Fixed
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Comments
su...@google.com
ap...@google.com
Can you explain your use case?
su...@google.com
I can explain my one. I have a navhost fragment, where I load a graph with just one instance of a screen of acceptance of terms of use. After the approval of the user I load the real nav graph into the same navhost. According to the documentation The current data of the graph should be reset, so the new Navigation items can be reached. But unfortunately the new items from the graph cannot be reached.
Description
Version used: 1.0.0-alpha06
Devices/Android versions reproduced on: Many
We can see a large number of ConcurrentModificationExceptions in WorkManager:
java.lang.RuntimeException: Error receiving broadcast Intent { act=android.net.conn.CONNECTIVITY_CHANGE flg=0x4000010 bqHint=4 (has extras) } in vu@2406837b
at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:988)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:7007)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199)
Caused by: java.util.ConcurrentModificationException
at java.util.LinkedHashMap$LinkedHashIterator.nextEntry(LinkedHashMap.java:346)
at java.util.LinkedHashMap$KeyIterator.next(LinkedHashMap.java:366)
at androidx.work.impl.constraints.trackers.ConstraintTracker.setState(OperaSrc:89)
at androidx.work.impl.constraints.trackers.NetworkStateTracker$NetworkStateBroadcastReceiver.onReceive(OperaSrc:157)
at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:978)
It looks like the mListeners set is being modified during the loop in ConstraintTracker.setState(). I see two potential issues with this method:
1. Maybe a listener is added or removed in onConstraintChanged(). I haven't seen this happen, but it might be good to make a copy of mListeners and iterate over the copy.
2. The NetworkStateTracker.mNetworkCallback is called on a different thread than the main thread. In consequence setState() is called on a different thread so there is a possibility that the main thread adds or removes a listener. This cannot be the (only) reason because the error happens in response to the CONNECTIVITY_CHANGE.
This may be fixed with synchronization or by registering mNetworkCallback to run on the main thread.