| /* |
| * Copyright 2012-present Facebook, Inc. |
| * |
| * 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.facebook.buck.util.concurrent; |
| |
| import com.google.common.base.Preconditions; |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.util.concurrent.Futures; |
| import com.google.common.util.concurrent.ListenableFuture; |
| import com.google.common.util.concurrent.ListeningExecutorService; |
| import com.google.common.util.concurrent.Uninterruptibles; |
| |
| import java.util.List; |
| import java.util.concurrent.Callable; |
| import java.util.concurrent.CancellationException; |
| import java.util.concurrent.ExecutionException; |
| |
| public class MoreFutures { |
| /** |
| * Invoke multiple callables on the provided executor and wait for all to return successfully. |
| * An exception is thrown (immediately) if any callable fails. |
| * @param executorService Executor service. |
| * @param callables Callables to call. |
| * @return List of values from each invoked callable in order if all callables execute without |
| * throwing. |
| * @throws ExecutionException If any callable throws an exception, the first of such is wrapped |
| * in an ExecutionException and thrown. Access via |
| * {@link java.util.concurrent.ExecutionException#getCause()}}. |
| */ |
| public static <V> List<V> getAllUninterruptibly( |
| ListeningExecutorService executorService, |
| Iterable<Callable<V>> callables) throws ExecutionException { |
| // Invoke. |
| ImmutableList.Builder<ListenableFuture<V>> futures = ImmutableList.builder(); |
| for (Callable<V> callable : callables) { |
| ListenableFuture<V> future = executorService.submit(callable); |
| futures.add(future); |
| } |
| |
| // Wait for completion. |
| ListenableFuture<List<V>> allAsOne = Futures.allAsList(futures.build()); |
| return Uninterruptibles.getUninterruptibly(allAsOne); |
| } |
| |
| /** |
| * Create a convenience method for checking whether a future completed successfully because this |
| * does not appear to be possible to do in a more direct way: |
| * https://groups.google.com/forum/?fromgroups=#!topic/guava-discuss/rofEhagKnOc. |
| * |
| * @return true if the specified future has been resolved without throwing an exception or being |
| * cancelled. |
| */ |
| public static boolean isSuccess(ListenableFuture<?> future) { |
| if (future.isDone()) { |
| try { |
| future.get(); |
| return true; |
| } catch (ExecutionException e) { |
| // The computation threw an exception, so it did not complete successfully. |
| return false; |
| } catch (CancellationException e) { |
| // The computation was cancelled, so it did not complete successfully. |
| return false; |
| } catch (InterruptedException e) { |
| throw new RuntimeException("Should not be possible to interrupt a resolved future.", e); |
| } |
| } else { |
| return false; |
| } |
| } |
| |
| /** |
| * Returns the failure for a {@link ListenableFuture}. |
| * @param future Must have completed unsuccessfully. |
| */ |
| public static Throwable getFailure(ListenableFuture<?> future) { |
| Preconditions.checkArgument(future.isDone()); |
| Preconditions.checkArgument(!isSuccess(future)); |
| try { |
| future.get(); |
| throw new IllegalStateException("get() should have thrown an exception"); |
| } catch (ExecutionException e) { |
| return e.getCause(); |
| } catch (CancellationException | InterruptedException e) { |
| throw new IllegalStateException(e); |
| } |
| } |
| } |