【笔记】【从Android Guide温习Android 二】ANR (Application Not Responding)

【笔记】【从Android Guide温习Android 二】ANR (Application Not Responding)

官方文档连接

http://developer.android.com/training/articles/perf-anr.html

ANR产生条件

KeyDispatchTimeout -- 按键或点击屏幕5秒内没反应

BroadcastTimeout -- BroadcastReceiver没有在10秒内结束

ServiceTimeout -- Service20秒内没有处理完成

Time out

虽然和ANR有关，但是并不是所有的Timeout都会引发ANR

因为解决办法和ANR的相同甚至更多。

可以看一下ActivityManagerService或者ActivityStack的源码，搜一下TIMEOUT,如下。

```
// How long we wait until giving up on the last activity to pause.  This
// is short because it directly impacts the responsiveness of starting the
// next activity.
static final int PAUSE_TIMEOUT = 500;

// How long we wait for the activity to tell us it has stopped before
// giving up.  This is a good amount of time because we really need this
// from the application in order to get its saved state.
static final int STOP_TIMEOUT = 10*1000;

// How long we wait until giving up on an activity telling us it has
// finished destroying itself.
static final int DESTROY_TIMEOUT = 10*1000;

```

可见Acitivy中Pause,Stop,Destory对处理的时间也是有限制的。

如何避免

耗时操作都放到工作线程(Worker Thread or Background Thread)中. 如网络请求，数据库读写，图片缩放

可用特性

AsyncTask

注意其生命周期

Thread

需设置

Process.setThreadPriority(THREAD_PRIORITY_BACKGROUND)。

不要使用一下方法阻塞主线程

Thread.wait() or Thread.sleep()

IntentService

特别适用于BroadcastReceiver中的耗时操作。

用户体验

100到200ms之间，用户会觉得软件运行缓慢。

分析ANR

下面是ANR的log信息

01-10 10:23:04.838      561-586/? E/ActivityManager﹕ ANR in com.android.memorycleaner:remote, time=3677664
Reason: Executing service com.android.memorycleaner/.service.PushService
Load: 1.13 / 1.26 / 1.3
CPU usage from 8110ms to 65ms ago:
11% 701/com.android.systemui: 4.9% user + 6.5% kernel / faults: 108 minor
4.7% 142/surfaceflinger: 1.6% user + 3% kernel
4.5% 561/system_server: 2.7% user + 1.8% kernel / faults: 611 minor
2.1% 4306/kworker/0:2: 0% user + 2.1% kernel
1.9% 5087/com.tangyu.component: 1.2% user + 0.7% kernel / faults: 135 minor
1.9% 5430/com.tencent.qqlive: 1.2% user + 0.7% kernel / faults: 450 minor
1.1% 5545/com.android.vending: 0.6% user + 0.4% kernel / faults: 1854 minor
1.7% 4598/kworker/0:3: 0% user + 1.7% kernel
1.4% 891/com.htc.launcher: 1.2% user + 0.2% kernel / faults: 28 minor
1.1% 140/netd: 0.9% user + 0.1% kernel / faults: 12 minor
0.7% 152/akmd: 0% user + 0.7% kernel
0.4% 153/ewtzmud: 0% user + 0.4% kernel
0.4% 4538/kworker/u:3: 0% user + 0.4% kernel
0.3% 3785/irq/210-host_sp: 0% user + 0.3% kernel
0.2% 111/mmcqd/0: 0% user + 0.2% kernel
0.2% 143/zygote: 0% user + 0.2% kernel / faults: 59 minor
0.2% 456/adbd: 0% user + 0.2% kernel
0.2% 1089/irq/340-wl12xx: 0% user + 0.2% kernel
0.1% 5143/com.android.memorycleaner: 0% user + 0% kernel / faults: 46 minor
0.1% 145/mediaserver: 0% user + 0.1% kernel
0.1% 507/logcat: 0% user + 0.1% kernel
0% 1110/wpa_supplicant: 0% user + 0% kernel
0.1% 3786/irq/214-host_sp: 0% user + 0.1% kernel
0% 5487/com.htc.dnatransfer: 0% user + 0% kernel / faults: 2 minor
0.1% 5616/com.google.android.gm: 0% user + 0.1% kernel
0.1% 5725/com.android.ss: 0.1% user + 0% kernel / faults: 20 minor
+0% 5747/com.htc.calendar: 0% user + 0% kernel
18% TOTAL: 8.2% user + 9.8% kernel + 0.4% iowait + 0% irq + 0.1% softirq
CPU usage from 1435ms to 1956ms later:
5.7% 561/system_server: 3.8% user + 1.9% kernel / faults: 2 minor
3.8% 586/ActivityManager: 1.9% user + 1.9% kernel
1.2% 142/surfaceflinger: 0% user + 1.2% kernel
1.2% 459/EventThread: 0% user + 1.2% kernel
1.3% 701/com.android.systemui: 1.3% user + 0% kernel
2.7% 701/ndroid.systemui: 1.3% user + 1.3% kernel
3.8% TOTAL: 1.9% user + 1.9% kernel

重点看一下这几点

原因：

Reason: Executing service com.android.memorycleaner/.service.PushService

啊，com.android.memorycleaner/.service.PushService这个东西引发了ANR

Total信息

ANR发生前

18% TOTAL: 8.2% user + 9.8% kernel + 0.4% iowait + 0% irq + 0.1% softirq

ANR发生后

3.8% TOTAL: 1.9% user + 1.9% kernel

可以抽出几个关键词:

CPU

若CPU彪到了100%，有可能是CPU饥饿导致了ANR

若CPU不多。说明主线程被BLOCK了。

当前为18%.

PID(进程号) + Package-name(包名)

方便确认是你程序的那个进程异常。

IOwait

若IOWait高，说明在主线程有读写操作导致ANR。

看上去数值没异常

正如此例子。

这时候就可能是另一种情况引起的ANR -- 主线程中有网络通讯

下面就祭上我们的神器 Trace文件

Traces.txt

此文件位于设备中的 /data/anr/traces.txt。

vi traces.txt

查看文件内容。内容有很多。我们只看开始就可以。如下。

1
2
3 ----- pid 13359 at 2014-01-10 12:33:03 -----
4 Cmd line: com.android.memorycleaner:remote
5
6 DALVIK THREADS:
7 (mutexes: tll=0 tsl=0 tscl=0 ghl=0)
8
9 "main" prio=5 tid=1 NATIVE
10   | group="main" sCount=1 dsCount=0 obj=0x41a42e50 self=0x400f6010
11   | sysTid=13359 nice=0 sched=0/0 cgrp=apps handle=1074345436
12   | state=S schedstat=( 626677000 787645000 1599 ) utm=32 stm=30 core=3
13   #00  pc 000180d0  /system/lib/libc.so (poll+12)
14   #01  pc 00020d73  /system/lib/libjavacore.so
15   #02  pc 0001e690  /system/lib/libdvm.so (dvmPlatformInvoke+112)
16   #03  pc 0005100f  /system/lib/libdvm.so (dvmCallJNIMethod(unsigned int const*, JValue*, Method const*, Thread*)+426)
17   #04  pc 00027aa0  /system/lib/libdvm.so
18   #05  pc 0002ce84  /system/lib/libdvm.so (dvmInterpret(Thread*, Method const*, JValue*)+232)
19   #06  pc 000674bf  /system/lib/libdvm.so (dvmInvokeMethod(Object*, Method const*, ArrayObject*, ArrayObject*, ClassObject*, bool)+374)
20   #07  pc 0007066f  /system/lib/libdvm.so
21   #08  pc 00027aa0  /system/lib/libdvm.so
22   #09  pc 0002ce84  /system/lib/libdvm.so (dvmInterpret(Thread*, Method const*, JValue*)+232)
23   #10  pc 000671a1  /system/lib/libdvm.so (dvmCallMethodV(Thread*, Method const*, Object*, bool, JValue*, std::__va_list)+272)
24   #11  pc 0004d2d7  /system/lib/libdvm.so
25   #12  pc 0004d391  /system/lib/libandroid_runtime.so
26   #13  pc 0004e22d  /system/lib/libandroid_runtime.so (android::AndroidRuntime::start(char const*, char const*)+540)
27   #14  pc 00000e67  /system/bin/app_process
28   #15  pc 000128b3  /system/lib/libc.so (__libc_init+38)
29   #16  pc 00000b74  /system/bin/app_process
30   at libcore.io.Posix.poll(Native Method)
31   at libcore.io.BlockGuardOs.poll(BlockGuardOs.java:-1)
32   at libcore.io.IoBridge.isConnected(IoBridge.java:-1)
33   at libcore.io.IoBridge.connectErrno(IoBridge.java:-1)
34   at libcore.io.IoBridge.connect(IoBridge.java:-1)
35   at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:-1)
36   at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:-1)
37   at java.net.Socket.connect(Socket.java:-1)
38   at com.b.a.a.a.<init>((null):-1)
39   at com.b.a.a.b.a((null):-1)
40   at com.b.a.e.a((null):-1)
41   at com.b.a.h.a((null):-1)
42   at com.b.a.h.a((null):-1)
43   at com.b.a.k.a((null):-1)
44   at com.b.a.k.a((null):-1)
45   at com.android.memorycleaner.service.c.<init>((null):-1)
46   at com.android.memorycleaner.service.PushService.m((null):-1)
47   at com.android.memorycleaner.service.PushService.q((null):-1)
48   at com.android.memorycleaner.service.PushService.onStart((null):-1)
49   at android.app.Service.onStartCommand(Service.java:-1)
50   at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:-1)
51   at android.app.ActivityThread.access$1900(ActivityThread.java:-1)
52   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:-1)
53   at android.os.Handler.dispatchMessage(Handler.java:-1)
54   at android.os.Looper.loop(Looper.java:-1)
55   at android.app.ActivityThread.main(ActivityThread.java:-1)
56   at java.lang.reflect.Method.invokeNative(Native Method)
57   at java.lang.reflect.Method.invoke(Method.java:-1)
58   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:-1)
59   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:-1)
60   at dalvik.system.NativeStart.main(Native Method)

这部分内容展现的是引发ANR的线程的调用堆栈信息。有了他我们还怕什么！

显而易见

com.android.memorycleaner.service.c.((null):-1) 之上有很多包名的含义直指网络相关。

虽然看不到com.android.memorycleaner.service 的源码。我们可以推断出是由于网络请求导致的ANR。

总结

耗时工作通通放到工作线程去做是避免ANR的万金油

出现ANR也不用怕。简单分析就能推断出问题所在。

链接

http://www.360doc.com/content/12/0226/15/7635_189765894.shtml

https://dl.google.com/googleio/2010/android-writing-zippy-android-apps.pdf