android-map-utils: Crash in ClusterTask

[claudiofelber]

The ClusterTask doInBackground() method does sometimes crash. It seems that the write lock is released in a different thread than it is being acquired. The internal ReentrantReadWriteLock.tryRelease() method complains that the lock is not being held exclusively. This might have something to do with the fact that the ClusterTask is now running on the thread pool executor.

Environment details

Tested with android-map-utils 1.0.0 on Android API 28.

Steps to reproduce

Execute the cluster() method repeatedly with lots of items.

Stack trace

2020-03-17 13:56:31.860 29075-29148/ch.infoflora.florapp.dev E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #1
    Process: ch.infoflora.florapp.dev, PID: 29075
    java.lang.RuntimeException: An error occurred while executing doInBackground()
        at android.os.AsyncTask$3.done(AsyncTask.java:354)
        at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:383)
        at java.util.concurrent.FutureTask.setException(FutureTask.java:252)
        at java.util.concurrent.FutureTask.run(FutureTask.java:271)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
        at java.lang.Thread.run(Thread.java:764)
     Caused by: java.lang.IllegalMonitorStateException
        at java.util.concurrent.locks.ReentrantReadWriteLock$Sync.tryRelease(ReentrantReadWriteLock.java:373)
        at java.util.concurrent.locks.AbstractQueuedSynchronizer.release(AbstractQueuedSynchronizer.java:1285)
        at java.util.concurrent.locks.ReentrantReadWriteLock$WriteLock.unlock(ReentrantReadWriteLock.java:1138)
        at com.google.maps.android.clustering.algo.AbstractAlgorithm.unlock(AbstractAlgorithm.java:37)
        at com.google.maps.android.clustering.ClusterManager$ClusterTask.doInBackground(ClusterManager.java:297)
        at com.google.maps.android.clustering.ClusterManager$ClusterTask.doInBackground(ClusterManager.java:290)
        at android.os.AsyncTask$2.call(AsyncTask.java:333)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167) 
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641) 
        at java.lang.Thread.run(Thread.java:764) 

[barbeau]

@claudiofelber Thanks for reporting this! We'll take a look.

[barbeau]

@claudiofelber This is new to v1.0.0, right? You didn't see this in previous versions?

[claudiofelber]

Yes, this is the new v1.0.0 release. I did not yet check with one of the previous versions but will do so in a couple of hours.

[barbeau]

@claudiofelber Ok, thanks. Also, how exactly are you producing this? I can't seem to reproduce it with the demo app.

[afluong]

Hi, I think I am facing the same issue that causes crashes with the same kind of context.

Environment details
Tested with android-map-utils 1.3.1 and android-map-utils 1.3.3
On several devices

Steps to reproduce

1. Execute the cluster() method repeatedly with lots of items.
2. If it's not happening on the first launch, kill it and launch it again, the crash happens 1 of 5 kills/launches

Stack Trace

I don't know if I am doing something wrong, but I just :

• first init algorithm (NonHierarchicalViewBasedAlgorithm) and renderer
• then I got an API call with all lat/lng I want to display on map and call the cluster() method to display them.

If you want me to create another issue regarding this, let me know !

[barbeau]

@afluong Thanks for the info! Re-opening. Could you provide an example app that reproduces this? I couldn't get it to reproduce with the demo app.