Removed compiler/ directory from repository

dart/compiler/java/com/google/dart/compiler/metrics/Tracer.java

Index: dart/compiler/java/com/google/dart/compiler/metrics/Tracer.java
diff --git a/dart/compiler/java/com/google/dart/compiler/metrics/Tracer.java b/dart/compiler/java/com/google/dart/compiler/metrics/Tracer.java
deleted file mode 100644
index 9103026b0b7e0711206c9c54035473d0bd1c69de..0000000000000000000000000000000000000000
--- a/dart/compiler/java/com/google/dart/compiler/metrics/Tracer.java
+++ /dev/null
@@ -1,959 +0,0 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-package com.google.dart.compiler.metrics;
-
-import org.json.JSONException;
-import org.json.JSONObject;
-import org.json.JSONArray;
-
-import java.io.BufferedWriter;
-import java.io.FileWriter;
-import java.io.IOException;
-import java.io.Writer;
-import java.lang.management.GarbageCollectorMXBean;
-import java.lang.management.ManagementFactory;
-import java.lang.management.OperatingSystemMXBean;
-import java.lang.management.ThreadMXBean;
-import java.lang.reflect.Method;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-import java.util.Map;
-import java.util.Stack;
-import java.util.concurrent.BlockingQueue;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.LinkedBlockingQueue;
-import java.util.concurrent.TimeUnit;
-
-/**
- * Logs performance metrics for internal development purposes. The output is
- * formatted so it can be opened directly in the SpeedTracer Chrome extension.
- * This class formats events using SpeedTracer's custom event feature. The html
- * file output can be viewed by using Chrome to open the file on a Chrome
- * browser that has the SpeedTracer extension installed.
- * 
- * <p>
- * Enable logging by setting the system property {@code dart.speedtracerlog} to
- * the output file path.
- * </p>
- * 
- * NB: This class has been copied almost verbatim from the gwt source tree
- */
-public final class Tracer {
-
-  // Log file name (logging is enabled if this is non-null)
-  private static final String logFile = System.getProperty("dart.speedtracerlog");
-
-  // Allow a system property to override the default output format
-  private static final String defaultFormatString = System.getProperty("dart.speedtracerformat");
-
-  // Use cumulative multi-threaded process cpu time instead of wall time
-  private static final boolean logProcessCpuTime =
-      getBooleanProperty("dart.speedtracer.logProcessCpuTime");
-
-  // Use per thread cpu time instead of wall time. If logProcessCpuTime is set,
-  // then this can remain false - we only need one or the other.
-  private static final boolean logThreadCpuTime =
-      getBooleanProperty("dart.speedtracer.logThreadCpuTime");
-
-  // Turn on logging summarizing gc time during an event
-  private static final boolean logGcTime = getBooleanProperty("dart.speedtracer.logGcTime");
-
-  // Turn on logging estimating overhead used for speedtracer logging.
-  private static final boolean logOverheadTime =
-      getBooleanProperty("dart.speedtracer.logOverheadTime");
-
-  static {
-    // verify configuration
-    if (logProcessCpuTime && logThreadCpuTime) {
-      throw new RuntimeException("System properties are misconfigured: "
-          + "Specify one or the other of 'dart.speedtracer.logProcessCpuTime' "
-          + "or 'dart.speedtracer.logThreadCpuTime', not both.");
-    }
-  }
-
-  /**
-   * Represents a node in a tree of SpeedTracer events.
-   */
-  public class TraceEvent {
-    protected final EventType type;
-    List<TraceEvent> children;
-    List<String> data;
-
-    long elapsedDurationNanos;
-    long elapsedStartTimeNanos;
-
-    long processCpuDurationNanos;
-    long processCpuStartTimeNanos;
-
-    long threadCpuDurationNanos;
-    long threadCpuStartTimeNanos;
-
-    TraceEvent() {
-      if (enabled) {
-        threadCpuTimeKeeper.resetTimeBase();
-        recordStartTime();
-        this.data = new ArrayList<String>();
-        this.children = new ArrayList<TraceEvent>();
-      } else {
-        this.processCpuStartTimeNanos = 0L;
-        this.threadCpuStartTimeNanos = 0L;
-        this.elapsedStartTimeNanos = 0L;
-        this.data = null;
-        this.children = null;
-      }
-      this.type = null;
-    }
-
-    TraceEvent(TraceEvent parent, EventType type, String... data) {
-
-      if (parent != null) {
-        parent.children.add(this);
-      }
-      this.type = type;
-      assert (data.length % 2 == 0);
-      recordStartTime();
-      this.data = new ArrayList<String>();
-      this.data.addAll(Arrays.asList(data));
-      this.children = new ArrayList<TraceEvent>();
-    }
-
-    /**
-     * @param data key/value pairs to add to JSON object.
-     */
-    public void addData(String... data) {
-      if (data != null) {
-        assert (data.length % 2 == 0);
-        this.data.addAll(Arrays.asList(data));
-      }
-    }
-
-    /**
-     * Signals the end of the current event.
-     */
-    public void end(String... data) {
-      endImpl(this, data);
-    }
-
-    /**
-     * Returns the event duration, in nanoseconds, for the log file. Depending
-     * on system properties, this will measured in elapsed time, process CPU
-     * time, or thread CPU time.
-     */
-    public long getDurationNanos() {
-      return logProcessCpuTime ? processCpuDurationNanos : (logThreadCpuTime
-          ? threadCpuDurationNanos : elapsedDurationNanos);
-    }
-
-    public long getElapsedDurationNanos() {
-      return this.elapsedDurationNanos;
-    }
-
-    public long getElapsedStartTimeNanos() {
-      return this.elapsedStartTimeNanos;
-    }
-
-    /**
-     * Returns the event start time, normalized in nanoseconds, for the log
-     * file. Depending on system properties, this will be normalized based on
-     * elapsed time, process CPU time, or thread CPU time.
-     */
-    public long getStartTimeNanos() {
-      return logProcessCpuTime ? processCpuStartTimeNanos : (logThreadCpuTime
-          ? threadCpuStartTimeNanos : elapsedStartTimeNanos);
-    }
-
-    public EventType getType() {
-      return type;
-    }
-
-    @Override
-    public String toString() {
-      return type.getName();
-    }
-
-    /**
-     * Extends the durations of the current event by the durations of the
-     * specified event.
-     */
-    void extendDuration(TraceEvent refEvent) {
-      elapsedDurationNanos += refEvent.elapsedDurationNanos;
-      processCpuDurationNanos += refEvent.processCpuDurationNanos;
-      threadCpuDurationNanos += refEvent.threadCpuDurationNanos;
-    }
-
-    /**
-     * Sets the start time of this event to start immediately after the
-     * specified event ends.
-     */
-    void setStartsAfter(TraceEvent refEvent) {
-      elapsedStartTimeNanos = refEvent.elapsedStartTimeNanos + refEvent.elapsedDurationNanos;
-      processCpuStartTimeNanos =
-          refEvent.processCpuStartTimeNanos + refEvent.processCpuDurationNanos;
-      threadCpuStartTimeNanos = refEvent.threadCpuStartTimeNanos + refEvent.threadCpuDurationNanos;
-    }
-
-    JSONObject toJson() throws JSONException {
-      JSONObject json = new JSONObject();
-      json.put("type", -2);
-      json.put("typeName", type.getName());
-      json.put("color", type.getColor());
-      double startMs = convertToMilliseconds(getStartTimeNanos());
-      json.put("time", startMs);
-      double durationMs = convertToMilliseconds(getDurationNanos());
-      json.put("duration", durationMs);
-
-      JSONObject jsonData = new JSONObject();
-      for (int i = 0; i < data.size(); i += 2) {
-        jsonData.put(data.get(i), data.get(i + 1));
-      }
-      json.put("data", jsonData);
-
-      JSONArray jsonChildren = new JSONArray();
-      for (TraceEvent child : children) {
-        jsonChildren.put(child.toJson());
-      }
-      json.put("children", jsonChildren);
-
-      return json;
-    }
-
-    /**
-     * Records the duration of this event based on the current time and the
-     * event's recorded start time.
-     */
-    void updateDuration() {
-      long elapsedEndTimeNanos = elapsedTimeKeeper.normalizedTimeNanos();
-      assert (elapsedEndTimeNanos >= elapsedStartTimeNanos);
-      elapsedDurationNanos = elapsedEndTimeNanos - elapsedStartTimeNanos;
-
-      // don't bother making expensive time keeping method calls unless
-      // necessary
-      if (logProcessCpuTime) {
-        long processCpuEndTimeNanos = processCpuTimeKeeper.normalizedTimeNanos();
-        assert (processCpuEndTimeNanos >= processCpuStartTimeNanos);
-        processCpuDurationNanos = processCpuEndTimeNanos - processCpuStartTimeNanos;
-      } else if (logThreadCpuTime) {
-        long threadCpuEndTimeNanos = threadCpuTimeKeeper.normalizedTimeNanos();
-        assert (threadCpuEndTimeNanos >= threadCpuStartTimeNanos);
-        threadCpuDurationNanos = threadCpuEndTimeNanos - threadCpuStartTimeNanos;
-      }
-    }
-
-    /**
-     * Marks the start time for this event. Three different time measurements
-     * are used:
-     * <ol>
-     * <li>Elapsed (wall-clock) time</li>
-     * <li>Process CPU time</li>
-     * <li>Thread CPU time</li>
-     * </ol>
-     */
-    private void recordStartTime() {
-      elapsedStartTimeNanos = elapsedTimeKeeper.normalizedTimeNanos();
-
-      // don't bother making expensive time keeping method calls unless
-      // necessary
-      if (logProcessCpuTime) {
-        processCpuStartTimeNanos = processCpuTimeKeeper.normalizedTimeNanos();
-      } else if (logThreadCpuTime) {
-        threadCpuStartTimeNanos = threadCpuTimeKeeper.normalizedTimeNanos();
-      }
-    }
-  }
-
-  /**
-   * Enumerated types for logging events implement this interface.
-   */
-  public interface EventType {
-    String getColor();
-
-    String getName();
-  }
-
-  static enum Format {
-    /**
-     * Standard SpeedTracer log that includes JSON wrapped in HTML that will
-     * launch a SpeedTracer monitor session.
-     */
-    HTML,
-
-    /**
-     * Only the JSON data without any HTML wrappers.
-     */
-    RAW
-  }
-
-  /**
-   * A dummy implementation to do nothing if logging has not been turned on.
-   */
-  private class DummyEvent extends TraceEvent {
-    @Override
-    public void addData(String... data) {
-      // do nothing
-    }
-
-    @Override
-    public void end(String... data) {
-      // do nothing
-    }
-
-    @Override
-    public String toString() {
-      return "Dummy";
-    }
-  }
-
-  /**
-   * Provides functionality specific to garbage collection events.
-   */
-  private class GcEvent extends TraceEvent {
-    private TraceEvent refEvent;
-
-    /**
-     * Constructs an event that represents garbage collection metrics.
-     * 
-     * @param refEvent the event during which the garbage collections took place
-     * @param gcType the garbage collector type
-     * @param collectionCount the total number of collections for this garbage
-     *        collector type
-     * @param durationNanos the total elapsed time spent in garbage collection
-     *        during the span of {@code refEvent}
-     */
-    GcEvent(TraceEvent refEvent, String gcType, long collectionCount, long durationNanos) {
-      super(null, SpeedTracerEventType.GC, "Collector Type", gcType, "Cumulative Collection Count",
-          Long.toString(collectionCount));
-
-      this.refEvent = refEvent;
-      // GarbageCollectorMXBean can only provide elapsed time, so that's all we
-      // record
-      this.elapsedDurationNanos = durationNanos;
-    }
-
-    /**
-     * Returns elapsed duration since that is the only duration we can measure
-     * for garbage collection events.
-     */
-    @Override
-    public long getDurationNanos() {
-      return getElapsedDurationNanos();
-    }
-
-    /**
-     * Returns a start time so that this event ends with its {@code refEvent}.
-     */
-    @Override
-    public long getElapsedStartTimeNanos() {
-      return refEvent.getElapsedStartTimeNanos() + refEvent.getElapsedDurationNanos()
-          - getElapsedDurationNanos();
-    }
-
-    /**
-     * Returns a start time so that this event ends with its {@code refEvent}.
-     */
-    @Override
-    public long getStartTimeNanos() {
-      return refEvent.getStartTimeNanos() + refEvent.getDurationNanos() - getDurationNanos();
-    }
-  }
-
-  /**
-   * Time keeper which uses wall time.
-   */
-  private class ElapsedNormalizedTimeKeeper {
-
-    private final long zeroTimeMillis;
-
-    public ElapsedNormalizedTimeKeeper() {
-      zeroTimeMillis = System.currentTimeMillis();
-    }
-
-    public long normalizedTimeNanos() {
-      return (System.currentTimeMillis() - zeroTimeMillis) * 1000000L;
-    }
-
-    public long zeroTimeMillis() {
-      return zeroTimeMillis;
-    }
-  }
-
-  /**
-   * Time keeper which uses process cpu time. This can be greater than wall
-   * time, since it is cumulative over the multiple threads of a process.
-   */
-  private class ProcessNormalizedTimeKeeper {
-    private final OperatingSystemMXBean osMXBean;
-    private final Method getProcessCpuTimeMethod;
-    private final long zeroTimeNanos;
-    private final long zeroTimeMillis;
-
-    public ProcessNormalizedTimeKeeper() {
-      try {
-        osMXBean = ManagementFactory.getOperatingSystemMXBean();
-        /*
-         * Find this method by reflection, since it's part of the Sun
-         * implementation for OperatingSystemMXBean, and we can't always assume
-         * that com.sun.management.OperatingSystemMXBean will be available.
-         */
-        getProcessCpuTimeMethod = osMXBean.getClass().getMethod("getProcessCpuTime");
-        getProcessCpuTimeMethod.setAccessible(true);
-        zeroTimeNanos = (Long) getProcessCpuTimeMethod.invoke(osMXBean);
-        zeroTimeMillis = (long) convertToMilliseconds(zeroTimeNanos);
-      } catch (Exception ex) {
-        throw new RuntimeException(ex);
-      }
-    }
-
-    public long normalizedTimeNanos() {
-      try {
-        return (Long) getProcessCpuTimeMethod.invoke(osMXBean) - zeroTimeNanos;
-      } catch (Exception ex) {
-        throw new RuntimeException(ex);
-      }
-    }
-
-    public long zeroTimeMillis() {
-      return zeroTimeMillis;
-    }
-  }
-
-  /**
-   * Time keeper which uses per thread cpu time. It is assumed that individual
-   * events logged will be single threaded, and that top-level events will call
-   * {@link #resetTimeBase()} prior to logging time. The resettable time base is
-   * needed since each individual thread starts its timing at 0, regardless of
-   * when the thread is created. So we reset the time base at the beginning of
-   * an event, so that we can generate a chronologically representative output,
-   * although the relation to wall time is actually compressed within a logged
-   * event (thread cpu time does not include wait time, etc.).
-   */
-  private class ThreadNormalizedTimeKeeper {
-
-    private final ThreadMXBean threadMXBean;
-    private final ThreadLocal<Long> resettableTimeBase = new ThreadLocal<Long>();
-    private final long zeroTimeNanos;
-    private final long zeroTimeMillis;
-
-    public ThreadNormalizedTimeKeeper() {
-      threadMXBean = ManagementFactory.getThreadMXBean();
-      if (!threadMXBean.isCurrentThreadCpuTimeSupported()) {
-        throw new RuntimeException("Current thread cpu time not supported");
-      }
-      zeroTimeNanos = System.nanoTime();
-      zeroTimeMillis = (long) convertToMilliseconds(zeroTimeNanos);
-    }
-
-    public long normalizedTimeNanos() {
-      return threadMXBean.getCurrentThreadCpuTime() + resettableTimeBase.get();
-    }
-
-    public void resetTimeBase() {
-      /*
-       * Since all threads start individually at time 0L, we use this to offset
-       * each event's time so we can generate chronological output.
-       */
-      resettableTimeBase.set(System.nanoTime() - zeroTimeNanos
-          - threadMXBean.getCurrentThreadCpuTime());
-    }
-
-    public long zeroTimeMillis() {
-      return zeroTimeMillis;
-    }
-  }
-
-  /**
-   * Initializes the singleton on demand.
-   */
-  private static class LazySpeedTracerLoggerHolder {
-    public static Tracer singleton = new Tracer();
-  }
-
-  /**
-   * Thread that converts log requests to JSON in the background.
-   */
-  private class LogWriterThread extends Thread {
-    private static final int FLUSH_TIMER_MSECS = 10000;
-    private final String fileName;
-    private final BlockingQueue<TraceEvent> threadEventQueue;
-    private final Writer writer;
-
-    public LogWriterThread(Writer writer, String fileName, final BlockingQueue<TraceEvent> eventQueue) {
-      super();
-      this.writer = writer;
-      this.fileName = fileName;
-      this.threadEventQueue = eventQueue;
-    }
-
-    @Override
-    public void run() {
-      long nextFlush = System.currentTimeMillis() + FLUSH_TIMER_MSECS;
-      try {
-        while (true) {
-          TraceEvent event =
-              threadEventQueue.poll(nextFlush - System.currentTimeMillis(), TimeUnit.MILLISECONDS);
-          if (event == null) {
-            // ignore.
-          } else if (event == shutDownSentinel) {
-            break;
-          } else if (event == flushSentinel) {
-            writer.flush();
-            flushLatch.countDown();
-          } else {
-            JSONObject json = event.toJson();
-            json.write(writer);
-            writer.write('\n');
-          }
-          if (System.currentTimeMillis() >= nextFlush) {
-            writer.flush();
-            nextFlush = System.currentTimeMillis() + FLUSH_TIMER_MSECS;
-          }
-        }
-        // All queued events have been written.
-        if (outputFormat.equals(Format.HTML)) {
-          writer.write("</div></body></html>\n");
-        }
-        writer.close();
-      } catch (InterruptedException ignored) {
-      } catch (IOException e) {
-        System.err.println("Unable to write to dart.speedtracerlog '"
-            + (fileName == null ? "" : fileName) + "'");
-        e.printStackTrace();
-      } catch (JSONException e) {
-        // TODO(jat): Auto-generated catch block
-        e.printStackTrace();
-      } finally {
-        shutDownLatch.countDown();
-      }
-    }
-  }
-
-  /**
-   * Records a LOG_MESSAGE type of SpeedTracer event.
-   */
-  private class MarkTimelineEvent extends TraceEvent {
-    public MarkTimelineEvent(TraceEvent parent) {
-      super();
-      if (parent != null) {
-        parent.children.add(this);
-      }
-    }
-
-    @Override
-    JSONObject toJson() throws JSONException {
-      JSONObject json = new JSONObject();
-      json.put("type", 11);
-      double startMs = convertToMilliseconds(getStartTimeNanos());
-      json.put("time", startMs);
-      json.put("duration", 0.0);
-      JSONObject jsonData = new JSONObject();
-      for (int i = 0; i < data.size(); i += 2) {
-        jsonData.put(data.get(i), data.get(i + 1));
-      }
-      json.put("data", jsonData);
-      return json;
-    }
-  }
-
-  /**
-   * Annotate the current event on the top of the stack with more information.
-   * The method expects key, value pairs, so there must be an even number of
-   * parameters.
-   * 
-   * @param data JSON property, value pair to add to current event.
-   */
-  public static void addData(String... data) {
-    Tracer.get().addDataImpl(data);
-  }
-
-  /**
-   * Create a new global instance. Force the zero time to be recorded and the
-   * log to be opened if the default logging is turned on with the <code>
-   * -Ddart.speedtracerlog</code> VM property.
-   * 
-   * This method is only intended to be called once.
-   */
-  public static void init() {
-    get();
-  }
-
-  /**
-   * Returns true if the trace output file is configured. This is intended to be
-   * the quickest possible check, statically determined.
-   */
-  public static boolean canTrace() {
-    return logFile != null;
-  }
-
-  /**
-   * Adds a LOG_MESSAGE SpeedTracer event to the log. This represents a single
-   * point in time and has a special representation in the SpeedTracer UI.
-   */
-  public static void markTimeline(String message) {
-    Tracer.get().markTimelineImpl(message);
-  }
-
-  /**
-   * Signals that a new event has started. You must end each event for each
-   * corresponding call to {@code start}. You may nest timing calls.
-   * 
-   * @param type the type of event
-   * @param data a set of key-value pairs (each key is followed by its value)
-   *        that contain additional information about the event
-   * @return an Event object to be ended by the caller
-   */
-  public static TraceEvent start(EventType type, String... data) {
-    return Tracer.get().startImpl(type, data);
-  }
-
-  private static double convertToMilliseconds(long nanos) {
-    return nanos / 1000000.0d;
-  }
-  
-  /**
-   * Convenience method for ending event, which might possibly be null.
-   */
-  public static void end(TraceEvent event, String... data) {
-    if (event != null) {
-      event.end(data);
-    }
-  }
-
-  /**
-   * For accessing the logger as a singleton, you can retrieve the global
-   * instance. It is prudent, but not necessary to first initialize the
-   * singleton with a call to {@link #init()} to set the base time.
-   * 
-   * @return the current global {@link Tracer} instance.
-   */
-  private static Tracer get() {
-    return LazySpeedTracerLoggerHolder.singleton;
-  }
-
-  private static boolean getBooleanProperty(String propName) {
-    try {
-      return System.getProperty(propName) != null;
-    } catch (RuntimeException ruEx) {
-      return false;
-    }
-  }
-
-  private final boolean enabled;
-
-  private final DummyEvent dummyEvent = new DummyEvent();
-
-  private BlockingQueue<TraceEvent> eventsToWrite;
-
-  private final boolean fileLoggingEnabled;
-
-  private CountDownLatch flushLatch;
-
-  private TraceEvent flushSentinel;
-
-  private Format outputFormat;
-
-  private ThreadLocal<Stack<TraceEvent>> pendingEvents;
-
-  private CountDownLatch shutDownLatch;
-
-  private TraceEvent shutDownSentinel;
-
-  private List<GarbageCollectorMXBean> gcMXBeans;
-
-  private Map<String, Long> lastGcTimes;
-
-  private final ElapsedNormalizedTimeKeeper elapsedTimeKeeper;
-
-  private final ProcessNormalizedTimeKeeper processCpuTimeKeeper;
-
-  private final ThreadNormalizedTimeKeeper threadCpuTimeKeeper;
-
-  /**
-   * Constructor intended for unit testing.
-   * 
-   * @param writer alternative {@link Writer} to send speed tracer output.
-   */
-  Tracer(Writer writer, Format format) {
-    enabled = true;
-    fileLoggingEnabled = true;
-    outputFormat = format;
-    eventsToWrite = openLogWriter(writer, "");
-    pendingEvents = initPendingEvents();
-    elapsedTimeKeeper = new ElapsedNormalizedTimeKeeper();
-    processCpuTimeKeeper = new ProcessNormalizedTimeKeeper();
-    threadCpuTimeKeeper = new ThreadNormalizedTimeKeeper();
-    shutDownSentinel = new DummyEvent();
-    flushSentinel = new DummyEvent();
-    shutDownLatch = new CountDownLatch(1);
-  }
-
-  private Tracer() {
-    fileLoggingEnabled = logFile != null;
-    enabled = fileLoggingEnabled;
-
-    if (enabled) {
-      elapsedTimeKeeper = new ElapsedNormalizedTimeKeeper();
-      processCpuTimeKeeper = new ProcessNormalizedTimeKeeper();
-      threadCpuTimeKeeper = new ThreadNormalizedTimeKeeper();
-
-      if (fileLoggingEnabled) {
-        // Allow a system property to override the default output format
-        Format format = Format.HTML;
-        if (defaultFormatString != null) {
-          for (Format value : Format.values()) {
-            if (value.name().toLowerCase().equals(defaultFormatString.toLowerCase())) {
-              format = value;
-              break;
-            }
-          }
-        }
-        outputFormat = format;
-        eventsToWrite = openDefaultLogWriter();
-
-        shutDownSentinel = new TraceEvent();
-        flushSentinel = new TraceEvent();
-        shutDownLatch = new CountDownLatch(1);
-      }
-
-      if (logGcTime) {
-        gcMXBeans = ManagementFactory.getGarbageCollectorMXBeans();
-        lastGcTimes = new ConcurrentHashMap<String, Long>();
-      }
-
-      pendingEvents = initPendingEvents();
-    } else {
-      elapsedTimeKeeper = null;
-      processCpuTimeKeeper = null;
-      threadCpuTimeKeeper = null;
-    }
-  }
-
-  public void addDataImpl(String... data) {
-    Stack<TraceEvent> threadPendingEvents = pendingEvents.get();
-    if (threadPendingEvents.isEmpty()) {
-      throw new IllegalStateException("Tried to add data to an event that never started!");
-    }
-
-    TraceEvent currentEvent = threadPendingEvents.peek();
-    currentEvent.addData(data);
-  }
-
-  public void markTimelineImpl(String message) {
-    Stack<TraceEvent> threadPendingEvents = pendingEvents.get();
-    TraceEvent parent = null;
-    if (!threadPendingEvents.isEmpty()) {
-      parent = threadPendingEvents.peek();
-    }
-    TraceEvent newEvent = new MarkTimelineEvent(parent);
-    threadPendingEvents.push(newEvent);
-    newEvent.end("message", message);
-  }
-
-  void addGcEvents(TraceEvent refEvent) {
-    // we're not sending GC events to the dartboard, so we only record them
-    // to file
-    if (!fileLoggingEnabled) {
-      return;
-    }
-
-    for (GarbageCollectorMXBean gcMXBean : gcMXBeans) {
-      String gcName = gcMXBean.getName();
-      Long lastGcTime = lastGcTimes.get(gcName);
-      long currGcTime = gcMXBean.getCollectionTime();
-      if (lastGcTime == null) {
-        lastGcTime = 0L;
-      }
-      if (currGcTime > lastGcTime) {
-        // create a new event
-        long gcDurationNanos = (currGcTime - lastGcTime) * 1000000L;
-        TraceEvent gcEvent =
-            new GcEvent(refEvent, gcName, gcMXBean.getCollectionCount(), gcDurationNanos);
-
-        eventsToWrite.add(gcEvent);
-        lastGcTimes.put(gcName, currGcTime);
-      }
-    }
-  }
-
-  void addOverheadEvent(TraceEvent refEvent) {
-    TraceEvent overheadEvent = new TraceEvent(refEvent, SpeedTracerEventType.OVERHEAD);
-    // measure the time between the end of refEvent and now
-    overheadEvent.setStartsAfter(refEvent);
-    overheadEvent.updateDuration();
-
-    refEvent.extendDuration(overheadEvent);
-  }
-
-  void endImpl(TraceEvent event, String... data) {
-    if (!enabled) {
-      return;
-    }
-
-    if (data.length % 2 == 1) {
-      throw new IllegalArgumentException("Unmatched data argument");
-    }
-
-    Stack<TraceEvent> threadPendingEvents = pendingEvents.get();
-    if (threadPendingEvents.isEmpty()) {
-      throw new IllegalStateException("Tried to end an event that never started!");
-    }
-    TraceEvent currentEvent = threadPendingEvents.pop();
-    currentEvent.updateDuration();
-
-    while (currentEvent != event && !threadPendingEvents.isEmpty()) {
-      // Missed a closing end for one or more frames! Try to sync back up.
-      currentEvent.addData("Missed",
-          "This event was closed without an explicit call to Event.end()");
-      currentEvent = threadPendingEvents.pop();
-      currentEvent.updateDuration();
-    }
-
-    if (threadPendingEvents.isEmpty() && currentEvent != event) {
-      currentEvent.addData("Missed", "Fell off the end of the threadPending events");
-    }
-
-    if (logGcTime) {
-      addGcEvents(currentEvent);
-    }
-
-    currentEvent.addData(data);
-
-    if (logOverheadTime) {
-      addOverheadEvent(currentEvent);
-    }
-
-    if (threadPendingEvents.isEmpty()) {
-      if (fileLoggingEnabled) {
-        eventsToWrite.add(currentEvent);
-      }
-    }
-  }
-
-  /**
-   * Notifies the background thread to finish processing all data in the queue.
-   * Blocks the current thread until the data is flushed in the Log Writer
-   * thread.
-   */
-  void flush() {
-    if (!fileLoggingEnabled) {
-      return;
-    }
-
-    try {
-      // Wait for the other thread to drain the queue.
-      flushLatch = new CountDownLatch(1);
-      eventsToWrite.add(flushSentinel);
-      flushLatch.await();
-    } catch (InterruptedException e) {
-      // Ignored
-    }
-  }
-
-  TraceEvent startImpl(EventType type, String... data) {
-    if (!enabled) {
-      return dummyEvent;
-    }
-
-    if (data.length % 2 == 1) {
-      throw new IllegalArgumentException("Unmatched data argument");
-    }
-
-    Stack<TraceEvent> threadPendingEvents = pendingEvents.get();
-    TraceEvent parent = null;
-    if (!threadPendingEvents.isEmpty()) {
-      parent = threadPendingEvents.peek();
-    } else {
-      // reset the thread CPU time base for top-level events (so events can be
-      // properly sequenced chronologically)
-      threadCpuTimeKeeper.resetTimeBase();
-    }
-
-    TraceEvent newEvent = new TraceEvent(parent, type, data);
-    // Add a field to the top level event in order to track the base time
-    // so we can re-normalize the data
-    if (threadPendingEvents.size() == 0) {
-      long baseTime =
-          logProcessCpuTime ? processCpuTimeKeeper.zeroTimeMillis() : (logThreadCpuTime
-              ? threadCpuTimeKeeper.zeroTimeMillis() : elapsedTimeKeeper.zeroTimeMillis());
-      newEvent.addData("baseTime", "" + baseTime);
-    }
-    threadPendingEvents.push(newEvent);
-    return newEvent;
-  }
-
-  private ThreadLocal<Stack<TraceEvent>> initPendingEvents() {
-    return new ThreadLocal<Stack<TraceEvent>>() {
-      @Override
-      protected Stack<TraceEvent> initialValue() {
-        return new Stack<TraceEvent>();
-      }
-    };
-  }
-
-  private BlockingQueue<TraceEvent> openDefaultLogWriter() {
-    Writer writer = null;
-    if (enabled) {
-      try {
-        writer = new BufferedWriter(new FileWriter(logFile));
-        return openLogWriter(writer, logFile);
-      } catch (IOException e) {
-        System.err.println("Unable to open dart.speedtracerlog '" + logFile + "'");
-        e.printStackTrace();
-      }
-    }
-    return null;
-  }
-
-  private BlockingQueue<TraceEvent> openLogWriter(final Writer writer, final String fileName) {
-    try {
-      if (outputFormat.equals(Format.HTML)) {
-        writer.write("<HTML isdump=\"true\"><body>"
-            + "<style>body {font-family:Helvetica; margin-left:15px;}</style>"
-            + "<h2>Performance dump from GWT</h2>"
-            + "<div>This file contains data that can be viewed with the "
-            + "<a href=\"http://code.google.com/speedtracer\">SpeedTracer</a> "
-            + "extension under the <a href=\"http://chrome.google.com/\">"
-            + "Chrome</a> browser.</div><p><span id=\"info\">"
-            + "(You must install the SpeedTracer extension to open this file)</span></p>"
-            + "<div style=\"display: none\" id=\"traceData\" version=\"0.17\">\n");
-      }
-    } catch (IOException e) {
-      System.err.println("Unable to write to dart.speedtracerlog '"
-          + (fileName == null ? "" : fileName) + "'");
-      e.printStackTrace();
-      return null;
-    }
-
-    final BlockingQueue<TraceEvent> eventQueue = new LinkedBlockingQueue<TraceEvent>();
-
-    Runtime.getRuntime().addShutdownHook(new Thread() {
-      @Override
-      public void run() {
-        try {
-          // Wait for the other thread to drain the queue.
-          eventQueue.add(shutDownSentinel);
-          shutDownLatch.await();
-        } catch (InterruptedException e) {
-          // Ignored
-        }
-      }
-    });
-
-    // Background thread to write SpeedTracer events to log
-    Thread logWriterWorker = new LogWriterThread(writer, fileName, eventQueue);
-
-    // Lower than normal priority.
-    logWriterWorker.setPriority((Thread.MIN_PRIORITY + Thread.NORM_PRIORITY) / 2);
-
-    /*
-     * This thread must be daemon, otherwise shutdown hooks would never begin to
-     * run, and an app wouldn't finish.
-     */
-    logWriterWorker.setDaemon(true);
-    logWriterWorker.setName("SpeedTracerLogger writer");
-    logWriterWorker.start();
-    return eventQueue;
-  }
-}