Deadlocks in operating systems
Deadlocks in operating systems Deadlock Introduction In a multiprogramming environment, several processes may compete for limited resources. When a process request resources and if resources are not available, then the process is going to be in the state of “wait state”. If the waiting state is not gonna change again since the resources are held by other waiting processes. It situation is called as “Deadlock”. Resources types: CPU cycles memory I/O devices Each process utilise the resources as follows: Request Use Release Deadlock Characterisation Mutual exclusion : only one process at a time can use a resource Hold and wait : A process holding at least one resource is waiting to acquire additional resources are held by other processes No preemption : A process can be released only voluntarily by the process it holding it, after that process has completed it task Circular wait : there exists a set of processes which are waiting for the resources circularly. Methods for