如何分析解决Android ANR

2023年7月12日 317次阅读来源: 爱情小傻蛋

参考文档：  
http://blog.csdn.net/tjy1985/article/details/6777346  
http://blog.csdn.net/tjy1985/article/details/6777355  
http://blog.csdn.net/tjy1985/article/details/6777983  
http://www.eoeandroid.com/forum.php?mod=viewthread&tid=165974

====================================================

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
other

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 waitstarted
04-0113:12:11.572 I/WindowManager(220): Input event dispatching timedout sending tocom.android.email/com.android.email.activity.SplitScreenActivity
04-01 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 / 8.53
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.emailDALVIK 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 */  
THREAD_VMWAIT = 8, /* waiting on a VM resource */  
THREAD_SUSPENDED = 9, /* suspended, usually by GC or debugger */

九：如何调查并解决ANR
1：首先分析log
2: 从trace.txt文件查看调用stack.
3: 看代码
4：仔细查看ANR的成因（iowait?block?memoryleak?）

十：案例
案例1：关键词:ContentResolver in AsyncTask onPostExecute, high iowait
Process:com.android.email
Activity:com.android.email/.activity.MessageView
Subject:keyDispatchingTimedOut
CPU usage from 2550ms to -2814ms ago:
5%187/system_server: 3.5% user + 1.4% kernel / faults: 86 minor 20major
4.4% 1134/com.android.email: 0.7% user + 3.7% kernel /faults: 38 minor 19 major
4% 372/com.android.eventstream: 0.7%user + 3.3% kernel / faults: 6 minor
1.1% 272/com.android.phone:0.9% user + 0.1% kernel / faults: 33 minor
0.9%252/com.android.systemui: 0.9% user + 0% kernel
0%409/com.android.eventstream.telephonyplugin: 0% user + 0% kernel /faults: 2 minor
0.1% 632/com.android.devicemonitor: 0.1% user + 0%kernel
100%TOTAL: 6.9% user + 8.2% kernel +****84%iowait

—–pid 1134 at 2010-12-17 17:46:51 —–
Cmd line:com.android.email

DALVIK THREADS:
(mutexes: tll=0 tsl=0tscl=0 ghl=0 hwl=0 hwll=0)
“main” prio=5 tid=1 WAIT
|group=”main” sCount=1 dsCount=0 obj=0x2aaca180self=0xcf20
| sysTid=1134 nice=0 sched=0/0 cgrp=[fopen-error:2]handle=1876218976
at java.lang.Object.wait(Native Method)
-waiting on <0x2aaca218> (a java.lang.VMThread)
atjava.lang.Thread.parkFor(Thread.java:1424)
atjava.lang.LangAccessImpl.parkFor(LangAccessImpl.java:48)
atsun.misc.Unsafe.park(Unsafe.java:337)
atjava.util.concurrent.locks.LockSupport.park(LockSupport.java:157)
atjava.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:808)
atjava.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:841)
atjava.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1171)
atjava.util.concurrent.locks.ReentrantLock$FairSync.lock(ReentrantLock.java:200)
atjava.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:261)
atandroid.database.sqlite.SQLiteDatabase.lock(SQLiteDatabase.java:378)
atandroid.database.sqlite.SQLiteCursor.<init>(SQLiteCursor.java:222)
atandroid.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:53)
atandroid.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1356)
atandroid.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1235)
atandroid.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1189)
atandroid.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1271)
atcom.android.email.provider.EmailProvider.query(EmailProvider.java:1098)
atandroid.content.ContentProvider$Transport.query(ContentProvider.java:187)
atandroid.content.ContentResolver.query(ContentResolver.java:268)
atcom.android.email.provider.EmailContent$Message.restoreMessageWithId(EmailContent.java:648)
atcom.android.email.Controller.setMessageRead(Controller.java:658)
atcom.android.email.activity.MessageView.onMarkAsRead(MessageView.java:700)
atcom.android.email.activity.MessageView.access$2500(MessageView.java:98)
atcom.android.email.activity.MessageView$LoadBodyTask.onPostExecute(MessageView.java:1290)
atcom.android.email.activity.MessageView$LoadBodyTask.onPostExecute(MessageView.java:1255)
atandroid.os.AsyncTask.finish(AsyncTask.java:417)
atandroid.os.AsyncTask.access$300(AsyncTask.java:127)
atandroid.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:429)
atandroid.os.Handler.dispatchMessage(Handler.java:99)
atandroid.os.Looper.loop(Looper.java:123)
atandroid.app.ActivityThread.main(ActivityThread.java:3652)
atjava.lang.reflect.Method.invokeNative(Native Method)
atjava.lang.reflect.Method.invoke(Method.java:507)
atcom.android.internal.os.ZygoteIn

原因：****IOWait****很高，说明当前系统在忙于****I/O****，因此数据库操作被阻塞
原来：

  finalMessagemessage=Message.restoreMessageWithId(mProviderContext,messageId);

        if(message==null){

           return;

        }

        Accountaccount=Account.restoreAccountWithId(mProviderContext,message.mAccountKey);

        if(account==null){

           return;//isMessagingController returns false for null, but let's make itclear.

        }

        if(isMessagingController(account)){

           newThread(){

               @Override

               publicvoidrun(){

                  mLegacyController.processPendingActions(message.mAccountKey);

               }

           }.start();

        }

解决后：

newThread() {
  finalMessagemessage=Message.restoreMessageWithId(mProviderContext,messageId);

        if(message==null){

           return;

        }

        Accountaccount=Account.restoreAccountWithId(mProviderContext,message.mAccountKey);

        if(account==null){

           return;//isMessagingController returns false for null, but let's make itclear.

        }

        if(isMessagingController(account)) {

                  mLegacyController.processPendingActions(message.mAccountKey);

              

           }

}.start();

AsyncTask:http://developer.android.com/reference/android/os/AsyncTask.html

案例2：关键词:在UI线程进行网络数据的读写

ANRin process: com.android.mediascape:PhotoViewer (last incom.android.mediascape:PhotoViewer)
Annotation:keyDispatchingTimedOut
CPU usage:
Load: 6.74 / 6.89 / 6.12
CPUusage from 8254ms to 3224ms ago:
ovider.webmedia: 4% = 4% user +0% kernel / faults: 68 minor
system_server: 2% = 1% user + 0%kernel / faults: 18 minor
re-initialized>: 0% = 0% user + 0%kernel / faults: 50 minor
events/0: 0% = 0% user + 0%kernel
TOTAL:7% = 6% user + 1% kernel

DALVIKTHREADS:
“”main”” prio=5 tid=3 NATIVE
|group=””main”” sCount=1 dsCount=0 s=Yobj=0x4001b240 self=0xbda8
| sysTid=2579 nice=0 sched=0/0cgrp=unknown handle=-1343993184
atorg.apache.harmony.luni.platform.OSNetworkSystem.receiveStreamImpl(NativeMethod)
atorg.apache.harmony.luni.platform.OSNetworkSystem.receiveStream(OSNetworkSystem.java:478)
atorg.apache.harmony.luni.NET.PlainSocketImpl.read(PlainSocketImpl.java:565)
atorg.apache.harmony.luni.net.SocketInputStream.read(SocketInputStream.java:87)
atorg.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnection$LimitedInputStream.read(HttpURLConnection.java:303)
atjava.io.InputStream.read(InputStream.java:133)
atjava.io.BufferedInputStream.fillbuf(BufferedInputStream.java:157)
atjava.io.BufferedInputStream.read(BufferedInputStream.java:346)
atandroid.graphics.BitmapFactory.nativeDecodeStream(Native Method)
atandroid.graphics.BitmapFactory.decodeStream(BitmapFactory.java:459)
atcom.android.mediascape.activity.PhotoViewerActivity.getPreviewImage(PhotoViewerActivity.java:4465)
atcom.android.mediascape.activity.PhotoViewerActivity.dispPreview(PhotoViewerActivity.java:4406)
atcom.android.mediascape.activity.PhotoViewerActivity.access$6500(PhotoViewerActivity.java:125)atcom.android.mediascape.activity.PhotoViewerActivity$33$****1.run(PhotoViewerActivity.java:4558)
atandroid.os.Handler.handleCallback(Handler.java:587)
atandroid.os.Handler.dispatchMessage(Handler.java:92)
atandroid.os.Looper.loop(Looper.java:123)
atandroid.app.ActivityThread.main(ActivityThread.java:4370)
atjava.lang.reflect.Method.invokeNative(Native Method)
atjava.lang.reflect.Method.invoke(Method.java:521)
atcom.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
atcom.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
atdalvik.system.NativeStart.main(Native Method)
关于网络连接，再设计的时候可以设置个timeout的时间或者放入独立的线程来处理。
关于Handler的问题，可以参考：http://developer.android.com/reference/android/os/Handler.html
案例3：
关键词：Memoryleak/Thread leak
11-1621:41:42.560 I/ActivityManager(1190): ANR in process:android.process.acore (last in android.process.acore)
11-1621:41:42.560 I/ActivityManager(1190): Annotation:keyDispatchingTimedOut
11-16 21:41:42.560 I/ActivityManager(1190): CPU usage:
11-16 21:41:42.560 I/ActivityManager(1190):Load: 11.5 / 11.1 / 11.09
11-16 21:41:42.560 I/ActivityManager(1190): CPU usage from 9046ms to 4018ms ago:
11-16 21:41:42.560I/ActivityManager(1190): d.process.acore:98%= 97% user + 0% kernel / faults: 1134 minor
11-16 21:41:42.560I/ActivityManager(1190): system_server: 0% = 0% user + 0% kernel /faults: 1 minor
11-16 21:41:42.560 I/ActivityManager(1190): adbd:0% = 0% user + 0% kernel
11-16 21:41:42.560 I/ActivityManager(1190): logcat: 0% = 0% user + 0% kernel
11-16 21:41:42.560I/ActivityManager(1190): TOTAL:100% = 98% user + 1% kernel
Cmdline: android.process.acore

DALVIK THREADS:
“main”prio=5 tid=3 VMWAIT
|group=”main” sCount=1 dsCount=0 s=N obj=0x40026240self=0xbda8
| sysTid=1815 nice=0 sched=0/0 cgrp=unknownhandle=-1344001376
atdalvik.system.VMRuntime.trackExternalAllocation(NativeMethod)**
atandroid.graphics.Bitmap.nativeCreate(Native Method)
atandroid.graphics.Bitmap.createBitmap(Bitmap.java:468)
atandroid.view.View.buildDrawingCache(View.java:6324)
atandroid.view.View.getDrawingCache(View.java:6178)
atandroid.view.ViewGroup.drawChild(ViewGroup.java:1541)
……
atcom.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:1830)
atandroid.view.ViewRoot.draw(ViewRoot.java:1349)
atandroid.view.ViewRoot.performTraversals(ViewRoot.java:1114)
atandroid.view.ViewRoot.handleMessage(ViewRoot.java:1633)
atandroid.os.Handler.dispatchMessage(Handler.java:99)
atandroid.os.Looper.loop(Looper.java:123)
atandroid.app.ActivityThread.main(ActivityThread.java:4370)
atjava.lang.reflect.Method.invokeNative(Native Method)
atjava.lang.reflect.Method.invoke(Method.java:521)
atcom.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
atcom.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
atdalvik.system.NativeStart.main(Native Method)
“Thread-408″prio=5 tid=329 WAIT
|group=”main” sCount=1 dsCount=0 s=N obj=0x46910d40self=0xcd0548
| sysTid=10602 nice=0 sched=0/0 cgrp=unknownhandle=15470792
at java.lang.Object.wait(Native Method)
-waiting on <0x468cd420> (a java.lang.Object)
atjava.lang.Object.wait(Object.java:288)
atcom.android.dialer.CallLogContentHelper$UiUpdaterExecutor$1.run(CallLogContentHelper.java:289)
atjava.lang.Thread.run(Thread.java:1096)
分析：
atdalvik.system.VMRuntime.trackExternalAllocation**(NativeMethod)内存不足导致block在创建bitmap上
**MEMINFO in pid 1360 [android.process.acore] **
native dalvik other total
size: 17036 23111 N/A 40147
allocated: 16484 20675 N/A 37159
free: 296 2436 N/A 2732
解决：如果机器的内存族，可以修改虚拟机的内存为36M或更大，不过最好是复查代码，查看哪些内存没有释放

Log的产生大家都知道，大家也都知道通过DDMS来看log ，但什么时候会产生log文件呢？一般在如下几种情况会产生log文件。
1，程序异常退出， uncaused exception
2，程序强制关闭，Force Closed (简称FC)
3，程序无响应， Application No Response （简称ANR) ，顺便，一般主线程超过5秒么有处理就会ANR
4，手动生成。

拿到一个日志文件，要分成多段来看。 log文件很长，其中包含十几个小单元信息，但不要被吓到，事实上他主要由三大块儿组成。

1，系统基本信息，包括内存，CPU ，进程队列，虚拟内存，垃圾回收等信息。
—— MEMORY INFO (/proc/meminfo) ——
—— CPU INFO (top -n 1 -d 1 -m 30 -t) ——
—— PROCRANK (procrank) ——
—— VIRTUAL MEMORY STATS (/proc/vmstat) ——
—— VMALLOC INFO (/proc/vmallocinfo) ——

格式如下：
—— MEMORY INFO (/proc/meminfo) ——
MemTotal: 347076 kB
MemFree: 56408 kB
Buffers: 7192 kB
Cached: 104064 kB
SwapCached: 0 kB
Active: 192592 kB
Inactive: 40548 kB
Active(anon): 129040 kB
Inactive(anon): 1104 kB
Active(file): 63552 kB
Inactive(file): 39444 kB
Unevictable: 7112 kB
Mlocked: 0 kB
SwapTotal: 0 kB
SwapFree: 0 kB
Dirty: 44 kB
Writeback: 0 kB
AnonPages: 129028 kB
Mapped: 73728 kB
Shmem: 1148 kB
Slab: 13072 kB
SReclaimable: 4564 kB
SUnreclaim: 8508 kB
KernelStack: 3472 kB
PageTables: 12172 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 173536 kB
Committed_AS: 7394524 kB
VmallocTotal: 319488 kB
VmallocUsed: 90752 kB
VmallocChunk: 181252 kB

2，时间信息，也是我们主要分析的信息。
—— VMALLOC INFO (/proc/vmallocinfo) ——
—— EVENT INFO (/proc/vmallocinfo) ——

格式如下：
—— SYSTEM LOG (logcat -b system -v time -d *:v) ——
01-15 16:41:43.671 W/PackageManager(2466): Unknown permission com.wsomacp.permission.PROVIDER in package com.android.mms
01-15 16:41:43.671 I/ActivityManager(2466): Force stopping package com.android.mms uid=10092
01-15 16:41:43.675 I/UsageStats(2466): Something wrong here, didn’t expect com.sec.android.app.twlauncher to be paused
01-15 16:41:44.108 I/ActivityManager(2466): Start proc com.sec.android.widgetapp.infoalarm for service com.sec.android.widgetapp.infoalarm/.engine.DataService: pid=20634 uid=10005 gids={3003, 1015, 3002}
01-15 16:41:44.175 W/ActivityManager(2466): Activity pause timeout for HistoryRecord{48589868 com.sec.android.app.twlauncher/.Launcher}
01-15 16:41:50.864 I/KeyInputQueue(2466): Input event
01-15 16:41:50.866 D/KeyInputQueue(2466): screenCaptureKeyFlag setting 0
01-15 16:41:50.882 I/PowerManagerService(2466): Ulight 0->7|0
01-15 16:41:50.882 I/PowerManagerService(2466): Setting target 2: cur=0.0 target=70 delta=4.6666665 nominalCurrentValue=0
01-15 16:41:50.882 I/PowerManagerService(2466): Scheduling light animator!
01-15 16:41:51.706 D/PowerManagerService(2466): enableLightSensor true
01-15 16:41:51.929 I/KeyInputQueue(2466): Input event
01-15 16:41:51.933 W/WindowManager(2466): No focus window, dropping: KeyEvent{action=0 code=26 repeat=0 meta=0 scancode=26 mFlags=9}

3，虚拟机信息，包括进程的，线程的跟踪信息，这是用来跟踪进程和线程具体点的好地方。
—— VM TRACES JUST NOW (/data/anr/traces.txt.bugreport: 2011-01-15 16:49:02) ——
—— VM TRACES AT LAST ANR (/data/anr/traces.txt: 2011-01-15 16:49:02) ——

格式如下：
—– pid 21161 at 2011-01-15 16:49:01 —–
Cmd line: com.android.mms

DALVIK THREADS:
“main” prio=5 tid=1 NATIVE
| group=”main” sCount=1 dsCount=0 s=N obj=0x4001d8d0 self=0xccc8
| sysTid=21161 nice=0 sched=0/0 cgrp=default handle=-1345017808
| schedstat=( 4151552996 5342265329 10995 )
at android.media.MediaPlayer._reset(Native Method)
at android.media.MediaPlayer.reset(MediaPlayer.java:1218)
at android.widget.VideoView.release(VideoView.java:499)
at android.widget.VideoView.access$2100(VideoView.java:50)
at android.widget.VideoView$6.surfaceDestroyed(VideoView.java:489)
at android.view.SurfaceView.reportSurfaceDestroyed(SurfaceView.java:572)
at android.view.SurfaceView.updateWindow(SurfaceView.java:476)
at android.view.SurfaceView.onWindowVisibilityChanged(SurfaceView.java:206)
at android.view.View.dispatchDetachedFromWindow(View.java:6082)
at android.view.ViewGroup.dispatchDetachedFromWindow(ViewGroup.java:1156)
at android.view.ViewGroup.removeAllViewsInLayout(ViewGroup.java:2296)
at android.view.ViewGroup.removeAllViews(ViewGroup.java:2254)
at com.android.mms.ui.SlideView.reset(SlideView.java:687)
at com.android.mms.ui.SlideshowPresenter.presentSlide(SlideshowPresenter.java:189)
at com.android.mms.ui.SlideshowPresenter$3.run(SlideshowPresenter.java:531)
at android.os.Handler.handleCallback(Handler.java:587)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:123)
at android.app.ActivityThread.main(ActivityThread.java:4627)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:521)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
at dalvik.system.NativeStart.main(Native Method)

闲话少说，我总结了观察log文件的基本步骤。 1，如果是ANR问题，则搜索“ANR”关键词。快速定位到关键事件信息。
2，如果是ForceClosed 和其它异常退出信息，则搜索”Fatal” 关键词，快速定位到关键事件信息。
3，定位到关键事件信息后，如果信息不够明确的，再去搜索应用程序包的虚拟机信息，查看具体的进程和线程跟踪的日志，来定位到代码。

用这种方法，出现问题，根本不需要断点调试，直接定位到问题，屡试不爽。
下面，我们就开始来分析这个例子的log 。

打开log文件，由于是ANR错误，因此搜索”ANR ” ，为何要加空格呢，你加上和去掉比较一下就知道了。可以屏蔽掉不少保存到anr.log文件的无效信息。

定位到关键的事件信息如下：
01-15 16:49:02.433 E/ActivityManager(2466): ANR in com.android.mms (com.android.mms/.ui.SlideshowActivity)
01-15 16:49:02.433 E/ActivityManager(2466): Reason: keyDispatchingTimedOut
01-15 16:49:02.433 E/ActivityManager(2466): Load: 0.6 / 0.61 / 0.42
01-15 16:49:02.433 E/ActivityManager(2466): CPU usage from 1337225ms to 57ms ago:
01-15 16:49:02.433 E/ActivityManager(2466): sensorserver_ya: 8% = 0% user + 8% kernel / faults: 40 minor
……

01-15 16:49:02.433 E/ActivityManager(2466): -com.android.mms: 0% = 0% user + 0% kernel
01-15 16:49:02.433 E/ActivityManager(2466): -flush-179:8: 0% = 0% user + 0% kernel
01-15 16:49:02.433 E/ActivityManager(2466): TOTAL: 25% = 10% user + 14% kernel + 0% iowait + 0% irq + 0% softirq
01-15 16:49:02.436 I/ (2466): dumpmesg > “/data/log/dumpstate_app_anr.log”

我们用自然语言来描述一下日志，这也算是一种能力吧。
01-15 16:49:02.433 E/ActivityManager(2466): ANR in com.android.mms (com.android.mms/.ui.SlideshowActivity)
翻译：在16:49分2秒433毫秒的时候 ActivityManager （进程号为2466) 发生了如下错误：com.android.mms包下面的.ui.SlideshowActivity 无响应。

01-15 16:49:02.433 E/ActivityManager(2466): Reason: keyDispatchingTimedOut
翻译：原因， keyDispatchingTimeOut – 按键分配超时

01-15 16:49:02.433 E/ActivityManager(2466): Load: 0.6 / 0.61 / 0.42
翻译：5分钟，10分钟，15分钟内的平均负载分别为：0.6 , 0.61 , 0.42

在这里我们大概知道问题是什么了，结合我们之前的操作流程，我们知道问题是在点击按钮某时候可能处理不过来按钮事件，导致超时无响应。那么现在似乎已经可以进行工作了。我们知道Activity中是通过重载dispatchTouchEvent(MotionEvent ev)来处理点击屏幕事件。然后我们可以顺藤摸瓜，一点点分析去查找原因。但这样够了么？
其实不够，至少我们不能准确的知道到底问题在哪儿，只是猜测，比如这个应用程序中，我就在顺藤摸瓜的时候发现了多个IO操作的地方都在主线程中，可能引起问题，但不好判断到底是哪个，所以我们目前掌握的信息还不够。

于是我们再分析虚拟机信息，搜索“Dalvik Thread”关键词，快速定位到本应用程序的虚拟机信息日志，如下：
—– pid 2922 at 2011-01-13 13:51:07 —–
Cmd line: com.android.mms

DALVIK THREADS:
“main” prio=5 tid=1 NATIVE
| group=”main” sCount=1 dsCount=0 s=N obj=0x4001d8d0 self=0xccc8
| sysTid=2922 nice=0 sched=0/0 cgrp=default handle=-1345017808
| schedstat=( 3497492306 15312897923 10358 )
at android.media.MediaPlayer._release(Native Method)
at android.media.MediaPlayer.release(MediaPlayer.java:1206)
at android.widget.VideoView.stopPlayback(VideoView.java:196)
at com.android.mms.ui.SlideView.stopVideo(SlideView.java:640)
at com.android.mms.ui.SlideshowPresenter.presentVideo(SlideshowPresenter.java:443)
at com.android.mms.ui.SlideshowPresenter.presentRegionMedia(SlideshowPresenter.java:219)
at com.android.mms.ui.SlideshowPresenter$4.run(SlideshowPresenter.java:516)
at android.os.Handler.handleCallback(Handler.java:587)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:123)
at android.app.ActivityThread.main(ActivityThread.java:4627)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:521)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
at dalvik.system.NativeStart.main(Native Method)

“Binder Thread #3” prio=5 tid=11 NATIVE
| group=”main” sCount=1 dsCount=0 s=N obj=0x4837f808 self=0x242280
| sysTid=3239 nice=0 sched=0/0 cgrp=default handle=2341032
| schedstat=( 32410506 932842514 164 )
at dalvik.system.NativeStart.run(Native Method)

“AsyncQueryWorker” prio=5 tid=9 WAIT
| group=”main” sCount=1 dsCount=0 s=N obj=0x482f4b80 self=0x253e10
| sysTid=3236 nice=0 sched=0/0 cgrp=default handle=2432120
| schedstat=( 3225061 26561350 27 )
at java.lang.Object.wait(Native Method)
-waiting on <0x482f4da8> (a android.os.MessageQueue)
at java.lang.Object.wait(Object.java:288)
at android.os.MessageQueue.next(MessageQueue.java:146)
at android.os.Looper.loop(Looper.java:110)
at android.os.HandlerThread.run(HandlerThread.java:60)

“Thread-9” prio=5 tid=8 WAIT
| group=”main” sCount=1 dsCount=0 s=N obj=0x4836e2b0 self=0x25af70
| sysTid=2929 nice=0 sched=0/0 cgrp=default handle=2370896
| schedstat=( 130248 4389035 2 )
at java.lang.Object.wait(Native Method)
-waiting on <0x4836e240> (a java.util.ArrayList)
at java.lang.Object.wait(Object.java:288)
at com.android.mms.data.Contact$ContactsCache$TaskStack$1.run(Contact.java:488)
at java.lang.Thread.run(Thread.java:1096)

“Binder Thread #2” prio=5 tid=7 NATIVE
| group=”main” sCount=1 dsCount=0 s=N obj=0x482f8ca0 self=0x130fd0
| sysTid=2928 nice=0 sched=0/0 cgrp=default handle=1215968
| schedstat=( 40610049 1837703846 195 )
at dalvik.system.NativeStart.run(Native Method)

“Binder Thread #1” prio=5 tid=6 NATIVE
| group=”main” sCount=1 dsCount=0 s=N obj=0x482f4a78 self=0x128a50
| sysTid=2927 nice=0 sched=0/0 cgrp=default handle=1201352
| schedstat=( 40928066 928867585 190 )
at dalvik.system.NativeStart.run(Native Method)

“Compiler” daemon prio=5 tid=5 VMWAIT
| group=”system” sCount=1 dsCount=0 s=N obj=0x482f1348 self=0x118960
| sysTid=2926 nice=0 sched=0/0 cgrp=default handle=1149216
| schedstat=( 753021350 3774113668 6686 )
at dalvik.system.NativeStart.run(Native Method)

“JDWP” daemon prio=5 tid=4 VMWAIT
| group=”system” sCount=1 dsCount=0 s=N obj=0x482f12a0 self=0x132940
| sysTid=2925 nice=0 sched=0/0 cgrp=default handle=1255680
| schedstat=( 2827103 29553323 19 )
at dalvik.system.NativeStart.run(Native Method)

“Signal Catcher” daemon prio=5 tid=3 RUNNABLE
| group=”system” sCount=0 dsCount=0 s=N obj=0x482f11e8 self=0x135988
| sysTid=2924 nice=0 sched=0/0 cgrp=default handle=1173688
| schedstat=( 11793815 12456169 7 )
at dalvik.system.NativeStart.run(Native Method)

“HeapWorker” daemon prio=5 tid=2 VMWAIT
| group=”system” sCount=1 dsCount=0 s=N obj=0x45496028 self=0x135848
| sysTid=2923 nice=0 sched=0/0 cgrp=default handle=1222608
| schedstat=( 79049792 1520840200 95 )
at dalvik.system.NativeStart.run(Native Method)

—– end 2922 —–

每一段都是一个线程，当然我们还是看线程号为1的主线程了。通过分析发现关键问题是这样：
at com.android.mms.ui.SlideshowPresenter$3.run(SlideshowPresenter.java:531)
定位到代码：

mHandler.post(new Runnable() {
                    public void run() {
                        try {
                            presentRegionMedia(view, (RegionMediaModel) model, dataChanged);
                        } catch (OMADRMException e) {
                            Log.e(TAG, e.getMessage(), e);
                            Toast.makeText(mContext,mContext.getString(R.string.insufficient_drm_rights),
                                    Toast.LENGTH_SHORT).show();
                        } catch (IOException e){
                            Log.e(TAG, e.getMessage(), e);
                            Toast.makeText(mContext, mContext.getString(R.string.insufficient_drm_rights), Toast.LENGTH_SHORT).show();
                        }
                    }

很清楚了， Handler.post 方法之后执行时间太长的问题。继续看presentRegionMedia(view, (RegionMediaModel) model, dataChanged);方法，发现最终是调用的framework 中MediaPlayer.stop方法。
至此，我们的日志分析算是告一段落。可以开始思考解决办法了。

    原文作者：爱情小傻蛋
    原文地址: https://www.jianshu.com/p/f4543a729619
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