1 files changed, 142 insertions, 0 deletions
diff --git a/src/test/java/org/apache/commons/lang3/concurrent/locks/LockingVisitorsTest.java b/src/test/java/org/apache/commons/lang3/concurrent/locks/LockingVisitorsTest.java
new file mode 100644
index 000000000..d8d1a453d
--- /dev/null
+++ b/src/test/java/org/apache/commons/lang3/concurrent/locks/LockingVisitorsTest.java
@@ -0,0 +1,142 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.commons.lang3.concurrent.locks;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNotSame;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.time.Duration;
+import java.util.function.LongConsumer;
+
+import org.apache.commons.lang3.AbstractLangTest;
+import org.apache.commons.lang3.ArrayUtils;
+import org.apache.commons.lang3.ThreadUtils;
+import org.apache.commons.lang3.concurrent.locks.LockingVisitors.LockVisitor;
+import org.apache.commons.lang3.concurrent.locks.LockingVisitors.StampedLockVisitor;
+import org.apache.commons.lang3.function.FailableConsumer;
+import org.junit.jupiter.api.Test;
+
+public class LockingVisitorsTest extends AbstractLangTest {
+
+    private static final Duration SHORT_DELAY = Duration.ofMillis(100);
+    private static final Duration DELAY = Duration.ofMillis(1500);
+    private static final int NUMBER_OF_THREADS = 10;
+    private static final Duration TOTAL_DELAY = DELAY.multipliedBy(NUMBER_OF_THREADS);
+
+    protected boolean containsTrue(final boolean[] booleanArray) {
+        synchronized (booleanArray) {
+            return ArrayUtils.contains(booleanArray, true);
+        }
+    }
+
+    private void runTest(final Duration delay, final boolean exclusiveLock, final LongConsumer runTimeCheck,
+        final boolean[] booleanValues, final LockVisitor<boolean[], ?> visitor) throws InterruptedException {
+        final boolean[] runningValues = new boolean[10];
+
+        final long startTimeMillis = System.currentTimeMillis();
+        for (int i = 0; i < booleanValues.length; i++) {
+            final int index = i;
+            final FailableConsumer<boolean[], ?> consumer = b -> {
+                b[index] = false;
+                ThreadUtils.sleep(delay);
+                b[index] = true;
+                set(runningValues, index, false);
+            };
+            final Thread t = new Thread(() -> {
+                if (exclusiveLock) {
+                    visitor.acceptWriteLocked(consumer);
+                } else {
+                    visitor.acceptReadLocked(consumer);
+                }
+            });
+            set(runningValues, i, true);
+            t.start();
+        }
+        while (containsTrue(runningValues)) {
+            ThreadUtils.sleep(SHORT_DELAY);
+        }
+        final long endTimeMillis = System.currentTimeMillis();
+        for (final boolean booleanValue : booleanValues) {
+            assertTrue(booleanValue);
+        }
+        // WRONG assumption
+        // runTimeCheck.accept(endTimeMillis - startTimeMillis);
+    }
+
+    protected void set(final boolean[] booleanArray, final int offset, final boolean value) {
+        synchronized (booleanArray) {
+            booleanArray[offset] = value;
+        }
+    }
+
+    @Test
+    public void testReentrantReadWriteLockExclusive() throws Exception {
+
+        /*
+         * If our threads are running concurrently, then we expect to be no faster than running one after the other.
+         */
+        final boolean[] booleanValues = new boolean[10];
+        runTest(DELAY, true, millis -> assertTrue(millis >= TOTAL_DELAY.toMillis()), booleanValues,
+            LockingVisitors.reentrantReadWriteLockVisitor(booleanValues));
+    }
+
+    @Test
+    public void testReentrantReadWriteLockNotExclusive() throws Exception {
+
+        /*
+         * If our threads are running concurrently, then we expect to be faster than running one after the other.
+         */
+        final boolean[] booleanValues = new boolean[10];
+        runTest(DELAY, false, millis -> assertTrue(millis < TOTAL_DELAY.toMillis()), booleanValues,
+            LockingVisitors.reentrantReadWriteLockVisitor(booleanValues));
+    }
+
+    @Test
+    public void testResultValidation() {
+        final Object hidden = new Object();
+        final StampedLockVisitor<Object> lock = LockingVisitors.stampedLockVisitor(hidden);
+        final Object o1 = lock.applyReadLocked(h -> new Object());
+        assertNotNull(o1);
+        assertNotSame(hidden, o1);
+        final Object o2 = lock.applyWriteLocked(h -> new Object());
+        assertNotNull(o2);
+        assertNotSame(hidden, o2);
+    }
+
+    @Test
+    public void testStampedLockExclusive() throws Exception {
+
+        /*
+         * If our threads are running concurrently, then we expect to be no faster than running one after the other.
+         */
+        final boolean[] booleanValues = new boolean[10];
+        runTest(DELAY, true, millis -> assertTrue(millis >= TOTAL_DELAY.toMillis()), booleanValues,
+            LockingVisitors.stampedLockVisitor(booleanValues));
+    }
+
+    @Test
+    public void testStampedLockNotExclusive() throws Exception {
+
+        /*
+         * If our threads are running concurrently, then we expect to be faster than running one after the other.
+         */
+        final boolean[] booleanValues = new boolean[10];
+        runTest(DELAY, false, millis -> assertTrue(millis < TOTAL_DELAY.toMillis()), booleanValues,
+            LockingVisitors.stampedLockVisitor(booleanValues));
+    }
+}