--- /dev/null
+/*
+ * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License, version 2.1 only,
+ * as published by the Free Software Foundation.
+ *
+ * This library 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 Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+package org.lttng.ust.jul;
+
+import java.io.IOException;
+import java.io.FileNotFoundException;
+import java.io.InputStream;
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.util.concurrent.Semaphore;
+import java.util.logging.FileHandler;
+import java.util.logging.Handler;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.logging.LogManager;
+import java.util.Enumeration;
+
+public class LTTngAgent {
+ private static LTTngLogHandler lttngHandler;
+ private static LogManager logManager;
+ private static LTTngThread lttngThread;
+ private static Thread sessiondTh;
+
+ /* Singleton agent object. */
+ private static LTTngAgent curAgent = null;
+
+ /* Indicate if this object has been initialized. */
+ private static boolean initialized = false;
+
+ private static Semaphore registerSem;
+
+ private static final String sessiondAddr = "127.0.0.1";
+ private static final int sessiondPort = 5345;
+
+ private static final String rootPortFile = "/var/run/lttng/jul.port";
+ private static final String userPortFile = "/.lttng/jul.port";
+
+ /*
+ * Constructor is private. This is a singleton and a reference should be
+ * acquired using getLTTngAgent().
+ */
+ private LTTngAgent() throws IOException {
+ this.logManager = LogManager.getLogManager();
+ this.lttngHandler = new LTTngLogHandler(this.logManager);
+ this.registerSem = new Semaphore(0, true);
+ }
+
+ private void removeHandlers() throws SecurityException, IOException {
+ String loggerName;
+ Logger logger;
+
+ Enumeration list = this.logManager.getLoggerNames();
+ while (list.hasMoreElements()) {
+ loggerName = list.nextElement().toString();
+ /* Somehow there is always an empty string at the end. */
+ if (loggerName == "") {
+ continue;
+ }
+
+ logger = this.logManager.getLogger(loggerName);
+ logger.removeHandler(this.lttngHandler);
+ }
+ }
+
+ private int getUID() throws IOException {
+ int uid;
+ byte b[] = new byte[4];
+ String userName = System.getProperty("user.name");
+ String command = "id -u " + userName;
+ Process child = Runtime.getRuntime().exec(command);
+ InputStream in = child.getInputStream();
+
+ in.read(b);
+ uid = Integer.parseInt(new String(b).trim(), 10);
+ in.close();
+
+ return uid;
+ }
+
+ private String getHomePath() {
+ return System.getProperty("user.home");
+ }
+
+ private int getPortFromFile() throws IOException {
+ int port;
+ int uid = getUID();
+ String path;
+ BufferedReader br;
+
+ /* Check if root or not, it tells where to get the port file. */
+ if (uid == 0) {
+ path = rootPortFile;
+ } else {
+ path = new String(getHomePath() + userPortFile);
+ }
+
+ try {
+ br = new BufferedReader(new FileReader(path));
+ String line = br.readLine();
+ port = Integer.parseInt(line, 10);
+ if (port < 0 || port > 65535) {
+ port = sessiondPort;
+ }
+ br.close();
+ } catch (FileNotFoundException e) {
+ port = sessiondPort;
+ }
+
+ return port;
+ }
+
+ /*
+ * Public getter to acquire a reference to this singleton object.
+ */
+ public static synchronized LTTngAgent getLTTngAgent() throws IOException {
+ if (curAgent == null) {
+ curAgent = new LTTngAgent();
+ curAgent.init();
+ }
+
+ return curAgent;
+ }
+
+ /*
+ * Initialize LTTngAgent. This will attach the log handler to all Logger
+ * returned by the logManager.
+ */
+ private synchronized void init() throws SecurityException, IOException {
+ if (this.initialized) {
+ return;
+ }
+
+ this.lttngThread = new LTTngThread(this.sessiondAddr,
+ getPortFromFile(), this.lttngHandler, this.registerSem);
+ this.sessiondTh = new Thread(lttngThread);
+ this.sessiondTh.start();
+
+ this.initialized = true;
+
+ /* Wait for the registration to end. */
+ try {
+ this.registerSem.acquire();
+ } catch (InterruptedException e) {
+ e.printStackTrace();
+ }
+ }
+
+ public void dispose() throws IOException {
+ this.lttngThread.dispose();
+
+ /* Make sure there is no more LTTng handler attach to logger(s). */
+ this.removeHandlers();
+
+ try {
+ this.sessiondTh.join();
+ } catch (InterruptedException e) {
+ e.printStackTrace();
+ }
+ }
+}
projects / lttng-ust.git / blobdiff