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

This patch adds a new configurable property "java.util.logging.FileHandler.maxLocks" to java.util.logging.FileHandler which can be defined in the logging configuration file and makes it possible to configure the maximum number of concurrent log file locks a FileHandler can handle. If not overridden, the default value of maxLocks (100) remains unchanged.

Reviewed-by: dfuchs, coffeys

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

@@ -94,6 +94,9 @@ import java.util.Set;
  * <li>   &lt;handler-name&gt;.append
  *        specifies whether the FileHandler should append onto
  *        any existing files (defaults to false). </li>
+ * <li>   &lt;handler-name&gt;.maxLocks
+ *        specifies the maximum number of concurrent locks held by
+ *        FileHandler (defaults to 100). </li>
  * </ul>
  * <p>
  * For example, the properties for {@code FileHandler} would be:
@@ -157,6 +160,7 @@ public class FileHandler extends StreamHandler {
     private FileChannel lockFileChannel;
     private File files[];
     private static final int MAX_LOCKS = 100;
+    private int maxLocks = MAX_LOCKS;
     private static final Set<String> locks = new HashSet<>();
 
     /**
@@ -235,6 +239,12 @@ public class FileHandler extends StreamHandler {
         setLevel(manager.getLevelProperty(cname + ".level", Level.ALL));
         setFilter(manager.getFilterProperty(cname + ".filter", null));
         setFormatter(manager.getFormatterProperty(cname + ".formatter", new XMLFormatter()));
+        // Initialize maxLocks from the logging.properties file.
+        // If invalid/no property is provided 100 will be used as a default value.
+        maxLocks = manager.getIntProperty(cname + ".maxLocks", MAX_LOCKS);
+        if(maxLocks <= 0) {
+            maxLocks = MAX_LOCKS;
+        }
         try {
             setEncoding(manager.getStringProperty(cname +".encoding", null));
         } catch (Exception ex) {
@@ -476,7 +486,7 @@ public class FileHandler extends StreamHandler {
         int unique = -1;
         for (;;) {
             unique++;
-            if (unique > MAX_LOCKS) {
+            if (unique > maxLocks) {
                 throw new IOException("Couldn't get lock for " + pattern);
             }
             // Generate a lock file name from the "unique" int.

jdk/src/java.logging/share/conf/logging.properties

@@ -37,6 +37,10 @@ handlers= java.util.logging.ConsoleHandler
 java.util.logging.FileHandler.pattern = %h/java%u.log
 java.util.logging.FileHandler.limit = 50000
 java.util.logging.FileHandler.count = 1
+# Default number of locks FileHandler can obtain synchronously.
+# This specifies maximum number of attempts to obtain lock file by FileHandler
+# implemented by incrementing the unique field %u as per FileHandler API documentation.
+java.util.logging.FileHandler.maxLocks = 100
 java.util.logging.FileHandler.formatter = java.util.logging.XMLFormatter
 
 # Limit the message that are printed on the console to INFO and above.

jdk/test/java/util/logging/FileHandlerMaxLocksTest.java

@@ -0,0 +1,114 @@
+/*
+ * Copyright (c) 2016, 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 8153955
+ * @summary test the FileHandler's new property
+ *  "java.util.logging.FileHandler.maxLocks" which will be present in
+ *  "logging.properties" file with default value of 100. This property can be
+ *  overriden by specifying this property in the custom config file.
+ * @library /lib/testlibrary
+ * @build jdk.testlibrary.FileUtils
+ * @author rpatil
+ * @run main/othervm FileHandlerMaxLocksTest
+ */
+import java.io.File;
+import java.io.FileWriter;
+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 MAX_LOCK_PROPERTY = "java.util.logging.FileHandler.maxLocks = 200";
+    private static final String CONFIG_FILE_NAME = "logging.properties";
+
+    public static void main(String[] args) throws Exception {
+        File loggerDir = createLoggerDir();
+        String configFilePath = loggerDir.getPath() + File.separator + CONFIG_FILE_NAME;
+        File configFile = new File(configFilePath);
+        createFile(configFile, false);
+        System.setProperty("java.util.logging.config.file", configFilePath);
+        List<FileHandler> fileHandlers = new ArrayList<>();
+        try (FileWriter writer = new FileWriter(configFile)) {
+            writer.write(MAX_LOCK_PROPERTY);
+            writer.flush();
+            // 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) {
+            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;
+            }
+        }
+    }
+}