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 * Copyright 2016, Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
 * met:
 *
 *    * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *    * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *
 *    * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.google.auth.oauth2;

import java.util.LinkedList;
import java.util.concurrent.Executor;

/** Mock thread-less executor. */
public final class MockExecutor implements Executor {
  private LinkedList<Runnable> tasks = new LinkedList<Runnable>();

  @Override
  public void execute(Runnable task) {
    tasks.add(task);
  }

  int runTasks() {
    LinkedList<Runnable> savedTasks = tasks;
    tasks = new LinkedList<Runnable>();
    for (Runnable task : savedTasks) {
      task.run();
    }
    return savedTasks.size();
  }

  int runTasksExhaustively() {
    int num = 0;
    while (true) {
      int thisNum = runTasks();
      if (thisNum == 0) {
        return num;
      }
      num += thisNum;
    }
  }

  int numTasks() {
    return tasks.size();
  }
}