8327137: Add test for ConcurrentModificationException in BasicDirecto…

…ryModel

Reviewed-by: serb, tr

test/jdk/javax/swing/plaf/basic/BasicDirectoryModel/ConcurrentModification.java

@@ -0,0 +1,273 @@
+/*
+ * Copyright (c) 2024, 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.
+ */
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Timer;
+import java.util.TimerTask;
+import java.util.concurrent.BrokenBarrierException;
+import java.util.concurrent.CyclicBarrier;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.stream.IntStream;
+import java.util.stream.LongStream;
+
+import javax.swing.JFileChooser;
+
+/*
+ * @test
+ * @bug 8323670 8307091 8240690
+ * @requires os.family == "mac" | os.family == "linux"
+ * @summary Verifies thread-safety of BasicDirectoryModel (JFileChooser)
+ * @run main/othervm -Djava.awt.headless=true ConcurrentModification
+ */
+public final class ConcurrentModification extends ThreadGroup {
+    /** Initial number of files. */
+    private static final long NUMBER_OF_FILES = 50;
+    /** Maximum number of files created on a timer tick. */
+    private static final long LIMIT_FILES = 10;
+
+    /** Timer period (delay) for creating new files. */
+    private static final long TIMER_PERIOD = 250;
+
+    /**
+     * Number of threads running {@code fileChooser.rescanCurrentDirectory()}.
+     */
+    private static final int NUMBER_OF_THREADS = 5;
+    /** Number of repeated calls to {@code rescanCurrentDirectory}. */
+    private static final int NUMBER_OF_REPEATS = 2_000;
+    /** Maximum amount a thread waits before initiating rescan. */
+    private static final long LIMIT_SLEEP = 100;
+
+
+    /** The barrier to start all the scanner threads simultaneously. */
+    private static final CyclicBarrier start = new CyclicBarrier(NUMBER_OF_THREADS);
+    /** The barrier to wait for all the scanner threads to complete, plus main thread. */
+    private static final CyclicBarrier end = new CyclicBarrier(NUMBER_OF_THREADS + 1);
+
+    /** List of scanner threads. */
+    private static final List<Thread> threads = new ArrayList<>(NUMBER_OF_THREADS);
+
+    /**
+     * Stores an exception caught by any of the threads.
+     * If more exceptions are caught, they're added as suppressed exceptions.
+     */
+    private static final AtomicReference<Throwable> exception =
+            new AtomicReference<>();
+
+    /**
+     * Stores an {@code IOException} thrown while removing the files.
+     */
+    private static final AtomicReference<IOException> ioException =
+            new AtomicReference<>();
+
+
+    public static void main(String[] args) throws Throwable {
+        try {
+            // Start the test in its own thread group to catch and handle
+            // all thrown exceptions, in particular in
+            // BasicDirectoryModel.FilesLoader which is created by Swing.
+            ThreadGroup threadGroup = new ConcurrentModification();
+            Thread runner = new Thread(threadGroup,
+                                       ConcurrentModification::wrapper,
+                                       "Test Runner");
+            runner.start();
+            runner.join();
+        } catch (Throwable throwable) {
+            handleException(throwable);
+        }
+
+        if (ioException.get() != null) {
+            System.err.println("An error occurred while removing files:");
+            ioException.get().printStackTrace();
+        }
+
+        if (exception.get() != null) {
+            throw exception.get();
+        }
+    }
+
+    private static void wrapper() {
+        final long timeStart = System.currentTimeMillis();
+        try {
+            runTest(timeStart);
+        } catch (Throwable throwable) {
+            handleException(throwable);
+        } finally {
+            System.out.printf("Duration: %,d\n",
+                              (System.currentTimeMillis() - timeStart));
+        }
+    }
+
+    private static void runTest(final long timeStart) throws Throwable {
+        final Path temp = Files.createDirectory(Paths.get("fileChooser-concurrency-" + timeStart));
+
+        final Timer timer = new Timer("File creator");
+
+        try {
+            createFiles(temp);
+
+            final JFileChooser fc = new JFileChooser(temp.toFile());
+
+            IntStream.range(0, NUMBER_OF_THREADS)
+                     .forEach(i -> {
+                         Thread thread = new Thread(new Scanner(fc));
+                         threads.add(thread);
+                         thread.start();
+                     });
+
+            timer.scheduleAtFixedRate(new CreateFilesTimerTask(temp),
+                                      0, TIMER_PERIOD);
+
+            end.await();
+        } catch (Throwable e) {
+            threads.forEach(Thread::interrupt);
+            throw e;
+        } finally {
+            timer.cancel();
+
+            deleteFiles(temp);
+            deleteFile(temp);
+        }
+    }
+
+
+    private ConcurrentModification() {
+        super("bdmConcurrency");
+    }
+
+    @Override
+    public void uncaughtException(Thread t, Throwable e) {
+        handleException(t, e);
+    }
+
+    private static void handleException(Throwable throwable) {
+        handleException(Thread.currentThread(), throwable);
+    }
+
+    private static void handleException(final Thread thread,
+                                        final Throwable throwable) {
+        System.err.println("Exception in " + thread.getName() + ": "
+                           + throwable.getClass()
+                           + (throwable.getMessage() != null
+                              ? ": " + throwable.getMessage()
+                              : ""));
+        if (!exception.compareAndSet(null, throwable)) {
+            exception.get().addSuppressed(throwable);
+        }
+        threads.stream()
+               .filter(t -> t != thread)
+               .forEach(Thread::interrupt);
+    }
+
+
+    private record Scanner(JFileChooser fileChooser)
+            implements Runnable {
+
+        @Override
+        public void run() {
+            try {
+                start.await();
+
+                int counter = 0;
+                try {
+                    do {
+                        fileChooser.rescanCurrentDirectory();
+                        Thread.sleep((long) (Math.random() * LIMIT_SLEEP));
+                    } while (++counter < NUMBER_OF_REPEATS
+                             && !Thread.interrupted());
+                } catch (InterruptedException e) {
+                    // Just exit the loop
+                }
+            } catch (Throwable throwable) {
+                handleException(throwable);
+            } finally {
+                try {
+                    end.await();
+                } catch (InterruptedException | BrokenBarrierException e) {
+                    handleException(e);
+                }
+            }
+        }
+    }
+
+    private static void createFiles(final Path parent) {
+        createFiles(parent, 0, NUMBER_OF_FILES);
+    }
+
+    private static void createFiles(final Path parent,
+                                    final long start,
+                                    final long end) {
+        LongStream.range(start, end)
+                  .forEach(n -> createFile(parent.resolve(n + ".file")));
+    }
+
+    private static void createFile(final Path file) {
+        try {
+            Files.createFile(file);
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    private static void deleteFiles(final Path parent) throws IOException {
+        try (var stream = Files.walk(parent)) {
+            stream.filter(p -> p != parent)
+                  .forEach(ConcurrentModification::deleteFile);
+        }
+    }
+
+    private static void deleteFile(final Path file) {
+        try {
+            Files.delete(file);
+        } catch (IOException e) {
+            if (!ioException.compareAndSet(null, e)) {
+                ioException.get().addSuppressed(e);
+            }
+        }
+    }
+
+    private static final class CreateFilesTimerTask extends TimerTask {
+        private final Path temp;
+        private long no;
+
+        public CreateFilesTimerTask(Path temp) {
+            this.temp = temp;
+            no = NUMBER_OF_FILES;
+        }
+
+        @Override
+        public void run() {
+            try {
+                long count = (long) (Math.random() * LIMIT_FILES);
+                createFiles(temp, no, no + count);
+                no += count;
+            } catch (Throwable t) {
+                handleException(t);
+            }
+        }
+    }
+}