Android 4.4 KitKat随机崩溃 [英] Android 4.4 KitKat random crash
问题描述
最近，我在为客户开发的应用中发现随机崩溃. 三年后，该应用程序现在已有大约100,000个活跃用户.
I recently discovered random crashes in an app I am developing for a customer. The app has roughly 100.000 active users now after 3 years.
我们已经看到Nexus 4和5在Android 4.4 KitKat上都崩溃了.
We've seen the crash on Nexus 4 and 5, both with Android 4.4 KitKat.
我们无法在运行4.4的Nexus 4和Nexus 5上重现它.
We cannot reproduce it on our own Nexus 4 and 5 running 4.4.
通过我们的支持，我们已经有了一个客户.他告诉我们，每次调用新活动时，崩溃都会在同一位置发生.他在经营Dalvik，而不是ART.重置固件后，该应用程序运行正常，无法再次复制！
We've had a customer through our support. He told us the crash happens every time at the same place when invoking a new activity. He was running Dalvik, not ART. After resetting the firmware the app worked fine and could not reproduce it again!
出于法律原因，我无法发布源代码或布局，但是具有以下堆栈跟踪信息:
I cannot post the source or layout for legal reasons, but have this stacktrace:
java.lang.RuntimeException: Unable to start activity ComponentInfo{xx.xxx.xxxxx.xxx.xxxxxx.prod/xx.xxx.xxxxx.xxx.PaymentsActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2176)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2226)
at android.app.ActivityThread.access$700(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1397)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4998)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
at de.robv.android.xposed.XposedBridge.main(XposedBridge.java:126)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at android.view.View.sendAccessibilityEventUncheckedInternal(View.java:4938)
at android.view.View.sendAccessibilityEventUnchecked(View.java:4919)
at android.view.View$SendViewStateChangedAccessibilityEvent.run(View.java:19433)
at android.view.View$SendViewStateChangedAccessibilityEvent.runOrPost(View.java:19465)
at android.view.View.notifyViewAccessibilityStateChangedIfNeeded(View.java:7265)
at android.view.View.setFlags(View.java:8990)
at android.view.View.setVisibility(View.java:6020)
at android.view.LayoutInflater.parseInclude(LayoutInflater.java:859)
at de.robv.android.xposed.XposedBridge.invokeOriginalMethodNative(Native Method)
at de.robv.android.xposed.XposedBridge.handleHookedMethod(XposedBridge.java:547)
at android.view.LayoutInflater.parseInclude(Native Method)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:745)
at android.view.LayoutInflater.inflate(LayoutInflater.java:492)
at de.robv.android.xposed.XposedBridge.invokeOriginalMethodNative(Native Method)
at de.robv.android.xposed.XposedBridge.handleHookedMethod(XposedBridge.java:547)
at android.view.LayoutInflater.inflate(Native Method)
at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:290)
at android.app.Activity.setContentView(Activity.java:1928)
at xx.xxx.xxxxx.xxx.StandardActivity.setContentView(StandardActivity.java:289)
at xx.xxx.xxxxx.xxx.PaymentsActivity.onCreate(PaymentsActivity.java:61)
at android.app.Activity.performCreate(Activity.java:5243)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2140)
... 12 more
第二个没有xposed的堆栈跟踪
Second stacktrace without xposed
java.lang.RuntimeException: Unable to start activity ComponentInfo{xx.xxx.xxxxx.xxx.xxxxx.prod/xx.xxx.xxxxx.xxx.PaymentsActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2176)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2226)
at android.app.ActivityThread.access$700(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1397)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4998)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at android.view.View.sendAccessibilityEventUncheckedInternal(View.java:4938)
at android.view.View.sendAccessibilityEventUnchecked(View.java:4919)
at android.view.View$SendViewStateChangedAccessibilityEvent.run(View.java:19433)
at android.view.View$SendViewStateChangedAccessibilityEvent.runOrPost(View.java:19465)
at android.view.View.notifyViewAccessibilityStateChangedIfNeeded(View.java:7265)
at android.view.View.setFlags(View.java:8990)
at android.view.View.setVisibility(View.java:6020)
at android.view.LayoutInflater.parseInclude(LayoutInflater.java:859)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:745)
at android.view.LayoutInflater.inflate(LayoutInflater.java:492)
at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:290)
at android.app.Activity.setContentView(Activity.java:1928)
at xx.xxx.xxxxx.xxx.StandardActivity.setContentView(StandardActivity.java:289)
at xx.xxx.xxxxx.xxx.PaymentsActivity.onCreate(PaymentsActivity.java:61)
at android.app.Activity.performCreate(Activity.java:5243)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2140)
... 11 more
在setContentView()中设置的布局包含框架，否则它非常标准和普通.
The layout being set in setContentView() contains frames, else it's pretty standard and plain.
任何输入均受到高度赞赏:-)
Any input is highly appreciated :-)
推荐答案
我也遇到了我要维护的某些代码的相同问题.通过在辅助功能选项中启用话语提示"，我能够始终如一地复制该错误.
I've also run into this same problem with some code I was maintaining. I was able to consistently replicate the bug by enabling TalkBack in the accessibility options.
首先，这是View.java中的方法，其中使用了导致崩溃的空引用(来自Android的KitKat版本)
First, here's the method from View.java where the null reference that caused the crash was used, from the KitKat release of Android:
void sendAccessibilityEventUncheckedInternal(AccessibilityEvent event) {
if (!isShown()) {
return;
}
onInitializeAccessibilityEvent(event);
// Only a subset of accessibility events populates text content.
if ((event.getEventType() & POPULATING_ACCESSIBILITY_EVENT_TYPES) != 0) {
dispatchPopulateAccessibilityEvent(event);
}
// In the beginning we called #isShown(), so we know that getParent() is not null.
getParent().requestSendAccessibilityEvent(this, event);
}
对我来说，根本原因是一个自定义View，它像下面这样覆盖了View.isShown():
For me, the root cause turned out to be a custom View which had overridden View.isShown() like so:
public boolean isShown(){
return someCondition;
}
这意味着sendAccessibilityEventUncheckedInternal将继续运行if(！isShown())进行的if(！isShown())检查，即使View的父级为空，也会导致崩溃.
This meant that sendAccessibilityEventUncheckedInternal would run past the if(!isShown()) check that it makes before proceeding even when the View had a null parent, and so caused the crash.
我本来以为这是一个并发问题，因为我假设isShown()检查确保了父级不为null，并且在执行sendAccessibilityEventUncheckedInternal的过程中更改了对视图父级的引用.错了！
I had originally thought it was a concurrency problem, because I assumed the isShown() check had ensured the parent wasn't null and that the reference to the View's parent had been changed during the execution of sendAccessibilityEventUncheckedInternal. Wrong!
如果您发现类似的问题，尤其是在您未编写的代码中，则可以通过包含超类的isShown()的结果(假设您在View的直接子类中更改代码)来轻松避免此崩溃:
If you find a similar problem, especially in code you didn't write, you can prevent this crash pretty easily by including the result of the superclass's isShown() (assuming you are changing code in a direct subClass of View):
public boolean isShown(){
return super.isShown() && someCondition;
}
这篇关于Android 4.4 KitKat随机崩溃的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
