Os Process Management Questions Medium
Deadlock is a situation in which two or more processes are unable to proceed because each is waiting for a resource held by the other. The necessary conditions for deadlock occurrence are as follows:
1. Mutual Exclusion: At least one resource must be held in a non-sharable mode, meaning that only one process can use it at a time. This condition ensures that once a process acquires a resource, no other process can access it until it is released.
2. Hold and Wait: A process must be holding at least one resource while waiting to acquire additional resources. This condition ensures that a process can request resources even if it is currently holding some, leading to potential resource allocation conflicts.
3. No Preemption: Resources cannot be forcibly taken away from a process. Once a process holds a resource, it can only release it voluntarily. This condition ensures that a process cannot be interrupted and have its resources reallocated to other processes.
4. Circular Wait: A circular chain of two or more processes exists, where each process is waiting for a resource held by the next process in the chain. This condition ensures that there is a cycle of dependencies among the processes, leading to a deadlock situation.
If all these conditions are present simultaneously, a deadlock can occur. It is important to note that the absence of any one of these conditions can prevent deadlock from happening. Therefore, to prevent or resolve deadlocks, various techniques such as resource allocation strategies, deadlock detection algorithms, and deadlock avoidance methods are employed in operating systems.