--- jsr166/src/jsr166e/ForkJoinWorkerThread.java 2012/08/13 15:52:33 1.1 +++ jsr166/src/jsr166e/ForkJoinWorkerThread.java 2012/11/19 18:12:28 1.3 @@ -6,6 +6,8 @@ package jsr166e; +import java.util.concurrent.atomic.AtomicInteger; + /** * A thread managed by a {@link ForkJoinPool}, which executes * {@link ForkJoinTask}s. @@ -25,10 +27,23 @@ public class ForkJoinWorkerThread extend * ForkJoinWorkerThreads are managed by ForkJoinPools and perform * ForkJoinTasks. For explanation, see the internal documentation * of class ForkJoinPool. + * + * This class just maintains links to its pool and WorkQueue. The + * pool field is set upon construction, but the workQueue field is + * not set until the thread has started (unless forced early by a + * subclass constructor call to poolIndex()). This provides + * better memory placement (because this thread allocates queue + * and bookkeeping fields) but because the field is non-final, we + * require that it never be accessed except by the owning thread. */ - final ForkJoinPool.WorkQueue workQueue; // Work-stealing mechanics final ForkJoinPool pool; // the pool this thread works in + ForkJoinPool.WorkQueue workQueue; // Work-stealing mechanics + + /** + * Sequence number for creating worker Names + */ + private static final AtomicInteger threadNumber = new AtomicInteger(); /** * Creates a ForkJoinWorkerThread operating in the given pool. @@ -37,14 +52,12 @@ public class ForkJoinWorkerThread extend * @throws NullPointerException if pool is null */ protected ForkJoinWorkerThread(ForkJoinPool pool) { - super(pool.nextWorkerName()); + super(pool.workerNamePrefix.concat(Integer.toString(threadNumber.incrementAndGet()))); setDaemon(true); + this.pool = pool; Thread.UncaughtExceptionHandler ueh = pool.ueh; if (ueh != null) setUncaughtExceptionHandler(ueh); - this.pool = pool; - pool.registerWorker(this.workQueue = new ForkJoinPool.WorkQueue - (pool, this, pool.localMode)); } /** @@ -66,7 +79,13 @@ public class ForkJoinWorkerThread extend * @return the index number */ public int getPoolIndex() { - return workQueue.poolIndex; + // force early registration if called before started + ForkJoinPool.WorkQueue q; + if ((q = workQueue) == null) { + pool.registerWorker(this); + q = workQueue; + } + return q.poolIndex; } /** @@ -100,6 +119,7 @@ public class ForkJoinWorkerThread extend public void run() { Throwable exception = null; try { + pool.registerWorker(this); onStart(); pool.runWorker(workQueue); } catch (Throwable ex) {