ShakaPlayer.getUiInfo possibly causing a crash

okycelt commented 4 years ago

Issue description

Calling ShakaPlayer.getUiInfo(block: (ShakaPlayerUiInfo) -> Void) some time during ViewController's life cycle leads to a crash after dismissing that ViewController. Originally, we thought it's related to calling that method within a Timer's block, but it's enough to call it e.g. in viewDidAppear(). This is what we're seeing in the logs:

...
[Info]: "Preparing to destroy walker..."
[INFO:/var/lib/jenkins/workspace/CDM_Arxan_Create_Release/oemcrypto-arxan/third_party/cdm/core/src/cdm_engine.cpp(198):CloseSession] CdmEngine::CloseSession: ksid24CA12AA
libc++abi.dylib: terminating with uncaught exception of type std::__1::system_error: thread::join failed: Resource deadlock avoided

If we don't call ShakaPlayer.getUiInfo(), we don't get any crash
It happens for both live and static DASH, including a random test asset from the sample app we've tried
We're not able to reproduce the issue using the sample app
We tried to dispose of ShakaPlayer exactly the same way as in the sample app, but we're getting the crash either way (The only difference is that our app is written in Swift, not Objective-C)
We thought it might be related to some changes addressing #64, but we're able to reproduce the issue with a previous commit as well

Reproduction steps

Present a ViewController with player
Start playback
Call ShakaPlayer.getUiInfo(block: (ShakaPlayerUiInfo) -> Void)
Dismiss the ViewController
It should crash in about 10-20 seconds

Version of Shaka Player Embedded

6b8337553f045005d5d6908725c680de84d62f9e (at this moment latest master) a8acedfa8152e341d97a2d3829c182b3e80c407a

Device(s) and version(s) of iOS being used

iPhone XR with iOS 13.4.1 Simulator with iOS 13.4

TheModMaker commented 4 years ago

Could you get a stack trace with debug symbols? It also says it is due to a deadlock, could you get stack traces for other threads too? The important ones would be the "Thread 1" and the "JS Main Thread", but other threads may be involved too.

okycelt commented 4 years ago

Here's the backtrace of all threads: 134_bt_all.txt

shaka-project / shaka-player-embedded