android 应用性能优化_david wu

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1、ImprovingAndroidApplicationPerformanceDavidWudave_wu@htc.comComputerScienceandInformationEngineering,NationalTaiwanUniversityDecember22,2011©2010HTCCorporation.Allrightsreserved.2H!,I’mD"v!dF#l$o%@w&m"n34567Agenda•Performance•FrameworkAPIs•UIperformance•I/Operformance•Scrollingperformance•Mem

2、ory•HowAndroidmemorymanagementworks•OOMkillerandlowmemorykiller•Memorymeasurementofanapplication•Identifyingmemoryleaks•Bestpractices8P'r(o)m"n*e9Whycareaboutperformance?10B"du+e)e,p'r!e-c'11Activitytakesalongtimetolaunch12Applicationnotrespondingtouserevents13Poorframerate14Framerates•Toachi

3、eve60fps,youhave16mstohandleeachframe.•Toachieve24fps,youhave41mstohandleeachframe.•BinderRPCcalltakes~0.12ms.•Readingabytefromflashtakes~5-25ms.•Writingtoflashtakes~5-100ms.•TCPsetup+HTTPfetchtakesseconds.15Numberstakenfromhttp://www.youtube.com/watch?v=c4znvD-7VDAWriteperformancevaries16Tak

4、enfromhttp://www.youtube.com/watch?v=c4znvD-7VDANeverstalltheUIthreadSpawnanewthreadtodowork17RunnableThreadFutureExecutorService18newThread(newRunnable(){@Overridepublicvoidrun(){//dosomeheavywork}}).start();!19newAsyncTask(){protectedLongdoInBackground(URL...urls){final

5、intcount=urls.length;for(inti=0;i

6、=newHandlerThread("WorkerThread");Handlerhandler=newHandler(mHandlerThread.getLooper()){@OverridepublicvoidhandleMessage(Messagemsg){switch(msg.what){caseJOB_1://dojob#1break;caseJOB_2://dojob#2break;}}};!21handler.sendEmptyMessage(JOB_1);handler.sendEmptyMessage(JOB_2);handler.post(newRunnab

7、le(){@Overridepublicvoidrun(){//domorework}});!22@OverrideprotectedvoidonDestroy(){mHandlerThread.quit();super.onDestroy();}!23newAsyncQueryHandler(getContentResolver()){@OverrideprotectedvoidonQueryComplete(inttoken,Objectcookie,Cursorcursor