server/src/main/scala/org/apache/livy/utils/Clock.scala

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.livy.utils

/**
 * A lot of Livy code relies on time related functions like Thread.sleep.
 * To timing effects from unit test, this class is created to mock out time.
 *
 * Code in Livy should not call Thread.sleep() directly. It should call this class instead.
 */
object Clock {
  private var _sleep: Long => Unit = Thread.sleep

  def withSleepMethod(mockSleep: Long => Unit)(f: => Unit): Unit = {
    try {
      _sleep = mockSleep
      f
    } finally {
      _sleep = Thread.sleep
    }
  }

  def sleep: Long => Unit = _sleep
}