Process forking for parallelism in Ruby - Mini Project: Build & Apply

Process Forking for Parallelism in Ruby

📖 Scenario: You have a list of tasks that take some time to complete. To finish faster, you want to run some tasks at the same time using Ruby's process forking.

🎯 Goal: Build a Ruby program that uses fork to run two tasks in parallel and then waits for both to finish before printing a message.

📋 What You'll Learn

Create an array called tasks with two strings: 'Task 1' and 'Task 2'.

Create an empty array called pids to store process IDs.

Use a for loop with variable task to iterate over tasks.

Inside the loop, use fork to create a child process that prints "Starting: #{task}", sleeps for 2 seconds, then prints "Finished: #{task}".

Store each child process ID in pids.

After the loop, use Process.wait(pid) for each pid in pids to wait for all child processes to finish.

Finally, print "All tasks completed.".

💡 Why This Matters

🌍 Real World

Running multiple tasks at the same time can save time in programs that do many independent jobs, like downloading files or processing data.

💼 Career

Understanding process forking is useful for backend developers and system programmers who need to optimize performance by running tasks in parallel.

1

Create the tasks array

Create an array called tasks with these exact strings: 'Task 1' and 'Task 2'.

Ruby

# Create the tasks array
# Your code here

Need a hint?

Use square brackets [] to create an array with two strings.

2

Create the pids array

Create an empty array called pids to store process IDs.

Ruby

tasks = ['Task 1', 'Task 2']
# Create an empty array called pids
# Your code here

Need a hint?

Use [] to create an empty array.

3

Fork processes for each task

Use a for loop with variable task to iterate over tasks. Inside the loop, use fork to create a child process that prints "Starting: #{task}", sleeps for 2 seconds, then prints "Finished: #{task}". Store each child process ID in pids.

Ruby

tasks = ['Task 1', 'Task 2']
pids = []
# Use a for loop to fork processes for each task
# Your code here

Need a hint?

Use fork do ... end to create a child process. Use pids << pid to add the process ID to the array.

4

Wait for all child processes and print completion

After the loop, use Process.wait(pid) for each pid in pids to wait for all child processes to finish. Then print "All tasks completed.".

Ruby

tasks = ['Task 1', 'Task 2']
pids = []
for task in tasks
  pid = fork do
    puts "Starting: #{task}"
    sleep 2
    puts "Finished: #{task}"
  end
  pids << pid
end
# Wait for all child processes and print completion
# Your code here

Need a hint?

Use Process.wait(pid) to wait for each child process. Then print the final message.