thread_local_variables

🧵 Leveraging Thread-Local Variables for Concurrency

Thread-local storage lets each thread maintain isolated state, preventing shared‑memory conflicts and enabling context‑specific data like request IDs or logging metadata. Store values in Thread.current and retrieve them anywhere in that thread without passing arguments through call chains.

require 'securerandom'

threads = 3.times.map do |i|
  Thread.new do
    # Assign a unique identifier per thread
    Thread.current[:request_id] = SecureRandom.uuid

    # Simulate work
    sleep(rand * 0.1)
    puts "Thread #{i} – Request ID: #{Thread.current[:request_id]}"
  end
end

threads.each(&:join)