Question

获取大量ANR报告，

“main”prio = 5 tid = 1 Runnable | group =“main”sCount = 0 dsCount = 0 flags = 0 obj = 0x72e8a568 self = 0xe65da000 | sysTid = 20592 nice = 0 cgrp =默认sched = 0/0 handle = 0xe9f6b4a8 | state = R schedstat =（35792446568 9751828904 97371）utm = 2328 stm = 1249 core = 2 HZ = 100 | stack = 0xff6e5000-0xff6e7000 stackSize = 8MB |持有互斥锁=“mutator lock”（共享持有） native：pc 00000000002c45b7 /system/lib/libart.so（_ZN3art15DumpNativeStackERNSt3__113basic_ostreamIcNS0_11char_traitsIcEEEEiP12BacktraceMapPKcPNS_9ArtMethodEPv + 130） native：pc 0000000000355a83 /system/lib/libart.so（_ZNK3art6Thread9DumpStackERNSt3__113basic_ostreamIcNS1_11char_traitsIcEEEEbP12BacktraceMapb + 202） native：pc 0000000000351f67 /system/lib/libart.so（_ZNK3art6Thread4DumpERNSt3__113basic_ostreamIcNS1_11char_traitsIcEEEEbP12BacktraceMapb + 34） native：pc 00000000003698df /system/lib/libart.so（_ZN3art14DumpCheckpoint3RunEPNS_6ThreadE + 654） native：pc 000000000035662b /system/lib/libart.so（_ZN3art6Thread21RunCheckpointFunctionEv + 298） native：pc 00000000003bbcff /system/lib/libart.so(__ZN3art16JniMethodFastEndEjPNS_6ThreadE + 46） native：pc 0000000000403fdb /system/framework/arm/boot-framework.oat （Java_android_os_Parcel_nativeReadInt__J + 114）在android.os.Parcel.nativeReadInt（Native方法）在android.os.Parcel.readInt（Parcel.java:1966）在android.os.Parcel.readExceptionCode（Parcel.java:1906）在android.os.Parcel.readException（Parcel.java:1885）在android.accessibilityservice.IAccessibilityServiceConnection $ Stub $ Proxy.findAccessibilityNodeInfoByAccessibilityId （IAccessibilityServiceConnection.java:447）在android.view.accessibility.AccessibilityInteractionClient.findAccessibilityNodeInfoByAccessibilityId （AccessibilityInteractionClient.java:286）在android.view.accessibility.AccessibilityNodeInfo.getChild（AccessibilityNodeInfo.java:959） at MyAccessibilityService.traverseNode（MyAccessibilityService.java:94） at MyAccessibilityService.traverseNode（MyAccessibilityService.java:100） at MyAccessibilityService.traverseNode（MyAccessibilityService.java:100） at MyAccessibilityService.traverseNode（MyAccessibilityService.java:100） at MyAccessibilityService.collectTextNodes（MyAccessibilityService.java:69） at MyAccessibilityService.onAccessibilityEvent（MyAccessibilityService.java:384）在android.accessibilityservice.AccessibilityService $ 2.onAccessibilityEvent （AccessibilityService.java:1527）在android.accessibilityservice.AccessibilityService $ IAccessibilityServiceClientWrapper.executeMessage （AccessibilityService.java:1712）在com.android.internal.os.HandlerCaller $ MyHandler.handleMessage （HandlerCaller.java:37）

    "main" prio=5 tid=1 Native
      | group="main" sCount=1 dsCount=0 flags=1 obj=0x72e8a568 self=0xe65da000
      | sysTid=11518 nice=0 cgrp=default sched=0/0 handle=0xe9f6b4a8
      | state=S schedstat=( 34572861602 18459176949 199877 ) utm=2350 stm=1106 core=1 HZ=100
      | stack=0xff6e5000-0xff6e7000 stackSize=8MB
      | held mutexes=
      native: pc 0000000000018dac  /system/lib/libc.so (syscall+28)
      native: pc 00000000000b3729  /system/lib/libart.so (_ZN3art17ConditionVariable16WaitHoldingLocksEPNS_6ThreadE+88)
      native: pc 00000000003bbbe3  /system/lib/libart.so (_ZN3artL12GoToRunnableEPNS_6ThreadE+306)
      native: pc 00000000003bba81  /system/lib/libart.so (_ZN3art12JniMethodEndEjPNS_6ThreadE+8)
      native: pc 00000000007ca401  /system/framework/arm/boot-framework.oat (Java_android_os_BinderProxy_transactNative__ILandroid_os_Parcel_2Landroid_os_Parcel_2I+144)
      at android.os.BinderProxy.transactNative (Native method)
      at android.os.BinderProxy.transact (Binder.java:748)
      at android.accessibilityservice.IAccessibilityServiceConnection$Stub$Proxy.findAccessibilityNodeInfoByAccessibilityId (IAccessibilityServiceConnection.java:446)
      at android.view.accessibility.AccessibilityInteractionClient.findAccessibilityNodeInfoByAccessibilityId (AccessibilityInteractionClient.java:286)
      at android.view.accessibility.AccessibilityNodeInfo.getChild (AccessibilityNodeInfo.java:959)
      at MyAccessibilityService.traverseNode (MyAccessibilityService.java:94)
      at MyAccessibilityService.traverseNode (MyAccessibilityService.java:100)
      at MyAccessibilityService.traverseNode (MyAccessibilityService.java:100)
      at MyAccessibilityService.traverseNode (MyAccessibilityService.java:100)
      at MyAccessibilityService.collectTextNodes (MyAccessibilityService.java:69)
      at MyAccessibilityService.onAccessibilityEvent (MyAccessibilityService.java:384)
      at android.accessibilityservice.AccessibilityService$2.onAccessibilityEvent (AccessibilityService.java:1527)
      at android.accessibilityservice.AccessibilityService$IAccessibilityServiceClientWrapper.executeMessage (AccessibilityService.java:1712)
      at com.android.internal.os.HandlerCaller$MyHandler.handleMessage (HandlerCaller.java:37)
      at android.os.Handler.dispatchMessage (Handler.java:105)


    "main" prio=5 tid=1 Runnable
      | group="main" sCount=0 dsCount=0 flags=0 obj=0x73bf7568 self=0xe7445000
      | sysTid=18941 nice=0 cgrp=default sched=0/0 handle=0xeae2e4a8
      | state=R schedstat=( 169234820933 190791369297 635928 ) utm=11752 stm=5170 core=0 HZ=100
      | stack=0xff795000-0xff797000 stackSize=8MB
      | held mutexes= "mutator lock"(shared held)
      at java.util.ArrayList.clear (ArrayList.java:565)
      at android.view.accessibility.AccessibilityNodeInfo.init (AccessibilityNodeInfo.java:3211)
      at android.view.accessibility.AccessibilityNodeInfo.obtain (AccessibilityNodeInfo.java:3015)
      at android.view.accessibility.AccessibilityCache.getNode (AccessibilityCache.java:231)
    - locked <0x0f41ae94> (a java.lang.Object)
      at android.view.accessibility.AccessibilityInteractionClient.findAccessibilityNodeInfoByAccessibilityId (AccessibilityInteractionClient.java:272)
      at android.view.accessibility.AccessibilityNodeInfo.getChild (AccessibilityNodeInfo.java:959)
      at MyAccessibilityService.traverseNode (MyAccessibilityService.java:84)
      at MyAccessibilityService.traverseNode (MyAccessibilityService.java:85)
      at MyAccessibilityService.traverseNode (MyAccessibilityService.java:85)
      at MyAccessibilityService.traverseNode (MyAccessibilityService.java:85)
      at MyAccessibilityService.collectTextNodes (MyAccessibilityService.java:66)
      at MyAccessibilityService.onAccessibilityEvent (MyAccessibilityService.java:360)
      at android.accessibilityservice.AccessibilityService$2.onAccessibilityEvent (AccessibilityService.java:1527)
      at android.accessibilityservice.AccessibilityService$IAccessibilityServiceClientWrapper.executeMessage (AccessibilityService.java:1712)
      at com.android.internal.os.HandlerCaller$MyHandler.handleMessage (HandlerCaller.java:37)
      at android.os.Handler.dispatchMessage (Handler.java:105)

"main" prio=5 tid=1 TimedWaiting
  | group="main" sCount=1 dsCount=0 flags=1 obj=0x73228568 self=0xed55a000
  | sysTid=19996 nice=0 cgrp=default sched=0/0 handle=0xed8414a8
  | state=S schedstat=( 39022541552 53623486893 130046 ) utm=3252 stm=648 core=2 HZ=100
  | stack=0xff636000-0xff638000 stackSize=8MB
  | held mutexes=
  at java.lang.Object.wait (Native method)
- waiting on <0x0b44b730> (a java.lang.Object)
  at java.lang.Object.wait (Object.java:422)
  at android.view.accessibility.AccessibilityInteractionClient.waitForResultTimedLocked (AccessibilityInteractionClient.java:687)
  at android.view.accessibility.AccessibilityInteractionClient.getFindAccessibilityNodeInfosResultAndClear (AccessibilityInteractionClient.java:582)
- locked <0x0b44b730> (a java.lang.Object)
  at android.view.accessibility.AccessibilityInteractionClient.findAccessibilityNodeInfoByAccessibilityId (AccessibilityInteractionClient.java:291)
  at android.view.accessibility.AccessibilityInteractionClient.getRootInActiveWindow (AccessibilityInteractionClient.java:160)
  at android.accessibilityservice.AccessibilityService.getRootInActiveWindow (AccessibilityService.java:572)
  at MyAccessibilityService.onAccessibilityEvent (MyAccessibilityService.java:370)

我的代码

ArrayList<AccessibilityNodeInfo> collectNodes(AccessibilityNodeInfo node) {

    ArrayList<AccessibilityNodeInfo> nodeInfoArrayList = new ArrayList<>();
    try {
        int childCount = node.getChildCount();
        for (int index = 0; index < childCount; index++) {
            AccessibilityNodeInfo childNode = node.getChild(index);


            traverseNode(childNode);
            if (childNodes != null && childNodes.size() > 0) {
                nodeInfoArrayList.addAll(childNodes);
                childNodes.clear();
            }
        }
    }
    catch (Exception e){
        e.printStackTrace();
    }
    return nodeInfoArrayList;
}

private void traverseNode(AccessibilityNodeInfo node) {
    try {
        AccessibilityNodeInfo edittextNode = null;
        if (null == node)
            return;

        final int count = node.getChildCount();
        if (count > 0) {
            for (int i = 0; i < count; i++) {
                AccessibilityNodeInfo childNode = node.getChild(i);
                if (childNode == null) {
                    node.recycle();
                    return;
                }
                else {
                    traverseNode(childNode);
                }
            }
        } else {

        }
    }
    catch (Exception error){
        error.printStackTrace();
    }
}

Android 8.0中的更多问题。知道如何处理这些ANR。

config.xml文件

<accessibility-service
    xmlns:android="http://schemas.android.com/apk/res/android"

    android:accessibilityEventTypes="typeWindowStateChanged|typeViewFocused|typeWindowContentChanged"

    android:notificationTimeout="100"
    android:canRetrieveWindowContent="true"

    android:accessibilityFeedbackType="feedbackGeneric"
    android:accessibilityFlags="flagReportViewIds|flagRequestEnhancedWebAccessibility"
    android:description="Test"/>

请注意几乎所有来自Android 8.0设备的ANR报告。

Answer 1

第一个重要的事情是回收getChild，findAccessibilityNodeInfoByAccessibilityId或任何其他功能分配的所有节点。所以你应该有这样的东西：

AccessibilityNodeInfo findFirstViewByText(AccessibilityNodeInfo rootNode, String text) {
        if (rootNode == null) return null;
        if (rootNode.getText() != null && rootNode.getText().toString().equals(text))
            return rootNode;
        int childCount = rootNode.getChildCount();
        for (int i = 0; i < childCount; i++) {
            AccessibilityNodeInfo tmpNode = rootNode.getChild(i);
            if (tmpNode != null) {
                AccessibilityNodeInfo res = findFirstViewByText(tmpNode, text);
                if (res != null) {
                    return res;
                } else {
                    tmpNode.recycle();
                }
            }
        }
        return null;
    }
}

node = findFirstViewByText(rootNode, "something");
if(node != null) {
  node.performAction(AccessibilityNodeInfo.ACTION_CLICK);
  node.recycle();
}

请记住，在与目标应用程序交互时，onAccessibilityEvent可能会被调用太频繁，而且此函数中的处理也会阻止目标应用程序上的UI线程。你可以通过以下方式解决这个问题：
- 限制对onAccessibilityEvent的调用，即如果上次执行的时间少于x毫秒，则不执行您的代码，但请确保最后一次调用将触发代码的执行。
- 通过避免不必要的遍历来提高代码的性能。定义状态，以便应用程序仅查找与当前状态相关的节点。
随意分享更多代码，以便我/我们可以了解您的目标究竟是什么，这样我们就可以提供更多帮助。正如我从您的日志中看到的那样，有几个线程遍历可访问性服务的虚拟dom，它们导致死锁。

Answer 2

我非常怀疑你的收集节点逻辑。这是非常愚蠢的。它确实花了我一段时间来确认它正在做我认为它正在做的事情，我仍然不相信，虽然主要是因为有一些你没有分享的类/全局变量，让我不能被100％肯定任何事情。请允许我描述一下我的想法：

CollectNodes：收集给定节点的所有后代，并在列表中返回它们。

因此，鉴于该描述，让我向您展示一个更简单的实现。

public ArrayList<AccessibilityNodeInfo> collectNodes() {
    ArrayList<AccessibilityNodeInfo> results = new ArrayList<>();

    try {
        collectNodes(getRootInActiveWindow(), results);    
    } catch (Exception e) {
        //Handle exceptions, though, if you don't do stupid things exceptions shouldn't happen
    }

    return results;
}

private void collectNodes(AccessibilityNodeInfo nodeInfo, ArrayList<AccessibilityNodeInfo> nodes) {

    if (nodeInfo == null) return;

    if (someFilteringFunctionYouWantToApplyToLimitNodes(nodeInfo)) {
        nodes.add(nodeInfo);
    }

    for (int i = 0; i < nodeInfo.getChildCount(); i++) {
        collectNodes(nodeInfo.getChildAt(i), nodes);
    }
}

现在，让我们谈谈一些事情，实际上我只是从你的实现中删除了一个特定的东西，就是这一行：

node.recycle();

我相信这是导致你出问题的实际行。在您的代码中，您没有创建任何自己的AccessibilityNodeInfo对象。您正在使用的所有对象都属于操作系统为您创建的节点层次结构。应该在某个时间点将这些节点视为应用程序的READ ONLY状态。你正在回收利用并重复使用它们。

由于AccessibilityNodeInfo getChild

2 个答案: