8153955: increase java.util.logging.FileHandler MAX_LOCKS limit

Summary: This patch adds a new JDK implementation specific system property "jdk.internal.FileHandlerLogging.maxLocks" to control java.util.logging.FileHandler's MAX_LOCKS limit.
Reviewed-by: coffeys, dfuchs

src/share/classes/java/util/logging/FileHandler.java

 /*
- * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 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
@@ -156,9 +156,27 @@ public class FileHandler extends StreamHandler {
     private String lockFileName;
     private FileChannel lockFileChannel;
     private File files[];
-    private static final int MAX_LOCKS = 100;
+    private static final int DEFAULT_MAX_LOCKS = 100;
+    private static int maxLocks;
     private static final Set<String> locks = new HashSet<>();
 
+    /*
+     * Initialize maxLocks from the System property if set.
+     * If invalid/no property is provided 100 will be used as a default value.
+     */
+    static {
+        maxLocks = java.security.AccessController.doPrivileged(
+                (PrivilegedAction<Integer>) () ->
+                        Integer.getInteger(
+                                "jdk.internal.FileHandlerLogging.maxLocks",
+                                DEFAULT_MAX_LOCKS)
+        );
+
+        if (maxLocks <= 0) {
+            maxLocks = DEFAULT_MAX_LOCKS;
+        }
+    }
+
     /**
      * A metered stream is a subclass of OutputStream that
      * (a) forwards all its output to a target stream
@@ -434,8 +452,9 @@ public class FileHandler extends StreamHandler {
         int unique = -1;
         for (;;) {
             unique++;
-            if (unique > MAX_LOCKS) {
-                throw new IOException("Couldn't get lock for " + pattern);
+            if (unique > maxLocks) {
+                throw new IOException("Couldn't get lock for " + pattern
+                        + ", maxLocks: " + maxLocks);
             }
             // Generate a lock file name from the "unique" int.
             lockFileName = generate(pattern, 0, unique).toString() + ".lck";

test/java/util/logging/FileHandlerMaxLocksTest.java

+/*
+ * 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
+ * @bug 8161266
+ * @summary test the FileHandler's new System property
+ *  "jdk.internal.FileHandlerLogging.maxLocks" with default value of 100.
+ * @library /lib/testlibrary
+ * @build jdk.testlibrary.FileUtils
+ * @author rpatil
+ * @run main/othervm -Djdk.internal.FileHandlerLogging.maxLocks=200 FileHandlerMaxLocksTest
+ * @run main/othervm -Djdk.internal.FileHandlerLogging.maxLocks=200ab FileHandlerMaxLocksTest
+ */
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.logging.FileHandler;
+import jdk.testlibrary.FileUtils;
+
+public class FileHandlerMaxLocksTest {
+
+    private static final String LOGGER_DIR = "logger-dir";
+    private static final String MX_LCK_SYS_PROPERTY =
+            "jdk.internal.FileHandlerLogging.maxLocks";
+
+    public static void main(String[] args) throws Exception {
+        String maxLocksSet = System.getProperty(MX_LCK_SYS_PROPERTY);
+        File loggerDir = createLoggerDir();
+        List<FileHandler> fileHandlers = new ArrayList<>();
+        try {
+            // 200 raises the default limit of 100, we try 102 times
+            for (int i = 0; i < 102; i++) {
+                fileHandlers.add(new FileHandler(loggerDir.getPath()
+                        + File.separator + "test_%u.log"));
+            }
+        } catch (IOException ie) {
+            if (maxLocksSet.equals("200ab")
+                    && ie.getMessage().contains("get lock for")) {
+                // Ignore: Expected exception while passing bad value- 200ab
+            } else {
+                throw new RuntimeException("Test Failed: " + ie.getMessage());
+            }
+        } finally {
+            for (FileHandler fh : fileHandlers) {
+                fh.close();
+            }
+            FileUtils.deleteFileTreeWithRetry(Paths.get(loggerDir.getPath()));
+        }
+    }
+
+    /**
+     * Create a writable directory in user directory for the test
+     *
+     * @return writable directory created that needs to be deleted when done
+     * @throws RuntimeException
+     */
+    private static File createLoggerDir() throws RuntimeException {
+        String userDir = System.getProperty("user.dir", ".");
+        File loggerDir = new File(userDir, LOGGER_DIR);
+        if (!createFile(loggerDir, true)) {
+            throw new RuntimeException("Test failed: unable to create"
+                    + " writable working directory "
+                    + loggerDir.getAbsolutePath());
+        }
+        // System.out.println("Created Logger Directory: " + loggerDir.getPath());
+        return loggerDir;
+    }
+
+    /**
+     * @param newFile File to be created
+     * @param makeDirectory is File to be created is directory
+     * @return true if file already exists or creation succeeded
+     */
+    private static boolean createFile(File newFile, boolean makeDirectory) {
+        if (newFile.exists()) {
+            return true;
+        }
+        if (makeDirectory) {
+            return newFile.mkdir();
+        } else {
+            try {
+                return newFile.createNewFile();
+            } catch (IOException ie) {
+                System.err.println("Not able to create file: " + newFile
+                        + ", IOException: " + ie.getMessage());
+                return false;
+            }
+        }
+    }
+}