Staged barrier

# title: Staged barrier
# category: Vibescript Showcase
# difficulty: Showcase
# summary: Spawn a batch of tasks, hold at an explicit tasks.wait barrier, then aggregate the results in order.
# description: tasks.wait is an explicit barrier inside a Tasks.run scope. Use it when later code in the same block must wait for all spawned work so far before continuing — here we wait for every segment, then read the handle values and total them.
# tags: concurrency, tasks, structured-concurrency, barrier
# vibe: 0.4

def warm_segment(segment)
  segment[:base] * segment[:multiplier]
end

def aggregate_segments(segments)
  Tasks.run(max: 4) do |tasks|
    handles = []
    segments.each do |segment|
      handles = handles.push(tasks.spawn(:warm_segment, segment))
    end

    tasks.wait

    totals = handles.map do |handle|
      handle.value
    end

    {
      segments: totals,
      total: totals.sum
    }
  end
end

def run
  aggregate_segments([
    { base: 10, multiplier: 2 },
    { base: 5, multiplier: 4 },
    { base: 8, multiplier: 3 }
  ])
end