Question

Write a program to model deadlock detection. The program will accept a list of processes, resources, requests, and releases:

A req R A req S A rel R A rel S B req S B req R B rel S B rel R
The program will then examine possible orderings of the resource requests/releases. Orderings within a process cannot be rearranged (so A must always request R before it can request S in the example above), however orderings across processes can be rearranged (B can request S and R before A requests R). Each ordering will be output with a header, the ordering, and an indication if the order causes a deadlock or not

Answer 1

The question requires creating a program to detect deadlocks by examining various orderings of resource requests and releases for a given list of processes. The program must keep the internal order of each process's requests but can rearrange the order of resource allocation between processes to test for deadlocks.

Step-by-step explanation:

The question deals with writing a program for deadlock detection in a system of concurrent processes. This is a concept studied in operating systems, a sub-discipline of computer science. The program should model and check for deadlocks based on resource allocation requests and releases from a set of processes. The solution involves exploring different orderings of requests and releases and determining whether a deadlock occurs.

A possible approach is to create a graph-based representation of processes and resources, then apply a deadlock detection algorithm such as the Banker's Algorithm or build a resource allocation graph to check for cycles. The program then outputs each resource allocation order along with its deadlock status. Here is a conceptual example:

• Initialize request and release sequences for all processes.
• Simulate the allocation and release of resources checking the system's state for deadlocks at each step.
• Output the sequences and indicate whether a deadlock occurs or not.