TaskAfter
TODO: Add description
Installation
Install this package by adding task_after
to your list of dependencies in mix.exs
:
def deps do
[
{:task_after, "~> 1.0.0"},
]
end
Global installation
To use this globally without needing to add it to your own supervision tree just add this to your configuration:
config :task_after, global_name: TaskAfter
Feel free to replace the global name of TaskAfter
with anything you want. If the global name is unspecified then all usage of TaskAfter must have the :name
or :pid
options specified.
Local Installation
To use this locally to your application or to give distinct names so you can have different schedulars then just add the TaskAfter.Worker.start_link/1
to your supervision tree as normal, such as via:
children = [
worker(TaskAfter.Worker, [[name: MyCustomName]]),
]
Note the 2 sets of list elements. You can have a nameless worker by leaving the name option out, such as:
children = [
worker(TaskAfter.Worker, [[]]),
]
You will have to acquire the PID some other way, such as by querying your supervisor.
Usage
The main interface point is TaskAfter.task_after/2
and TaskAfter.task_after/3
where TaskAfter.task_after/2
just calls TaskAfter.task_after/3
with an empty set of options to use the defaults.
The arguments to TaskAfter.task_after/3
are, in this order:
- timeout_after_ms -> integer millisecond timeout
- callback -> The 0-arg callback function
opts -> Can be:
name: name
|pid: pid
-> Specify a non-global task handler, if unspecified that the application:global_name
must be specifiedid: id
-> A unique id, if nil or unspecified then it is auto-generatedcall_timeout: timeout
-> Override the timeout on calling to theTaskAfter.Worker
no_return: true
-> Do not return the id or error, just try to register and forget results otherwisesend_result: pid
-> Sends the result of the task to the specified pidsend_result: :in_process
-> Runs the task in theTaskAfter.Worker
process to do internal work, do not use this
It can be used as in these examples:
defmodule TaskAfterTest do
use ExUnit.Case, async: true
doctest TaskAfter
test "TaskAfter and forget" do
s = self()
{:ok, _auto_id} = TaskAfter.task_after(500, fn -> send(s, 42) end)
assert_receive(42, 600)
end
test "TaskAfter and receive" do
{:ok, _auto_id} = TaskAfter.task_after(500, fn -> 42 end, send_result: self())
assert_receive(42, 600)
end
test "TaskAfter with custom id" do
assert {:ok, :my_id} = TaskAfter.task_after(500, fn -> 42 end, id: :my_id, send_result: self())
assert_receive(42, 600)
end
test "TaskAfter with custom id duplicate fails" do
assert {:ok, :dup_id} = TaskAfter.task_after(500, fn -> 42 end, id: :dup_id, send_result: self())
assert {:error, {:duplicate_id, :dup_id}} = TaskAfter.task_after(500, fn -> 42 end, id: :dup_id, send_result: self())
assert_receive(42, 600)
end
test "TaskAfter lots of tasks" do
assert {:ok, _} = TaskAfter.task_after(400, fn -> 400 end, send_result: self())
assert {:ok, _} = TaskAfter.task_after(200, fn -> 200 end, send_result: self())
assert {:ok, _} = TaskAfter.task_after(500, fn -> 500 end, send_result: self())
assert {:ok, _} = TaskAfter.task_after(100, fn -> 100 end, send_result: self())
assert {:ok, _} = TaskAfter.task_after(300, fn -> 300 end, send_result: self())
assert {:ok, _} = TaskAfter.task_after(600, fn -> 600 end, send_result: self())
assert_receive(100, 150)
assert_receive(200, 150)
assert_receive(300, 150)
assert_receive(400, 150)
assert_receive(500, 150)
assert_receive(600, 150)
end
test "TaskAfter non-global by name" do
assert {:ok, pid} = TaskAfter.Worker.start_link(name: :testing_name)
{:ok, _auto_id} = TaskAfter.task_after(500, fn -> 42 end, send_result: self(), name: :testing_name)
assert_receive(42, 600)
GenServer.stop(pid)
end
test "TaskAfter non-global by pid" do
assert {:ok, pid} = TaskAfter.Worker.start_link()
assert {:ok, _auto_id} = TaskAfter.task_after(500, fn -> 42 end, send_result: self(), pid: pid)
assert_receive(42, 600)
GenServer.stop(pid)
end
test "TaskAfter in process (unsafe, can freeze the task worker if the task does not return fast)" do
assert {:ok, pid} = TaskAfter.Worker.start_link()
s = self()
assert {:ok, _auto_id} = TaskAfter.task_after(500, fn -> send(s, self()) end, send_result: :in_process, pid: pid)
assert_receive(^pid, 600)
GenServer.stop(pid)
end
end