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/concurrent/ConcurrentHashMap/WhiteBox.java

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+/*
+ * 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.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * Written by Martin Buchholz with assistance from members of JCP
+ * JSR-166 Expert Group and released to the public domain, as
+ * explained at http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/*
+ * @test
+ * @modules java.base/java.util.concurrent:open
+ * @run testng WhiteBox
+ * @summary White box tests of implementation details
+ */
+
+import static org.testng.Assert.*;
+import org.testng.annotations.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.MethodType;
+import java.lang.invoke.VarHandle;
+import java.util.List;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.function.Supplier;
+
+@Test
+public class WhiteBox {
+    final ThreadLocalRandom rnd = ThreadLocalRandom.current();
+    final VarHandle TABLE, NEXTTABLE, SIZECTL;
+    final MethodHandle TABLE_SIZE_FOR;
+
+    WhiteBox() throws ReflectiveOperationException {
+        Class<?> mClass = ConcurrentHashMap.class;
+        String nodeClassName = mClass.getName() + "$Node";
+        Class<?> nodeClass = Class.forName(nodeClassName);
+        Class<?> nodeArrayClass = Class.forName("[L" + nodeClassName + ";");
+        MethodHandles.Lookup lookup
+            = MethodHandles.privateLookupIn(mClass, MethodHandles.lookup());
+        TABLE = lookup.findVarHandle(mClass, "table", nodeArrayClass);
+        NEXTTABLE = lookup.findVarHandle(mClass, "nextTable", nodeArrayClass);
+        SIZECTL = lookup.findVarHandle(mClass, "sizeCtl", int.class);
+        TABLE_SIZE_FOR = lookup.findStatic(
+                mClass, "tableSizeFor",
+                MethodType.methodType(int.class, int.class));
+    }
+
+    Object[] table(ConcurrentHashMap m) { return (Object[]) TABLE.getVolatile(m); }
+    Object[] nextTable(ConcurrentHashMap m) { return (Object[]) NEXTTABLE.getVolatile(m); }
+    int sizeCtl(ConcurrentHashMap m) { return (int) SIZECTL.getVolatile(m); }
+    int tableSizeFor(int n) {
+        try {
+            return (int) TABLE_SIZE_FOR.invoke(n);
+        } catch (Throwable t) { throw new AssertionError(t); }
+    }
+
+    List<Supplier<ConcurrentHashMap>> newConcurrentHashMapSuppliers(
+        int initialCapacity) {
+        return List.of(
+            () -> new ConcurrentHashMap(initialCapacity),
+            () -> new ConcurrentHashMap(initialCapacity, 0.75f),
+            () -> new ConcurrentHashMap(initialCapacity, 0.75f, 1));
+    }
+
+    ConcurrentHashMap newConcurrentHashMap(int initialCapacity) {
+        List<Supplier<ConcurrentHashMap>> suppliers
+            = newConcurrentHashMapSuppliers(initialCapacity);
+        return suppliers.get(rnd.nextInt(suppliers.size())).get();
+    }
+
+    @Test
+    public void defaultConstructor() {
+        ConcurrentHashMap m = new ConcurrentHashMap();
+        assertNull(table(m));
+        assertEquals(sizeCtl(m), 0);
+        assertResizeNotInProgress(m);
+    }
+
+    @Test
+    public void shouldNotResizeWhenInitialCapacityProvided() {
+        int initialCapacity = rnd.nextInt(1, 100);
+        Object[] initialTable = null;
+        ConcurrentHashMap m = newConcurrentHashMap(initialCapacity);
+
+        // table is lazily initialized
+        assertNull(table(m));
+        int expectedInitialTableLength = sizeCtl(m);
+
+        assertInvariants(m);
+        for (int i = 0; i < initialCapacity; i++) {
+            m.put(i * 100 + rnd.nextInt(100), i);
+            if (i == 0)
+                initialTable = table(m);
+            else
+                assertSame(table(m), initialTable);
+            assertInvariants(m);
+        }
+        assertEquals(initialTable.length, expectedInitialTableLength);
+    }
+
+    @Test
+    public void constructorsShouldGiveSameInitialCapacity() {
+        int initialCapacity = rnd.nextInt(1, 256);
+        long distinctTableLengths
+            = newConcurrentHashMapSuppliers(initialCapacity).stream()
+            .map(Supplier::get)
+            .mapToInt(map -> { map.put(42, 42); return table(map).length; })
+            .distinct()
+            .count();
+        assertEquals(1L, distinctTableLengths);
+    }
+
+    @Test
+    public void testTableSizeFor() {
+        assertEquals(1, tableSizeFor(0));
+        assertEquals(1, tableSizeFor(1));
+        assertEquals(2, tableSizeFor(2));
+        assertEquals(4, tableSizeFor(3));
+        assertEquals(16, tableSizeFor(15));
+        assertEquals(16, tableSizeFor(16));
+        assertEquals(32, tableSizeFor(17));
+        int maxSize = 1 << 30;
+        assertEquals(maxSize, tableSizeFor(maxSize - 1));
+        assertEquals(maxSize, tableSizeFor(maxSize));
+        assertEquals(maxSize, tableSizeFor(maxSize + 1));
+        assertEquals(maxSize, tableSizeFor(Integer.MAX_VALUE));
+    }
+
+    byte[] serialBytes(Object o) {
+        try {
+            ByteArrayOutputStream bos = new ByteArrayOutputStream();
+            ObjectOutputStream oos = new ObjectOutputStream(bos);
+            oos.writeObject(o);
+            oos.flush();
+            oos.close();
+            return bos.toByteArray();
+        } catch (Exception fail) {
+            throw new AssertionError(fail);
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    <T> T serialClone(T o) {
+        try {
+            ObjectInputStream ois = new ObjectInputStream
+                (new ByteArrayInputStream(serialBytes(o)));
+            T clone = (T) ois.readObject();
+            assertNotSame(o, clone);
+            assertSame(o.getClass(), clone.getClass());
+            return clone;
+        } catch (Exception fail) {
+            throw new AssertionError(fail);
+        }
+    }
+
+    @Test
+    public void testSerialization() {
+        assertInvariants(serialClone(new ConcurrentHashMap()));
+
+        ConcurrentHashMap m = newConcurrentHashMap(rnd.nextInt(100));
+        m.put(1, 1);
+        ConcurrentHashMap clone = serialClone(m);
+        assertInvariants(clone);
+        assertNotSame(table(m), table(clone));
+        assertEquals(m, clone);
+        assertResizeNotInProgress(m);
+        assertResizeNotInProgress(clone);
+    }
+
+    /** Checks conditions which should always be true. */
+    void assertInvariants(ConcurrentHashMap m) {
+        if (!m.isEmpty())
+            assertNotNull(table(m));
+    }
+
+    void assertResizeNotInProgress(ConcurrentHashMap m) {
+        assertTrue(sizeCtl(m) >= 0);
+        assertNull(nextTable(m));
+    }
+}