| 1 | package com.hammurapi.common.concurrent; |
| 2 | |
| 3 | import java.util.LinkedList; |
| 4 | import java.util.List; |
| 5 | import java.util.concurrent.AbstractExecutorService; |
| 6 | import java.util.concurrent.ExecutorService; |
| 7 | import java.util.concurrent.TimeUnit; |
| 8 | import java.util.concurrent.atomic.AtomicLong; |
| 9 | |
| 10 | /** |
| 11 | * In-JMV tracking executor service. |
| 12 | * @author Pavel Vlasov |
| 13 | * |
| 14 | */ |
| 15 | public class LocalTrackingExecutorService extends AbstractExecutorService implements TrackingExecutorService { |
| 16 | |
| 17 | private boolean oneOff; |
| 18 | |
| 19 | private AtomicLong joinDone = new AtomicLong(-1); |
| 20 | |
| 21 | private final AtomicLong TASK_COUNTER = new AtomicLong(); |
| 22 | |
| 23 | private String name; |
| 24 | |
| 25 | private final ThreadLocal<TrackingRunnable> contextTask = new ThreadLocal<TrackingRunnable>(); |
| 26 | |
| 27 | /** |
| 28 | * @param master Master executor. |
| 29 | * @param oneOff If true, join can be invoked only once. No tasks can be submitted to the executor once |
| 30 | * join() returns. |
| 31 | */ |
| 32 | public LocalTrackingExecutorService(ExecutorService master, boolean oneOff, String name) { |
| 33 | this.master = master; |
| 34 | this.oneOff = oneOff; |
| 35 | this.name = name; |
| 36 | } |
| 37 | |
| 38 | @Override |
| 39 | public void shutdown() { |
| 40 | master.shutdown(); |
| 41 | } |
| 42 | |
| 43 | @Override |
| 44 | public List<Runnable> shutdownNow() { |
| 45 | return master.shutdownNow(); |
| 46 | } |
| 47 | |
| 48 | @Override |
| 49 | public boolean isShutdown() { |
| 50 | return master.isShutdown(); |
| 51 | } |
| 52 | |
| 53 | @Override |
| 54 | public boolean isTerminated() { |
| 55 | return master.isTerminated(); |
| 56 | } |
| 57 | |
| 58 | @Override |
| 59 | public boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException { |
| 60 | return master.awaitTermination(timeout, unit); |
| 61 | } |
| 62 | |
| 63 | @Override |
| 64 | public void execute(Runnable command) { |
| 65 | checkJoinDone(); |
| 66 | master.execute(new TrackingRunnable(command)); |
| 67 | } |
| 68 | |
| 69 | private void checkJoinDone() { |
| 70 | if (oneOff && joinDone.get()!=-1) { |
| 71 | throw new IllegalStateException("Can't execute any more tasks"); |
| 72 | } |
| 73 | } |
| 74 | |
| 75 | // private Lock serviceLock = new ReentrantLock(); |
| 76 | |
| 77 | private Thread joinThread; |
| 78 | |
| 79 | /** |
| 80 | * Executes and removes pending tasks, exits when all tasks are completed. |
| 81 | */ |
| 82 | @Override |
| 83 | public void join() throws InterruptedException { |
| 84 | join(0); |
| 85 | } |
| 86 | |
| 87 | public boolean join(long timeout) throws InterruptedException { |
| 88 | long start = timeout>0 ? System.currentTimeMillis() : 0; |
| 89 | checkJoinDone(); |
| 90 | joinThread = Thread.currentThread(); |
| 91 | while (true) { |
| 92 | TrackingRunnable toRun = null; |
| 93 | boolean hasRunning = false; |
| 94 | synchronized (tasks) { |
| 95 | for (TrackingRunnable task: tasks) { |
| 96 | if (task.state==TaskState.PENDING) { |
| 97 | toRun = task; |
| 98 | break; |
| 99 | } else if (task.state==TaskState.RUNNING && task.runner!=Thread.currentThread()) { |
| 100 | hasRunning = true; |
| 101 | } |
| 102 | } |
| 103 | if (toRun==null) { |
| 104 | if (!hasRunning) { |
| 105 | if (oneOff) { |
| 106 | joinDone.set(TASK_COUNTER.get()); |
| 107 | } |
| 108 | return true; |
| 109 | } |
| 110 | tasks.wait(10); // Wakes up if all tasks finish execution. |
| 111 | if (start>0) { |
| 112 | if (System.currentTimeMillis()-start>timeout) { |
| 113 | return false; |
| 114 | } |
| 115 | } |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | if (toRun!=null) { |
| 120 | toRun.run(); |
| 121 | } |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | private ExecutorService master; |
| 126 | |
| 127 | // private Collection<Thread> runners = new LinkedList<Thread>(); |
| 128 | |
| 129 | // Tasks which are not yet being executed. |
| 130 | private LinkedList<TrackingRunnable> tasks = new LinkedList<TrackingRunnable>(); |
| 131 | |
| 132 | private enum TaskState { |
| 133 | PENDING, |
| 134 | RUNNING, |
| 135 | DONE |
| 136 | } |
| 137 | |
| 138 | private class TrackingRunnable implements Runnable { |
| 139 | |
| 140 | volatile TaskState state; |
| 141 | volatile Thread runner; |
| 142 | |
| 143 | private Runnable master; |
| 144 | private final long taskID = TASK_COUNTER.incrementAndGet(); |
| 145 | private TrackingRunnable submitter = contextTask.get(); |
| 146 | |
| 147 | TrackingRunnable(Runnable master) { |
| 148 | this.master = master; |
| 149 | synchronized (tasks) { |
| 150 | state = TaskState.PENDING; |
| 151 | tasks.add(this); |
| 152 | } |
| 153 | } |
| 154 | |
| 155 | @Override |
| 156 | public void run() { |
| 157 | synchronized (tasks) { |
| 158 | if (state!=TaskState.PENDING) { |
| 159 | return; |
| 160 | } |
| 161 | runner = Thread.currentThread(); |
| 162 | state = TaskState.RUNNING; |
| 163 | contextTask.set(this); |
| 164 | } |
| 165 | try { |
| 166 | master.run(); |
| 167 | } finally { |
| 168 | synchronized (tasks) { |
| 169 | runner = null; |
| 170 | state = TaskState.DONE; |
| 171 | contextTask.set(null); |
| 172 | tasks.remove(this); |
| 173 | boolean hasIncompleteTasks = false; |
| 174 | for (TrackingRunnable task: tasks) { |
| 175 | if (task.state!=TaskState.DONE) { |
| 176 | hasIncompleteTasks = true; |
| 177 | break; |
| 178 | } |
| 179 | } |
| 180 | if (!hasIncompleteTasks) { |
| 181 | tasks.notifyAll(); |
| 182 | } |
| 183 | } |
| 184 | } |
| 185 | } |
| 186 | } |
| 187 | |
| 188 | } |