Separate metrics scheduling from job logic

ch10/todo_metrics/lib/todo/cron.ex

@@ -0,0 +1,14 @@
+defmodule Todo.Cron do
+  use Task
+
+  def start_link(_) do
+    IO.puts("Starting cron")
+    Task.start_link(&loop/0)
+  end
+
+  defp loop() do
+    Process.sleep(:timer.seconds(10))
+    Todo.Metrics.start()
+    loop()
+  end
+end

ch10/todo_metrics/lib/todo/metrics.ex

@@ -1,21 +1,14 @@
 defmodule Todo.Metrics do
   use Task
 
-  def start_link(_) do
-    IO.puts("Starting metrics")
-    Task.start_link(&loop/0)
+  def start() do
+    Task.start(&execute/0)
   end
 
-  defp loop() do
-    Process.sleep(:timer.seconds(10))
-    IO.inspect(collect_metrics())
-    loop()
-  end
-
-  defp collect_metrics() do
-    [
+  defp execute() do
+    IO.inspect([
       memory_usage: :erlang.memory(:total),
       process_count: :erlang.system_info(:process_count)
-    ]
+    ])
   end
 end

ch10/todo_metrics/lib/todo/system.ex

@@ -3,7 +3,7 @@ defmodule Todo.System do
   def start_link() do
     Supervisor.start_link(
       [
-        Todo.Metrics,
+        Todo.Cron,
         Todo.ProcessRegistry,
         Todo.Database,
         Todo.Cache