Locality.cpp

// SPDX-License-Identifier: LGPL-3.0-or-later
// Copyright © 2020 Florian Schmaus
#include <unistd.h>	 // for getopt, optarg

#include <algorithm>	// for generate
#include <chrono>			// for microseconds, high_resol...
#include <cstdint>		// for uint8_t, UINT8_MAX
#include <cstdlib>		// for abort, exit, EXIT_SUCCESS
#include <iostream>		// for operator<<, basic_ostream
#include <random>			// for mt19937, uniform_int_dis...
#include <string>			// for string, operator<<, oper...

#include "CountingPrivateSemaphore.hpp"			 // for CPS
#include "Debug.hpp"												 // for DBG
#include "Fiber.hpp"												 // for Fiber, Fiber::NOT_AFFINE
#include "PrivateSemaphore.hpp"							 // for PS
#include "Runtime.hpp"											 // for Runtime
#include "emper-common.h"										 // for workeraffinity_t, UNUSED...
#include "lib/DebugUtil.hpp"								 // for enableStacktraceOnAborts
#include "strategies/laws/LawsStrategy.hpp"	 // for LawsStrategy, LawsStrate...

#define L1_CACHE_LINE_SIZE 64	 // 64 Bytes

#define L1_DCACHE_SIZE (32 * 1024)		// 32 KiB
#define L2_DCACHE_SIZE (256 * 1024)		// 256 KiB
#define L3_DCACHE_SIZE (4096 * 1024)	// 4 MiB

//#define FIBER_METADATA

static std::uniform_int_distribution<> UINT8_UNIFORM_DISTRIBUTION(0, UINT8_MAX);

struct FiberMetadata {
	workerid_t workerId;
	workeraffinity_t currentAffinity;
	std::chrono::time_point<std::chrono::high_resolution_clock> start;
	std::chrono::time_point<std::chrono::high_resolution_clock> end;
};

struct State {
	const unsigned int fiberCount;
	const unsigned int bytesPerFiber;
	const unsigned int rounds;

	Runtime& runtime;
	std::mt19937 randomGenerator;
	// TODO: Should the affinities in the affinity array be cache line
	// aligned to avoid false sharing?
	workeraffinity_t* affinity;
	uint8_t* data;
	FiberMetadata* fiberMetadata;
	// std::map<unsigned int, std::vector<FiberMetadata>> fiberMetadata;

	// NOLINTNEXTLINE(cert-msc32-c,cert-msc51-cpp)
	State(Runtime& runtime, unsigned int fiberCount, unsigned int bytesPerFiber, unsigned int rounds,
				unsigned int seed)
			: fiberCount(fiberCount), bytesPerFiber(bytesPerFiber), rounds(rounds), runtime(runtime) {
		randomGenerator = std::mt19937(seed);
		affinity = new workeraffinity_t[fiberCount];
		for (unsigned int i = 0; i < fiberCount; ++i) {
			affinity[i] = Fiber::NOT_AFFINE;
		}
		data = new uint8_t[fiberCount * bytesPerFiber];
#ifdef FIBER_METADATA
		fiberMetadata = new FiberMetadata[fiberCount * rounds];
#endif

		std::generate(data, data + fiberCount, [this] { return getNextRandom(); });
	}

	~State() {
		delete[] affinity;
		delete[] data;
#ifdef FIBER_METADATA
		delete[] fiberMetadata;
#endif
	}

	auto getNextRandom() -> uint8_t { return UINT8_UNIFORM_DISTRIBUTION(randomGenerator); }

	[[nodiscard]] auto getFiberMetadata(unsigned int fiberNum, unsigned int roundNum) const
			-> FiberMetadata* {
		return fiberMetadata + (fiberNum * fiberCount) + roundNum;
	}
};

struct FiberArgs {
	uint8_t* fiberData;
	uint8_t roundData;
	PS* ps;
	// TODO: Check if this member is still needed
	State* state;
#ifdef FIBER_METADATA
	FiberMetadata* fiberMetadata;
#endif
};

static void performRound(State& state,
#ifndef FIBER_METADATA
												 UNUSED_ARG
#endif
												 unsigned int round) {
	uint8_t roundData = state.getNextRandom();
	CPS cps(state.fiberCount);

	auto* fiberArgs = new FiberArgs[state.fiberCount];

	DBG("Starting round " << round);

	for (unsigned int i = 0; i < state.fiberCount; ++i) {
		fiberArgs[i].fiberData = state.data + (i * state.bytesPerFiber);
		fiberArgs[i].roundData = roundData;
		fiberArgs[i].ps = &cps;
		fiberArgs[i].state = &state;
#ifdef FIBER_METADATA
		fiberArgs[i].fiberMetadata = state.getFiberMetadata(i, round);
#endif

		Fiber* fiber = Fiber::from(
				[](void* fiberArgsPtr) {
					auto* fiberArgs = (FiberArgs*)fiberArgsPtr;

#ifdef FIBER_METADATA
					FiberMetadata* fiberMetadata = fiberArgs->fiberMetadata;

					fiberMetadata->start = std::chrono::high_resolution_clock::now();
					fiberMetadata->workerId = Runtime::getWorkerId();
					fiberMetadata->currentAffinity = Dispatcher::getCurrentFiber().getAffinity();
#endif

					uint8_t* fiberData = fiberArgs->fiberData;
					unsigned int bytesPerFiber = fiberArgs->state->bytesPerFiber;
					for (unsigned int j = (bytesPerFiber - 1); j > (bytesPerFiber - 10); --j) {
						for (unsigned int i = 0; i < bytesPerFiber; i++) {
							unsigned int next = (i + L1_DCACHE_SIZE + fiberData[j]) % bytesPerFiber;
							fiberData[i] -= fiberData[next];

							fiberData[i] += fiberArgs->roundData;
							/*
							if (fiberData[i] < 128) {
								fiberData[i] += fiberArgs->roundData / 2;
							}
							if (fiberData[i] > 192) {
								fiberData[i] -= (fiberArgs->roundData * 4);
							}

							if (i == (bytesPerFiber * 0.75)) {
								if (fiberData[i] < 128) {
									break;
								}
							}
							*/
						}
					}

#ifdef FIBER_METADATA
					fiberMetadata->end = std::chrono::high_resolution_clock::now();
#endif

					fiberArgs->ps->signal();
				},
				(void*)(fiberArgs + i), state.affinity + i);

		state.runtime.schedule(*fiber);
	}

	cps.wait();

	DBG("Finished round " << round);

	delete[] fiberArgs;
}

/*
IGNORE_UNUSED_FUNCTION
static void printState(State& state) {
	std::ostream& ostream = std::cout;
	for (unsigned int fiberNum = 0; fiberNum < state.fiberCount; ++fiberNum) {
		for (unsigned int roundNum = 0; roundNum < state.rounds; ++roundNum) {
			FiberMetadata* fiberMetadata = state.getFiberMetadata(fiberNum, roundNum);

			ostream << fiberNum
					<< ", " << roundNum
					<< ", " << fiberMetadata->workerId
					<< ", " << fiberMetadata->currentAffinity
					<< ", " << fiberMetadata->start.time_since_epoch().count()
					<< ", " << fiberMetadata->end.time_since_epoch().count()
					<< std::endl;
		}
	}
}
POP_DIAGNOSTIC
*/

static void run(Runtime& runtime, unsigned int fiberCount, unsigned int bytesPerFiber,
								unsigned int rounds, unsigned int seed) {
	runtime.executeAndWait([&] {
		State state(runtime, fiberCount, bytesPerFiber, rounds, seed);

		auto start = std::chrono::high_resolution_clock::now();
		for (unsigned int i = 0; i < state.rounds; ++i) {
			performRound(state, i);
		}
		auto end = std::chrono::high_resolution_clock::now();

		auto diff = std::chrono::duration_cast<std::chrono::microseconds>(end - start);

		std::cout << "Inner " << diff.count() << " us" << std::endl;
		// printState(state);
	});
}

enum RuntimeVariant {
	ws,
	wslh,
};

auto main(UNUSED_ARG int argc, UNUSED_ARG char* argv[]) -> int {
	enableStacktraceOnAborts();

	RuntimeVariant runtimeVariant = ws;
	unsigned int rounds = 10;
	unsigned int seed = 4231;

	int opt;
	while ((opt = getopt(argc, argv, "m:")) != -1) {
		std::string optargString;
		switch (opt) {
			case 'm':
				optargString = std::string(optarg);
				if (optargString == "ws") {
					runtimeVariant = ws;
				} else if (optargString == "wslh") {
					runtimeVariant = wslh;
				} else {
					std::cerr << "Invalid -m argument " << optargString << std::endl;
					abort();
				}
				break;
			default:
				abort();
		}
	}

	unsigned int coreCount = 80;
	unsigned int bytesPerFiber = L1_DCACHE_SIZE / 2;
	unsigned int fiberCount = coreCount * 4;

	std::chrono::time_point<std::chrono::high_resolution_clock> start, end;

	Runtime* runtime;
	switch (runtimeVariant) {
		case ws:
			runtime = new Runtime();
			break;
		case wslh:
			runtime = new Runtime(LawsStrategy::INSTANCE);
			break;
	}

	start = std::chrono::high_resolution_clock::now();
	run(*runtime, fiberCount, bytesPerFiber, rounds, seed);
	end = std::chrono::high_resolution_clock::now();
	auto diff = std::chrono::duration_cast<std::chrono::microseconds>(end - start);

	std::string variantName;
	switch (runtimeVariant) {
		case ws:
			variantName = "W/o Locality: ";
			break;
		case wslh:
			variantName = "W   Locality: ";
			break;
	}

	std::cout << variantName << diff.count() << " us" << std::endl;

	exit(EXIT_SUCCESS);
}