Fix App does not automatically reconnect to HU after changing language

[zhouxin627]

Fixes #1532

This PR is ready for review.

Risk

This PR makes no API changes.

Testing Plan

Covered by Unit tests.

Summary

Reason

1. There are two threads (ioStreamThread and lifecycleThread) have Proxy object
2. After HU changing language, Proxy's UnregisterApp is invoked
3. Then lifecycleThread's stopManager is invoked
4. set Proxy = nil and then Proxy's reference count will reduce to 0
5. when Proxy's reference count reaches 0，Proxy's dealloc method will be invoked

Normal case：
5.1.1 Proxy's dealloc is invoked in the lifecycleThread
5.1.2 set ioStreamThread's cancel flag true
5.1.3 ioStreamThread exit
5.1.4 close Session
5.1.5 ioStreamThread = nil
5.1.6 create new session successfully

Abnormal case：
5.2.1 Proxy's dealloc is invoked in the ioStreamThread
5.2.2 set ioStreamThread's cancel falg true
5.2.3 ioStreamThread = nil
5.2.4 ioStreamThread exit faild
5.2.5 create new session failed

Solution
Avoid ioStreamThread do expensive operations, so move the methods in the dealloc to the new method of disconnectSession, before set Proxy = nil, execute disconnectSession.

1. There are two threads (ioStreamThread and lifecycleThread) have Proxy object
2. After HU changing language, Proxy's UnregisterApp is invoked
3. Then lifecycleThread's stopManager is invoked
4. Invoke Proxy's disconnectSession method in the lifecycleThread
5. Set ioStreamThread's cancel flag true
6. ioStreamThread exit
7. Close Session
8. ioStreamThread = nil
9. Set Proxy = nil and then Proxy's reference count will reduce to 0
10. When Proxy's reference count reaches 0，Proxy's dealloc method will be invoked
11. Create new session successful
    

CLA

• I have signed the CLA

[joeljfischer]

@zhouxin627 Thanks for the PR. Have you determined if this PR or something similar is needed on Java_Suite?

[zhouxin627]

Hi @joeljfischer, I think there is no need to modify Java_Suite because it can work well.

[joeljfischer]

A few questions:

There are two threads (ioStreamThread and lifecycleThread) have Proxy object

This doesn't seem to be true, only the lifecycle manager has a proxy object.

Proxy's dealloc is invoked in the ioStreamThread

Where does this happen. proxy = nil only occurs in SDLLifecycleManager.sdl_stopManager: that I can find (7 on your "abnormal case" chart).

[zhouxin627]

Hi @joeljfischer

This doesn't seem to be true, only the lifecycle manager has a proxy object.

When the head unit sends data to the phone, the session will transfer data to Proxy, and this
transferring is handled in ioStreamThread.

Where does this happen. proxy = nil only occurs in SDLLifecycleManager.sdl_stopManager: that I can find (7 on your "abnormal case" chart).

The function(proxy = nil) is indeed handled in sdl_stopManager, but the iOS project manages resources with ARC. When ARC works, the time of dealloc and execution thread is based on the release function called by the system, which is used in the case of the count is zero.

The proxy object is owed by ioStreamThread and LlifecycleThread, so the last time releasing will probably happen in the ioStreamThread, and this will cause dealloc to execute in ioStreamThread.

[joeljfischer]

Hello @zhouxin627, are you considering this bug no longer as needing a fix? Are you planning on re-opening this PR?

[zhouxin627]

Hi @joeljfischer, yes, I want to re-opening this PR. It was closed automatically when I revert NSInteger const MAXDATACOUNT = 200;. Now, It is showing No commits yet and Pushing new commits will allow the pull request to be re-opened.. I'm investigating how to deal with it.

[theresalech]

@zhouxin627 can you please confirm if this PR is now ready for Livio's review?

[zhouxin627]

@theresalech Hi, this PR is now ready for review.

[joeljfischer]

Just one small comment for you to alter!