Mutual Exclusion in Multiprocessor Systems Essay

Mutual Exclusion in Multiprocessor Systems - Essay Example This issue can be resolved by employing an appropriate mutual exclusion of the programs and their resources so that no two programs would request for the same resource if one of them is using it already. Therefore, under many occasions, it is important for the programs to recognise the usage of any of the resources and should provide for resolving the same at the earliest possible opportunity. This paper aims at studying the possible mutual exclusion algorithms that are employed in a uni-processor system and in a multi-processor system. With reference to the execution of a code or a section of a code, these should not be executed by two processes at the same time. They are to be critical code. Assuming that there will be multiple processes running on multiple processors, there could be more than one process requesting for the same resource. It is important for all the requesting processes to allow one process to run at a time. Mutual exclusion algorithms should ideally provide lee-way for the following options: 1. Freedom from deadlock: Locking is the simplest way of avoiding repeat use of critical processes. While locking can be effective for stopping execution of a job, when another one is running, it might not be fool proof. For instance, if process 1 locks a critical section A for its use and it makes use of section B for execution of the section A and suppose process 2 locks section B and for its execution if it needs section A which is locked already by process 1, then a dead lock occurs. (Figure 1). Any successful mutual exclusion should also avoid deadlocking. 2. Freedom from Livelocking: This is a desirable requirement for the algorithms offering the mutual exclusion. This would ensure that there is no permanent lock existing for any process; a corollary of the deadlocking. But it also says that if some process wants to enter a critical section, one such process will enter the critical section. This implies that the one