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
三:KeyDispatchTimeout
Akey or touch event was not dispatched
within the specified time(按键或触摸事件在特定时间内无响应)
具体的超时时间的定义在framework下的
ActivityManagerService.java
//How long we wait until we timeout
on key dispatching.
staticfinal int KEY_DISPATCHING_TIMEOUT
= 5*1000
四:为什么会超时呢?
超时时间的计数一般是从按键分发给app开始。超时的原因一般有两种:
(1)当前的事件没有机会得到处理(即UI线程正在处理前一个事件,没有及时的完成或者looper被某种原因阻塞住了)
(2)当前的事件正在处理,但没有及时完成
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七:如何去分析ANR
先看个LOG:
04-01 13:12:11.572 I/InputDispatcher( 220):
Application is not responding:Window{2b263310com.android.email/com.android.email.activity.SplitScreenActivitypaused=false}.
5009.8ms since event, 5009.5ms since waitstarted04-0113:12:11.572 I/WindowManager( 220): Input event dispatching
timedout sending tocom.android.email/com.android.email.activity.SplitScreenActivity04-01 13:12:14.123 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 /
8.5304-0113:12:15.872
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 minor04-0113:12:15.872 E/ActivityManager( 220): 4.3%220/system_server:
2.7% user + 1.5% kernel / faults: 11 minor 2 major04-0113:12:15.872 E/ActivityManager( 220): 0.9%52/spi_qsd.0:
0% user + 0.9% kernel04-0113:12:15.872 E/ActivityManager( 220): 0.5%65/irq/170-cyttsp-:
0% user + 0.5% kernel04-0113:12:15.872 E/ActivityManager( 220): 0.5%296/com.android.systemui:
0.5% user + 0% kernel04-0113:12:15.872
E/ActivityManager( 220): 100%TOTAL:
4.8% user + 7.6% kernel + 87% iowait04-0113:12:15.872
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 minor04-0113:12:15.872 E/ActivityManager( 220): 16% 21603/__eas(par.hakan:
16% user + 0% kernel04-0113:12:15.872 E/ActivityManager( 220): 7.2% 21406/GC: 7.2%
user + 0% kernel04-0113:12:15.872 E/ActivityManager( 220): 1.8% 21409/Compiler:
1.8% user + 0% kernel04-0113:12:15.872 E/ActivityManager( 220): 5.5%220/system_server:
0% user + 5.5% kernel / faults: 1 minor04-0113:12:15.872 E/ActivityManager( 220): 5.5% 263/InputDispatcher:
0% user + 5.5% kernel04-0113:12:15.872
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
八:Thread状态
ThreadState (defined at “dalvik/vm/thread.h “)
THREAD_UNDEFINED =
-1, /* makes enum compatible with int32_t */THREAD_ZOMBIE =
0, /* TERMINATED */THREAD_RUNNING =
1, /* RUNNABLE or running now */THREAD_TIMED_WAIT =
2, /* TIMED_WAITING in Object.wait() */THREAD_MONITOR =
3, /* BLOCKED on a monitor */THREAD_WAIT =
4, /* WAITING in Object.wait() */THREAD_INITIALIZING= 5, /* allocated, not yet running */
THREAD_STARTING = 6, /* started, not yet on thread list */
THREAD_NATIVE =
7, /* off in a JNI native method */ -