Deadlock Characteristics

In a deadlock process never finish executing and system resources are tied up. A deadlock situation can arise if the following four conditions hold simultaneously in a system.
• Mutual Exclusion: At a time only one process can use the resources. If another process requests that resource, requesting process must wait until the resource has been released.
• Hold and wait: A process must be holding at least one resource and waiting to additional resource that is currently held by other processes.
• No Preemption: Resources allocated to a process can’t be forcibly taken out from it unless it releases that resource after completing the task.
• Circular Wait: A set {P0, P1 , …….Pn} of waiting state/ process must exists such that P0 is waiting for a resource that is held by P1, P1 is waiting for the resource that is held by P2 …..P(n – 1) is waiting for the resource that is held by Pn and Pn is waiting for the resources that is held by P4