
021 *
022 * @since 16.0
023 */
024@GwtCompatible
025public final class Runnables {
026  /*
027   * If we inline this, it's not longer a singleton under Android (at least under the Lollipop
028   * version that we're testing under) or J2CL.
029   *
030   * That's not necessarily a real-world problem, but it does break our tests.
031   */
032  @SuppressWarnings({"InlineLambdaConstant", "UnnecessaryLambda"})
033  private static final Runnable EMPTY_RUNNABLE = () -> {};
034
035  /** Returns a {@link Runnable} instance that does nothing when run. */
036  public static Runnable doNothing() {
037    return EMPTY_RUNNABLE;
038  }
039
040  private Runnables() {}
041}