Files
elixir-koans/lib/koans/16_tasks.ex
2018-05-22 21:46:54 +01:00

60 lines
1.3 KiB
Elixir

defmodule Tasks do
use Koans
@intro "Tasks"
koan "Tasks can be used for asynchronous computations with results" do
task = Task.async(fn -> 3 * 3 end)
do_other_stuff()
assert Task.await(task) + 1 == ___
end
koan "If you don't need a result, use start_link/1" do
{result, _pid} = Task.start_link(fn -> 1 + 1 end)
assert result == ___
end
koan "Yield returns nil if the task isn't done yet" do
handle =
Task.async(fn ->
:timer.sleep(100)
3 * 3
end)
assert Task.yield(handle, 10) == ___
end
koan "Tasks can be aborted with shutdown" do
handle =
Task.async(fn ->
:timer.sleep(100)
3 * 3
end)
%Task{pid: pid} = handle
Task.shutdown(handle)
assert Process.alive?(pid) == ___
end
koan "Shutdown will give you an answer if it has it" do
handle = Task.async(fn -> 3 * 3 end)
:timer.sleep(10)
assert Task.shutdown(handle) == {:ok, ___}
end
koan "You can yield to multiple tasks at once and extract the results" do
squares =
[1, 2, 3, 4]
|> Enum.map(fn number -> Task.async(fn -> number * number end) end)
|> Task.yield_many(100)
|> Enum.map(fn {_task, {:ok, result}} -> result end)
assert squares == ___
end
def do_other_stuff do
:timer.sleep(50)
end
end