Function pthread_spin_trylock 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn pthread_spin_trylock(
    lock: *mut pthread_spinlock_t,
) -> c_int

See https://pubs.opengroup.org/onlinepubs/9799919799/functions/pthread_spin_trylock.html.

Locks the spin lock referenced by lock if it is not held by any thread.

Upon success, returns 0. Upon failure, an error number is returned.

Safety

It is undefined behaviour if lock is uninitialized.