| /* |
| * Copyright (C) 2006 The Guava Authors |
| * |
| * 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.common.util.concurrent; |
| |
| import static com.google.common.collect.Sets.newHashSet; |
| |
| import java.util.Set; |
| |
| /** Emulation of AggregateFutureState. */ |
| abstract class AggregateFutureState { |
| // Lazily initialized the first time we see an exception; not released until all the input futures |
| // & this future completes. Released when the future releases the reference to the running state |
| private Set<Throwable> seenExceptions = null; |
| private int remaining; |
| |
| AggregateFutureState(int remainingFutures) { |
| this.remaining = remainingFutures; |
| } |
| |
| final Set<Throwable> getOrInitSeenExceptions() { |
| if (seenExceptions == null) { |
| seenExceptions = newHashSet(); |
| addInitialException(seenExceptions); |
| } |
| return seenExceptions; |
| } |
| |
| abstract void addInitialException(Set<Throwable> seen); |
| |
| final int decrementRemainingAndGet() { |
| return --remaining; |
| } |
| } |