Resource allocation graph in Operating Systems - Mini Project: Build & Apply

Resource Allocation Graph

📖 Scenario: You are learning how operating systems manage resources among processes. A resource allocation graph helps visualize which processes hold or request resources.

🎯 Goal: Create a simple resource allocation graph using a dictionary to represent processes and resources, then identify which processes are waiting for resources.

📋 What You'll Learn

Create a dictionary named graph with processes and resources as keys and their connections as values.

Add a variable named waiting_processes to hold processes that are waiting for resources.

Use a loop to find all processes that have edges pointing to resources they are requesting.

Complete the graph by adding a final key to show all waiting processes.

💡 Why This Matters

🌍 Real World

Resource allocation graphs help operating systems and system administrators understand how processes and resources interact, which is important to avoid deadlocks.

💼 Career

Understanding resource allocation graphs is useful for roles in system administration, software development, and IT support where managing system resources efficiently is critical.

1

Create the resource allocation graph dictionary

Create a dictionary called graph with these exact entries: 'P1': ['R1'], 'P2': ['R2'], 'R1': ['P2'], 'R2': [].

Operating Systems

# Create the resource allocation graph dictionary
# Your code here

Need a hint?

Think of processes as keys with lists of resources they request or hold.

2

Add a list to hold waiting processes

Create an empty list called waiting_processes to store processes that are waiting for resources.

Operating Systems

graph = {'P1': ['R1'], 'P2': ['R2'], 'R1': ['P2'], 'R2': []}
# Create an empty list called waiting_processes
# Your code here

Need a hint?

This list will collect processes that are waiting for resources.

3

Find processes waiting for resources

Use a for loop with variables process and resources to iterate over graph.items(). Inside the loop, if process starts with 'P' and resources is not empty, append process to waiting_processes.

Operating Systems

graph = {'P1': ['R1'], 'P2': ['R2'], 'R1': ['P2'], 'R2': []}
waiting_processes = []
for process, resources in graph.items():
    # Check if process is waiting
    # Your code here

Need a hint?

Processes that have a non-empty list of resources are waiting.

4

Add waiting processes to the graph

Add a new key 'Waiting' to the graph dictionary with the value waiting_processes.

Operating Systems

graph = {'P1': ['R1'], 'P2': ['R2'], 'R1': ['P2'], 'R2': []}
waiting_processes = []
for process, resources in graph.items():
    if process.startswith('P') and resources:
        waiting_processes.append(process)
# Add 'Waiting' key to graph
# Your code here

Need a hint?

This final step adds the list of waiting processes to the graph for easy reference.