Anti-delta FJP update for now due to worker spinning

Author: AlanBateman

src/java.base/share/classes/java/util/concurrent/ForkJoinPool.java

@@ -792,25 +792,25 @@ static final class DefaultForkJoinWorkerThreadFactory
         private static final AccessControlContext ACC = contextWithPermissions(
             new RuntimePermission("getClassLoader"),
             new RuntimePermission("setContextClassLoader"));
+
         public final ForkJoinWorkerThread newThread(ForkJoinPool pool) {
             return AccessController.doPrivileged(
                 new PrivilegedAction<>() {
                     public ForkJoinWorkerThread run() {
-                        return new ForkJoinWorkerThread(null, pool, true, false);
+                        return new ForkJoinWorkerThread(null, pool, true, true);
                     }},
                 ACC);
         }
     }
 
     /**
-     * Factory for CommonPool unless overridded by System
-     * property. Creates InnocuousForkJoinWorkerThreads if a security
-     * manager is present at time of invocation. Support requires that
-     * we break quite a lot of encapsulation (some via helper methods
-     * in ThreadLocalRandom) to access and set Thread fields.
+     * Factory for InnocuousForkJoinWorkerThread. Support requires
+     * that we break quite a lot of encapsulation (some via helper
+     * methods in ThreadLocalRandom) to access and set Thread fields.
      */
-    static final class DefaultCommonPoolForkJoinWorkerThreadFactory
+    static final class InnocuousForkJoinWorkerThreadFactory
         implements ForkJoinWorkerThreadFactory {
+        // ACC for access to the factory
         private static final AccessControlContext ACC = contextWithPermissions(
             modifyThreadPermission,
             new RuntimePermission("enableContextClassLoaderOverride"),
@@ -820,13 +820,11 @@ static final class DefaultCommonPoolForkJoinWorkerThreadFactory
 
         public final ForkJoinWorkerThread newThread(ForkJoinPool pool) {
             return AccessController.doPrivileged(
-		 new PrivilegedAction<>() {
-		     public ForkJoinWorkerThread run() {
-			 return System.getSecurityManager() == null ?
-			     new ForkJoinWorkerThread(null, pool, true, true):
-			     new ForkJoinWorkerThread.
-			     InnocuousForkJoinWorkerThread(pool); }},
-		 ACC);
+                new PrivilegedAction<>() {
+                    public ForkJoinWorkerThread run() {
+                        return new ForkJoinWorkerThread.
+                            InnocuousForkJoinWorkerThread(pool); }},
+                ACC);
         }
     }
 
@@ -1712,19 +1710,11 @@ else if (deadline != 0L)
     // Utilities used by ForkJoinTask
 
     /**
-     * Returns true if all workers are busy, possibly creating one if allowed
+     * Returns true if all workers are busy
      */
     final boolean isSaturated() {
-        int maxTotal = bounds >>> SWIDTH;
-        for (long c;;) {
-            if (((int)(c = ctl) & ~UNSIGNALLED) != 0)
-                return false;
-            if ((short)(c >>> TC_SHIFT) >= maxTotal)
-                return true;
-            long nc = ((c + TC_UNIT) & TC_MASK) | (c & ~TC_MASK);
-            if (compareAndSetCtl(c, nc))
-                return !createWorker();
-        }
+        long c;
+        return (int)((c = ctl) >> RC_SHIFT) >= 0 && ((int)c & ~UNSIGNALLED) == 0;
     }
 
     /**
@@ -1787,7 +1777,7 @@ private int tryCompensate(long c) {
                 }
                 return -1;                        // retry
             }
-            else if (active - minActive > 1) {    // reduce parallelism
+            else if (active > minActive) {        // reduce parallelism
                 long nc = ((RC_MASK & (c - RC_UNIT)) | (~RC_MASK & c));
                 return compareAndSetCtl(c, nc) ? UNCOMPENSATE : -1;
             }
@@ -2544,7 +2534,9 @@ private ForkJoinPool(byte forCommonPoolOnly) {
         int p = this.mode = Math.min(Math.max(parallelism, 0), MAX_CAP);
         int size = 1 << (33 - Integer.numberOfLeadingZeros(p > 0 ? p - 1 : 1));
         this.factory = (fac != null) ? fac :
-	    new DefaultCommonPoolForkJoinWorkerThreadFactory();
+            (System.getSecurityManager() == null ?
+             defaultForkJoinWorkerThreadFactory :
+             new InnocuousForkJoinWorkerThreadFactory());
         this.ueh = handler;
         this.keepAlive = DEFAULT_KEEPALIVE;
         this.saturate = null;
@@ -2684,10 +2676,7 @@ public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks) {
                 ForkJoinTask<T> f =
                     new ForkJoinTask.AdaptedInterruptibleCallable<T>(t);
                 futures.add(f);
-                if (isSaturated())
-                    f.doExec();
-                else
-                    externalSubmit(f);
+                externalSubmit(f);
             }
             for (int i = futures.size() - 1; i >= 0; --i)
                 ((ForkJoinTask<?>)futures.get(i)).quietlyJoin();
@@ -2710,10 +2699,7 @@ public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks,
                 ForkJoinTask<T> f =
                     new ForkJoinTask.AdaptedInterruptibleCallable<T>(t);
                 futures.add(f);
-                if (isSaturated())
-                    f.doExec();
-                else
-                    externalSubmit(f);
+                externalSubmit(f);
             }
             long startTime = System.nanoTime(), ns = nanos;
             boolean timedOut = (ns < 0L);
@@ -2749,22 +2735,14 @@ static final class InvokeAnyRoot<E> extends ForkJoinTask<E> {
         final AtomicInteger count;              // in case all throw
         InvokeAnyRoot(int n) { count = new AtomicInteger(n); }
         final void tryComplete(Callable<E> c) { // called by InvokeAnyTasks
-            Throwable ex = null;
-            boolean failed = false;
-            if (c != null) {                    // raciness OK
-                if (isCancelled())
-                    failed = true;
-                else if (!isDone()) {
-                    try {
-                        complete(c.call());
-                    } catch (Throwable tx) {
-                        ex = tx;
-                        failed = true;
-                    }
+            if (c != null && !isDone()) {       // raciness OK
+                try {
+                    complete(c.call());
+                } catch (Throwable ex) {
+                    if (count.getAndDecrement() <= 1)
+                        trySetThrown(ex);
                 }
             }
-            if (failed && count.getAndDecrement() <= 1)
-                trySetThrown(ex != null ? ex : new CancellationException());
         }
         public final boolean exec()         { return false; } // never forked
         public final E getRawResult()       { return result; }

test/jdk/java/lang/Thread/virtual/WithDeadlineTest.java

@@ -63,7 +63,6 @@ public Object[][] executors() {
             { Executors.newCachedThreadPool() },
             { Executors.newFixedThreadPool(1) },
             { new ForkJoinPool() },
-            { new ForkJoinPool(1) },
         };
     }