sol2/tests/test_coroutines.cpp

#define SOL_CHECK_ARGUMENTS

#include <catch.hpp>
#include <sol.hpp>

TEST_CASE("coroutines/threading", "ensure calling a coroutine works") {
	const auto& script = R"(counter = 20
 
function loop()
    while counter ~= 30
    do
        coroutine.yield(counter);
        counter = counter + 1;
    end
    return counter
end
)";

	sol::state lua;
	lua.open_libraries(sol::lib::base, sol::lib::coroutine);
	lua.safe_script(script);
	sol::coroutine cr = lua["loop"];

	int counter;
	for (counter = 20; counter < 31 && cr; ++counter) {
		int value = cr();
		if (counter != value) {
			throw std::logic_error("fuck");
		}
	}
	counter -= 1;
	REQUIRE(counter == 30);
}

TEST_CASE("coroutines/new thread coroutines", "ensure calling a coroutine works when the work is put on a different thread") {
	const auto& script = R"(counter = 20
 
function loop()
    while counter ~= 30
    do
        coroutine.yield(counter);
        counter = counter + 1;
    end
    return counter
end
)";

	sol::state lua;
	lua.open_libraries(sol::lib::base, sol::lib::coroutine);
	lua.safe_script(script);
	sol::thread runner = sol::thread::create(lua.lua_state());
	sol::state_view runnerstate = runner.state();
	sol::coroutine cr = runnerstate["loop"];

	int counter;
	for (counter = 20; counter < 31 && cr; ++counter) {
		int value = cr();
		if (counter != value) {
			throw std::logic_error("fuck");
		}
	}
	counter -= 1;
	REQUIRE(counter == 30);
}

TEST_CASE("coroutines/transfer", "test that things created inside of a coroutine can have their state transferred using lua_xmove constructors") {
	for (std::size_t tries = 0; tries < 200; ++tries) {
		sol::state lua;
		lua.open_libraries();
		{
			sol::function f2;
			lua["f"] = [&lua, &f2](sol::object t) {
				f2 = sol::function(lua, t);
			};

			lua.script(R"(
i = 0
function INIT()
	co = coroutine.create(
		function()
			local g = function() i = i + 1 end
			f(g)
			g = nil
			collectgarbage()
		end
	)
	coroutine.resume(co)
	co = nil
	collectgarbage()
end
)");
			sol::function f3;
			sol::function f1;

			lua.safe_script("INIT()");
			f2();
			sol::function update = lua.safe_script("return function() collectgarbage() end");
			update();
			f3 = f2;
			f3();
			update();
			f1 = f2;
			f1();
			update();
			int i = lua["i"];
			REQUIRE(i == 3);
		}
	}
}

TEST_CASE("coroutines/implicit transfer", "check that copy and move assignment constructors implicitly shift things around") {
	const std::string code = R"(
-- main thread - L1
-- co - L2
-- co2 - L3

x = co_test.new("x")
local co = coroutine.wrap(
	function()
		local t = co_test.new("t")
		local co2 = coroutine.wrap(
			function()
				local t2 = { "SOME_TABLE" }
				t:copy_store(t2) -- t2 = [L3], t.obj = [L2]
			end
		)

		co2()
		co2 = nil

		collectgarbage() -- t2 ref in t remains valid!

		x:store(t:get()) -- t.obj = [L2], x.obj = [L1]
    end
)

co()
collectgarbage()
collectgarbage()
co = nil
)";

	struct co_test {
		std::string identifier;
		sol::reference obj;

		co_test(sol::this_state L, std::string id) : identifier(id), obj(L, sol::lua_nil) {

		}

		void store(sol::table ref) {
			// must be explicit
			obj = sol::reference(obj.lua_state(), ref);
		}

		void copy_store(sol::table ref) {
			// must be explicit
			obj = sol::reference(obj.lua_state(), ref);
		}

		sol::reference get() {
			return obj;
		}

		~co_test() {

		}
	};

	sol::state lua;
	lua.open_libraries(sol::lib::coroutine, sol::lib::base);

	lua.new_usertype<co_test>("co_test",
		sol::constructors<co_test(sol::this_state, std::string)>(),
		"store", &co_test::store,
		"copy_store", &co_test::copy_store,
		"get", &co_test::get
		);


	auto r = lua.safe_script(code);
	REQUIRE(r.valid());

	co_test& ct = lua["x"];

	lua_State* Lmain1 = lua.lua_state();
	lua_State* Lmain2 = sol::main_thread(lua);
	lua_State* Lmain3 = ct.get().lua_state();
	REQUIRE(Lmain1 == Lmain2);
	REQUIRE(Lmain1 == Lmain3);

	sol::table t = ct.get();
	REQUIRE(t.size() == 1);
	std::string s = t[1];
	REQUIRE(s == "SOME_TABLE");
}