The Tor Browser: mobile/android/base/GeckoJavaSampler.java@b8a032363ba2 (annotated)

mobile/android/base/GeckoJavaSampler.java@b8a032363ba2 (annotated)

mobile/android/base/GeckoJavaSampler.java

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- Mode: Java; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: nil; -*-
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 package org.mozilla.gecko;
 import android.os.SystemClock;
 import android.util.Log;
 import android.util.SparseArray;
 import org.mozilla.gecko.mozglue.generatorannotations.WrapElementForJNI;
 import java.lang.Thread;
 import java.util.Set;
 public class GeckoJavaSampler {
     private static final String LOGTAG = "JavaSampler";
     private static Thread sSamplingThread = null;
     private static SamplingThread sSamplingRunnable = null;
     private static Thread sMainThread = null;
     private static volatile boolean sLibsLoaded = false;
     // Use the same timer primitive as the profiler
     // to get a perfect sample syncing.
     private static native double getProfilerTime();
     private static class Sample {
         public Frame[] mFrames;
         public double mTime;
         public long mJavaTime; // non-zero if Android system time is used
         public Sample(StackTraceElement[] aStack) {
             mFrames = new Frame[aStack.length];
             if (sLibsLoaded) {
                 mTime = getProfilerTime();
             }
             if (mTime == 0.0d) {
                 // getProfilerTime is not available yet; either libs are not loaded,
                 // or profiling hasn't started on the Gecko side yet
                 mJavaTime = SystemClock.elapsedRealtime();
             }
             for (int i = 0; i < aStack.length; i++) {
                 mFrames[aStack.length - 1 - i] = new Frame();
                 mFrames[aStack.length - 1 - i].fileName = aStack[i].getFileName();
                 mFrames[aStack.length - 1 - i].lineNo = aStack[i].getLineNumber();
                 mFrames[aStack.length - 1 - i].methodName = aStack[i].getMethodName();
                 mFrames[aStack.length - 1 - i].className = aStack[i].getClassName();
             }
         }
     }
     private static class Frame {
         public String fileName;
         public int lineNo;
         public String methodName;
         public String className;
     }
     private static class SamplingThread implements Runnable {
         private final int mInterval;
         private final int mSampleCount;
         private boolean mPauseSampler = false;
         private boolean mStopSampler = false;
         private SparseArray<Sample[]> mSamples = new SparseArray<Sample[]>();
         private int mSamplePos;
         public SamplingThread(final int aInterval, final int aSampleCount) {
             // If we sample faster then 10ms we get to many missed samples
             mInterval = Math.max(10, aInterval);
             mSampleCount = aSampleCount;
         }
         public void run() {
             synchronized (GeckoJavaSampler.class) {
                 mSamples.put(0, new Sample[mSampleCount]);
                 mSamplePos = 0;
                 // Find the main thread
                 Set<Thread> threadSet = Thread.getAllStackTraces().keySet();
                 for (Thread t : threadSet) {
                     if (t.getName().compareToIgnoreCase("main") == 0) {
                         sMainThread = t;
                         break;
                     }
                 }
                 if (sMainThread == null) {
                     Log.e(LOGTAG, "Main thread not found");
                     return;
                 }
             }
             while (true) {
                 try {
                     Thread.sleep(mInterval);
                 } catch (InterruptedException e) {
                     e.printStackTrace();
                 }
                 synchronized (GeckoJavaSampler.class) {
                     if (!mPauseSampler) {
                         StackTraceElement[] bt = sMainThread.getStackTrace();
                         mSamples.get(0)[mSamplePos] = new Sample(bt);
                         mSamplePos = (mSamplePos+1) % mSamples.get(0).length;
                     }
                     if (mStopSampler) {
                         break;
                     }
                 }
             }
         }
         private Sample getSample(int aThreadId, int aSampleId) {
             if (aThreadId < mSamples.size() && aSampleId < mSamples.get(aThreadId).length &&
                 mSamples.get(aThreadId)[aSampleId] != null) {
                 int startPos = 0;
                 if (mSamples.get(aThreadId)[mSamplePos] != null) {
                     startPos = mSamplePos;
                 }
                 int readPos = (startPos + aSampleId) % mSamples.get(aThreadId).length;
                 return mSamples.get(aThreadId)[readPos];
             }
             return null;
         }
     }
     @WrapElementForJNI(allowMultithread = true, stubName = "GetThreadNameJavaProfilingWrapper")
     public synchronized static String getThreadName(int aThreadId) {
         if (aThreadId == 0 && sMainThread != null) {
             return sMainThread.getName();
         }
         return null;
     }
     private synchronized static Sample getSample(int aThreadId, int aSampleId) {
         return sSamplingRunnable.getSample(aThreadId, aSampleId);
     }
     @WrapElementForJNI(allowMultithread = true, stubName = "GetSampleTimeJavaProfiling")
     public synchronized static double getSampleTime(int aThreadId, int aSampleId) {
         Sample sample = getSample(aThreadId, aSampleId);
         if (sample != null) {
             if (sample.mJavaTime != 0) {
                 return (double)(sample.mJavaTime -
                     SystemClock.elapsedRealtime()) + getProfilerTime();
             }
             System.out.println("Sample: " + sample.mTime);
             return sample.mTime;
         }
         return 0;
     }
     @WrapElementForJNI(allowMultithread = true, stubName = "GetFrameNameJavaProfilingWrapper")
     public synchronized static String getFrameName(int aThreadId, int aSampleId, int aFrameId) {
         Sample sample = getSample(aThreadId, aSampleId);
         if (sample != null && aFrameId < sample.mFrames.length) {
             Frame frame = sample.mFrames[aFrameId];
             if (frame == null) {
                 return null;
             }
             return frame.className + "." + frame.methodName + "()";
         }
         return null;
     }
     @WrapElementForJNI(allowMultithread = true, stubName = "StartJavaProfiling")
     public static void start(int aInterval, int aSamples) {
         synchronized (GeckoJavaSampler.class) {
             if (sSamplingRunnable != null) {
                 return;
             }
             sSamplingRunnable = new SamplingThread(aInterval, aSamples);
             sSamplingThread = new Thread(sSamplingRunnable, "Java Sampler");
             sSamplingThread.start();
         }
     }
     @WrapElementForJNI(allowMultithread = true, stubName = "PauseJavaProfiling")
     public static void pause() {
         synchronized (GeckoJavaSampler.class) {
             sSamplingRunnable.mPauseSampler = true;
         }
     }
     @WrapElementForJNI(allowMultithread = true, stubName = "UnpauseJavaProfiling")
     public static void unpause() {
         synchronized (GeckoJavaSampler.class) {
             sSamplingRunnable.mPauseSampler = false;
         }
     }
     @WrapElementForJNI(allowMultithread = true, stubName = "StopJavaProfiling")
     public static void stop() {
         synchronized (GeckoJavaSampler.class) {
             if (sSamplingThread == null) {
                 return;
             }
             sSamplingRunnable.mStopSampler = true;
             try {
                 sSamplingThread.join();
             } catch (InterruptedException e) {
                 e.printStackTrace();
             }
             sSamplingThread = null;
             sSamplingRunnable = null;
         }
     }
     public static void setLibsLoaded() {
         sLibsLoaded = true;
     }
 }

The Tor Browser / annotate

mobile/android/base/GeckoJavaSampler.java@b8a032363ba2 (annotated)

mobile/android/base/GeckoJavaSampler.java