Expose new LocalCluster interface and use in example

src/LocalCluster.h

@@ -0,0 +1,62 @@
+/* This header is highly experimental and needs refactorings but will do for now */
+
+#include <thread>
+#include <algorithm>
+#include <mutex>
+
+unsigned int roundRobin = 0;
+unsigned int hardwareConcurrency = std::thread::hardware_concurrency();
+std::vector<std::thread *> threads(hardwareConcurrency);
+std::vector<uWS::SSLApp *> apps;
+std::mutex m;
+
+namespace uWS {
+struct LocalCluster {
+
+    //std::vector<std::thread *> threads = std::thread::hardware_concurrency();
+    //std::vector<uWS::SSLApp *> apps;
+    //std::mutex m;
+
+
+    static void loadBalancer() {
+        static std::atomic<unsigned int> roundRobin = 0; // atomic fetch_add
+    }
+
+    LocalCluster(SocketContextOptions options = {}, std::function<void(uWS::SSLApp &)> cb = nullptr) {
+        std::transform(threads.begin(), threads.end(), threads.begin(), [options, &cb](std::thread *) {
+
+            return new std::thread([options, &cb]() {
+
+                // lock this
+                m.lock();
+                apps.emplace_back(new uWS::SSLApp(options));
+                uWS::SSLApp *app = apps.back();
+
+                cb(*app);
+                
+                app->preOpen([](LIBUS_SOCKET_DESCRIPTOR fd) {
+
+                    /* Distribute this socket in round robin fashion */
+                    //std::cout << "About to load balance " << fd << " to " << roundRobin << std::endl;
+
+                    auto receivingApp = apps[roundRobin];
+                    apps[roundRobin]->getLoop()->defer([fd, receivingApp]() {
+                        receivingApp->adoptSocket(fd);
+                    });
+
+                    roundRobin = (roundRobin + 1) % hardwareConcurrency;
+                    return -1;
+                });
+                m.unlock();
+                app->run();
+                std::cout << "Fallthrough!" << std::endl;
+                delete app;
+            });
+        });
+
+        std::for_each(threads.begin(), threads.end(), [](std::thread *t) {
+            t->join();
+        });
+    }
+};
+}