8022213: Intermittent test failures in java/net/URLClassLoader

Reviewed-by: dxu, alanb

jdk/test/java/net/URLClassLoader/closetest/CloseTest.java

@@ -25,7 +25,8 @@
  * @test
  * @bug 4167874
  * @library ../../../../com/sun/net/httpserver
- * @build FileServerHandler
+ * @library /lib/testlibrary
+ * @build FileServerHandler jdk.testlibrary.FileUtils
  * @run shell build.sh
  * @run main/othervm CloseTest
  * @summary URL-downloaded jar files can consume all available file descriptors

jdk/test/java/net/URLClassLoader/closetest/Common.java

@@ -23,6 +23,9 @@
 
 import java.io.*;
 import java.net.*;
+import java.nio.file.Files;
+import jdk.testlibrary.FileUtils;
+import static java.nio.file.StandardCopyOption.*;
 
 public class Common {
 
@@ -39,42 +42,16 @@ public class Common {
             if (!src.isFile()) {
                 throw new RuntimeException ("File not found: " + src.toString());
             }
-            dst.delete();
-            dst.createNewFile();
-            FileInputStream i = new FileInputStream (src);
-            FileOutputStream o = new FileOutputStream (dst);
-            byte[] buf = new byte [1024];
-            int count;
-            while ((count=i.read(buf)) >= 0) {
-                o.write (buf, 0, count);
-            }
-            i.close();
-            o.close();
+            Files.copy(src.toPath(), dst.toPath(), REPLACE_EXISTING);
         } catch (IOException e) {
             throw new RuntimeException (e);
         }
     }
 
-    static void rm_minus_rf (File path) {
-        if (!path.exists()) {
+    static void rm_minus_rf (File path) throws IOException, InterruptedException {
+        if (!path.exists())
             return;
-        }
-        if (path.isFile()) {
-            if (!path.delete()) {
-                throw new RuntimeException ("Could not delete " + path);
-            }
-        } else if (path.isDirectory ()) {
-            String[] names = path.list();
-            File[] files = path.listFiles();
-            for (int i=0; i<files.length; i++) {
-                rm_minus_rf (new File(path, names[i]));
-            }
-            if (!path.delete()) {
-                throw new RuntimeException ("Could not delete " + path);
-            }
-        } else {
-            throw new RuntimeException ("Trying to delete something that isn't a file or a directory");
-        }
+        FileUtils.deleteFileTreeWithRetry(path.toPath());
     }
 
     static void copyDir (File src, File dst) {

jdk/test/java/net/URLClassLoader/closetest/GetResourceAsStream.java

@@ -24,6 +24,8 @@
 /**
  * @test
  * @bug 6899919
+ * @library /lib/testlibrary
+ * @build jdk.testlibrary.FileUtils
  * @run shell build2.sh
  * @run main/othervm GetResourceAsStream
  */

jdk/test/lib/testlibrary/jdk/testlibrary/FileUtils.java

@@ -0,0 +1,169 @@
+/*
+ * Copyright (c) 2013, 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.
+ */
+
+package jdk.testlibrary;
+
+import java.io.IOException;
+import java.nio.file.DirectoryNotEmptyException;
+import java.nio.file.FileVisitResult;
+import java.nio.file.Files;
+import java.nio.file.NoSuchFileException;
+import java.nio.file.Path;
+import java.nio.file.SimpleFileVisitor;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.util.ArrayList;
+import java.util.List;
+
+
+/**
+ * Common library for various test file utility functions.
+ */
+public final class FileUtils {
+
+    private static final boolean isWindows =
+                            System.getProperty("os.name").startsWith("Windows");
+    private static final int RETRY_DELETE_MILLIS = isWindows ? 500 : 0;
+    private static final int MAX_RETRY_DELETE_TIMES = isWindows ? 15 : 0;
+
+    /**
+     * Deletes a file, retrying if necessary.
+     *
+     * @param path  the file to delete
+     *
+     * @throws NoSuchFileException
+     *         if the file does not exist (optional specific exception)
+     * @throws DirectoryNotEmptyException
+     *         if the file is a directory and could not otherwise be deleted
+     *         because the directory is not empty (optional specific exception)
+     * @throws IOException
+     *         if an I/O error occurs
+     */
+    public static void deleteFileWithRetry(Path path)
+        throws IOException
+    {
+        try {
+            deleteFileWithRetry0(path);
+        } catch (InterruptedException x) {
+            throw new IOException("Interrupted while deleting.", x);
+        }
+    }
+
+    private static void deleteFileWithRetry0(Path path)
+        throws IOException, InterruptedException
+    {
+        int times = 0;
+        IOException ioe = null;
+        while (true) {
+            try {
+                Files.delete(path);
+                while (Files.exists(path)) {
+                    times++;
+                    if (times > MAX_RETRY_DELETE_TIMES)
+                        throw new IOException("File still exists after " + times + " waits.");
+                    Thread.sleep(RETRY_DELETE_MILLIS);
+                }
+                break;
+            } catch (NoSuchFileException | DirectoryNotEmptyException x) {
+                throw x;
+            } catch (IOException x) {
+                // Backoff/retry in case another process is accessing the file
+                times++;
+                if (ioe == null)
+                    ioe = x;
+                else
+                    ioe.addSuppressed(x);
+
+                if (times > MAX_RETRY_DELETE_TIMES)
+                    throw ioe;
+                Thread.sleep(RETRY_DELETE_MILLIS);
+            }
+        }
+    }
+
+    /**
+     * Deletes a directory and its subdirectories, retrying if necessary.
+     *
+     * @param dir  the directory to delete
+     *
+     * @throws  IOException
+     *          If an I/O error occurs. Any such exceptions are caught
+     *          internally. If only one is caught, then it is re-thrown.
+     *          If more than one exception is caught, then the second and
+     *          following exceptions are added as suppressed exceptions of the
+     *          first one caught, which is then re-thrown.
+     */
+    public static void deleteFileTreeWithRetry(Path dir)
+         throws IOException
+    {
+        IOException ioe = null;
+        final List<IOException> excs = deleteFileTreeUnchecked(dir);
+        if (!excs.isEmpty()) {
+            ioe = excs.remove(0);
+            for (IOException x : excs)
+                ioe.addSuppressed(x);
+        }
+        if (ioe != null)
+            throw ioe;
+    }
+
+    public static List<IOException> deleteFileTreeUnchecked(Path dir) {
+        final List<IOException> excs = new ArrayList<>();
+        try {
+            java.nio.file.Files.walkFileTree(dir, new SimpleFileVisitor<Path>() {
+                @Override
+                public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
+                    try {
+                        deleteFileWithRetry0(file);
+                    } catch (IOException x) {
+                        excs.add(x);
+                    } catch (InterruptedException x) {
+                        excs.add(new IOException("Interrupted while deleting.", x));
+                        return FileVisitResult.TERMINATE;
+                    }
+                    return FileVisitResult.CONTINUE;
+                }
+                @Override
+                public FileVisitResult postVisitDirectory(Path dir, IOException exc) {
+                    try {
+                        deleteFileWithRetry0(dir);
+                    } catch (IOException x) {
+                        excs.add(x);
+                    } catch (InterruptedException x) {
+                        excs.add(new IOException("Interrupted while deleting.", x));
+                        return FileVisitResult.TERMINATE;
+                    }
+                    return FileVisitResult.CONTINUE;
+                }
+                @Override
+                public FileVisitResult visitFileFailed(Path file, IOException exc) {
+                    excs.add(exc);
+                    return FileVisitResult.CONTINUE;
+                }
+            });
+        } catch (IOException x) {
+            excs.add(x);
+        }
+        return excs;
+    }
+}
+