Function update_thread_exception

crates/vm/src/vm/thread.rs:403–411

(exc: Option<PyBaseExceptionRef>)

/// Called from push_exception/pop_exception/set_exception.
#[cfg(feature = "threading")]
pub fn update_thread_exception(exc: Option<PyBaseExceptionRef>) {
    CURRENT_THREAD_SLOT.with(|slot| {
        if let Some(s) = slot.borrow().as_ref() {
            // SAFETY: Called only from the owning thread. The old ref is dropped
            // here on the owning thread, which is safe.
            let _old = unsafe { s.exception.swap(exc) };
        }
    });
}

/// Collect all threads' current exceptions for sys._current_exceptions().
/// Acquires the global registry lock briefly, then reads each slot's exception atomically.