[Lldb-commits] [lldb] [lldb] Unify thread detaching by making HostThreadPosix override Reset() (PR #179470)

[Brian Cain via lldb-commits]

androm3da wrote:

Could this PR (which landed quite a while ago) be related to recent premerge builder failures?

Speculating wildly....

In HostThreadPosix::Join()
1. pthread_join(m_thread) is called -- this consumes the thread handle                           
2. Then Reset() is called
3. Reset() sees IsJoinable() returns true (because m_thread hasn't been cleared yet)                     
4. It calls pthread_detach(m_thread) on an already-joined thread -- is this UB?

https://github.com/llvm/llvm-project/pull/179470