luanti/src/benchmark/benchmark_ipc_channel.cpp

/*
Minetest
Copyright (C) 2024 DS

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include "catch.h"
#include "threading/ipc_channel.h"
#include <thread>

TEST_CASE("benchmark_ipc_channel")
{
	auto end_a_thread_b_p = make_test_ipc_channel([](IPCChannelEnd end_b) {
		// echos back messages. stops if "" is sent
		for (;;) {
			end_b.recv();
			end_b.send(end_b.getRecvData());
			if (end_b.getRecvData().size() == 0)
				break;
		}
	});
	// Can't use structured bindings before C++20, because of lamda captures below.
	auto end_a = std::move(end_a_thread_b_p.first);
	auto thread_b = std::move(end_a_thread_b_p.second);

	BENCHMARK("simple_call_1", i) {
		char buf[16] = {};
		buf[i & 0xf] = i;
		end_a.exchange({buf, 16});
		return end_a.getRecvData()[i & 0xf];
	};

	BENCHMARK("simple_call_1000", i) {
		char buf[16] = {};
		buf[i & 0xf] = i;
		for (int k = 0; k < 1000; ++k) {
			buf[0] = k & 0xff;
			end_a.exchange({buf, 16});
		}
		return end_a.getRecvData()[i & 0xf];
	};

	// stop thread_b
	end_a.exchange({nullptr, 0});
	REQUIRE(end_a.getRecvData().size() == 0);

	thread_b.join();
}