OS2: Deadlocks-Unit 1: Deadlock Characterization

In a multiprogramming environment, several processes may compete for a finite number of resources. A process requests resources; if the resources are not available, at that time, the process enters a wait state. Waiting processes may never again change state, because the resources they have requested are held by other waiting processes. This situation is called deadlock. We have already mentioned this briefly in module 4 in connection with semaphores. In this module, you will be taken through methods that an operating system can use to prevent or deal with deadlocks Objectives At the end of this unit, you should be able to: Define deadlock State the necessary conditions for deadlock to occur Describe Resource-Allocation graph Explain how it can be used to describe deadlocks Describe some of the methods for handling deadlocks.