**[Sphinx Review — MEDIUM]** Lines 311–313 (`__pthread_unregister_cancel`, `sigaction` restore, `ProfiledThread::release()`) are unreachable dead code. The `while(true)` loop above only exits via `pthread_testcancel()` triggering cancellation, which longjmps to the setjmp handler block at line 295 — the normal-return path can never reach line 311.

[zhengyu123]

@DataDog fix this