| /* |
| * 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.cassandra.stress; |
| |
| import java.util.concurrent.atomic.AtomicLong; |
| |
| public interface WorkManager |
| { |
| // -1 indicates consumer should terminate |
| int takePermits(int count); |
| |
| // signal all consumers to terminate |
| void stop(); |
| |
| static final class FixedWorkManager implements WorkManager |
| { |
| |
| final AtomicLong permits; |
| |
| public FixedWorkManager(long permits) |
| { |
| this.permits = new AtomicLong(permits); |
| } |
| |
| @Override |
| public int takePermits(int count) |
| { |
| while (true) |
| { |
| long cur = permits.get(); |
| if (cur == 0) |
| return -1; |
| count = (int) Math.min(count, cur); |
| long next = cur - count; |
| if (permits.compareAndSet(cur, next)) |
| return count; |
| } |
| } |
| |
| @Override |
| public void stop() |
| { |
| permits.getAndSet(0); |
| } |
| } |
| |
| static final class ContinuousWorkManager implements WorkManager |
| { |
| |
| volatile boolean stop = false; |
| |
| @Override |
| public int takePermits(int count) |
| { |
| if (stop) |
| return -1; |
| return count; |
| } |
| |
| @Override |
| public void stop() |
| { |
| stop = true; |
| } |
| |
| } |
| } |