"In computer science, the dining philosophers problem is an illustrative example of a common computing problem in concurrency. It is a classic multi-process synchronization problem, and is included in nearly all university-level computer science curricula. In 1971, Edsger Dijkstra set an examination question on a synchronization problem where five computers competed for access to five shared tape drive peripherals. Soon afterwards the problem was retold by Tony Hoare as the dining philosophers problem. This is a theoretical explanation of deadlock and resource starvation by assuming that each philosopher takes a different fork as a first priority and then looks for another." "The philosophers never speak to each other, which creates a dangerous possibility of deadlock when every philosopher holds a left fork and waits perpetually for a right fork (or vice versa). Originally used as a means of illustrating the problem of deadlock, this system reaches deadlock when there is a 'cycle of unwarranted requests'. In this case philosopher P1 waits for the fork grabbed by philosopher P2 who is waiting for the fork of philosopher P3 and so forth, making a circular chain. Starvation (and the pun was intended in the original problem description) might also occur independently of deadlock if a philosopher is unable to acquire both forks due to a timing issue. For example there might be a rule that the philosophers put down a fork after waiting five minutes for the other fork to become available and wait a further five minutes before making their next attempt. This scheme eliminates the possibility of deadlock (the system can always advance to a different state) but still suffers from the problem of livelock. If all five philosophers appear in the dining room at exactly the same time and each picks up their left fork at the same time the philosophers will wait five minutes until they all put their forks down and then wait a further five minutes before they all pick them up again. The lack of available forks is an analogy to the locking of shared resources in real computer programming, a situation known as concurrency. Locking a resource is a common technique to ensure the resource is accessed by only one program or chunk of code at a time. When the resource a program is interested in is already locked by another one, the program waits until it is unlocked. When several programs are involved in locking resources, deadlock might happen, depending on the circumstances. For example, one program needs two files to process. When two such programs lock one file each, both programs wait for the other one to unlock the other file, which will never happen. In general the dining philosophers problem is a generic and abstract problem used for explaining various issues which arise in problems which hold mutual exclusion as a core idea. For example, as in the above case deadlock/livelock is well explained with the dining philosophers problem." Source and further information: http://en.wikipedia.org/wiki/Dining_philosophers