fix host game client connecting too early

unfortunately, still crashes when ssock add_fd fails

Author: FolkertVanVerseveld

game/src/engine.cpp

@@ -505,7 +505,9 @@ void Engine::start_server(uint16_t port) {
 			}, port);
 			t2.detach();
 
+			server->wait_active(true);
 			start_client_now("127.0.0.1", port, info);
+
 			guard.good = true;
 		} catch (std::exception &e) {
 			fprintf(stderr, "%s: cannot start server: %s\n", func, e.what());

game/src/net/client.cpp

@@ -13,7 +13,7 @@ LocalClient::LocalClient()
 	: IClient(), IServer(), w() {}
 
 void LocalClient::close() {
-	m_active = false;
+	set_active(false);
 	stop();
 }
 

game/src/net/net.cpp

@@ -1040,6 +1040,8 @@ int ServerSocket::mainloop(uint16_t port, int backlog, ServerSocketController &c
 	s.set_nonblocking();
 	step = false;
 
+	ctl.started();
+
 	for (int nfds; (nfds = epoll_wait(h, events.data(), events.size(), -1)) >= 0; step = false) {
 		for (int i = 0; i < nfds; ++i)
 			if (!event_step(i)) {

game/src/net/net.hpp

@@ -71,7 +71,7 @@ class TcpSocket final {
 public:
 	TcpSocket();
 	TcpSocket(SOCKET s) : s((int)s) {}
-	TcpSocket(const TcpSocket &) = delete;
+	TcpSocket(const TcpSocket&) = delete;
 	TcpSocket(TcpSocket &&s) noexcept : s(s.s.load()) { s.s.store((int)INVALID_SOCKET); }
 	~TcpSocket();
 
@@ -166,6 +166,9 @@ class ServerSocketController {
 	/* A peer has just left or has been kicked from this server. */
 	virtual void dropped(ServerSocket &s, const Peer &p) = 0;
 
+	/* Server has started and is actively listening to incoming connections. */
+	virtual void started() = 0;
+
 	/* Server has been stopped. */
 	virtual void stopped() = 0;
 

game/src/server.cpp

@@ -7,6 +7,27 @@
 
 namespace aoe {
 
+IServer::IServer() : cv_active(), lk_active(), m_active(false) {}
+
+bool IServer::active() noexcept {
+	std::lock_guard<std::mutex> lk(lk_active);
+	return m_active;
+}
+
+void IServer::set_active(bool v) {
+	{
+		std::lock_guard<std::mutex> lk(lk_active);
+		m_active = v;
+	}
+	cv_active.notify_all();
+}
+
+void IServer::wait_active(bool exp) {
+	std::unique_lock<std::mutex> lk(lk_active);
+	while (m_active != exp)
+		cv_active.wait(lk);
+}
+
 Server::Server()
 	: ServerSocketController(), IServer()
 	, s(), m_running(false), m_peers(), port(0), protocol(0), peers(), refs(), w(), civs() {}
@@ -241,14 +262,16 @@ int Server::mainloop(uint16_t port, uint16_t protocol, bool testing) {
 		old_lang.collect_civs(civnames);
 	}
 
-	m_active = true;
-	int r = s.mainloop(port, 10, *this);
+	return s.mainloop(port, 10, *this);
+}
 
-	return r;
+void Server::started() {
+	set_active(true);
 }
 
 void Server::stop() {
-	m_running = m_active = false;
+	m_running = false;
+	set_active(false);
 }
 
 void Server::close() {

game/src/server.hpp

@@ -13,6 +13,7 @@
 #include <thread>
 #include <variant>
 #include <optional>
+#include <condition_variable>
 
 #include "game.hpp"
 #include "debug.hpp"
@@ -179,14 +180,17 @@ class World final {
 };
 
 class IServer {
-protected:
-	std::atomic<bool> m_active;
+private:
+	std::condition_variable cv_active;
+	std::mutex lk_active;
+	bool m_active;
 public:
-	IServer() : m_active(false) {}
-
+	IServer();
 	virtual ~IServer() = default;
 
-	bool active() const noexcept { return m_active; }
+	bool active() noexcept;
+	void set_active(bool v);
+	void wait_active(bool exp);
 
 	virtual bool is_running() const noexcept =0;
 	virtual void close() =0;
@@ -214,6 +218,7 @@ class Server final : public ServerSocketController, public IServer {
 	~Server() override;
 
 	void stop();
+	void started() override;
 	void close() override; // this will block till everything is stopped
 
 	int mainloop(uint16_t port, uint16_t protocol, bool testing=false);