| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.hadoop.hbase.procedure2; |
| |
| import java.util.ArrayDeque; |
| import java.util.Deque; |
| import java.util.concurrent.locks.Condition; |
| import java.util.concurrent.locks.ReentrantLock; |
| |
| import org.apache.hadoop.hbase.classification.InterfaceAudience; |
| import org.apache.hadoop.hbase.classification.InterfaceStability; |
| |
| /** |
| * Simple runqueue for the procedures |
| */ |
| @InterfaceAudience.Private |
| @InterfaceStability.Evolving |
| public class ProcedureSimpleRunQueue implements ProcedureRunnableSet { |
| private final Deque<Long> runnables = new ArrayDeque<Long>(); |
| private final ReentrantLock lock = new ReentrantLock(); |
| private final Condition waitCond = lock.newCondition(); |
| |
| @Override |
| public void addFront(final Procedure proc) { |
| lock.lock(); |
| try { |
| runnables.addFirst(proc.getProcId()); |
| waitCond.signal(); |
| } finally { |
| lock.unlock(); |
| } |
| } |
| |
| @Override |
| public void addBack(final Procedure proc) { |
| lock.lock(); |
| try { |
| runnables.addLast(proc.getProcId()); |
| waitCond.signal(); |
| } finally { |
| lock.unlock(); |
| } |
| } |
| |
| @Override |
| public void yield(final Procedure proc) { |
| addBack(proc); |
| } |
| |
| @Override |
| @edu.umd.cs.findbugs.annotations.SuppressWarnings("WA_AWAIT_NOT_IN_LOOP") |
| public Long poll() { |
| lock.lock(); |
| try { |
| if (runnables.isEmpty()) { |
| waitCond.await(); |
| if (!runnables.isEmpty()) { |
| return runnables.pop(); |
| } |
| } else { |
| return runnables.pop(); |
| } |
| } catch (InterruptedException e) { |
| Thread.currentThread().interrupt(); |
| return null; |
| } finally { |
| lock.unlock(); |
| } |
| return null; |
| } |
| |
| @Override |
| public void signalAll() { |
| lock.lock(); |
| try { |
| waitCond.signalAll(); |
| } finally { |
| lock.unlock(); |
| } |
| } |
| |
| @Override |
| public void clear() { |
| lock.lock(); |
| try { |
| runnables.clear(); |
| } finally { |
| lock.unlock(); |
| } |
| } |
| |
| @Override |
| public int size() { |
| lock.lock(); |
| try { |
| return runnables.size(); |
| } finally { |
| lock.unlock(); |
| } |
| } |
| |
| @Override |
| public void completionCleanup(Procedure proc) { |
| } |
| } |