Worker pool

.travis.yml

@@ -10,7 +10,7 @@ otp_release:
 
 script: PATH=.:$PATH make update test dialyzer coveralls
 
-install: wget https://github.com/erlang/rebar3/releases/download/3.3.1/rebar3 && chmod 755 rebar3
+install: wget https://github.com/erlang/rebar3/releases/download/3.3.6/rebar3 && chmod 755 rebar3
 
 cache:
   directories:

rebar.config

@@ -6,7 +6,7 @@
 
 {deps, [
         {cowlib, "1.0.0"},
-        {gproc, "0.5.0"},
+        {worker_pool, "2.2.3"},
         {metrics, "1.1.0"}
        ]}.
 
@@ -32,7 +32,7 @@
 
 {dialyzer, [
     {warnings, [no_return, unmatched_returns, error_handling]},
-    {plt_extra_apps, [cowlib, gproc]}
+    {plt_extra_apps, [cowlib, worker_pool]}
 ]}.
 
 {shell, [{apps, [katipo]}]}.

rebar.lock

@@ -1,10 +1,10 @@
 {"1.1.0",
 [{<<"cowlib">>,{pkg,<<"cowlib">>,<<"1.0.0">>},0},
- {<<"gproc">>,{pkg,<<"gproc">>,<<"0.5.0">>},0},
- {<<"metrics">>,{pkg,<<"metrics">>,<<"1.1.0">>},0}]}.
+ {<<"metrics">>,{pkg,<<"metrics">>,<<"1.1.0">>},0},
+ {<<"worker_pool">>,{pkg,<<"worker_pool">>,<<"2.2.3">>},0}]}.
 [
 {pkg_hash,[
  {<<"cowlib">>, <<"397D890D669E56D486B0B5329973AD1A07012412BC110D34A737698DD6941741">>},
- {<<"gproc">>, <<"2DF2D886F8F8A7B81A4B04AA17972B5965BBC5BF0100EA6D8E8AC6A0E7389AFE">>},
- {<<"metrics">>, <<"41450DFFBA18B1206BF44FA1AD4E29324D1E561617C2DAF4EF32E3CE50DF08F3">>}]}
+ {<<"metrics">>, <<"41450DFFBA18B1206BF44FA1AD4E29324D1E561617C2DAF4EF32E3CE50DF08F3">>},
+ {<<"worker_pool">>, <<"2CD7B2C289B900940297D283922D7E119C540CB8F29B5254639ABB9BFB100CAE">>}]}
 ].

src/katipo.app.src

@@ -1,13 +1,13 @@
 {application, 'katipo',
  [{description, "HTTP client based on libcurl"},
-  {vsn, "0.4.0"},
+  {vsn, "0.5.0"},
   {registered, []},
   {mod, {'katipo_app', []}},
   {applications,
    [kernel,
     stdlib,
     cowlib,
-    gproc,
+    worker_pool,
     metrics
    ]},
   {env, [{mod_metrics, dummy}]},
@@ -24,7 +24,6 @@
            "src/katipo_app.erl",
            "src/katipo_metrics.erl",
            "src/katipo_pool.erl",
-           "src/katipo_pool_sup.erl",
            "src/katipo_session.erl",
            "src/katipo_sup.erl"]}
  ]}.

src/katipo.erl

@@ -4,7 +4,7 @@
 
 -compile({no_auto_import,[put/2]}).
 
--export([start_link/3]).
+-export([start_link/1]).
 
 -export([init/1]).
 -export([handle_call/3]).
@@ -316,8 +316,8 @@ req(PoolName, Opts)
             Timeout = ?MODULE:get_timeout(Req),
             Req2 = Req#req{timeout=Timeout},
             Ts = os:timestamp(),
-            Pid = gproc_pool:pick_worker(PoolName),
-            {Result, {Response, Metrics}} = gen_server:call(Pid, Req2, infinity),
+            {Result, {Response, Metrics}} =
+                wpool:call(PoolName, Req2, best_worker, infinity),
             TotalUs = timer:now_diff(os:timestamp(), Ts),
             Response2 = maybe_return_metrics(Req2, Metrics, Response),
             Ret = {Result, Response2},
@@ -328,17 +328,15 @@ req(PoolName, Opts)
             Error
     end.
 
-start_link(PoolName, CurlOpts, WorkerId) when is_list(CurlOpts) andalso
-                                              is_atom(WorkerId) ->
-    Args = [PoolName, CurlOpts, WorkerId],
+start_link(CurlOpts) when is_list(CurlOpts) ->
+    Args = [CurlOpts],
     gen_server:start_link(?MODULE, Args, []).
 
-init([PoolName, CurlOpts, WorkerId]) ->
+init([CurlOpts]) ->
     process_flag(trap_exit, true),
     Args = get_mopts(CurlOpts),
     Prog = filename:join([code:priv_dir(katipo), "katipo"]),
     Port = open_port({spawn, Prog ++ " " ++ Args}, [{packet, 4}, binary]),
-    true = gproc_pool:connect_worker(PoolName, WorkerId),
     {ok, #state{port=Port, reqs=#{}}}.
 
 handle_call(#req{method = Method,

src/katipo_pool.erl

@@ -3,7 +3,6 @@
 -export([start/2]).
 -export([start/3]).
 -export([stop/1]).
--export([worker_name/2]).
 
 -type name() :: atom().
 -export_type([name/0]).
@@ -18,28 +17,13 @@ start(PoolName, PoolSize, WorkerOpts)
   when is_atom(PoolName) andalso
        is_integer(PoolSize) andalso
        is_list(WorkerOpts) ->
-    Args = [PoolName, PoolSize, WorkerOpts],
+    Args = [WorkerOpts],
 
-    ChildSpec = #{id => PoolName,
-                  start => {katipo_pool_sup, start_link, Args},
-                  restart => permanent,
-                  shutdown => 2000,
-                  type => supervisor,
-                  modules => [katipo_pool_sup]},
+    PoolOpts = [{worker, {katipo, Args}},
+                {workers, PoolSize}],
 
-    ok = gproc_pool:new(PoolName, round_robin, [{size, PoolSize}]),
-    _ = [gproc_pool:add_worker(PoolName, worker_name(PoolName, N))
-         || N <- lists:seq(1, PoolSize)],
-
-    supervisor:start_child(katipo_sup, ChildSpec).
+    wpool:start_sup_pool(PoolName, PoolOpts).
 
 -spec stop(name()) -> ok.
 stop(PoolName) when is_atom(PoolName) ->
-    ok = supervisor:terminate_child(katipo_sup, PoolName),
-    true = gproc_pool:force_delete(PoolName),
-    ok = supervisor:delete_child(katipo_sup, PoolName).
-
--spec worker_name(name(), pos_integer()) -> atom().
-worker_name(PoolName, N) when is_integer(N) ->
-    PoolNameList = atom_to_list(PoolName),
-    list_to_atom("katipo_" ++ PoolNameList ++ "_" ++ integer_to_list(N)).
+    wpool:stop_pool(PoolName).

test/katipo_SUITE.erl

@@ -5,14 +5,15 @@
 -include_lib("common_test/include/ct.hrl").
 
 -define(POOL, katipo_test_pool).
+-define(POOL_SIZE, 2).
 
 suite() ->
     [{timetrap, {seconds, 30}}].
 
 init_per_suite(Config) ->
     application:ensure_all_started(katipo),
     application:ensure_all_started(meck),
-    {ok, _} = katipo_pool:start(?POOL, 2, []),
+    {ok, _} = katipo_pool:start(?POOL, ?POOL_SIZE),
     Config.
 
 end_per_suite(_Config) ->
@@ -110,7 +111,6 @@ groups() ->
        proxy_couldnt_connect]},
      {pool, [],
       [pool_start_stop,
-       pool_death,
        worker_death,
        port_death,
        port_late_response]},
@@ -413,47 +413,32 @@ pool_start_stop(_) ->
     PoolSize = 2,
     {ok, Pid} = katipo_pool:start(PoolName, PoolSize, []),
     ok = katipo_pool:stop(PoolName),
+    receive
+    after 2500 ->
+            ok
+    end,
     {ok, Pid2} = katipo_pool:start(PoolName, PoolSize, []),
     ok = katipo_pool:stop(PoolName),
     true = Pid =/= Pid2.
 
-pool_death(_) ->
-    PoolName = die_pool,
-    PoolSize = 2,
-    {ok, Pid} = katipo_pool:start(PoolName, PoolSize, []),
-
-    Active = gproc_pool:active_workers(PoolName),
-    exit(Pid, kill),
-    Fun = fun() ->
-                  whereis(PoolName) =/= Pid andalso
-                      whereis(PoolName) =/= undefined
-          end,
-    true = repeat_until_true(Fun),
-    Fun2 = fun() ->
-                  Active2 = gproc_pool:active_workers(?POOL),
-                  [] == Active2 -- (Active2 -- Active)
-          end,
-    true = repeat_until_true(Fun2),
-    Fun3 = fun() ->
-                  length(Active) == length(gproc_pool:active_workers(PoolName))
-          end,
-    true = repeat_until_true(Fun3),
-    Fun4 = fun() ->
-                   {ok, #{status := 200}} = katipo:get(PoolName, <<"http://httpbin.org/get">>),
-                   true
-           end,
-    true = repeat_until_true(Fun4).
+active_workers() ->
+    Pids = [begin
+                Name = lists:flatten(io_lib:format("wpool_pool-~s-~B", [?POOL, N])),
+                NameAtom = list_to_existing_atom(Name),
+                whereis(NameAtom)
+            end || N <- lists:seq(1, ?POOL_SIZE)],
+    [P || P <- Pids, P /= undefined].
 
 worker_death(_) ->
-    Active = gproc_pool:active_workers(?POOL),
-    _ = [exit(W, kill) || {_, W} <- Active],
+    Active = active_workers(),
+    _ = [exit(W, kill) || W <- Active],
     Fun = fun() ->
-                  Active2 = gproc_pool:active_workers(?POOL),
+                  Active2 = active_workers(),
                   [] == Active2 -- (Active2 -- Active)
           end,
     true = repeat_until_true(Fun),
     Fun2 = fun() ->
-                  length(Active) == length(gproc_pool:active_workers(?POOL))
+                  length(Active) == length(active_workers())
           end,
     true = repeat_until_true(Fun2),
     Fun3 = fun() ->
@@ -465,12 +450,16 @@ worker_death(_) ->
 port_death(_) ->
     PoolName = this_process_will_be_killed,
     PoolSize = 1,
-    {ok, _} = katipo_pool:start(PoolName, PoolSize, []),
-    {state, Port, _} = sys:get_state(gproc_pool:pick_worker(PoolName)),
+    {ok, _} = katipo_pool:start(PoolName, PoolSize),
+    WorkerName = wpool_pool:best_worker(PoolName),
+    WorkerPid = whereis(WorkerName),
+    {state, _, katipo, {state, Port, _}, _} = sys:get_state(WorkerPid),
     true = port_command(Port, <<"hdfjkshkjsdfgjsgafdjgsdjgfj">>),
     Fun = fun() ->
-                  case sys:get_state(gproc_pool:pick_worker(PoolName)) of
-                      {state, Port2, _} when Port =/= Port2 ->
+                  WorkerName2 = wpool_pool:best_worker(PoolName),
+                  WorkerPid2 = whereis(WorkerName2),
+                  case sys:get_state(WorkerPid2) of
+                      {state, _, katipo, {state, Port2, _}, _} when Port =/= Port2 ->
                           {ok, #{status := 200}} =
                               katipo:get(PoolName, <<"http://httpbin.org/get">>),
                           true