liblttng-ust-jul/org/lttng/ust/jul/LTTngLogHandler.java

   1 /*
   2  * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
   3  *
   4  * This library is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU Lesser General Public License, version 2.1 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This library is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
  11  * for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public License
  14  * along with this library; if not, write to the Free Software Foundation,
  15  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  16  */
  17
  18 package org.lttng.ust.jul;
  19
  20 import java.lang.String;
  21 import java.util.logging.Handler;
  22 import java.util.logging.LogRecord;
  23 import java.util.logging.LogManager;
  24 import java.util.logging.Level;
  25 import java.util.logging.Logger;
  26 import java.util.Collections;
  27 import java.util.HashMap;
  28 import java.util.Map;
  29
  30 import org.lttng.ust.jul.LTTngUst;
  31
  32 class LTTngLogger {
  33         /*
  34          * The log handler is attached to the logger when the reference count is
  35          * nonzero. Each event referring to a logger holds a reference to that
  36          * logger. If down to 0, this object is removed from the handler.
  37          */
  38         public int refcount;
  39         public String name;
  40         Logger logger;
  41
  42         public LTTngLogger(String name, Logger logger) {
  43                 this.name = name;
  44                 this.refcount = 0;
  45                 this.logger = logger;
  46         }
  47
  48         public void attach(LTTngLogHandler handler) {
  49                 this.logger.addHandler(handler);
  50         }
  51
  52         public void detach(LTTngLogHandler handler) {
  53                 this.logger.removeHandler(handler);
  54         }
  55 }
  56
  57 public class LTTngLogHandler extends Handler {
  58         /* Am I a root Log Handler. */
  59         public int is_root = 0;
  60
  61         public LogManager logManager;
  62
  63         /* Logger object attached to this handler that can trigger a tracepoint. */
  64         private Map<String, LTTngLogger> loggerMap =
  65                 Collections.synchronizedMap(new HashMap<String, LTTngLogger>());
  66
  67         /* Constructor */
  68         public LTTngLogHandler(LogManager logManager) {
  69                 super();
  70
  71                 this.logManager = logManager;
  72
  73                 /* Initialize LTTng UST tracer. */
  74                 LTTngUst.init();
  75         }
  76
  77         /*
  78          * Return true if the logger is enabled and attached. Else, if not found,
  79          * return false.
  80          */
  81         public boolean exists(String name) {
  82                 if (loggerMap.get(name) != null) {
  83                         return true;
  84                 } else {
  85                         return false;
  86                 }
  87         }
  88
  89         /*
  90          * Attach an event to this handler. If no logger object exists, one is
  91          * created else the refcount is incremented.
  92          */
  93         public void attachEvent(LTTngEvent event) {
  94                 Logger logger;
  95                 LTTngLogger lttngLogger;
  96
  97                 /* Does the logger actually exist. */
  98                 logger = this.logManager.getLogger(event.name);
  99                 if (logger == null) {
 100                         /* Stop attach right now. */
 101                         return;
 102                 }
 103
 104                 lttngLogger = loggerMap.get(event.name);
 105                 if (lttngLogger == null) {
 106                         lttngLogger = new LTTngLogger(event.name, logger);
 107
 108                         /* Attach the handler to the logger and add is to the map. */
 109                         lttngLogger.attach(this);
 110                         lttngLogger.refcount = 1;
 111                         loggerMap.put(lttngLogger.name, lttngLogger);
 112                 } else {
 113                         lttngLogger.refcount += 1;
 114                 }
 115         }
 116
 117         /*
 118          * Dettach an event from this handler. If the refcount goes down to 0, the
 119          * logger object is removed thus not attached anymore.
 120          */
 121         public void detachEvent(LTTngEvent event) {
 122                 LTTngLogger logger;
 123
 124                 logger = loggerMap.get(event.name);
 125                 if (logger != null) {
 126                         logger.refcount -= 1;
 127                         if (logger.refcount == 0) {
 128                                 /* Dettach from handler since no more event is associated. */
 129                                 logger.detach(this);
 130                                 loggerMap.remove(logger);
 131                         }
 132                 }
 133         }
 134
 135         /*
 136          * Cleanup this handler state meaning put it back to a vanilla state.
 137          */
 138         public void clear() {
 139                 this.loggerMap.clear();
 140         }
 141
 142         @Override
 143         public void close() throws SecurityException {}
 144
 145         @Override
 146         public void flush() {}
 147
 148         @Override
 149         public void publish(LogRecord record) {
 150                 LTTngLogger logger;
 151
 152                 logger = loggerMap.get(record.getLoggerName());
 153                 if (logger == null) {
 154                         /* Ignore and don't fire TP. */
 155                         return;
 156                 }
 157
 158                 /*
 159                  * Specific tracepoing designed for JUL events. The source class of the
 160                  * caller is used for the event name, the raw message is taken, the
 161                  * loglevel of the record and the thread ID.
 162                  */
 163                 if (this.is_root == 1) {
 164                         LTTngUst.tracepointS(record.getMessage(),
 165                                         record.getLoggerName(), record.getSourceClassName(),
 166                                         record.getSourceMethodName(), record.getMillis(),
 167                                         record.getLevel().intValue(), record.getThreadID());
 168                 } else {
 169                         LTTngUst.tracepointU(record.getMessage(),
 170                                         record.getLoggerName(), record.getSourceClassName(),
 171                                         record.getSourceMethodName(), record.getMillis(),
 172                                         record.getLevel().intValue(), record.getThreadID());
 173                 }
 174         }
 175 }