Android - 我如何调查 ANR？

小编典典

Android - 我如何调查 ANR？

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有没有办法找出我的应用程序在哪里抛出了 ANR（应用程序无响应）。我查看了 /data 中的 traces.txt
文件，并看到了我的应用程序的跟踪。这就是我在跟踪中看到的。

DALVIK THREADS:
"main" prio=5 tid=3 TIMED_WAIT
  | group="main" sCount=1 dsCount=0 s=0 obj=0x400143a8
  | sysTid=691 nice=0 sched=0/0 handle=-1091117924
  at java.lang.Object.wait(Native Method)
  - waiting on <0x1cd570> (a android.os.MessageQueue)
  at java.lang.Object.wait(Object.java:195)
  at android.os.MessageQueue.next(MessageQueue.java:144)
  at android.os.Looper.loop(Looper.java:110)
  at android.app.ActivityThread.main(ActivityThread.java:3742)
  at java.lang.reflect.Method.invokeNative(Native Method)
  at java.lang.reflect.Method.invoke(Method.java:515)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:739)
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:497)
  at dalvik.system.NativeStart.main(Native Method)

"Binder Thread #3" prio=5 tid=15 NATIVE
  | group="main" sCount=1 dsCount=0 s=0 obj=0x434e7758
  | sysTid=734 nice=0 sched=0/0 handle=1733632
  at dalvik.system.NativeStart.run(Native Method)

"Binder Thread #2" prio=5 tid=13 NATIVE
  | group="main" sCount=1 dsCount=0 s=0 obj=0x433af808
  | sysTid=696 nice=0 sched=0/0 handle=1369840
  at dalvik.system.NativeStart.run(Native Method)

"Binder Thread #1" prio=5 tid=11 NATIVE
  | group="main" sCount=1 dsCount=0 s=0 obj=0x433aca10
  | sysTid=695 nice=0 sched=0/0 handle=1367448
  at dalvik.system.NativeStart.run(Native Method)

"JDWP" daemon prio=5 tid=9 VMWAIT
  | group="system" sCount=1 dsCount=0 s=0 obj=0x433ac2a0
  | sysTid=694 nice=0 sched=0/0 handle=1367136
  at dalvik.system.NativeStart.run(Native Method)

"Signal Catcher" daemon prio=5 tid=7 RUNNABLE
  | group="system" sCount=0 dsCount=0 s=0 obj=0x433ac1e8
  | sysTid=693 nice=0 sched=0/0 handle=1366712
  at dalvik.system.NativeStart.run(Native Method)

"HeapWorker" daemon prio=5 tid=5 VMWAIT
  | group="system" sCount=1 dsCount=0 s=0 obj=0x4253ef88
  | sysTid=692 nice=0 sched=0/0 handle=1366472
  at dalvik.system.NativeStart.run(Native Method)

----- end 691 -----

我怎样才能找出问题出在哪里？trace 中的方法都是 SDK 方法。

阅读 183

2022-08-24

共1个答案

小编典典

当“主”线程中发生一些长时间的操作时，就会发生 ANR。这是事件循环线程，如果它很忙，Android 将无法在应用程序中处理任何进一步的 GUI
事件，从而引发 ANR 对话框。

现在，在您发布的跟踪中，主线程似乎运行良好，没有问题。它在 MessageQueue 中空闲，等待另一条消息进来。在您的情况下，ANR
可能是一个更长的操作，而不是永久阻塞线程的东西，因此事件线程在操作完成后恢复，并且您的跟踪通过了在 ANR 之后。

Detecting where ANRs happen is easy if it is a permanent block (deadlock
acquiring some locks for instance), but harder if it’s just a temporary delay.
First, go over your code and look for vunerable spots and long running
operations. Examples may include using sockets, locks, thread sleeps, and
other blocking operations from within the event thread. You should make sure
these all happen in separate threads. If nothing seems the problem, use DDMS
and enable the thread view. This shows all the threads in your application
similar to the trace you have. Reproduce the ANR, and refresh the main thread
at the same time. That should show you precisely whats going on at the time of
the ANR

2022-08-24