Codecov Report

Merging #407 (23668af) into develop (4372862) will increase coverage by 0.11%.
The diff coverage is 63.15%.

@@             Coverage Diff             @@
##           develop     #407      +/-   ##
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+ Coverage    51.29%   51.40%   +0.11%     
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  Files          423      423              
  Lines        13439    13444       +5     
===========================================
+ Hits          6893     6911      +18     
+ Misses        6546     6533      -13     

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Since I had to play in LinkContext, I made a fix for #396. This would replace #395. Instead of owning the shared_ptr in the callbacks and waiting in the destructor for them to release, the callbacks instead own a weak_ptr and checks that it's still valid (the shared_ptr automatically gets destroyed in the LinkContext default destructor).

As noted by Nicholas Lee, even with the original fix, the keep-alive timers were internally expiring early, just to restart a very short timer afterwards. This was caused by how we used to drive the keep-alive timer. It was not restarted on every link activity, we were just waiting for the old one to expire and then we were re-calculating a new timer based on the recorded last link activity. I made the change to simply restart the timer on every link activity, I think it's cleaner.

As for the LinkContext lifetime issue, I ended up superseding #435 by simply having the LinkContext be shared_from_this. Shutdown is properly done in the OnLowerLayerDown and checked in the callbacks. I also found that MContext could possibly have a similar issue (if a shutdown occurs while waiting for a response), so I applied the same fix. Shutdown is also properly checked.