| /* |
| * Copyright (c) 2015, the Dart project authors. |
| * |
| * Licensed under the Eclipse Public License v1.0 (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.eclipse.org/legal/epl-v10.html |
| * |
| * 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.dartlang.vm.service; |
| |
| import java.util.concurrent.CountDownLatch; |
| import java.util.concurrent.TimeUnit; |
| |
| /** |
| * {@link OpLatch} is used by one thread to wait for another thread to complete (see |
| * {@link OpLatch#waitOpComplete()} and {@link OpLatch#waitAndAssertOpComplete()}). If the operation |
| * does not complete before the expiration time then {@link OpLatch#waitOpComplete()} returns |
| * {@code false} and {@link OpLatch#waitAndAssertOpComplete()} throws an exception. |
| */ |
| class OpLatch { |
| final CountDownLatch latch = new CountDownLatch(1); |
| private long endTime; |
| |
| /** |
| * Set or increase the time after which the operation is considered failed. This is automatically |
| * called by {@link #waitAndAssertOp()} and {@link #waitOpComplete()}. |
| */ |
| public void opWorking() { |
| endTime = System.currentTimeMillis() + 5000; |
| } |
| |
| /** |
| * Call to indicate that the operation completed successfully. |
| */ |
| void opComplete() { |
| latch.countDown(); |
| } |
| |
| /** |
| * Wait for the operation to complete or the time limit to expire. Periodically call |
| * {@link #opWorking()} to increase the expiration time. Throw a {@link RuntimeException} if the |
| * operation did not complete before the expiration time. |
| */ |
| void waitAndAssertOpComplete() { |
| if (!waitOpComplete()) { |
| System.out.println(">>> No response received"); |
| throw new RuntimeException("No response received"); |
| } |
| } |
| |
| /** |
| * Wait for the operation to complete or the time limit to expire. Periodically call |
| * {@link #opWorking()} to increase the expiration time. |
| * |
| * @return {@code true} if the operation completed, or {@code false} otherwise |
| */ |
| boolean waitOpComplete() { |
| opWorking(); |
| while (true) { |
| long waitTimeMillis = endTime - System.currentTimeMillis(); |
| if (waitTimeMillis <= 0) { |
| return latch.getCount() == 0; |
| } |
| try { |
| if (latch.await(waitTimeMillis, TimeUnit.MILLISECONDS)) { |
| return true; |
| } |
| } catch (InterruptedException e) { |
| // ignore and loop to check if timeout has changed |
| } |
| } |
| } |
| } |