A concurrent object is an object that can be concurrently accessed by several processes. It has been shown by Maurice Herlihy that any concurrent object O defined by a sequential specification can be wait-free implemented from reliable atomic registers (shared variables) and consensus objects. Wait-free means that any invocation of an operation of the object O issued by a non-faulty process does terminate, whatever the behavior of the other processes (e.g., despite the fact they are very slow or even have crashed).