// Copyright 2015 The Bazel Authors. All rights reserved.
//
// Licensed 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 com.google.devtools.build.lib.concurrent;

import java.util.concurrent.Callable;

/**
 * Helper class for dealing with {@link InterruptedException}.
 */
public final class Uninterruptibles {

  /**
   * Calls the given callable uninterruptibly.
   *
   * <p>If the callable throws {@link InterruptedException}, calls it again, until the callable
   * returns a result. Sets the {@code currentThread().interrupted()} bit if the callable threw
   * {@link InterruptedException} at least once.
   */
  public static final <T> T callUninterruptibly(Callable<T> callable) throws Exception {
    boolean interrupted = false;
    try {
      while (true) {
        try {
          return callable.call();
        } catch (InterruptedException e) {
          interrupted = true;
        }
      }
    } finally {
      if (interrupted) {
        Thread.currentThread().interrupt();
      }
    }
  }
}