Gemfile

source 'https://rubygems.org'

ruby "3.4.4"

gem "async"

Gemfile.lock

GEM
  remote: https://rubygems.org/
  specs:
    async (2.24.0)
      console (~> 1.29)
      fiber-annotation
      io-event (~> 1.9)
      metrics (~> 0.12)
      traces (~> 0.15)
    console (1.30.2)
      fiber-annotation
      fiber-local (~> 1.1)
      json
    fiber-annotation (0.2.0)
    fiber-local (1.1.0)
      fiber-storage
    fiber-storage (1.0.1)
    io-event (1.10.0)
    json (2.12.0)
    metrics (0.12.2)
    traces (0.15.2)

PLATFORMS
  arm64-darwin-24
  ruby

DEPENDENCIES
  async

RUBY VERSION
   ruby 3.4.4p34

BUNDLED WITH
   2.6.7

test.rb

require "bundler/setup"
require "async"
require "async/barrier"
require "async/waiter"

Async do
  barrier = Async::Barrier.new
  waiter = Async::Waiter.new(parent: barrier)

  t1 = waiter.async do
    2.times do
      puts "t1"
      sleep 1
    end
  end

  t2 = waiter.async do 
    loop do
      puts "t2"
      sleep 1
    end
  end

  begin
    done = waiter.wait(1)
    puts "done: #{done}"
  rescue => err
    pp err
  ensure
    barrier.stop
  end
end