ReactiveX
group_by with not completed observable issue
I found an potential issue with flat_map operation when source the is a scoped observable using a factory holding a shared pointer.
In this case my shared pointer is not released after the last unsubscribe of the observable returned by flat_map.
I didn't succeed to produce a minimal example that trigger this issue, but a quick and dirty hack seems to solve the issue:
if I "reset" the state_type source (which is manly not used):
this->source = source_type();
my smart pointer is released when I unsubscribe.
Maybe this is an issue on my side, but I go many times through my code, I don't see the issue
Hard to say without specific repro, but I would assume that something has stored the flat_map. the source must stay valid while the flat_map observable exists because it has to assume that subscribe might be called again.
The source is still valid in the initial variable. I will try harder to create minimal example
Here the issue: https://gist.github.com/diorcety/4cbded6fd3583ae001ebc9cf1d3e409d
Commented on_completed:
Hello, World!
Abcd
Value: 0
Value: 20
Unsubscribe
End of World!
Uncommented
Hello, World!
Abcd
Value: 0
Value: 20
~Abcd
Unsubscribe
End of World!
In both case at the unsubscribe, the hook (held by the lambda) should be released. Because there is no link to the observable anymore
this is probably a bug in the lifetime - possibly introduced by (https://github.com/Reactive-Extensions/RxCpp/commit/8065a799545f6541f2ef95f38c2743bc92c54c8b#diff-9430ecceb5eeb688548de212b7fd57be)
Pure speculation, but it may be similar to the bug in window_toggle fixed here (https://github.com/Reactive-Extensions/RxCpp/commit/b41b15f1daf97519433742ff86adad9d0ae8acdd)
I will add this to the backlog - thank you for the report!
as a workaround until this bug is fixed, adding a take_until before the group_by where the trigger parameter was a subject whose on_next was called each time the cancellation was desired should complete the stream cleanly.