CPSC 321 – Assignment 4: Banker’s Algorithm

University of Northern British Columbia
Course: Operating Systems – Fall 2025
Instructor: Dr. Sajal Saha
Student: Zohaib Rahim
File: assignment4.c

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Overview

This program implements the Banker's Algorithm to determine whether a system state is safe or unsafe.
It accepts the following input:

• Number of customers
• Number of resource types
• Total instances of each resource
• Available resources
• Maximum demand matrix
• Current allocation matrix
• A new resource request

The program computes the Need matrix, runs the Safety Algorithm, and outputs:

• State Safe + safe sequence
• or
• State Unsafe

The formatting and prompts match the assignment specification exactly.

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Concepts Implemented

• Resource allocation model (Available, Maximum, Allocation, Need)
• Safety Algorithm for deadlock avoidance
• Request validation logic
• Dynamic variable-length arrays (C99)
• Modular input helper functions

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File Structure

• Assignment4.c
• Assignment4.exe
• README.md

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How to Compile and Run

Compile

gcc Assignment4.c -o Assignment4

Run

Assignment4.exe

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Program Flow

• Read number of customers and resources
• Read instances, available resources
• Read Maximum matrix
• Read Allocation matrix
• Compute Need = Maximum - Allocation
• Read new resource request
• Execute Safety Algorithm
• Output safe/unsafe result
• If safe, print the safe sequence

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Functions Included

read_array(arr, n)

Reads a 1D array (instances, available, request).

read_matrix(cust, resource, matrix)

Reads a customer-by-resource matrix (maximum, allocation).

compute_need(max, alloc, need)

Computes the Need matrix.

These help reduce repetition while keeping the exact same I/O behavior.