| 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; |
| } |
| |
| } |
| } |