content: /*
   * 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.kafka.common.utils;
  
  import java.time.Duration;
  import java.util.concurrent.ExecutionException;
  import java.util.concurrent.Future;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.TimeoutException;
  import java.util.function.Supplier;
  
  /**
   * An interface abstracting the clock to use in unit testing classes that make use of clock time.
   *
   * Implementations of this class should be thread-safe.
   */
  public interface Time {
  
      Time SYSTEM = SystemTime.getSystemTime();
  
      /**
       * Returns the current time in milliseconds.
       */
      long milliseconds();
  
      /**
       * Returns the value returned by `nanoseconds` converted into milliseconds.
       */
      default long hiResClockMs() {
          return TimeUnit.NANOSECONDS.toMillis(nanoseconds());
      }
  
      /**
       * Returns the current value of the running JVM's high-resolution time source, in nanoseconds.
       *
       * <p>This method can only be used to measure elapsed time and is
       * not related to any other notion of system or wall-clock time.
       * The value returned represents nanoseconds since some fixed but
       * arbitrary <i>origin</i> time (perhaps in the future, so values
       * may be negative).  The same origin is used by all invocations of
       * this method in an instance of a Java virtual machine; other
       * virtual machine instances are likely to use a different origin.
       */
      long nanoseconds();
  
      /**
       * Sleep for the given number of milliseconds
       */
      void sleep(long ms);
  
      /**
       * Wait for a condition using the monitor of a given object. This avoids the implicit
       * dependence on system time when calling {@link Object#wait()}.
       *
       * @param obj The object that will be waited with {@link Object#wait()}. Note that it is the responsibility
       *      of the caller to call notify on this object when the condition is satisfied.
       * @param condition The condition we are awaiting
       * @param deadlineMs The deadline timestamp at which to raise a timeout error
       *
       * @throws org.apache.kafka.common.errors.TimeoutException if the timeout expires before the condition is satisfied
       */
      void waitObject(Object obj, Supplier<Boolean> condition, long deadlineMs) throws InterruptedException;
  
      /**
       * Get a timer which is bound to this time instance and expires after the given timeout
       */
      default Timer timer(long timeoutMs) {
          return new Timer(this, timeoutMs);
      }
  
      /**
       * Get a timer which is bound to this time instance and expires after the given timeout
       */
      default Timer timer(Duration timeout) {
          return timer(timeout.toMillis());
      }
  
      /**
       * Wait for a future to complete, or time out.
       *
       * @param future        The future to wait for.
       * @param deadlineNs    The time in the future, in monotonic nanoseconds, to time out.
       * @return              The result of the future.
       * @param <T>           The type of the future.
       */
      default <T> T waitForFuture(
          Future<T> future,
          long deadlineNs
      ) throws TimeoutException, InterruptedException, ExecutionException  {
          TimeoutException timeoutException = null;
          while (true) {
              long nowNs = nanoseconds();
              if (deadlineNs <= nowNs) {
                  throw (timeoutException == null) ? new TimeoutException() : timeoutException;
              }
              long deltaNs = deadlineNs - nowNs;
              try {
                  return future.get(deltaNs, TimeUnit.NANOSECONDS);
              } catch (TimeoutException t) {
                  timeoutException = t;
              }
          }
      }
  }
  