paiza.ioでelixir その5

概要

paiza.ioでelixirやってみた。
Fibonacci Serverやってみた。

参考にしたページ

サンプルコード

defmodule FibSolver do
	def fib(scheduler) do
		send scheduler, {:ready, self()}
		receive do
			{:fib, n, client} -> 
				send client, {:answer, n, fib_calc(n), self()}
				fib(scheduler)
			{:shutdown} -> 
				exit(0)
		end
	end
	defp fib_calc(0), do: 1
	defp fib_calc(1), do: 1
	defp fib_calc(n), do: fib_calc(n - 1) + fib_calc(n - 2)
end

defmodule Scheduler do
	def run(num_processes, module, func, to_calculate) do
		(1..num_processes)
		|> Enum.map(fn(_) -> 
		      spawn(module, func, [self()]) 
		   end)
		|> schedule_processes(to_calculate, [])
	end
	defp schedule_processes(processes, queue, results) do
		receive do
			{:ready, pid} when length(queue) > 0 -> 
				[next | tail] = queue
				send pid, {:fib, next, self()}
				schedule_processes(processes, tail, results)
			{:ready, pid} -> 
				send pid, {:shutdown}
				if length(processes) > 1 do
					schedule_processes(List.delete(processes, pid), queue, results)
				else
					Enum.sort(results, fn {n1, _}, {n2, _} -> 
					    n1 <= n2 
					end)
				end
			{:answer, number, result, _pid} -> 
				schedule_processes(processes, queue, [{number, result} | results])
		end
	end
end

to_process = [9, 10, 11]
Enum.each 1..4, fn num_processes -> 
    {time, result} = :timer.tc(Scheduler, :run, [num_processes, FibSolver, :fib, to_process])
	if num_processes == 1 do
		IO.puts inspect result
		IO.puts "\n # time (ms)"
	end
	:io.format "~2B ~.2f~n", [num_processes, time / 1000.0]
end

実行結果

[{9, 55}, {10, 89}, {11, 144}]

 # time (ms)
 1 1.89
 2 0.04
 3 0.05
 4 0.07

成果物

以上。