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
//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：
-
:onCreate(), onResume(), onDestroy(), onKeyDown(), onClick(),etc
-
: onPreExecute(), onProgressUpdate(), onPostExecute(), onCancel,etc
-
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{/=false}. 5009.8ms since event, 5009.5ms since waitstarted
04-0113:12:11.572 I/WindowManager( 220): Input event dispatching timedout sending /
04-01 13:12:14.123 I/Process( 220): Sending signal. PID: 21404 SIG: 3---发生ANR的时间和生成的时间
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 (/.)
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/: 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/: 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/: 25% user + 0% kernel / faults: 191 minor
04-0113:12:15.872 E/ActivityManager( 220): 16% 21603/__eas(: 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还得需要文件，如何获取呢？可以用如下命令获取
$chmod 777 /data/anr
$rm /data/anr/
$ps
$kill -3 PID
adbpull data/anr/ ./
从文件，看到最多的是如下的信息：
-----pid 21404 at 2011-04-01 13:12:14 -----
Cmdline:
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
(Native Method)
(:119)
(:110)
at (:3688)
at (Native Method)
(:507)
$(:866)
at (:624)
at (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_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 () */
THREAD_MONITOR = 3, /* BLOCKED on a monitor */
THREAD_WAIT = 4, /* WAITING in () */
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: 从文件查看调用stack.
3: 看代码
4：仔细查看ANR的成因（iowait?block?memoryleak?）other
十：案例
案例1：关键词:ContentResolver in AsyncTask onPostExecute, high iowait
Process:
Activity:/.
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/: 0.7% user + 3.7% kernel /faults: 38 minor 19 major
4% 372/: 0.7%user + 3.3% kernel / faults: 6 minor
1.1% 272/:0.9% user + 0.1% kernel / faults: 33 minor
0.9%252/: 0.9% user + 0% kernel
0%409/: 0% user + 0% kernel /faults: 2 minor
0.1% 632/: 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:
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 (Native Method)
-waiting on <0x2aaca218> (a )
(:1424)
(:48)
(:337)
(:157)
(:808)
(:841)
(:1171)
$(:200)
(:261)
(:378)
.<init>(:222)
(:53)
(:1356)
(:1235)
(:1189)
(:1271)
(:1098)
$(:187)
(:268)
$(:648)
(:658)
(:700)
$2500(:98)
$(:1290)
$(:1255)
(:417)
$300(:127)
$(:429)
(:99)
(:123)
(:3652)
(Native Method)
(:507)
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 =(mProviderContext,messageId);
if(message==null){
return;
}
Accountaccount =(mProviderContext,);
if(account==null){
return;//isMessagingController returns false for null, but let's make itclear.
}
if(isMessagingController(account)){
newThread(){
@Override
publicvoidrun(){
();
}
}.start();
}
解决后：
newThread() {
finalMessagemessage =(mProviderContext,messageId);
if(message==null){
return;
}
Accountaccount =(mProviderContext,);
if(account==null){
return;//isMessagingController returns false for null, but let's make itclear.
}
if(isMessagingController(account)) {
();
}
}.start();
关于AsyncTask:/reference/android/os/
案例2：关键词:在UI线程进行网络数据的读写
ANRin process: :PhotoViewer (last :PhotoViewer)
Annotation:keyDispatchingTimedOut
CPU usage:
Load: 6.74 / 6.89 / 6.12
CPUusage from 8254ms to 3224ms ago:
: 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
(NativeMethod)
(:478)
(:565)
(:87)
$(:303)
(:133)
(:157)
(:346)
(Native Method)
(:459)
(:4465)
(:4406)
$6500(:125)
$33$(:4558)
(:587)
(:92)
(:123)
(:4370)
(Native Method)
(:521)
$(:868)
(:626)
(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：/reference/android/os/
案例3：
关键词：Memoryleak/Thread leak
11-1621:41:42.560 I/ActivityManager( 1190): ANR in process: (last in )
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): :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:
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
(NativeMethod)
(Native Method)
(:468)
(:6324)
(:6178)
(:1541)
……
$(:1830)
(:1349)
(:1114)
(:1633)
(:99)
(:123)
(:4370)
(Native Method)
(:521)
$(:868)
(:626)
(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 (Native Method)
-waiting on <0x468cd420> (a )
(:288)
$UiUpdaterExecutor$(:289)
(:1096)
分析：
(NativeMethod)内存不足导致block在创建bitmap上
**MEMINFO in pid 1360 [] **
native dalvik other total
size: 17036 23111 N/A 40147
allocated: 16484 20675 N/A 37159
free: 296 2436 N/A 2732