marostkacik / parallel_union_find

C++ library for finding Strongly Connected Components in parallel, based on paper: https://dl.acm.org/citation.cfm?id=2851161

Header-only library for finding strongly connected components in parallel

Usage example:

#include <vector>
#include <thread>
#include <cassert>

#include "parallel_union_find/algorithm/multi_core_on_the_fly_scc_decomposition_algorithm.hpp"
#include "parallel_union_find/graph_node/on_the_fly_scc_graph_node.hpp"
#include "parallel_union_find/union_find/blocking/on_the_fly_scc_union_find.hpp"

using namespace parallel_union_find::algorithm;
using namespace parallel_union_find::graph_node;
using namespace parallel_union_find::union_find::blocking;

using node = on_the_fly_scc_graph_node<on_the_fly_scc_union_find>;

node n1;
node n2;

int main()
{
    // create graph
    n1.add_son(&n2);
    n2.add_son(&n1);

    // run on as many threads as you wish
    std::vector<std::thread> threads;

    for (unsigned int i = 0; i < std::thread::hardware_concurrency(); ++i)
        threads.emplace_back(multi_core_on_the_fly_scc_decomposition_algorithm<node>, &n1, (1 << i));

    for (std::thread& t : threads)
        t.join();

    // reconstruct strongly connected components
    assert(n1.find_set() == n2.find_set());
}

Customized graph: TODO

APIs

TODO

Performance Comparison

Comparing performance on real-world data from Slovak social network Pokec: https://snap.stanford.edu/data/soc-pokec.html. Algorithms are finding SCCs(Strongly Connected Components) in oriented graph which represents friendships. It looks for SCCs which are reachable from node with 'ID = 1'.

Algorithm based on paper in green, randomized algorithm in red.

Looking for SCCs in friendships from LiveJournal SocialNetwork: https://snap.stanford.edu/data/soc-LiveJournal1.html.