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I have some async/await code that runs well on Mono.Mac and Xamarin.IOS, but consistently crashes on Android. I've attached a piece of sample code that appears to reproduce the bug.
Created attachment 3885 [details]
Some more details I had originally posted to the forums: I have some concurrently network code that makes heavy use of async/await. It runs fine on Xamarin.iOS and Mono.mac. But when I run the code on Xamarin.Android (Version: 4.7.4 (Indie Edition)), I get a SIGSEGV about 7 times out of 10.
Interestingly, there's a particular line of code I've toggled on and off, which should do nothing more than add another network connection into the mix. When the line is enabled, I see the crash frequently, and when it's disabled, I rarely crash at all.
Another curious data point is that right around when the SIGSEGV hits, one of the network tasks faults with a "connection reset by peer". What's interesting is we would be much more likely to encounter this exception on the other network connection, so I was wondering if it was possible for the tasks generated by async/await to be getting their flows mixed up.
I'm unable to easily reproduce on my Nexus 10/Android 4.2.
What target device and Android version are you testing on? Is it armeabi or armeabi-v7a or x86?
> I get a SIGSEGV about 7 times out of 10.
Can you please provide the full logcat output?
> When the line is enabled, I see the crash frequently, and when it's disabled,
> I rarely crash at all.
Which line is this? I don't see anything in the source code that mentions this.
> Another curious data point is that right around when the SIGSEGV hits, one of
> the network tasks faults with a "connection reset by peer".
Is it from the same PID?
The writeup is regarding our app, which is different from the test case I attached. That crash was from the x86 simulator running in non-debug mode. The following is the test case that stably reproduces the crash for us, running on a few devices including Nexus S, under debug mode. We think the debugger has something to do with it, as we can't stably reproduce when running without it.
We've also ruled out async/await as the main culprit here-- we've reduced the test case to run our network connections in tasks and still get the fault.
Created attachment 3903 [details]
Logcat from test case
Created attachment 3904 [details]
Simplified test case
Causes stable crash when the debugger is attached. Test case does not reproduce crash without the debugger.
I"m unable to reproduce the crash in the debugger with 188.8.131.527139499, so I hope/assume that it will be fixed in the next beta release.
I suspect that this is a dup of Bug #11858 (same assert).