Function mutex_trylock_impl

src/bthread/mutex.cpp:1041–1048

#endif // BRPC_DEBUG_LOCK

inline int mutex_trylock_impl(bthread_mutex_t* m) {
    MutexInternal* split = (MutexInternal*)m->butex;
    if (!split->locked.exchange(1, butil::memory_order_acquire)) {
        BTHREAD_MUTEX_SET_OWNER;
        return 0;
    }
    return EBUSY;
}

const int MAX_SPIN_ITER = 4;