source: doc/theses/thierry_delisle_PhD/code/relaxed_list.cpp @ 50aeb6f

#include "relaxed_list.hpp"

#include <array>
#include <iostream>
#include <locale>
#include <string>
#include <thread>
#include <vector>

#include <unistd.h>
#include <sys/sysinfo.h>

#include "utils.hpp"

struct __attribute__((aligned(64))) Node {
        static std::atomic_size_t creates;
        static std::atomic_size_t destroys;

        _LinksFields_t<Node> _links;

        int value;
        Node(int value): value(value) {
                creates++;
        }

        ~Node() {
                destroys++;
        }
};

std::atomic_size_t Node::creates  = { 0 };
std::atomic_size_t Node::destroys = { 0 };

static const constexpr int nodes_per_threads = 128;
struct NodeArray {
        __attribute__((aligned(64))) Node * array[nodes_per_threads];
        __attribute__((aligned(64))) char pad;
};

bool enable_stats = false;

struct local_stat_t {
        size_t in  = 0;
        size_t out = 0;
        size_t empty = 0;
        size_t crc_in  = 0;
        size_t crc_out = 0;
};

__attribute__((noinline)) void run_body(
        std::atomic<bool>& done,
        Random & rand,
        Node * (&my_nodes)[128],
        local_stat_t & local,
        relaxed_list<Node> & list
) {
        while(__builtin_expect(!done.load(std::memory_order_relaxed), true)) {
                int idx = rand.next() % nodes_per_threads;
                if (auto node = my_nodes[idx]) {
                        local.crc_in += node->value;
                        list.push(node);
                        my_nodes[idx] = nullptr;
                        local.in++;
                }
                else if(auto node = list.pop()) {
                        local.crc_out += node->value;
                        my_nodes[idx] = node;
                        local.out++;
                }
                else {
                        local.empty++;
                }
        }
}

void run(unsigned nthread, unsigned nqueues, unsigned fill, double duration) {
        // List being tested
        relaxed_list<Node> list = { nthread * nqueues };

        // Barrier for synchronization
        barrier_t barrier(nthread + 1);

        // Data to check everything is OK
        struct {
                std::atomic_size_t in  = { 0 };
                std::atomic_size_t out = { 0 };
                std::atomic_size_t empty = { 0 };
                std::atomic_size_t crc_in  = { 0 };
                std::atomic_size_t crc_out = { 0 };
                struct {
                        struct {
                                std::atomic_size_t attempt = { 0 };
                                std::atomic_size_t success = { 0 };
                        } push;
                        struct {
                                std::atomic_size_t attempt = { 0 };
                                std::atomic_size_t success = { 0 };
                        } pop;
                } pick;
        } global;

        // Flag to signal termination
        std::atomic_bool done  = { false };

        // Prep nodes
        std::cout << "Initializing" << std::endl;
        NodeArray all_nodes[nthread];
        for(auto & nodes : all_nodes) {
                Random rand(rdtscl());
                for(auto & node : nodes.array) {
                        auto r = rand.next() % 100;
                        if(r < fill)
                                node = new Node(rand.next() % 100);
                }

                for(int i = 0; i < 10; i++) {
                        int idx = rand.next() % nodes_per_threads;
                        if (auto node = nodes.array[idx]) {
                                global.crc_in += node->value;
                                list.push(node);
                                nodes.array[idx] = nullptr;
                        }
                }
        }

        enable_stats = true;

        std::thread * threads[nthread];
        unsigned i = 1;
        for(auto & t : threads) {
                auto & my_nodes = all_nodes[i - 1].array;
                t = new std::thread([&done, &list, &barrier, &global, &my_nodes](unsigned tid) {
                        Random rand(tid + rdtscl());

                        local_stat_t local;

                        // affinity(tid);

                        barrier.wait(tid);

                        // EXPERIMENT START

                        run_body(done, rand, my_nodes, local, list);

                        // EXPERIMENT END

                        barrier.wait(tid);

                        global.in    += local.in;
                        global.out   += local.out;
                        global.empty += local.empty;

                        for(auto node : my_nodes) {
                                delete node;
                        }

                        global.crc_in  += local.crc_in;
                        global.crc_out += local.crc_out;

                        global.pick.push.attempt += relaxed_list<Node>::tls.pick.push.attempt;
                        global.pick.push.success += relaxed_list<Node>::tls.pick.push.success;
                        global.pick.pop .attempt += relaxed_list<Node>::tls.pick.pop.attempt;
                        global.pick.pop .success += relaxed_list<Node>::tls.pick.pop.success;
                }, i++);
        }

        std::cout << "Starting" << std::endl;
        auto before = Clock::now();
        barrier.wait(0);

        while(true) {
                usleep(100000);
                auto now = Clock::now();
                duration_t durr = now - before;
                if( durr.count() > duration ) {
                        done = true;
                        break;
                }
                std::cout << "\r" << durr.count();
                std::cout.flush();
        }

        barrier.wait(0);
        auto after = Clock::now();
        duration_t durr = after - before;
        duration = durr.count();
        std::cout << "\nClosing down" << std::endl;

        for(auto t : threads) {
                t->join();
                delete t;
        }

        enable_stats = false;

        while(auto node = list.pop()) {
                global.crc_out += node->value;
                delete node;
        }

        assert(Node::creates == Node::destroys);
        assert(global.crc_in == global.crc_out);

        std::cout << "Done" << std::endl;

        size_t ops = global.in + global.out;
        size_t ops_sec = size_t(double(ops) / duration);
        size_t ops_thread = ops_sec / nthread;
        auto dur_nano = duration_cast<std::nano>(1.0);

        std::cout << "Duration      : " << duration << "s\n";
        std::cout << "ns/Op         : " << ( dur_nano / ops_thread )<< "\n";
        std::cout << "Ops/sec/thread: " << ops_thread << "\n";
        std::cout << "Ops/sec       : " << ops_sec << "\n";
        std::cout << "Total ops     : " << ops << "(" << global.in << "i, " << global.out << "o, " << global.empty << "e)\n";
        #ifndef NO_STATS
                double push_sur = (100.0 * double(global.pick.push.success) / global.pick.push.attempt);
                double pop_sur  = (100.0 * double(global.pick.pop .success) / global.pick.pop .attempt);
                std::cout << "Push Pick %   : " << push_sur << "(" << global.pick.push.success << " / " << global.pick.push.attempt << ")\n";
                std::cout << "Pop  Pick %   : " << pop_sur  << "(" << global.pick.pop .success << " / " << global.pick.pop .attempt << ")\n";
        #endif
}

void usage(char * argv[]) {
        std::cerr << argv[0] << ": [DURATION (FLOAT:SEC)] [NTHREADS] [NQUEUES] [FILL]" << std::endl;;
        std::exit(1);
}

int main(int argc, char * argv[]) {

        double duration   = 5.0;
        unsigned nthreads = 2;
        unsigned nqueues  = 2;
        unsigned fill     = 100;

        std::cout.imbue(std::locale(""));

        switch (argc)
        {
        case 5:
                nqueues = std::stoul(argv[4]);
                [[fallthrough]];
        case 4:
                nqueues = std::stoul(argv[3]);
                [[fallthrough]];
        case 3:
                nthreads = std::stoul(argv[2]);
                [[fallthrough]];
        case 2:
                duration = std::stod(argv[1]);
                if( duration <= 0.0 ) {
                        std::cerr << "Duration must be positive, was " << argv[1] << "(" << duration << ")" << std::endl;
                        usage(argv);
                }
                [[fallthrough]];
        case 1:
                break;
        default:
                usage(argv);
                break;
        }

        check_cache_line_size();

        std::cout << "Running " << nthreads << " threads (" << (nthreads * nqueues) << " queues) for " << duration << " seconds" << std::endl;
        run(nthreads, nqueues, duration, fill);

        return 0;
}

template<>
thread_local relaxed_list<Node>::TLS relaxed_list<Node>::tls = {};

template<>
relaxed_list<Node>::intrusive_queue_t::stat::Dif relaxed_list<Node>::intrusive_queue_t::stat::dif = {};

const char * __my_progname = "Relaxed List";