Enable descentralized counters (#314)

Author: josevalim

.github/workflows/ci.yml

@@ -16,10 +16,10 @@ jobs:
       matrix:
         include:
           - pair:
-              elixir: 1.8.2
-              otp: 20.3
+              elixir: 1.11
+              otp: 23.0
           - pair:
-              elixir: 1.14.3
+              elixir: 1.17
               otp: 25.3
             lint: lint
     steps:

integration_test/ownership/test_helper.exs

@@ -1,9 +1,7 @@
-excludes = if Version.match?(System.version(), ">= 1.8.0"), do: [], else: [:requires_callers]
-
 ExUnit.start(
   capture_log: true,
   assert_receive_timeout: 1000,
-  exclude: [:idle_time, :idle_interval | excludes]
+  exclude: [:idle_time, :idle_interval]
 )
 
 Code.require_file("../../test/test_support.exs", __DIR__)

lib/db_connection/connection_pool.ex

@@ -52,7 +52,7 @@ defmodule DBConnection.ConnectionPool do
   def init({mod, opts}) do
     DBConnection.register_as_pool(mod)
 
-    queue = :ets.new(__MODULE__.Queue, [:protected, :ordered_set])
+    queue = :ets.new(__MODULE__.Queue, [:protected, :ordered_set, decentralized_counters: true])
     ts = {System.monotonic_time(), 0}
     {:ok, _} = DBConnection.ConnectionPool.Pool.start_supervised(queue, mod, opts)
     target = Keyword.get(opts, :queue_target, @queue_target)

lib/db_connection/holder.ex

@@ -17,7 +17,7 @@ defmodule DBConnection.Holder do
   @spec new(pid, reference, module, term) :: t
   def new(pool, ref, mod, state) do
     # Insert before setting heir so that pool can't receive empty table
-    holder = :ets.new(__MODULE__, [:public, :ordered_set])
+    holder = :ets.new(__MODULE__, [:public, :ordered_set, decentralized_counters: true])
 
     conn = conn(connection: self(), module: mod, state: state, ts: System.monotonic_time())
     true = :ets.insert_new(holder, conn)

lib/db_connection/ownership/manager.ex

@@ -74,7 +74,13 @@ defmodule DBConnection.Ownership.Manager do
     ets =
       case Keyword.fetch(owner_opts, :name) do
         {:ok, name} when is_atom(name) ->
-          :ets.new(name, [:set, :named_table, :protected, read_concurrency: true])
+          :ets.new(name, [
+            :set,
+            :named_table,
+            :protected,
+            read_concurrency: true,
+            decentralized_counters: true
+          ])
 
         _ ->
           nil

mix.exs

@@ -3,13 +3,13 @@ defmodule DBConnection.Mixfile do
 
   @source_url "https://github.com/elixir-ecto/db_connection"
   @pools [:connection_pool, :ownership]
-  @version "2.7.0"
+  @version "2.8.0-dev"
 
   def project do
     [
       app: :db_connection,
       version: @version,
-      elixir: "~> 1.8",
+      elixir: "~> 1.11",
       deps: deps(),
       docs: docs(),
       description: description(),

test/db_connection_test.exs

@@ -63,21 +63,23 @@ defmodule DBConnectionTest do
   end
 
   describe "connection_module/1" do
-    test "returns the connection module when given a pool pid" do
-      {:ok, pool} = P.start_link([])
+    setup do
+      {:ok, agent} = A.start_link([{:ok, :state}, {:idle, :state}, {:idle, :state}])
+      [agent: agent]
+    end
+
+    test "returns the connection module when given a pool pid", %{agent: agent} do
+      {:ok, pool} = P.start_link(agent: agent)
       assert {:ok, TestConnection} = DBConnection.connection_module(pool)
     end
 
-    test "returns the connection module when given a pool name", %{test: name} do
-      {:ok, _pool} = P.start_link(name: name)
+    test "returns the connection module when given a pool name", %{test: name, agent: agent} do
+      {:ok, _pool} = P.start_link(name: name, agent: agent)
       assert {:ok, TestConnection} = DBConnection.connection_module(name)
     end
 
-    test "returns the connection module when given a locked connection reference" do
-      {:ok, agent} = A.start_link([{:ok, :state}, {:idle, :state}, {:idle, :state}])
-
-      opts = [agent: agent]
-      {:ok, pool} = P.start_link(opts)
+    test "returns the connection module when given a locked connection reference", %{agent: agent} do
+      {:ok, pool} = P.start_link(agent: agent)
 
       P.run(pool, fn conn ->
         assert {:ok, TestConnection} = DBConnection.connection_module(conn)