一、簡介

TracePlugin這個模塊中包含EvilMethodTracer（函數(shù)耗時檢測）、StartupTracer（啟動時間檢測）、FrameTracer（幀率檢測）、AnrTracer（ANR檢測）。

二、功能簡介

TracePlugin中主要根據(jù)Activity生命周期的對4個Tracer的開啟、關(guān)閉進(jìn)行管理。

三、主要方法解析

1、init方法

該方法主要是對4個Tracer進(jìn)行初始化操作，代碼如下：

  @Override
public void init(Application app, PluginListener listener) {
    super.init(app, listener);
    MatrixLog.i(TAG, "trace plugin init, trace config: %s", traceConfig.toString());
    //APi小于16 不支持
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
        MatrixLog.e(TAG, "[FrameBeat] API is low Build.VERSION_CODES.JELLY_BEAN(16), TracePlugin is not supported");
        unSupportPlugin();
        return;
    }

    anrTracer = new AnrTracer(traceConfig);

    frameTracer = new FrameTracer(traceConfig);

    evilMethodTracer = new EvilMethodTracer(traceConfig);

    startupTracer = new StartupTracer(traceConfig);
}

2、TracePlugin.start()

在start方法中主要是啟動UIThreadMonitor、AppMethodBeat和4個Tracer。關(guān)于UIThreadMonitor和AppMethodBeat的作用后續(xù)在解析Tracer時會分析。

 @Override
public void start() {
    super.start();
    if (!isSupported()) {
        MatrixLog.w(TAG, "[start] Plugin is unSupported!");
        return;
    }
    MatrixLog.w(TAG, "start!");
    Runnable runnable = new Runnable() {
        @Override
        public void run() {

            //初始化 UIThreadMonitor
            if (!UIThreadMonitor.getMonitor().isInit()) {
                try {
                    UIThreadMonitor.getMonitor().init(traceConfig);
                } catch (java.lang.RuntimeException e) {
                    MatrixLog.e(TAG, "[start] RuntimeException:%s", e);
                    return;
                }
            }

            //啟動 AppMethodBeat
            AppMethodBeat.getInstance().onStart();

            //啟動 UIThreadMonitor
            UIThreadMonitor.getMonitor().onStart();

            anrTracer.onStartTrace();

            frameTracer.onStartTrace();

            evilMethodTracer.onStartTrace();

            startupTracer.onStartTrace();
        }
    };

    if (Thread.currentThread() == Looper.getMainLooper().getThread()) {
        runnable.run();
    } else {
        //提示 warning TracePlugin 應(yīng)該在 主線程啟動
        MatrixLog.w(TAG, "start TracePlugin in Thread[%s] but not in mainThread!", Thread.currentThread().getId());

        //post到主線程啟動
        MatrixHandlerThread.getDefaultMainHandler().post(runnable);
    }

}

3、TracePlugin.stop()

stop()中主要是在主線程中關(guān)閉和停止Tracer、AppMethodBeat、UIThreadMonitor，代碼如下：

  @Override
public void stop() {
    super.stop();
    if (!isSupported()) {
        MatrixLog.w(TAG, "[stop] Plugin is unSupported!");
        return;
    }
    MatrixLog.w(TAG, "stop!");
    Runnable runnable = new Runnable() {
        @Override
        public void run() {

            AppMethodBeat.getInstance().onStop();

            UIThreadMonitor.getMonitor().onStop();

            anrTracer.onCloseTrace();

            frameTracer.onCloseTrace();

            evilMethodTracer.onCloseTrace();

            startupTracer.onCloseTrace();

        }
    };

    if (Thread.currentThread() == Looper.getMainLooper().getThread()) {
        runnable.run();
    } else {
        MatrixLog.w(TAG, "stop TracePlugin in Thread[%s] but not in mainThread!", Thread.currentThread().getId());
        MatrixHandlerThread.getDefaultMainHandler().post(runnable);
    }

}

4、TracePlugin.onForeground()

onForeground就是將App當(dāng)前處于前臺或者是后臺的狀態(tài)分發(fā)給各個Tracer。代碼如下：

@Override
public void onForeground(boolean isForeground) {
    super.onForeground(isForeground);
    if (!isSupported()) {
        return;
    }

    if (frameTracer != null) {
        frameTracer.onForeground(isForeground);
    }

    if (anrTracer != null) {
        anrTracer.onForeground(isForeground);
    }

    if (evilMethodTracer != null) {
        evilMethodTracer.onForeground(isForeground);
    }

    if (startupTracer != null) {
        startupTracer.onForeground(isForeground);
    }

}

總結(jié)

• TracePlugin中有4個主要方法，分別是init,onStart,onStop,onForeground。
• TracePlugin中主要是對Tracer、AppMethodBeat、UIThreadMonitor進(jìn)行初始化、啟動、暫停以及App前后臺狀態(tài)分發(fā)等操作。