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?）
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：
final Message message=Message.restoreMessageWithId(mProviderContext,messageId); if(message==null){ return; } Account account=Account.restoreAccountWithId(mProviderContext,message.mAccountKey); if(account==null){ return;//isMessagingController returns false for null, but let's make itclear. } if(isMessagingController(account)){ new Thread(){ @Override public void run(){ 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();
关于 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，在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
