微信Android客户端的卡顿监控方案

for (;;) {    Message msg = queue.next(); // might block        // This must be in a local variable, in case a UI event sets the logger    final Printer logging = me.mLogging;    if (logging != null) {        logging.println(">>>>> Dispatching to " + msg.target + " " +                msg.callback + ": " + msg.what);    }
    msg.target.dispatchMessage(msg);
    if (logging != null) {        logging.println("<<<<< Finished to " + msg.target + " " + msg.callback);    }}

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for (;;) {    if (nextPollTimeoutMillis != 0) {        Binder.flushPendingCommands();    }
    nativePollOnce(ptr, nextPollTimeoutMillis);
    //......
    // Run the idle handlers.    // We only ever reach this code block during the first iteration.    for (int i = 0; i < pendingIdleHandlerCount; i++) {        final IdleHandler idler = mPendingIdleHandlers[i];        mPendingIdleHandlers[i] = null; // release the reference to the handler
        boolean keep = false;        try {            keep = idler.queueIdle();        } catch (Throwable t) {            Log.wtf(TAG, "IdleHandler threw exception", t);        }
        if (!keep) {            synchronized (this) {                mIdleHandlers.remove(idler);            }        }    }    //......}

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void scheduleTraversals() {    if (!mTraversalScheduled) {        mTraversalScheduled = true;        mTraversalBarrier = mHandler.getLooper().getQueue().postSyncBarrier();        mChoreographer.postCallback(                Choreographer.CALLBACK_TRAVERSAL, mTraversalRunnable, null);        notifyRendererOfFramePending();        pokeDrawLockIfNeeded();    }}
void unscheduleTraversals() {    if (mTraversalScheduled) {        mTraversalScheduled = false;        mHandler.getLooper().getQueue().removeSyncBarrier(mTraversalBarrier);        mChoreographer.removeCallbacks(                Choreographer.CALLBACK_TRAVERSAL, mTraversalRunnable, null);    }}

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private static void detectIdleHandler() {    try {        MessageQueue mainQueue = Looper.getMainLooper().getQueue();        Field field = MessageQueue.class.getDeclaredField("mIdleHandlers");        field.setAccessible(true);        MyArrayList myIdleHandlerArrayList = new MyArrayList<>();        field.set(mainQueue, myIdleHandlerArrayList);    } catch (Throwable t) {        t.printStackTrace();    }}
static class MyArrayList extends ArrayList {    Map map = new HashMap<>();
    @Override    public boolean add(Object o) {        if (o instanceof MessageQueue.IdleHandler) {            MyIdleHandler myIdleHandler = new MyIdleHandler((MessageQueue.IdleHandler) o);            map.put((MessageQueue.IdleHandler) o, myIdleHandler);            return super.add(myIdleHandler);        }        return super.add(o);    }
    @Override    public boolean remove(@Nullable Object o) {        if (o instanceof MyIdleHandler) {            MessageQueue.IdleHandler idleHandler = ((MyIdleHandler) o).idleHandler;            map.remove(idleHandler);            return super.remove(o);        } else {            MyIdleHandler myIdleHandler = map.remove(o);            if (myIdleHandler != null) {                return super.remove(myIdleHandler);            }            return super.remove(o);        }    }}

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MessageQueue mainQueue = Looper.getMainLooper().getQueue();Field field = mainQueue.getClass().getDeclaredField("mMessages");field.setAccessible(true);Message mMessage = (Message) field.get(mainQueue);  //通过反射得到当前正在等待执行的Messageif (mMessage != null) {    currentMessageToString = mMessage.toString();    long when = mMessage.getWhen() - SystemClock.uptimeMillis();    if (when < -3000 && mMessage.getTarget() == null) { //target == null则为sync barrier        int token = mMessage.arg1;        startCheckLeaking(token);    }}
private static void startCheckLeaking(int token) {    int checkCount = 0;    barrierCount = 0;    while (checkCount < CHECK_STRICTLY_MAX_COUNT) {        checkCount++;        int latestToken = getSyncBarrierToken();        if (token != latestToken) {     //token变了，不是同一个barrier，return            break;        }        if (DetectSyncBarrierOnce()) {            //发生了sync barrier泄漏            removeSyncBarrier(token);   //手动remove泄漏的sync barrier            break;        }        try {            Thread.sleep(1000);        } catch (InterruptedException e) {            e.printStackTrace();        }    }}
private static void removeSyncBarrier(int token) {    MessageQueue mainQueue = Looper.getMainLooper().getQueue();    Method method = mainQueue.getClass().getDeclaredMethod("removeSyncBarrier", int.class);    method.setAccessible(true);    method.invoke(mainQueue, token);}
private static boolean DetectSyncBarrierOnce() {    Handler mainHandler = new Handler(Looper.getMainLooper()) {        @Override        public void handleMessage(Message msg) {            super.handleMessage(msg);            if (msg.arg1 == 0) {                barrierCount ++;    //收到了异步消息，count++            } else if (msg.arg1 == 1) {                barrierCount = 0;   //收到了同步消息，说明同步屏障不在, count设置为0            }        }    };
    Message asyncMessage = Message.obtain();    asyncMessage.setAsynchronous(true);    asyncMessage.setTarget(mainHandler);    asyncMessage.arg1 = 0;
    Message syncNormalMessage = Message.obtain();     syncNormalMessage.arg1 = 1;
    mainHandler.sendMessage(asyncMessage);      //发送一个异步消息    mainHandler.sendMessage(syncNormalMessage); //发送一个同步消息
    if(barrierCount > 3){        return true;    }    return false;}

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