A hardware or software method of coordinating and/or synchronizing multiple processes in a computer. Such a method can be used, for example, in the situation in which a certain process should not begin until another process is completed. A common interlock method uses flags to do this. Another typical situation is one in which requests for some service, e.g. memory access, arrive simultaneously. A hardware interlock procedure will force the requests to become sequential, usually according to a predefined rule.