Fiber for cooperative concurrency in Ruby - Mini Project: Build & Apply

Fiber for cooperative concurrency

📖 Scenario: You are building a simple program that uses Ruby Fiber to switch between two tasks cooperatively. This simulates how two workers take turns doing their jobs without interrupting each other.

🎯 Goal: Create two Fiber objects that print messages in turns, showing how cooperative concurrency works with Fiber.yield and Fiber.resume.

📋 What You'll Learn

Create two Fiber objects named fiber1 and fiber2.

Each fiber should print a message and then yield control.

Use a loop to resume each fiber alternately two times.

Print the messages exactly as specified.

💡 Why This Matters

🌍 Real World

Fibers let programs switch between tasks without waiting for one to finish, useful in games, network servers, or UI where tasks share time smoothly.

💼 Career

Understanding fibers helps in writing efficient Ruby programs that handle multiple tasks cooperatively, improving responsiveness and resource use.

1

Create two Fiber objects

Create two Fiber objects called fiber1 and fiber2. fiber1 should print "Fiber 1: Step 1" and then yield. fiber2 should print "Fiber 2: Step 1" and then yield.

Ruby

# Create fiber1 and fiber2 with initial print and yield
# Your code here

Need a hint?

Use Fiber.new do ... end to create fibers. Inside each, print the message and call Fiber.yield to pause.

2

Add second steps inside fibers

Inside fiber1, after the first yield, print "Fiber 1: Step 2". Inside fiber2, after the first yield, print "Fiber 2: Step 2". Add these lines after the first Fiber.yield in each fiber.

Ruby

fiber1 = Fiber.new do
  puts "Fiber 1: Step 1"
  Fiber.yield
  # Your code here
end

fiber2 = Fiber.new do
  puts "Fiber 2: Step 1"
  Fiber.yield
  # Your code here
end

Need a hint?

After Fiber.yield, add a puts line for the second step message inside each fiber.

3

Create a loop to resume fibers alternately

Create a 2.times do loop. Inside the loop, resume fiber1 and then resume fiber2 to switch between them.

Ruby

fiber1 = Fiber.new do
  puts "Fiber 1: Step 1"
  Fiber.yield
  puts "Fiber 1: Step 2"
end

fiber2 = Fiber.new do
  puts "Fiber 2: Step 1"
  Fiber.yield
  puts "Fiber 2: Step 2"
end

# Your code here to resume fibers alternately 2 times

Need a hint?

Use 2.times do to repeat two times. Inside, call fiber1.resume then fiber2.resume.

4

Run the program and print the output

Run the program as is. The output should show the fibers printing their steps alternately. No extra code needed, just run the existing code.

Ruby

fiber1 = Fiber.new do
  puts "Fiber 1: Step 1"
  Fiber.yield
  puts "Fiber 1: Step 2"
end

fiber2 = Fiber.new do
  puts "Fiber 2: Step 1"
  Fiber.yield
  puts "Fiber 2: Step 2"
end

2.times do
  fiber1.resume
  fiber2.resume
end

# Run the program to see the output

Need a hint?

Just run the program. You will see the fibers print their messages in turns twice.