| /** |
| * 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.Collections; |
| import java.util.List; |
| import org.apache.yetus.audience.InterfaceAudience; |
| import org.apache.yetus.audience.InterfaceStability; |
| |
| /** |
| * Simple scheduler for procedures |
| */ |
| @InterfaceAudience.Private |
| @InterfaceStability.Evolving |
| public class SimpleProcedureScheduler extends AbstractProcedureScheduler { |
| private final ProcedureDeque runnables = new ProcedureDeque(); |
| |
| @Override |
| protected void enqueue(final Procedure procedure, final boolean addFront) { |
| if (addFront) { |
| runnables.addFirst(procedure); |
| } else { |
| runnables.addLast(procedure); |
| } |
| } |
| |
| @Override |
| protected Procedure dequeue() { |
| return runnables.poll(); |
| } |
| |
| @Override |
| public void clear() { |
| schedLock(); |
| try { |
| runnables.clear(); |
| } finally { |
| schedUnlock(); |
| } |
| } |
| |
| @Override |
| public void yield(final Procedure proc) { |
| addBack(proc); |
| } |
| |
| @Override |
| public boolean queueHasRunnables() { |
| return runnables.size() > 0; |
| } |
| |
| @Override |
| public int queueSize() { |
| return runnables.size(); |
| } |
| |
| @Override |
| public void completionCleanup(Procedure proc) { |
| } |
| |
| @Override |
| public List<LockedResource> getLocks() { |
| return Collections.emptyList(); |
| } |
| |
| @Override |
| public LockedResource getLockResource(LockedResourceType resourceType, |
| String resourceName) { |
| return null; |
| } |
| } |