Page 124 - Computer_Science_F5

Exercise 2.9

1. Imagine a multithreaded program downloading a large file (Thread A) and
performing a complex mathematical calculation (Thread B) concurrently. How
might data dependencies between these threads impact their execution? Explain
your answer.
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2. Imagine you have a program that involves a large number of independent tasks. Chapter Two: Performance and optimisation of computer processor
Discuss the potential advantages and disadvantages of using SMT versus a
multi-core processor with separate processes for each task.

3. Modern operating systems employ scheduling algorithms to manage threads
and processes. Research different scheduling algorithms used for multithreading
and explain how they impact performance and resource utilisation.
4. Imagine a single CPU core with SMT that supports two logical cores. The
program has two threads:
# Thread 1 (Print Numbers)
def print_numbers():
for i in range(1, 6):
print(i)
# Thread 2 (Calculate Factorial)
def calculate_factorial(n):
result = 1
for i in range(1, n + 1):
result *= i
print(f”Factorial of {n} is: {result}”)
# Main Program
start_thread(print_numbers) # Start thread to print numbers 1-5
start_thread(calculate_factorial, 5) # Start thread to calculate facto
rial of 5

# Wait for threads to finish (pseudocode)
wait_for_threads()
(a) Explain the expected output of the program. In what order will the
numbers be printed (from Thread 1) and the factorial result (from
Thread 2) be displayed?
(b) Imagine running this program with a single thread instead of two. How
might the output and execution order differ?
(c) Considering the scenario above, explain how multithreading can
potentially improve the responsiveness of the program, especially for
a user interacting with it.
(d) While this program demonstrates multithreading, can SMT further
improve its performance within a single core? Explain your reasoning.

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Student’s Book Form Five

Computer Science Form 5.indd 115 23/07/2024 12:33