parallel.lua

local memory = require "memory"
local channel = require "coutil.channel"
local spawn = require "coutil.spawn"
local system = require "coutil.system"
local threads = require "coutil.threads"

spawn.catch(print, function ()

	local ncpu<const> = #system.cpuinfo()
	local pool<const> = threads.create(ncpu)
	local worker<const> = arg[0]:gsub("parallel%.lua$", "worker.lua")
	for i = 1, ncpu do
		assert(pool:dofile(worker, "t", i))
	end

	local repeats<const> = 100

	spawn.catch(print, function ()
		local histoch<close> = channel.create("histogram")
		local histogram<const> = {}
		for i = 1, repeats do
			local partial<const> = { select(2, assert(system.awaitch(histoch, "in"))) }
			for pos, count in ipairs(partial) do
				histogram[pos] = (histogram[pos] or 0) + count
			end
			io.write("+"); io.flush()
		end
		pool:resize(0)
		print()
		print(table.unpack(histogram))
	end)

	local startch<close> = channel.create("start")
	for i = 1, repeats do
		io.write("."); io.flush()
		assert(system.awaitch(startch, "out"))
	end
	io.write("!"); io.flush()

end)

system.run()