undefect. CWE-407 — 63 sites patched across 27 ecosystems

Authors: russell@unturf.com · brackishbert@gmail.com · foxhop.net · TimeHexOn.com

Patches, unit tests, benchmarks, whitepaper, and outreach briefs.
Public domain — no copyright claimed. Use freely.

test/jdk/java/util/stream/CustomFJPoolTest.java

@@ -0,0 +1,152 @@
+/*
+ * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @summary Tests stream execution in a custom ForkJoinPool
+ * @bug 8190974
+ * @run testng/othervm CustomFJPoolTest
+ * @run testng/othervm -Djava.util.concurrent.ForkJoinPool.common.parallelism=0 CustomFJPoolTest
+ */
+
+import org.testng.annotations.Test;
+
+import java.util.Comparator;
+import java.util.Spliterator;
+import java.util.concurrent.ForkJoinPool;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Consumer;
+import java.util.stream.IntStream;
+import java.util.stream.StreamSupport;
+
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertTrue;
+
+@Test
+public class CustomFJPoolTest {
+
+    // A Spliterator that counts the number of spliterators created
+    // including itself, thus the count starts at 1
+    static class SplitCountingSpliterator<T> implements Spliterator<T> {
+        final Spliterator<T> s;
+        final AtomicInteger nsplits;
+
+        // Top-level constructor
+        public SplitCountingSpliterator(Spliterator<T> s) {
+            this.s = s;
+            nsplits = new AtomicInteger(1);
+        }
+
+        // Splitting constructor
+        SplitCountingSpliterator(Spliterator<T> s, AtomicInteger nsplits) {
+            this.s = s;
+            this.nsplits = nsplits;
+        }
+
+        int splits() {
+            return nsplits.get();
+        }
+
+        @Override
+
+        public boolean tryAdvance(Consumer<? super T> action) {
+            return s.tryAdvance(action);
+        }
+
+        @Override
+        public void forEachRemaining(Consumer<? super T> action) {
+            s.forEachRemaining(action);
+        }
+
+        @Override
+        public Spliterator<T> trySplit() {
+            var split = s.trySplit();
+            if (split != null) {
+                nsplits.incrementAndGet();
+                return new SplitCountingSpliterator<>(split, nsplits);
+            }
+            else {
+                return null;
+            }
+        }
+
+        @Override
+        public long estimateSize() {
+            return s.estimateSize();
+        }
+
+        @Override
+        public long getExactSizeIfKnown() {
+            return s.getExactSizeIfKnown();
+        }
+
+        @Override
+        public int characteristics() {
+            return s.characteristics();
+        }
+
+        @Override
+        public boolean hasCharacteristics(int characteristics) {
+            return s.hasCharacteristics(characteristics);
+        }
+
+        @Override
+        public Comparator<? super T> getComparator() {
+            return s.getComparator();
+        }
+    }
+
+    public void testCustomPools() throws Exception {
+        int splitsForP1 = countSplits(new ForkJoinPool(1));
+        int splitsForP2 = countSplits(new ForkJoinPool(2));
+        assertEquals(splitsForP2, splitsForP1 * 2);
+
+        int commonParallelism = ForkJoinPool.getCommonPoolParallelism();
+        if (commonParallelism > 1 && commonParallelism < 128) {
+            int splitsForPHalfC = countSplits(new ForkJoinPool(commonParallelism / 2));
+            int splitsForPC = countSplits(ForkJoinPool.commonPool());
+
+            assertTrue(splitsForPHalfC < splitsForPC);
+            assertEquals(splitsForPC / splitsForPHalfC,
+                         nearestPowerOfTwo(commonParallelism) / nearestPowerOfTwo(commonParallelism / 2));
+        }
+    }
+
+    static int countSplits(ForkJoinPool fjp) throws Exception {
+        // The number of splits will be equivalent to the number of leaf nodes
+        // and will be a power of 2
+        var fInteger = fjp.submit(() -> {
+            var s = IntStream.range(0, 1024).boxed().parallel().spliterator();
+            var cs = new SplitCountingSpliterator<>(s);
+            StreamSupport.stream(cs, true).forEach(e -> {});
+            return cs.splits();
+        });
+        return fInteger.get();
+    }
+
+    static int nearestPowerOfTwo(int i) {
+        return (i & (i - 1)) == 0
+               ? i
+               : 1 << (32 - Integer.numberOfLeadingZeros(i));
+    }
+}