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author | Trygve Laugstøl <trygvis@inamo.no> | 2024-02-23 07:08:18 +0100 |
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committer | Trygve Laugstøl <trygvis@inamo.no> | 2024-02-23 07:08:18 +0100 |
commit | 5a9cdd3cc89507d4d74f8bded56ce5e037b3b56e (patch) | |
tree | 982ca2e7f9ac4e8c350dfb5c4f60bcfdfff5afaf /learn-you-some-erlang/pool | |
parent | 05ae56e5e89abf2993f84e6d52b250131f247c35 (diff) | |
download | erlang-workshop-5a9cdd3cc89507d4d74f8bded56ce5e037b3b56e.tar.gz erlang-workshop-5a9cdd3cc89507d4d74f8bded56ce5e037b3b56e.tar.bz2 erlang-workshop-5a9cdd3cc89507d4d74f8bded56ce5e037b3b56e.tar.xz erlang-workshop-5a9cdd3cc89507d4d74f8bded56ce5e037b3b56e.zip |
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Diffstat (limited to 'learn-you-some-erlang/pool')
-rw-r--r-- | learn-you-some-erlang/pool/ppool.erl | 25 | ||||
-rw-r--r-- | learn-you-some-erlang/pool/ppool_nagger.erl | 50 | ||||
-rw-r--r-- | learn-you-some-erlang/pool/ppool_serv.erl | 113 | ||||
-rw-r--r-- | learn-you-some-erlang/pool/ppool_sup.erl | 17 | ||||
-rw-r--r-- | learn-you-some-erlang/pool/ppool_supersup.erl | 31 | ||||
-rw-r--r-- | learn-you-some-erlang/pool/ppool_tests.erl | 200 | ||||
-rw-r--r-- | learn-you-some-erlang/pool/ppool_worker_sup.erl | 15 |
7 files changed, 451 insertions, 0 deletions
diff --git a/learn-you-some-erlang/pool/ppool.erl b/learn-you-some-erlang/pool/ppool.erl new file mode 100644 index 0000000..b5d34c0 --- /dev/null +++ b/learn-you-some-erlang/pool/ppool.erl @@ -0,0 +1,25 @@ +%%% API module for the pool +-module(ppool). +-export([start_link/0, stop/0, start_pool/3, + run/2, sync_queue/2, async_queue/2, stop_pool/1]). + +start_link() -> + ppool_supersup:start_link(). + +stop() -> + ppool_supersup:stop(). + +start_pool(Name, Limit, {M,F,A}) -> + ppool_supersup:start_pool(Name, Limit, {M,F,A}). + +stop_pool(Name) -> + ppool_supersup:stop_pool(Name). + +run(Name, Args) -> + ppool_serv:run(Name, Args). + +async_queue(Name, Args) -> + ppool_serv:async_queue(Name, Args). + +sync_queue(Name, Args) -> + ppool_serv:sync_queue(Name, Args). diff --git a/learn-you-some-erlang/pool/ppool_nagger.erl b/learn-you-some-erlang/pool/ppool_nagger.erl new file mode 100644 index 0000000..903f821 --- /dev/null +++ b/learn-you-some-erlang/pool/ppool_nagger.erl @@ -0,0 +1,50 @@ +%% demo module, a nagger for tasks, +%% because the previous one wasn't good enough +%% +%% Can take: +%% - a time delay for which to nag, +%% - an adress to say where the messages should be sent +%% - a message to send in the mailbox telling you what to nag, +%% with an id to be able to call: -> +%% - a command to say the task is done +-module(ppool_nagger). +-behaviour(gen_server). +-export([start_link/4, stop/1]). +-export([init/1, handle_call/3, handle_cast/2, + handle_info/2, code_change/3, terminate/2]). + +start_link(Task, Delay, Max, SendTo) -> + gen_server:start_link(?MODULE, {Task, Delay, Max, SendTo} , []). + +stop(Pid) -> + gen_server:call(Pid, stop). + +init({Task, Delay, Max, SendTo}) -> + process_flag(trap_exit, true), % for tests & terminate too + {ok, {Task, Delay, Max, SendTo}, Delay}. + +%%% OTP Callbacks +handle_call(stop, _From, State) -> + {stop, normal, ok, State}; +handle_call(_Msg, _From, State) -> + {noreply, State}. + +handle_cast(_Msg, State) -> + {noreply, State}. + +handle_info(timeout, {Task, Delay, Max, SendTo}) -> + SendTo ! {self(), Task}, + if Max =:= infinity -> + {noreply, {Task, Delay, Max, SendTo}, Delay}; + Max =< 1 -> + {stop, normal, {Task, Delay, 0, SendTo}}; + Max > 1 -> + {noreply, {Task, Delay, Max-1, SendTo}, Delay} + end; +handle_info(_Msg, State) -> + {noreply, State}. + +code_change(_OldVsn, State, _Extra) -> + {ok, State}. + +terminate(_Reason, _State) -> ok. diff --git a/learn-you-some-erlang/pool/ppool_serv.erl b/learn-you-some-erlang/pool/ppool_serv.erl new file mode 100644 index 0000000..512b49f --- /dev/null +++ b/learn-you-some-erlang/pool/ppool_serv.erl @@ -0,0 +1,113 @@ +-module(ppool_serv). +-behaviour(gen_server). +-export([start/4, start_link/4, run/2, sync_queue/2, async_queue/2, stop/1]). +-export([init/1, handle_call/3, handle_cast/2, handle_info/2, + code_change/3, terminate/2]). + +%% The friendly supervisor is started dynamically! +-define(SPEC(MFA), + {worker_sup, + {ppool_worker_sup, start_link, [MFA]}, + temporary, + 10000, + supervisor, + [ppool_worker_sup]}). + +-record(state, {limit=0, + sup, + refs, + queue=queue:new()}). + +start(Name, Limit, Sup, MFA) when is_atom(Name), is_integer(Limit) -> + gen_server:start({local, Name}, ?MODULE, {Limit, MFA, Sup}, []). + +start_link(Name, Limit, Sup, MFA) when is_atom(Name), is_integer(Limit) -> + gen_server:start_link({local, Name}, ?MODULE, {Limit, MFA, Sup}, []). + +run(Name, Args) -> + gen_server:call(Name, {run, Args}). + +sync_queue(Name, Args) -> + gen_server:call(Name, {sync, Args}, infinity). + +async_queue(Name, Args) -> + gen_server:cast(Name, {async, Args}). + +stop(Name) -> + gen_server:call(Name, stop). + +%% Gen server +init({Limit, MFA, Sup}) -> + %% We need to find the Pid of the worker supervisor from here, + %% but alas, this would be calling the supervisor while it waits for us! + self() ! {start_worker_supervisor, Sup, MFA}, + {ok, #state{limit=Limit, refs=gb_sets:empty()}}. + +handle_call({run, Args}, _From, S = #state{limit=N, sup=Sup, refs=R}) when N > 0 -> + {ok, Pid} = supervisor:start_child(Sup, Args), + Ref = erlang:monitor(process, Pid), + {reply, {ok,Pid}, S#state{limit=N-1, refs=gb_sets:add(Ref,R)}}; +handle_call({run, _Args}, _From, S=#state{limit=N}) when N =< 0 -> + {reply, noalloc, S}; + +handle_call({sync, Args}, _From, S = #state{limit=N, sup=Sup, refs=R}) when N > 0 -> + {ok, Pid} = supervisor:start_child(Sup, Args), + Ref = erlang:monitor(process, Pid), + {reply, {ok,Pid}, S#state{limit=N-1, refs=gb_sets:add(Ref,R)}}; +handle_call({sync, Args}, From, S = #state{queue=Q}) -> + {noreply, S#state{queue=queue:in({From, Args}, Q)}}; + +handle_call(stop, _From, State) -> + {stop, normal, ok, State}; +handle_call(_Msg, _From, State) -> + {noreply, State}. + + +handle_cast({async, Args}, S=#state{limit=N, sup=Sup, refs=R}) when N > 0 -> + {ok, Pid} = supervisor:start_child(Sup, Args), + Ref = erlang:monitor(process, Pid), + {noreply, S#state{limit=N-1, refs=gb_sets:add(Ref,R)}}; +handle_cast({async, Args}, S=#state{limit=N, queue=Q}) when N =< 0 -> + {noreply, S#state{queue=queue:in(Args,Q)}}; + +handle_cast(_Msg, State) -> + {noreply, State}. + +handle_info({'DOWN', Ref, process, _Pid, _}, S = #state{refs=Refs}) -> + io:format("received down msg~n"), + case gb_sets:is_element(Ref, Refs) of + true -> + handle_down_worker(Ref, S); + false -> %% Not our responsibility + {noreply, S} + end; +handle_info({start_worker_supervisor, Sup, MFA}, S = #state{}) -> + {ok, Pid} = supervisor:start_child(Sup, ?SPEC(MFA)), + link(Pid), + {noreply, S#state{sup=Pid}}; +handle_info(Msg, State) -> + io:format("Unknown msg: ~p~n", [Msg]), + {noreply, State}. + +code_change(_OldVsn, State, _Extra) -> + {ok, State}. + +terminate(_Reason, _State) -> + ok. + +handle_down_worker(Ref, S = #state{limit=L, sup=Sup, refs=Refs}) -> + case queue:out(S#state.queue) of + {{value, {From, Args}}, Q} -> + {ok, Pid} = supervisor:start_child(Sup, Args), + NewRef = erlang:monitor(process, Pid), + NewRefs = gb_sets:insert(NewRef, gb_sets:delete(Ref,Refs)), + gen_server:reply(From, {ok, Pid}), + {noreply, S#state{refs=NewRefs, queue=Q}}; + {{value, Args}, Q} -> + {ok, Pid} = supervisor:start_child(Sup, Args), + NewRef = erlang:monitor(process, Pid), + NewRefs = gb_sets:insert(NewRef, gb_sets:delete(Ref,Refs)), + {noreply, S#state{refs=NewRefs, queue=Q}}; + {empty, _} -> + {noreply, S#state{limit=L+1, refs=gb_sets:delete(Ref,Refs)}} + end. diff --git a/learn-you-some-erlang/pool/ppool_sup.erl b/learn-you-some-erlang/pool/ppool_sup.erl new file mode 100644 index 0000000..71ec31d --- /dev/null +++ b/learn-you-some-erlang/pool/ppool_sup.erl @@ -0,0 +1,17 @@ +-module(ppool_sup). +-export([start_link/3, init/1]). +-behaviour(supervisor). + +start_link(Name, Limit, MFA) -> + supervisor:start_link(?MODULE, {Name, Limit, MFA}). + +init({Name, Limit, MFA}) -> + MaxRestart = 1, + MaxTime = 3000, + {ok, {{one_for_all, MaxRestart, MaxTime}, + [{serv, + {ppool_serv, start_link, [Name, Limit, self(), MFA]}, + permanent, + 5000, + worker, + [ppool_serv]}]}}. diff --git a/learn-you-some-erlang/pool/ppool_supersup.erl b/learn-you-some-erlang/pool/ppool_supersup.erl new file mode 100644 index 0000000..5790c5f --- /dev/null +++ b/learn-you-some-erlang/pool/ppool_supersup.erl @@ -0,0 +1,31 @@ +-module(ppool_supersup). +-behaviour(supervisor). +-export([start_link/0, stop/0, start_pool/3, stop_pool/1]). +-export([init/1]). + +start_link() -> + supervisor:start_link({local, ppool}, ?MODULE, []). + +%% technically, a supervisor can not be killed in an easy way. +%% Let's do it brutally! +stop() -> + case whereis(ppool) of + P when is_pid(P) -> + exit(P, kill); + _ -> ok + end. + +start_pool(Name, Limit, MFA) -> + ChildSpec = {Name, + {ppool_sup, start_link, [Name, Limit, MFA]}, + permanent, 10500, supervisor, [ppool_sup]}, + supervisor:start_child(ppool, ChildSpec). + +stop_pool(Name) -> + supervisor:terminate_child(ppool, Name), + supervisor:delete_child(ppool, Name). + +init([]) -> + MaxRestart = 6, + MaxTime = 3000, + {ok, {{one_for_one, MaxRestart, MaxTime}, []}}. diff --git a/learn-you-some-erlang/pool/ppool_tests.erl b/learn-you-some-erlang/pool/ppool_tests.erl new file mode 100644 index 0000000..7cec6d0 --- /dev/null +++ b/learn-you-some-erlang/pool/ppool_tests.erl @@ -0,0 +1,200 @@ +-module(ppool_tests). +-include_lib("eunit/include/eunit.hrl"). +-export([test_mfa/1, wait_mfa/1]). + +%%% All Test Fixtures +start_test_() -> + {"It should be possible to start a pool server and give it a name", + {setup, + fun find_unique_name/0, + fun(Name) -> + [start_and_test_name(Name)] + end}}. + +mfa_test_() -> + {"A pool process can be allocated which will be ordered " + "to run an MFA call determined at start time, with arguments " + "provided at call time", + {setup, + fun start_ppool/0, + fun kill_ppool/1, + fun(Name) -> + [pool_run_mfa(Name)] + end} + }. + +alloc_test_() -> + {"A pool process can be allocated which will be ordered " + "to run a worker, only if there are enough which " + "haven't been ordered to run yet.", + {setup, + fun start_ppool/0, + fun kill_ppool/1, + fun(Name) -> + [pool_run_alloc(Name), + pool_run_noalloc(Name)] + end} + }. + +realloc_test_() -> + {"When an allocated process dies, " + "A new one can be allocated to replace it.", + {setup, + fun start_ppool/0, + fun kill_ppool/1, + fun(Name) -> + [pool_run_realloc(Name)] + end} + }. + +queue_test_() -> + {"The queue function can be used to run the function as soon as possible. " + "If no space is available, the worker call is added to the queue.", + {foreach, + fun start_ppool/0, + fun kill_ppool/1, + [fun(Name) -> test_async_queue(Name) end, + fun(Name) -> test_sync_queue(Name) end]} + }. + +supervision_test_() -> + {"The ppool will never restart a dead child, but all children (OTP " + "compliant) will be shut down when closing the pool, even if they " + "are trapping exits", + {setup, + fun find_unique_name/0, + fun test_supervision/1}}. + +auth_test_() -> + {"The ppool should only dequeue tasks after receiving a down signal " + "from a worker and nobody else", + {setup, + fun start_ppool/0, + fun kill_ppool/1, + fun test_auth_dealloc/1}}. + +%%% Setups/teardowns +find_unique_name() -> + ppool:start_link(), + Name = list_to_atom(lists:flatten(io_lib:format("~p",[now()]))), + ?assertEqual(undefined, whereis(Name)), + Name. + +start_ppool() -> + Name = find_unique_name(), + ppool:start_pool(Name, 2, {ppool_nagger, start_link, []}), + Name. + +kill_ppool(Name) -> + ppool:stop_pool(Name). + +%%% Actual tests +start_and_test_name(Name) -> + ppool:start_pool(Name, 1, {ppool_nagger, start_link, []}), + A = whereis(Name), + ppool:stop_pool(Name), + timer:sleep(100), + B = whereis(Name), + [?_assert(undefined =/= A), + ?_assertEqual(undefined, B)]. + +pool_run_mfa(Name) -> + ppool:run(Name, [i_am_running, 1, 1, self()]), + X = receive + {_Pid, i_am_running} -> ok + after 3000 -> + timeout + end, + ?_assertEqual(ok, X). + +pool_run_alloc(Name) -> + {ok, Pid} = ppool:run(Name, [i_am_running, 1, 1, self()]), + X = receive + {Pid, i_am_running} -> ok + after 3000 -> + timeout + end, + [?_assert(is_pid(Pid)), + ?_assertEqual(ok, X)]. + +pool_run_noalloc(Name) -> + %% Init function should have set the limit to 2 + ppool:run(Name, [i_am_running, 300, 1, self()]), + ppool:run(Name, [i_am_running, 300, 1, self()]), + X = ppool:run(Name, [i_am_running, 1, 1, self()]), + ?_assertEqual(noalloc, X). + +pool_run_realloc(Name) -> + %% Init function should have set the limit to 2 + {ok, A} = ppool:run(Name, [i_am_running, 500, 1, self()]), + timer:sleep(100), + {ok, B} = ppool:run(Name, [i_am_running, 500, 1, self()]), + timer:sleep(600), + {ok, Pid} = ppool:run(Name, [i_am_running, 1, 1, self()]), + timer:sleep(100), + L = flush(), + [?_assert(is_pid(Pid)), + ?_assertEqual([{A,i_am_running}, {B,i_am_running}, {Pid,i_am_running}], + L)]. + +test_async_queue(Name) -> + %% Still two elements max! + ok = ppool:async_queue(Name, [i_am_running, 2000, 1, self()]), + ok = ppool:async_queue(Name, [i_am_running, 2000, 1, self()]), + noalloc = ppool:run(Name, [i_am_running, 2000, 1, self()]), + ok = ppool:async_queue(Name, [i_am_running, 500, 1, self()]), + timer:sleep(3500), + L = flush(), + ?_assertMatch([{_, i_am_running}, {_, i_am_running}, {_, i_am_running}], L). + +test_sync_queue(Name) -> + %% Hell yase, two max + {ok, Pid} = ppool:sync_queue(Name, [i_am_running, 200, 1, self()]), + ok = ppool:async_queue(Name, [i_am_running, 200, 1, self()]), + ok = ppool:async_queue(Name, [i_am_running, 200, 1, self()]), + {ok, Pid2} = ppool:sync_queue(Name, [i_am_running, 100, 1, self()]), + timer:sleep(300), + L = flush(), + [?_assert(is_pid(Pid)), + ?_assert(is_pid(Pid2)), + ?_assertMatch([{_,i_am_running}, {_,i_am_running}, + {_,i_am_running}, {_,i_am_running}], + L)]. + +test_supervision(Name) -> + ppool:start_pool(Name, 1, {ppool_nagger, start_link, []}), + {ok, Pid} = ppool:run(Name, [sup, 10000, 100, self()]), + ppool:stop_pool(Name), + timer:sleep(100), + ?_assertEqual(undefined, process_info(Pid)). + +test_auth_dealloc(Name) -> + %% Hell yase, two max + {ok, _Pid} = ppool:sync_queue(Name, [i_am_running, 500, 1, self()]), + ok = ppool:async_queue(Name, [i_am_running, 10000, 1, self()]), + ok = ppool:async_queue(Name, [i_am_running, 10000, 1, self()]), + ok = ppool:async_queue(Name, [i_am_running, 1, 1, self()]), + timer:sleep(600), + Name ! {'DOWN', make_ref(), process, self(), normal}, + Name ! {'DOWN', make_ref(), process, self(), normal}, + Name ! {'DOWN', make_ref(), process, self(), normal}, + timer:sleep(200), + L = flush(), + ?_assertMatch([{_,i_am_running}], L). + + + +flush() -> + receive + X -> [X|flush()] + after 0 -> + [] + end. + +%% Exported Helper functions +test_mfa(Pid) -> + Pid ! i_am_running. + +wait_mfa(Pid) -> + Pid ! i_am_running, + timer:sleep(3000). diff --git a/learn-you-some-erlang/pool/ppool_worker_sup.erl b/learn-you-some-erlang/pool/ppool_worker_sup.erl new file mode 100644 index 0000000..2467c47 --- /dev/null +++ b/learn-you-some-erlang/pool/ppool_worker_sup.erl @@ -0,0 +1,15 @@ +-module(ppool_worker_sup). +-export([start_link/1, init/1]). +-behaviour(supervisor). + +start_link(MFA = {_,_,_}) -> + supervisor:start_link(?MODULE, MFA). + +init({M,F,A}) -> + MaxRestart = 5, + MaxTime = 3600, + {ok, {{simple_one_for_one, MaxRestart, MaxTime}, + [{ppool_worker, + {M,F,A}, + temporary, 5000, worker, [M]}]}}. + |