Maintaining order and consistency in multi-access data

The problem of controlling simultaneous access to shared data runs throughout the history of computer science. In order to preserve the consistency and integrity of such data, computer scientists and programmers have developed locks, 6 semaphores, 3 the notion of critical sections, 4 , 3 monitors, 5 and innumerable other techniques, both concrete and abstract. The great interest in such mechanisms throughout the computer community, both in the literature and in practice, is indicative of the importance of the problem.