Static TRY_LOCK_FAILURE_COUNT 

pub static TRY_LOCK_FAILURE_COUNT: AtomicU64

Total number of try_lock() calls that returned Err (lock contended) across all call sites in the application. Incremented via record_try_lock_failure.

Deliberately a module-level static so it is zero-cost when the counter is never read — the increment itself is a single fetch_add(Relaxed).