Add an example to test server concurrency.

examples/hello_world_server.cc

@@ -4,24 +4,47 @@
 
 class HelloView : public webcc::View {
 public:
+  HelloView(int sleep_seconds) : sleep_seconds_(sleep_seconds) {
+  }
+
   webcc::ResponsePtr Handle(webcc::RequestPtr request) override {
+    if (sleep_seconds_ > 0) {
+      std::this_thread::sleep_for(std::chrono::seconds(sleep_seconds_));
+    }
+
     if (request->method() == "GET") {
       return webcc::ResponseBuilder{}.OK().Body("Hello, World!")();
     }
 
     return {};
   }
+
+private:
+  int sleep_seconds_;
 };
 
-int main() {
+int main(int argc, const char* argv[]) {
   WEBCC_LOG_INIT("", webcc::LOG_CONSOLE);
 
+  int workers = 1;
+  int sleep_seconds = 0;
+
+  if (argc > 1) {
+    workers = std::stoi(argv[1]);
+    if (argc > 2) {
+      sleep_seconds = std::stoi(argv[2]);
+    }
+  }
+
+  LOG_USER("Workers: %d", workers);
+  LOG_USER("Sleep seconds: %d", sleep_seconds);
+
   try {
     webcc::Server server(8080);
 
-    server.Route("/", std::make_shared<HelloView>());
+    server.Route("/", std::make_shared<HelloView>(sleep_seconds));
 
-    server.Run();
+    server.Run(workers);
 
   } catch (const std::exception&) {
     return 1;