I recently deprecated the SBHostOS threading functionality (see: ⚙ D153900 [lldb] Deprecate SBHostOS threading functionality).
Reasoning and justification aside, the next logical step is to actually “gut” the implementation and have them do nothing at all. Although we’ve decided to deprecate this functionality, there may be people still relying on it and I don’t want it to be a surprise that the next version of LLDB released has this functionality removed entirely. I’d like to remove the functionality sooner rather than later, but I think it would be fine to wait a release or two to give downstream folks and end-users the ability to migrate away from it.
If we can determine that nobody (or nobody that we can reach) is using this functionality, I will remove it approximately a month after making this post. Due to ABI stability issues, we cannot remove these functions entirely. They will exist as empty shells that do nothing at all.