%%% @copyright (C) 2019-2023, Maxim Fedorov
%%% @doc
%%% Job is an instance of a benchmark.
%%%
%%% Every job has a corresponding temporary Erlang module generated. Use
%%% {@link source/1} to get the source code of the generated module.
%%% The structure of this code is an implementation detail and may change
%%% between releases.
%%%
%%% Job controls how many workers are executing runner code in
%%% a tight loop. It does not restart a failing worker, user must ensure
%%% proper error handing and reporting. If a worker process crashes,
%%% standard CRASH REPORT message is printed to the log (console).
%%%
%%% Job accepts a {@link code_map()} containing at least a runner
%%% function definition.
%%%
%%% See {@link callable()} for accepted function definitions.
%%%
%%% Different callable forms have different performance overhead. Overhead can be measured
%%% with {@link erlperf:compare/2}:
%%% ```erlang
%%% erlperf:compare([
%%% #{runner => fun (V) -> rand:mwc59(V) end, init_runner => {rand, mwc59_seed, []}},
%%% #{runner => "run(V) -> rand:mwc59(V).", init_runner => {rand, mwc59_seed, []}}
%%% ], #{}).
%% [4371541,131460130]
%%% '''
%%% In the example above, callable defined as `fun' is 30 times slower than the code compiled
%%% from the source. The difference is caused by the Erlang Runtime implementation, where
%%% indirect calls via `fun' are considerably more expensive. As a rule of thumb, source
%%% code provides the smallest overhead, followed by MFA tuples.
%%%
%%% You can mix & match various definition styles. In the example below, `init/0'
%%% starts an extra {@link pg} scope, `done/0' stops it, and `init_runner/1' takes
%%% the total heap size of `pg' scope controller to pass it to the `runner/1'.
%%% ```erlang
%%% erlperf_job:start_link(
%%% #{
%%% runner => "run(Max) -> rand:uniform(Max).",
%%% init => {pg, start_link, [scope]},
%%% init_runner =>
%%% fun ({ok, Pid}) ->
%%% {total_heap_size, THS} = erlang:process_info(Pid, total_heap_size),
%%% THS
%%% end,
%%% done => fun ({ok, Pid}) -> gen_server:stop(Pid) end
%%% }
%%% ).
%%% '''
%%% Same example defined with just the source code:
%%% ```erlang
%%% erlperf_job:start_link(
%%% #{
%%% runner => "runner(Max) -> rand:uniform(Max).",
%%% init => "init() -> pg:start_link().",
%%% init_runner => "init_runner({ok, Pid}) ->
%%% {total_heap_size, THS} = erlang:process_info(Pid, total_heap_size),
%%% THS.",
%%% done => "done({ok, Pid}) -> gen_server:stop(Pid)."
%%% }
%%% ).
%%% '''
%%%
%%% <h2>Runner function</h2>
%%% Runner function represents code that is run in the tight loop, counting iterations
%%% aggregated between all workers. To give an example, benchmarking a function that takes
%%% exactly a millisecond to execute, with 2 workers, for 2 seconds, will result in
%%% 4000 iterations in total. This would be the value returned by {@link sample/1}.
%%%
%%%
%%% Runner definition can accept zero, one or two arguments.
%%%
%%% `runner/0' ignores the value returned by init_runner/0,1.
%%%
%%% `runner/1' accepts the value returned by init_runner/0,1. It is an error to define
%%% `runner/1' without `init_runner/0,1' defined. This example prints "0" in a
%%% tight loop, measuring {@link io:format/2} performance:
%%% ```erlang
%%% #{
%%% runner => "run(Init) -> io:format(\"~b~n\", [Init]).",
%%% init_runner => "0."
%%% }
%%% '''
%%%
%%% `runner/2' adds second argument, accumulator, initially set to the
%%% value returned by init_runner/0,1. Subsequent invocations receive
%%% value returned by the previous runner invocation. Example:
%%% ```erlang
%%% #{
%%% runner => "run(Init, Acc) -> io:format(\"~b~n\", [Init + Acc]), Acc + 1.",
%%% init_runner => "0."
%%% }
%%% '''
%%% Running this benchmark prints monotonically increasing numbers. This
%%% may be useful to test stateful functions, for example, fast Random Number
%%% Generators introduced in OTP 25:
%%% ```bash
%%% ./erlperf --init_runner 'rand:mwc59_seed().' 'run(_, Cur) -> rand:mwc59(Cur).'
%%% Code || QPS Time
%%% run(_, Cur) -> rand:mwc59(Cur). 1 123 Mi 8 ns
%%% '''
%%%
%%%
%%% <h2>Common Test usage</h2>
%%%
%%% Example using `erlperf_job' directly, as a part of Common Test test case:
%%% ```erlang
%%% benchmark_rand(Config) when is_list(Config) ->
%%% %% run timer:sleep(1000) for 5 second, 4 runners
%%% {ok, Job} = erlperf_job:start_link(#{runner => {timer, sleep, [1000]}}),
%%% Handle = erlperf_job:handle(Job),
%%% ok = erlperf_job:set_concurrency(Job, 4), %% 4 runner instances
%%% InitialIterations = erlperf_job:sample(Handle),
%%% timer:sleep(5000),
%%% IterationsIn5Sec = erlperf_job:sample(Handle) - InitialIterations,
%%% erlperf_job:request_stop(Job), %% use gen:stop(Job) for synchronous call
%%% %% expect at least 16 iterations (and up to 20)
%%% ?assert(IterationsIn5Sec >= 16, {too_slow, IterationsIn5Sec}),
%%% ?assert(IterationsIn5Sec =< 20, {too_fast, IterationsIn5Sec}).
%%% '''
%%%
%%% @end
-module(erlperf_job).
-author("maximfca@gmail.com").
-behaviour(gen_server).
%% Job API
-export([
start/1,
start_link/1,
request_stop/1,
concurrency/1,
set_concurrency/2,
measure/2,
sample/1,
handle/1,
source/1,
set_priority/2
]).
%% gen_server callbacks
-export([
init/1,
handle_call/3,
handle_cast/2,
handle_info/2,
terminate/2
]).
%% MFArgs: module, function, arguments.
-type mfargs() :: {Module :: module(), Function :: atom(), Args :: [term()]}.
%% `Module', `Function', `Args' accepted by {@link erlang:apply/3}.
%% Callable: one or more MFArgs, or a function object, or source code
-type callable() ::
string() |
fun() |
fun((term()) -> term()) |
fun((term(), term()) -> term()) |
mfargs() |
[mfargs()].
%% Function definition to use as a runner, init, done or init_runner.
%%
%% <ul>
%% <li>`string().' Erlang code ending with `.' (period). Example, zero arity:
%% `"runner() -> timer:sleep(1)."', arity one: `"runner(T) -> timer:sleep(T)."',
%% arity two: `"runner(Init, Acc) -> Acc + Init."'. It is allowed to omit the header
%% for zero arity function, so it becomes `"timer:sleep(1)."'</li>
%% <li>`fun()' function accepting no arguments, example: `fun() -> timer:sleep(1000) end'</li>
%% <li>`fun(term()) -> term()' function accepting one argument, example: `fun(Time) -> timer:sleep(Time) end'</li>
%% <li>`fun(term(), term()) -> term()' function accepting two arguments, example: `fun() -> timer:sleep(1000) end'</li>
%% <li>`mfargs()' tuple accepted by {@link erlang:apply/3}.
%% Example: `{rand, uniform, [10]}'</li>
%% <li>`[mfargs()]' list of MFA tuples, example: `[{rand, uniform, [10]}]'.
%% This functionality is experimental, and only used to replay a recorded calls
%% list. May not be supported in future releases.</li>
%% </ul>
%% Benchmark code: init, init_runner, runner, done.
-type code_map() :: #{
runner := callable(),
init => callable(),
init_runner => callable(),
done => callable()
}.
%% Code map contains definitions for:
%%
%% <ul>
%% <li>`init/0' - called once when starting the job for the first time.
%% The call is made in the context of the job controller. It is
%% guaranteed to run through the entire benchmark job. So if your
%% benchmark needs to create additional resources - ETS tables, or
%% linked processes, like extra {@link pg} scopes, - init/0 is a
%% good choice. If init/0 fails, the entire job startup fails</li>
%% <li>`init_runner/0,1' - called when the job starts a new worker. init_runner/1
%% accepts the value returned by init/0. It is an error to omit init/0
%% if init_runner/1 is defined. It is allowed to have init_runner/0
%% when init/0 exists. The call to init_runner is made in the context of the
%% worker process, so you can initialise process-local values (e.g.
%% process dictionary)</li>
%% <li>`runner/0,1,2' defines the function that will be called in a tight loop.
%% See detailed description below</li>
%% <li>`done/0,1' - called when the job terminates, to clean up any resources
%% that are not destroyed automatically. done/0 accepts the return of init/0.
%% Call is made in the context of the job controller</li>
%% </ul>
%% Internal (opaque) type, please do not use
-opaque handle() :: {module(), non_neg_integer()}.
%% Temporary type until OTP25+ is everywhere, and OTP <25 support is no longer needed
-type server_ref() :: gen_server:server_ref().
-export_type([mfargs/0, handle/0, callable/0, code_map/0]).
%% @doc
%% Starts the benchmark job.
%%
%% Job starts with no workers, use {@link set_concurrency/2} to start workers.
-spec start(code_map()) -> {ok, pid()} | {error, term()}.
start(#{runner := _MustHave} = Code) ->
gen_server:start(?MODULE, generate(Code), []).
%% @doc
%% Starts the job and links it to caller.
%%
%% Job starts with no workers, use {@link set_concurrency/2} to start workers.
-spec start_link(code_map()) -> {ok, pid()} | {error, term()}.
start_link(#{runner := _MustHave} = Code) ->
gen_server:start_link(?MODULE, generate(Code), []).
%% @doc
%% Requests this job to stop.
%%
%% Job is stopped asynchronously. Caller should monitor the job process
%% to find out when the job actually stopped.
-spec request_stop(server_ref()) -> ok.
request_stop(JobId) ->
gen_server:cast(JobId, stop).
%% @doc
%% Returns the number of concurrently running workers for this job.
%%
%% This number may be lower than the amount requested by {@link set_concurrency/2}
%% if workers crash.
-spec concurrency(server_ref()) -> Concurrency :: non_neg_integer().
concurrency(JobId) ->
gen_server:call(JobId, concurrency).
%% @doc
%% Sets the number of concurrently running workers for this job.
%%
%% Does not reset counting. May never return if init_runner
%% hangs and does not return control the the job.
%% `Concurrency': number of processes to run. It can be higher than
%% the current count (making the job to start more workers), or
%% lower, making the job to stop some.
%%
%% Workers that crashes are not restarted automatically.
-spec set_concurrency(server_ref(), non_neg_integer()) -> ok.
set_concurrency(JobId, Concurrency) ->
gen_server:call(JobId, {set_concurrency, Concurrency}, infinity).
%% @doc
%% Run the timed mode benchmark for a job, similar to {@link timer:tc/3}.
%%
%% Executes the runner `SampleCount' times. Returns time in microseconds.
%% Has less overhead compared to continuous benchmarking, therefore can
%% be used even for very fast functions.
-spec measure(server_ref(), SampleCount :: non_neg_integer()) ->
TimeUs :: non_neg_integer() | already_started.
measure(JobId, SampleCount) ->
gen_server:call(JobId, {measure, SampleCount}, infinity).
%% @doc
%% Returns the sampling handle for the job.
%%
%% The returned value is opaque, and is an implementation detail,
%% do not use it in any quality other than passing to {@link sample/1}.
-spec handle(server_ref()) -> handle().
handle(JobId) ->
gen_server:call(JobId, handle).
%% @doc
%% Returns the current iteration counter.
%%
%% The iteration counter (sample) monotonically grows by 1
%% every time the runner function is called (without waiting
%% for it to return, so a function that unconditionally crashes
%% still generates a counter of 1).
-spec sample(Handle :: handle()) -> non_neg_integer() | undefined.
sample({Module, Arity}) ->
{call_count, Count} = erlang:trace_info({Module, Module, Arity}, call_count),
Count.
%% @doc
%% Returns the source code that was generated for this job.
-spec source(server_ref()) -> [string()].
source(JobId) ->
gen_server:call(JobId, source).
%% @doc
%% Sets job process priority when there are workers running.
%%
%% Worker processes may utilise all schedulers, making job
%% process to lose control over starting and stopping workers.
%% By default, job process sets 'high' priority when there are
%% any workers running.
%% Returns the previous setting.
%%
%% This function must be called before {@link set_concurrency/2},
%% otherwise it has no effect until all workers are stopped, and
%% then restarted.
-spec set_priority(server_ref(), erlang:priority_level()) -> erlang:priority_level().
set_priority(JobId, Priority) ->
gen_server:call(JobId, {priority, Priority}).
%%--------------------------------------------------------------------
%% Internal definitions
-include_lib("kernel/include/logger.hrl").
-record(exec, {
name :: atom(), %% generated module name (must be generated for tracing to work)
source :: [string()], %% module source code
binary :: binary(), %% generated bytecode
init :: fun(() -> term()), %% init function
init_runner :: fun((term()) -> term()), %% must accept 1 argument
runner :: {fun((term()) -> term()), non_neg_integer()},
sample_runner :: {fun((non_neg_integer(), term()) -> term()), non_neg_integer()},
done :: fun((term()) -> term()) %% must accept 1 argument
}).
-type exec() :: #exec{}.
-record(erlperf_job_state, {
%% original spec
exec :: exec(),
%% return value of init/1
init_result :: term(),
%% continuous workers
workers = [] :: [pid()],
%% temporary workers (for sample_count call)
sample_workers = #{} :: #{pid() => {pid(), reference()}},
%% priority to return to when no workers left
initial_priority :: erlang:priority_level(),
%% priority to set when workers are running
priority = high :: erlang:priority_level()
}).
-type state() :: #erlperf_job_state{}.
%%%===================================================================
%%% gen_server callbacks
%% @private
init(#exec{name = Mod, binary = Bin, init = Init, runner = {_Fun, Arity}} = Exec) ->
%% need to trap exits to avoid crashing and not cleaning up the loaded module
erlang:process_flag(trap_exit, true),
{module, Mod} = code:load_binary(Mod, Mod, Bin),
%% run the init/0 if defined
InitRet =
try Init()
catch
Class:Reason:Stack ->
%% clean up loaded module before crashing
code:purge(Mod),
code:delete(Mod),
erlang:raise(Class, Reason, Stack)
end,
%% register in the monitor
ok = erlperf_monitor:register(self(), {Mod, Arity}, 0),
%% start tracing this module runner function
1 = erlang:trace_pattern({Mod, Mod, Arity}, true, [local, call_count]),
{priority, Prio} = erlang:process_info(self(), priority),
{ok, #erlperf_job_state{exec = Exec, init_result = InitRet, initial_priority = Prio}}.
%% @private
-spec handle_call(term(), {pid(), reference()}, state()) -> {reply, term(), state()}.
handle_call(handle, _From, #erlperf_job_state{exec = #exec{name = Name, runner = {_Fun, Arity}}} = State) ->
{reply, {Name, Arity}, State};
handle_call(concurrency, _From, #erlperf_job_state{workers = Workers} = State) ->
{reply, length(Workers), State};
handle_call({measure, SampleCount}, From, #erlperf_job_state{sample_workers = SampleWorkers,
exec = #exec{init_runner = InitRunner, sample_runner = SampleRunner},
init_result = IR} = State) when SampleWorkers =:= #{} ->
{noreply, State#erlperf_job_state{sample_workers =
start_sample_count(SampleCount, From, InitRunner, IR, SampleRunner)}};
handle_call({measure, _SampleCount}, _From, #erlperf_job_state{} = State) ->
{reply, already_started, State};
handle_call(source, _From, #erlperf_job_state{exec = #exec{source = Source}} = State) ->
{reply, Source, State};
handle_call({priority, Prio}, _From, #erlperf_job_state{priority = Old} = State) ->
{reply, Old, State#erlperf_job_state{priority = Prio}};
handle_call({set_concurrency, Concurrency}, _From, #erlperf_job_state{workers = Workers} = State) ->
{reply, ok, State#erlperf_job_state{workers = set_concurrency_impl(length(Workers), Concurrency, State)}}.
%% @private
handle_cast(stop, State) ->
{stop, normal, State}.
%% @private
-spec handle_info(term(), state()) -> {noreply, state()}.
handle_info({'EXIT', SampleWorker, Reason},
#erlperf_job_state{sample_workers = SampleWorkers} = State) when is_map_key(SampleWorker, SampleWorkers) ->
{ReplyTo, MoreSW} = maps:take(SampleWorker, SampleWorkers),
gen:reply(ReplyTo, Reason),
{noreply, State#erlperf_job_state{sample_workers = MoreSW}};
handle_info({'EXIT', Worker, Reason}, #erlperf_job_state{workers = Workers} = State) when Reason =:= shutdown ->
{noreply, State#erlperf_job_state{workers = lists:delete(Worker, Workers)}};
handle_info({'EXIT', Worker, Reason}, #erlperf_job_state{workers = Workers} = State) ->
{stop, Reason, State#erlperf_job_state{workers = lists:delete(Worker, Workers)}}.
%% @private
-spec terminate(term(), state()) -> ok.
terminate(_Reason, #erlperf_job_state{init_result = IR, workers = Workers, exec = #exec{name = Mod, done = Done}} = State) ->
%% terminate all workers first
set_concurrency_impl(length(Workers), 0, State),
%% call "done" for cleanup
try Done(IR)
catch
Class:Reason:Stack ->
%% duly note, but do not crash, it is pointless at this moment
?LOG_ERROR("Exception while executing 'done': ~s:~0p~n~0p", [Class, Reason, Stack])
after
_ = code:purge(Mod),
true = code:delete(Mod)
end.
%%%===================================================================
%%% Internal: runner implementation
%% Single run
start_sample_count(SampleCount, ReplyTo, InitRunner, InitRet, {SampleRunner, _}) ->
Child = erlang:spawn_link(
fun() ->
%% need to send a message even if init_runner fails, hence 'after'
IRR = InitRunner(InitRet),
T1 = erlang:monotonic_time(),
SampleRunner(SampleCount, IRR),
T2 = erlang:monotonic_time(),
Time = erlang:convert_time_unit(T2 - T1, native, microsecond),
exit(Time)
end
),
#{Child => ReplyTo}.
set_concurrency_impl(OldConcurrency, Concurrency, #erlperf_job_state{workers = Workers, init_result = IR, exec = Exec,
priority = Prio, initial_priority = InitialPrio}) ->
case Concurrency - OldConcurrency of
0 ->
Workers;
NeedMore when NeedMore > 0 ->
%% this process must run with higher priority to avoid being de-scheduled by runners
OldConcurrency =:= 0 andalso erlang:process_flag(priority, Prio),
Workers ++ add_workers(NeedMore, Exec, IR, []);
NeedLess ->
{Fire, Keep} = lists:split(-NeedLess, Workers),
stop_workers(Fire),
Keep =:= [] andalso erlang:process_flag(priority, InitialPrio),
Keep
end.
add_workers(0, _ExecMap, _InitRet, NewWorkers) ->
%% ensure all new workers completed their InitRunner routine
[receive {Worker, init_runner} -> ok end || Worker <- NewWorkers],
[Worker ! go || Worker <- NewWorkers],
NewWorkers;
add_workers(More, #exec{init_runner = InitRunner, runner = {Runner, _RunnerArity}} = Exec, InitRet, NewWorkers) ->
Control = self(),
%% spawn all processes, and then wait until they complete InitRunner
Worker = erlang:spawn_link(
fun () ->
%% need to send a message even if init_runner fails, hence 'after'
IRR = try InitRunner(InitRet) after Control ! {self(), init_runner} end,
receive go -> ok end,
Runner(IRR)
end),
add_workers(More - 1, Exec, InitRet, [Worker | NewWorkers]).
stop_workers(Workers) ->
%% try to stop concurrently
[exit(Worker, kill) || Worker <- Workers],
[receive {'EXIT', Worker, _Reason} -> ok end || Worker <- Workers].
%%%===================================================================
%%% Internal: code generation
%% @doc Creates an Erlang module (text) based on the code map passed
%% Returns module name (may be generated), runner arity (for tracing purposes),
%% and module source code (text)
%% Exception: raises error with Reason = {generate, {FunName, Arity, ...}}
%%
%% Important: early erlperf versions were generating AST (forms) instead
%% of source code, which isn't exactly supported - AST is internal thing
%% that can change over time.
-spec generate(code_map()) -> exec().
generate(Code) ->
Name = list_to_atom(lists:concat(["job_", os:getpid(), "_", erlang:unique_integer([positive])])),
generate(Name, Code).
generate(Name, #{runner := Runner} = Code) ->
{InitFun, InitArity, InitExport, InitText} = generate_init(Name, maps:get(init, Code, error)),
{IRFun, IRArity, IRExport, IRText} = generate_one(Name, init_runner, maps:get(init_runner, Code, error)),
{DoneFun, DoneArity, DoneExport, DoneText} = generate_one(Name, done, maps:get(done, Code, error)),
%% RunnerArity: how many arguments _original_ runner wants to accept.
%% Example: run(State) is 1, and run() is 0.
%% Pass two function names: one that is for sample_count, and one for continuous
ContName = atom_to_list(Name),
SampleCountName = list_to_atom(ContName ++ "_" ++ integer_to_list(erlang:unique_integer([positive]))),
{RunnerFun, SampleRunnerFun, RunnerArity, RunArity, RunnerText} = generate_runner(Name, SampleCountName, Runner),
RunnerExports = [{Name, RunArity}, {SampleCountName, RunArity + 1}],
%% verify compatibility between 4 pieces of code
%% 1. done/1 requires init/0 return value
DoneArity =:= 1 andalso InitArity =:= undefined andalso erlang:error({generate, {done, 1, requires, init}}),
%% 2. init_runner/1 requires init/0,1
IRArity =:= 1 andalso InitArity =:= undefined andalso erlang:error({generate, {init_runner, 1, requires, init}}),
%% 3. runner/1,2 requires init/0,1
RunnerArity > 0 andalso IRArity =:= undefined andalso erlang:error({generate, {runner, RunnerArity, requires, init_runner}}),
%% 4. runner/[3+] is not allowed
RunnerArity > 2 andalso erlang:error({generate, {runner, RunnerArity, not_supported}}),
%% 5. TODO: Verify there are no name clashes
%%
Exports = lists:concat(lists:join(", ", [io_lib:format("~s/~b", [F, Arity]) || {F, Arity} <-
[InitExport, IRExport, DoneExport | RunnerExports], Arity =/= undefined])),
Texts = [Text || Text <- [InitText, IRText, DoneText | RunnerText], Text =/= ""],
Source = ["-module(" ++ atom_to_list(Name) ++ ").", "-export([" ++ Exports ++ "])." | Texts],
#exec{name = Name, binary = compile(Name, Source), init = InitFun, init_runner = IRFun, source = Source,
runner = {RunnerFun, RunArity}, sample_runner = {SampleRunnerFun, RunArity}, done = DoneFun}.
%% generates init/0 code
generate_init(_Mod, Fun) when is_function(Fun, 0) ->
{Fun, 0, {[], undefined}, ""};
generate_init(_Mod, {M, F, Args}) when is_atom(M), is_atom(F), is_list(Args) ->
{fun () -> erlang:apply(M, F, Args) end, 0, {[], undefined}, ""};
generate_init(_Mod, [{M, F, Args} | _Tail] = MFAList) when is_atom(M), is_atom(F), is_list(Args) ->
[erlang:error({generate, {init, 0, invalid}}) ||
{M1, F1, A} <- MFAList, not is_atom(M1) orelse not is_atom(F1) orelse not is_list(A)],
{fun () -> [erlang:apply(M1, F1, A) || {M1, F1, A} <- MFAList] end, 0, {[], undefined}, ""};
generate_init(Mod, Text) when is_list(Text) ->
case generate_text(init, Text, false) of
{0, NewName, FullText} ->
{fun () -> Mod:NewName() end, 0, {NewName, 0}, FullText};
{WrongArity, NewName, _} ->
erlang:error({generate, {init, NewName, WrongArity}})
end;
generate_init(_Mod, error) ->
{fun () -> undefined end, undefined, undefined, ""}.
%% generates init_runner/1 or done/1
generate_one(_Mod, _FunName, error) ->
{fun (_Ignore) -> undefined end, undefined, {[], undefined}, ""};
generate_one(_Mod, _FunName, Fun) when is_function(Fun, 1) ->
{Fun, 1, {[], undefined}, ""};
generate_one(_Mod, _FunName, Fun) when is_function(Fun, 0) ->
{fun (_Ignore) -> Fun() end, 0, {[], undefined}, ""};
generate_one(_Mod, _FunName, {M, F, Args}) when is_atom(M), is_atom(F), is_list(Args) ->
{fun (_Ignore) -> erlang:apply(M, F, Args) end, 0, {[], undefined}, ""};
generate_one(_Mod, FunName, [{M, F, Args} | _Tail] = MFAList) when is_atom(M), is_atom(F), is_list(Args) ->
[erlang:error({generate, {FunName, 1, invalid, {M1, F1, A}}}) ||
{M1, F1, A} <- MFAList, not is_atom(M1) orelse not is_atom(F1) orelse not is_list(A)],
{fun (_Ignore) -> [erlang:apply(M1, F1, A) || {M1, F1, A} <- MFAList] end, 0, {[], undefined}, ""};
generate_one(Mod, FunName, Text) when is_list(Text) ->
case generate_text(FunName, Text, false) of
{0, NewName, FullText} ->
{fun (_Ignore) -> Mod:NewName() end, 0, {NewName, 0}, FullText};
{1, NewName, FullText} ->
{fun (Arg) -> Mod:NewName(Arg) end, 1, {NewName, 1}, FullText};
{WrongArity, NewName, _} ->
erlang:error({generate, {FunName, WrongArity, NewName}})
end.
%% runner wrapper:
%% Generates at least 2 functions, one for continuous, and one for
%% sample-count benchmarking.
generate_runner(Mod, SampleCountName, Fun) when is_function(Fun, 0) ->
{
fun (_Ignore) -> Mod:Mod(Fun) end,
fun (SampleCount, _Ignore) -> Mod:SampleCountName(SampleCount, Fun) end,
0, 1,
[lists:concat([Mod, "(Fun) -> Fun(), ", Mod, "(Fun)."]),
lists:concat([SampleCountName, "(0, _Fun) -> ok; ", SampleCountName, "(Count, Fun) -> Fun(), ",
SampleCountName, "(Count - 1, Fun)."])]
};
generate_runner(Mod, SampleCountName, Fun) when is_function(Fun, 1) ->
{
fun (Init) -> Mod:Mod(Init, Fun) end,
fun (SampleCount, Init) -> Mod:SampleCountName(SampleCount, Init, Fun) end,
1, 2,
[lists:concat([Mod, "(Init, Fun) -> Fun(Init), ", Mod, "(Init, Fun)."]),
lists:concat([SampleCountName, "(0, _Init, _Fun) -> ok; ", SampleCountName, "(Count, Init, Fun) -> Fun(Init), ",
SampleCountName, "(Count - 1, Init, Fun)."])]
};
generate_runner(Mod, SampleCountName, Fun) when is_function(Fun, 2) ->
{
fun (Init) -> Mod:Mod(Init, Init, Fun) end,
fun (SampleCount, Init) -> Mod:SampleCountName(SampleCount, Init, Init, Fun) end,
2, 3,
[lists:concat([Mod, "(Init, State, Fun) -> ", Mod, "(Init, Fun(Init, State), Fun)."]),
lists:concat([SampleCountName, "(0, _Init, _State, _Fun) -> ok; ", SampleCountName, "(Count, Init, State, Fun) -> ",
SampleCountName, "(Count - 1, Init, Fun(Init, State), Fun)."])]
};
%% runner wrapper: MFA
generate_runner(Mod, SampleCountName, {M, F, Args}) when is_atom(M), is_atom(F), is_list(Args) ->
{
fun (_Ignore) -> Mod:Mod(M, F, Args) end,
fun (SampleCount, _Ignore) -> Mod:SampleCountName(SampleCount, M, F, Args) end,
0, 3,
[lists:concat([Mod, "(M, F, A) -> erlang:apply(M, F, A), ", Mod, "(M, F, A)."]),
lists:concat([SampleCountName, "(0, _M, _F, _A) -> ok; ", SampleCountName,
"(Count, M, F, A) -> erlang:apply(M, F, A), ", SampleCountName, "(Count - 1, M, F, A)."])]
};
%% runner wrapper: MFAList
generate_runner(Mod, SampleCountName, [{M, F, Args} | _Tail] = MFAList) when is_atom(M), is_atom(F), is_list(Args) ->
[erlang:error({generate, {runner, 0, invalid, {M1, F1, A}}}) ||
{M1, F1, A} <- MFAList, not is_atom(M1) orelse not is_atom(F1) orelse not is_list(A)],
{
fun (_Ignore) -> Mod:Mod(MFAList) end,
fun (SampleCount, _Ignore) -> Mod:SampleCountName(SampleCount, MFAList) end,
0, 1,
[lists:concat([Mod, "(MFAList) -> [erlang:apply(M, F, A) || {M, F, A} <- MFAList], ", Mod, "(MFAList)."]),
lists:concat([SampleCountName, "(0, _MFAList) -> ok; ", SampleCountName,
"(Count, MFAList) -> [erlang:apply(M, F, A) || {M, F, A} <- MFAList], ", SampleCountName, "(Count - 1, MFAList)."])]
};
generate_runner(Mod, SampleCountName, Text) when is_list(Text) ->
case generate_text(runner, Text, true) of
{0, NoDotText} ->
%% very special case: embedding the text directly, without creating a new function
%% at all.
{
fun (_Ignore) -> Mod:Mod() end,
fun (SampleCount, _Ignore) -> Mod:SampleCountName(SampleCount) end,
0, 0,
[lists:concat([Mod, "() -> ", NoDotText, ", ", Mod, "()."]),
lists:concat([SampleCountName, "(0) -> ok;", SampleCountName, "(Count) -> ",
NoDotText, ", ", SampleCountName, "(Count - 1)."]),
""]
};
{0, NewName, FullText} ->
{
fun (_Ignore) -> Mod:Mod() end,
fun (SampleCount, _Ignore) -> Mod:SampleCountName(SampleCount) end,
0, 0,
[lists:concat([Mod, "() -> ", NewName, "(), ", Mod, "()."]),
lists:concat([SampleCountName, "(0) -> ok;", SampleCountName, "(Count) -> ",
NewName, "(), ", SampleCountName, "(Count - 1)."]),
FullText]
};
{1, NewName, FullText} ->
{
fun (Init) -> Mod:Mod(Init) end,
fun (SampleCount, Init) -> Mod:SampleCountName(SampleCount, Init) end,
1, 1,
[lists:concat([Mod, "(Init) -> ", NewName, "(Init), ", Mod, "(Init)."]),
lists:concat([SampleCountName, "(0, _Init) -> ok;", SampleCountName, "(Count, Init) -> ",
NewName, "(Init), ", SampleCountName, "(Count - 1, Init)."]),
FullText]
};
{2, NewName, FullText} ->
{
fun (Init) -> Mod:Mod(Init, Init) end,
fun (SampleCount, Init) -> Mod:SampleCountName(SampleCount, Init, Init) end,
2, 2,
[lists:concat([Mod, "(Init, State) -> ", Mod, "(Init, ", NewName, "(Init, State))."]),
lists:concat([SampleCountName, "(0, _Init, _State) -> ok;", SampleCountName, "(Count, Init, State) -> ",
SampleCountName, "(Count - 1, Init, ", NewName, "(Init, State))."]),
FullText]
}
end;
generate_runner(_Mod, _SampleCountName, Any) ->
erlang:error({generate, {parse, runner, Any}}).
%% generates function text
generate_text(Name, Text, AllowRaw) when is_list(Text) ->
case erl_scan:string(Text) of
{ok, Scan, _} ->
case erl_parse:parse_form(Scan) of
{ok, {function, _, AnyName, Arity, _}} ->
{Arity, AnyName, Text};
{error, _} ->
% try if it's an expr
case erl_parse:parse_exprs(Scan) of
{ok, _Clauses} when AllowRaw ->
{0, lists:droplast(Text)};
{ok, _Clauses} ->
%% just wrap it in fun_name/0
{0, Name, lists:concat([Name, "() -> ", Text])};
{error, {_Line, ParseMod, Es}} ->
Errors = ParseMod:format_error(Es),
erlang:error({generate, {parse, Name, Errors}})
end
end;
{error, ErrorInfo, ErrorLocation} ->
error({generate, {scan, Name, ErrorInfo, ErrorLocation}})
end.
%% @doc Compiles text string into a binary module ready for code loading.
compile(Name, Lines) ->
%% might not be the best way, but OTP simply does not have file:compile(Source, ...)
%% Original design was to write the actual source file to temporary disk location,
%% but for diskless or write-protected hosts it was less convenient.
Tokens = [begin {ok, T, _} = erl_scan:string(Line), T end || Line <- Lines],
Forms = [begin {ok, F} = erl_parse:parse_form(T), F end || T <- Tokens],
case compile:forms(Forms, [no_spawn_compiler_process, binary, return]) of
{ok, Name, Bin} ->
Bin;
{ok, Name, Bin, _Warnings} ->
Bin;
{error, Errors, Warnings} ->
erlang:error({compile, Errors, Warnings})
end.
