android程序卡死无响应,防止android应用程序无响应ANR(Application Not Responding)

在android中应用被单个线程操作:主线程,或者叫做UI线程。

一:什么是ANR

ANR:Application Not Responding,即应用无响应

二:ANR的类型

ANR一般有三种类型:

1:KeyDispatchTimeout(5 seconds) --主要类型

按键或触摸事件在特定时间内无响应

2:BroadcastTimeout(10 seconds)

BroadcastReceiver在特定时间内无法处理完成

3:ServiceTimeout(20 seconds) --小概率类型

Service在特定的时间内无法处理完成

五:如何避免KeyDispatchTimeout

1:UI线程尽量只做跟UI相关的工作

2:耗时的工作(比如数据库操作,I/O,连接网络或者别的有可能阻碍UI线程的操作)把它放入单独的线程处理

3:尽量用Handler来处理UIthread和别的thread之间的交互

六:UI线程

说了那么多的UI线程,那么哪些属于UI线程呢?

UI线程主要包括如下:

Activity:onCreate(), onResume(), onDestroy(), onKeyDown(), onClick(),etc

AsyncTask: onPreExecute(), onProgressUpdate(), onPostExecute(), onCancel,etc

Mainthread handler: handleMessage(), post*(runnable r), etc

other

七:如何去分析ANR

先看个LOG:

04-01 13:12:11.572I/InputDispatcher( 220): Application is not responding:Window{2b263310com.android.email/com.android.email.activity.SplitScreenActivitypaused=false}.

5009.8ms since event, 5009.5ms since waitstarted

04-0113:12:11.572 I/WindowManager( 220): Input event dispatching timedout sending tocom.android.email/com.android.email.activity.SplitScreenActivity

04-0113:12:14.123 I/Process(  220): Sending signal. PID: 21404 SIG: 3---发生ANR的时间和生成trace.txt的时间

04-01 13:12:14.123 I/dalvikvm(21404):threadid=4: reacting to signal 3

……

04-0113:12:15.872 E/ActivityManager(  220): ANR in com.android.email(com.android.email/.activity.SplitScreenActivity)

04-0113:12:15.872 E/ActivityManager(  220): Reason:keyDispatchingTimedOut

04-0113:12:15.872 E/ActivityManager(  220): Load: 8.68 / 8.37 / 8.53

04-0113:12:15.872 E/ActivityManager(  220):CPUusage from 4361ms to 699ms ago----CPU在ANR发生前的使用情况

04-0113:12:15.872 E/ActivityManager(  220):   5.5%21404/com.android.email: 1.3% user + 4.1% kernel / faults: 10 minor

04-0113:12:15.872 E/ActivityManager(  220):   4.3%220/system_server: 2.7% user + 1.5% kernel / faults: 11 minor 2 major

04-0113:12:15.872 E/ActivityManager(  220):   0.9%52/spi_qsd.0: 0% user + 0.9% kernel

04-0113:12:15.872 E/ActivityManager(  220):   0.5%65/irq/170-cyttsp-: 0% user + 0.5% kernel

04-0113:12:15.872 E/ActivityManager(  220):   0.5%296/com.android.systemui: 0.5% user + 0% kernel

04-0113:12:15.872 E/ActivityManager(  220):100%TOTAL: 4.8% user + 7.6% kernel + 87% iowait

04-0113:12:15.872 E/ActivityManager(  220):CPUusage from 3697ms to 4223ms later:--

ANR后CPU的使用量

04-0113:12:15.872 E/ActivityManager(  220):   25%21404/com.android.email: 25% user + 0% kernel / faults: 191 minor

04-0113:12:15.872 E/ActivityManager(  220):    16% 21603/__eas(par.hakan: 16% user + 0% kernel

04-0113:12:15.872 E/ActivityManager(  220):    7.2% 21406/GC: 7.2% user + 0% kernel

04-0113:12:15.872 E/ActivityManager(  220):    1.8% 21409/Compiler: 1.8% user + 0% kernel

04-0113:12:15.872 E/ActivityManager(  220):   5.5%220/system_server: 0% user + 5.5% kernel / faults: 1 minor

04-0113:12:15.872 E/ActivityManager(  220):    5.5% 263/InputDispatcher: 0% user + 5.5% kernel

04-0113:12:15.872 E/ActivityManager(  220):32%TOTAL: 28% user + 3.7% kernel

从LOG可以看出ANR的类型,CPU的使用情况,如果CPU使用量接近100%,说明当前设备很忙,有可能是CPU饥饿导致了ANR

如果CPU使用量很少,说明主线程被BLOCK了

如果IOwait很高,说明ANR有可能是主线程在进行I/O操作造成的

除了看LOG,解决ANR还得需要trace.txt文件,

如何获取呢?可以用如下命令获取

$chmod 777 /data/anr

$rm /data/anr/traces.txt

$ps

$kill -3 PID

adbpull data/anr/traces.txt ./mytraces.txt

从trace.txt文件,看到最多的是如下的信息:

-----pid 21404 at 2011-04-01 13:12:14 -----

Cmdline: com.android.email

DALVIK THREADS:

(mutexes: tll=0tsl=0 tscl=0 ghl=0 hwl=0 hwll=0)

"main" prio=5 tid=1NATIVE

| group="main" sCount=1 dsCount=0obj=0x2aad2248 self=0xcf70

| sysTid=21404 nice=0 sched=0/0cgrp=[fopen-error:2] handle=1876218976

atandroid.os.MessageQueue.nativePollOnce(Native Method)

atandroid.os.MessageQueue.next(MessageQueue.java:119)

atandroid.os.Looper.loop(Looper.java:110)

at android.app.ActivityThread.main(ActivityThread.java:3688)

at java.lang.reflect.Method.invokeNative(Native Method)

atjava.lang.reflect.Method.invoke(Method.java:507)

atcom.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)

at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:624)

at dalvik.system.NativeStart.main(Native Method)

说明主线程在等待下条消息进入消息队列

七:STRICTMODE

这个工具会检测发生在主线程上的磁盘或者网络操作并且会采取行动来警告开发者(包括日志记录和应用程序崩溃)

StrictMode.setThreadPolicy(new StrictMode.VmPolicy.Builder()

.detectAll()

.penaltyLog()

.penaltyDialog()

.build());(monitor specific thread)

StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()

.detectAll()

.penaltyLog()

.penaltyDeath()

.build());(monitor all threads)

只在调试模式下启动StrictMode

如何检测:

public class Util {

public static boolean isDebugMode(Context context) {

PackageManager pm = context.getPackageManager();

try {

ApplicationInfo info = pm.getApplicationInfo(context.getPackageName(), 0);

return (info.flags & ApplicationInfo.FLAG_DEBUGGABLE) != 0;

} catch (NameNotFoundException e) {

}

return true;

}

public static boolean useStrictMode(Context context) {

return isDebugMode(context) && Build.VERSIONSDK_INT >= 9;

}

}

你可能感兴趣的:(android程序卡死无响应)