Transaction deadlock when combining suspend DAO functions and beginTransaction() [120854786]

Fixed

Bug

Status Update

No update yet.

Description

da...@google.com

created issue #1

Dec 11, 2018 08:45PM

A query performed in a suspend function might deadlock if the suspend function invocation was done after a transaction was started. For example:

withContext(Dispatchers.Default) {
db.beginTransaction()
db.insert(data) // DAO suspend function
db.update(anotherData) // DAO suspend function
db.setTransactionSuccessful()
db.endTransaction()
}

This can deadlock because transaction are exclusive and are ThreadLocal, meaning once a transaction is started in a thread form the default dispatcher, another coroutine dispatcher thread will get blocked even if we are within the same coroutine.

Comments

ia...@gmail.com <ia...@gmail.com> #2Dec 11, 2018 09:15PM

Have same problem

yb...@google.com <yb...@google.com> Dec 13, 2018 06:15PM

Reassigned to yb...@google.com.

yb...@google.com <yb...@google.com> #3Dec 14, 2018 08:21PM

Reassigned to da...@google.com.

java.util.ConcurrentModificationException
at java.util.WeakHashMap$HashIterator.next(WeakHashMap.java:165)
at androidx.work.impl.utils.WakeLocks.checkWakeLocks(WakeLocks.java:70)
at androidx.work.impl.background.systemalarm.SystemAlarmService.onAllCommandsCompleted(SystemAlarmService.java:69)
at androidx.work.impl.background.systemalarm.SystemAlarmDispatcher.dequeueAndCheckForCompletion(SystemAlarmDispatcher.java:217)
at androidx.work.impl.background.systemalarm.SystemAlarmDispatcher$DequeueAndCheckForCompletion.run(SystemAlarmDispatcher.java:317)
at android.os.Handler.handleCallback(Handler.java:615)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4960)
at java.lang.reflect.Method.invokeNative(Method.java)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805)
at dalvik.system.NativeStart.main(NativeStart.java)

yb...@google.com <yb...@google.com> #4Dec 14, 2018 08:21PM

https://android-review.googlesource.com/c/platform/frameworks/support/+/857873

ia...@gmail.com <ia...@gmail.com> #5Dec 14, 2018 08:38PM

Will this be released in the next beta? Thanks

yb...@google.com <yb...@google.com> #6Dec 14, 2018 10:34PM

Yes, it will.

ap...@google.com <ap...@google.com> #7Feb 26, 2019 11:06PM

Seems like it's still not fixed:

Fatal Exception: java.util.ConcurrentModificationException
at java.util.WeakHashMap$HashIterator.next(WeakHashMap.java:165)
at androidx.work.impl.utils.WakeLocks.checkWakeLocks(WakeLocks.java:78)
at androidx.work.impl.background.systemalarm.SystemAlarmService.onAllCommandsCompleted(SystemAlarmService.java:69)
at androidx.work.impl.background.systemalarm.SystemAlarmDispatcher.dequeueAndCheckForCompletion(SystemAlarmDispatcher.java:217)
at androidx.work.impl.background.systemalarm.SystemAlarmDispatcher$DequeueAndCheckForCompletion.run(SystemAlarmDispatcher.java:317)
at android.os.Handler.handleCallback(Handler.java:810)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:189)
at android.app.ActivityThread.main(ActivityThread.java:5532)
at java.lang.reflect.Method.invoke(Method.java)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:950)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:745)

ap...@google.com <ap...@google.com> #8Feb 26, 2019 11:08PM

Still happened on beta02, Android 5.0.2

da...@google.com <da...@google.com> Feb 26, 2019 11:11PM

Marked as fixed.