Server: move shutdown parts to a specific shutdown state object (#7437)

* Server: move shutdown parts to a specific shutdown state object

7 files changed, 296 insertions, 137 deletions

diff --git a/src/game.cpp b/src/game.cpp
index 0da8e1661..6e2583412 100644
--- a/src/game.cpp
+++ b/src/game.cpp
@@ -1065,7 +1065,7 @@ void Game::run()
 
 	while (RenderingEngine::run()
 			&& !(*kill || g_gamecallback->shutdown_requested
-			|| (server && server->getShutdownRequested()))) {
+			|| (server && server->isShutdownRequested()))) {
 
 		const irr::core::dimension2d<u32> &current_screen_size =
 			RenderingEngine::get_video_driver()->getScreenSize();
@@ -1271,6 +1271,7 @@ bool Game::createSingleplayerServer(const std::string &map_dir,
 	}
 
 	server = new Server(map_dir, gamespec, simple_singleplayer_mode, bind_addr, false);
+	server->init();
 	server->start();
 
 	return true;
diff --git a/src/main.cpp b/src/main.cpp
index d9073cfb8..005e1acc7 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -870,6 +870,7 @@ static bool run_dedicated_server(const GameParams &game_params, const Settings &
 			// Create server
 			Server server(game_params.world_path, game_params.game_spec,
 					false, bind_addr, true, &iface);
+			server.init();
 
 			g_term_console.setup(&iface, &kill, admin_nick);
 
@@ -904,6 +905,7 @@ static bool run_dedicated_server(const GameParams &game_params, const Settings &
 			// Create server
 			Server server(game_params.world_path, game_params.game_spec, false,
 				bind_addr, true);
+			server.init();
 			server.start();
 
 			// Run server
diff --git a/src/network/serverpackethandler.cpp b/src/network/serverpackethandler.cpp
index c961d406e..bb5eed92b 100644
--- a/src/network/serverpackethandler.cpp
+++ b/src/network/serverpackethandler.cpp
@@ -402,11 +402,8 @@ void Server::handleCommand_ClientReady(NetworkPacket* pkt)
 	m_clients.event(peer_id, CSE_SetClientReady);
 	m_script->on_joinplayer(playersao);
 	// Send shutdown timer if shutdown has been scheduled
-	if (m_shutdown_timer > 0.0f) {
-		std::wstringstream ws;
-		ws << L"*** Server shutting down in "
-				<< duration_to_string(myround(m_shutdown_timer)).c_str() << ".";
-		SendChatMessage(pkt->getPeerId(), ws.str());
+	if (m_shutdown_state.isTimerRunning()) {
+		SendChatMessage(pkt->getPeerId(), m_shutdown_state.getShutdownTimerMessage());
 	}
 }
 
diff --git a/src/server.cpp b/src/server.cpp
index 13a3b4552..67910e53a 100644
--- a/src/server.cpp
+++ b/src/server.cpp
@@ -139,7 +139,60 @@ v3f ServerSoundParams::getPos(ServerEnvironment *env, bool *pos_exists) const
 	return v3f(0,0,0);
 }
 
+void Server::ShutdownState::reset()
+{
+	m_timer = 0.0f;
+	message.clear();
+	should_reconnect = false;
+	is_requested = false;
+}
+
+void Server::ShutdownState::trigger(float delay, const std::string &msg, bool reconnect)
+{
+	m_timer = delay;
+	message = msg;
+	should_reconnect = reconnect;
+}
 
+void Server::ShutdownState::tick(float dtime, Server *server)
+{
+	if (m_timer <= 0.0f)
+		return;
+
+	// Timed shutdown
+	static const float shutdown_msg_times[] =
+	{
+		1, 2, 3, 4, 5, 10, 20, 40, 60, 120, 180, 300, 600, 1200, 1800, 3600
+	};
+
+	// Automated messages
+	if (m_timer < shutdown_msg_times[ARRLEN(shutdown_msg_times) - 1]) {
+		for (float t : shutdown_msg_times) {
+			// If shutdown timer matches an automessage, shot it
+			if (m_timer > t && m_timer - dtime < t) {
+				std::wstring periodicMsg = getShutdownTimerMessage();
+
+				infostream << wide_to_utf8(periodicMsg).c_str() << std::endl;
+				server->SendChatMessage(PEER_ID_INEXISTENT, periodicMsg);
+				break;
+			}
+		}
+	}
+
+	m_timer -= dtime;
+	if (m_timer < 0.0f) {
+		m_timer = 0.0f;
+		is_requested = true;
+	}
+}
+
+std::wstring Server::ShutdownState::getShutdownTimerMessage() const
+{
+	std::wstringstream ws;
+	ws << L"*** Server shutting down in "
+		<< duration_to_string(myround(m_timer)).c_str() << ".";
+	return ws.str();
+}
 
 /*
 	Server
@@ -174,22 +227,96 @@ Server::Server(
 {
 	m_lag = g_settings->getFloat("dedicated_server_step");
 
-	if (path_world.empty())
+	if (m_path_world.empty())
 		throw ServerError("Supplied empty world path");
 
-	if(!gamespec.isValid())
+	if (!gamespec.isValid())
 		throw ServerError("Supplied invalid gamespec");
+}
+
+Server::~Server()
+{
+	infostream << "Server destructing" << std::endl;
+
+	// Send shutdown message
+	SendChatMessage(PEER_ID_INEXISTENT, ChatMessage(CHATMESSAGE_TYPE_ANNOUNCE,
+			L"*** Server shutting down"));
+
+	if (m_env) {
+		MutexAutoLock envlock(m_env_mutex);
+
+		infostream << "Server: Saving players" << std::endl;
+		m_env->saveLoadedPlayers();
 
-	infostream<<"Server created for gameid \""<<m_gamespec.id<<"\"";
-	if(m_simple_singleplayer_mode)
-		infostream<<" in simple singleplayer mode"<<std::endl;
+		infostream << "Server: Kicking players" << std::endl;
+		std::string kick_msg;
+		bool reconnect = false;
+		if (isShutdownRequested()) {
+			reconnect = m_shutdown_state.should_reconnect;
+			kick_msg = m_shutdown_state.message;
+		}
+		if (kick_msg.empty()) {
+			kick_msg = g_settings->get("kick_msg_shutdown");
+		}
+		m_env->kickAllPlayers(SERVER_ACCESSDENIED_SHUTDOWN,
+			kick_msg, reconnect);
+	}
+
+	// Do this before stopping the server in case mapgen callbacks need to access
+	// server-controlled resources (like ModStorages). Also do them before
+	// shutdown callbacks since they may modify state that is finalized in a
+	// callback.
+	if (m_emerge)
+		m_emerge->stopThreads();
+
+	if (m_env) {
+		MutexAutoLock envlock(m_env_mutex);
+
+		// Execute script shutdown hooks
+		infostream << "Executing shutdown hooks" << std::endl;
+		m_script->on_shutdown();
+
+		infostream << "Server: Saving environment metadata" << std::endl;
+		m_env->saveMeta();
+	}
+
+	// Stop threads
+	if (m_thread) {
+		stop();
+		delete m_thread;
+	}
+
+	// Delete things in the reverse order of creation
+	delete m_emerge;
+	delete m_env;
+	delete m_rollback;
+	delete m_banmanager;
+	delete m_itemdef;
+	delete m_nodedef;
+	delete m_craftdef;
+
+	// Deinitialize scripting
+	infostream << "Server: Deinitializing scripting" << std::endl;
+	delete m_script;
+
+	// Delete detached inventories
+	for (auto &detached_inventory : m_detached_inventories) {
+		delete detached_inventory.second;
+	}
+}
+
+void Server::init()
+{
+	infostream << "Server created for gameid \"" << m_gamespec.id << "\"";
+	if (m_simple_singleplayer_mode)
+		infostream << " in simple singleplayer mode" << std::endl;
 	else
-		infostream<<std::endl;
-	infostream<<"- world:  "<<m_path_world<<std::endl;
-	infostream<<"- game:   "<<m_gamespec.path<<std::endl;
+		infostream << std::endl;
+	infostream << "- world:  " << m_path_world << std::endl;
+	infostream << "- game:   " << m_gamespec.path << std::endl;
 
 	// Create world if it doesn't exist
-	if(!loadGameConfAndInitWorld(m_path_world, m_gamespec))
+	if (!loadGameConfAndInitWorld(m_path_world, m_gamespec))
 		throw ServerError("Failed to initialize world");
 
 	// Create server thread
@@ -202,8 +329,7 @@ Server::Server(
 	std::string ban_path = m_path_world + DIR_DELIM "ipban.txt";
 	m_banmanager = new BanManager(ban_path);
 
-	m_modmgr = std::unique_ptr<ServerModManager>(new ServerModManager(
-		m_path_world));
+	m_modmgr = std::unique_ptr<ServerModManager>(new ServerModManager(m_path_world));
 	std::vector<ModSpec> unsatisfied_mods = m_modmgr->getUnsatisfiedMods();
 	// complain about mods with unsatisfied dependencies
 	if (!m_modmgr->isConsistent()) {
@@ -214,10 +340,10 @@ Server::Server(
 	MutexAutoLock envlock(m_env_mutex);
 
 	// Create the Map (loads map_meta.txt, overriding configured mapgen params)
-	ServerMap *servermap = new ServerMap(path_world, this, m_emerge);
+	ServerMap *servermap = new ServerMap(m_path_world, this, m_emerge);
 
 	// Initialize scripting
-	infostream<<"Server: Initializing Lua"<<std::endl;
+	infostream << "Server: Initializing Lua" << std::endl;
 
 	m_script = new ServerScripting(this);
 
@@ -279,74 +405,6 @@ Server::Server(
 	m_csm_noderange_limit = g_settings->getU32("csm_flavour_noderange_limit");
 }
 
-Server::~Server()
-{
-	infostream << "Server destructing" << std::endl;
-
-	// Send shutdown message
-	SendChatMessage(PEER_ID_INEXISTENT, ChatMessage(CHATMESSAGE_TYPE_ANNOUNCE,
-			L"*** Server shutting down"));
-
-	{
-		MutexAutoLock envlock(m_env_mutex);
-
-		infostream << "Server: Saving players" << std::endl;
-		m_env->saveLoadedPlayers();
-
-		infostream << "Server: Kicking players" << std::endl;
-		std::string kick_msg;
-		bool reconnect = false;
-		if (getShutdownRequested()) {
-			reconnect = m_shutdown_ask_reconnect;
-			kick_msg = m_shutdown_msg;
-		}
-		if (kick_msg.empty()) {
-			kick_msg = g_settings->get("kick_msg_shutdown");
-		}
-		m_env->kickAllPlayers(SERVER_ACCESSDENIED_SHUTDOWN,
-			kick_msg, reconnect);
-	}
-
-	// Do this before stopping the server in case mapgen callbacks need to access
-	// server-controlled resources (like ModStorages). Also do them before
-	// shutdown callbacks since they may modify state that is finalized in a
-	// callback.
-	m_emerge->stopThreads();
-
-	{
-		MutexAutoLock envlock(m_env_mutex);
-
-		// Execute script shutdown hooks
-		infostream << "Executing shutdown hooks" << std::endl;
-		m_script->on_shutdown();
-
-		infostream << "Server: Saving environment metadata" << std::endl;
-		m_env->saveMeta();
-	}
-
-	// Stop threads
-	stop();
-	delete m_thread;
-
-	// Delete things in the reverse order of creation
-	delete m_emerge;
-	delete m_env;
-	delete m_rollback;
-	delete m_banmanager;
-	delete m_itemdef;
-	delete m_nodedef;
-	delete m_craftdef;
-
-	// Deinitialize scripting
-	infostream << "Server: Deinitializing scripting" << std::endl;
-	delete m_script;
-
-	// Delete detached inventories
-	for (auto &detached_inventory : m_detached_inventories) {
-		delete detached_inventory.second;
-	}
-}
-
 void Server::start()
 {
 	infostream << "Starting server on " << m_bind_addr.serializeString()
@@ -916,38 +974,7 @@ void Server::AsyncRunStep(bool initial_step)
 		}
 	}
 
-	// Timed shutdown
-	static const float shutdown_msg_times[] =
-	{
-		1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 45, 60, 120, 180, 300, 600, 1200, 1800, 3600
-	};
-
-	if (m_shutdown_timer > 0.0f) {
-		// Automated messages
-		if (m_shutdown_timer < shutdown_msg_times[ARRLEN(shutdown_msg_times) - 1]) {
-			for (u16 i = 0; i < ARRLEN(shutdown_msg_times) - 1; i++) {
-				// If shutdown timer matches an automessage, shot it
-				if (m_shutdown_timer > shutdown_msg_times[i] &&
-					m_shutdown_timer - dtime < shutdown_msg_times[i]) {
-					std::wstringstream ws;
-
-					ws << L"*** Server shutting down in "
-						<< duration_to_string(myround(m_shutdown_timer - dtime)).c_str()
-						<< ".";
-
-					infostream << wide_to_utf8(ws.str()).c_str() << std::endl;
-					SendChatMessage(PEER_ID_INEXISTENT, ws.str());
-					break;
-				}
-			}
-		}
-
-		m_shutdown_timer -= dtime;
-		if (m_shutdown_timer < 0.0f) {
-			m_shutdown_timer = 0.0f;
-			m_shutdown_requested = true;
-		}
-	}
+	m_shutdown_state.tick(dtime, this);
 }
 
 void Server::Receive()
@@ -3398,16 +3425,13 @@ void Server::requestShutdown(const std::string &msg, bool reconnect, float delay
 {
 	if (delay == 0.0f) {
 	// No delay, shutdown immediately
-		m_shutdown_requested = true;
+		m_shutdown_state.is_requested = true;
 		// only print to the infostream, a chat message saying
 		// "Server Shutting Down" is sent when the server destructs.
 		infostream << "*** Immediate Server shutdown requested." << std::endl;
-	} else if (delay < 0.0f && m_shutdown_timer > 0.0f) {
-	// Negative delay, cancel shutdown if requested
-		m_shutdown_timer = 0.0f;
-		m_shutdown_msg = "";
-		m_shutdown_ask_reconnect = false;
-		m_shutdown_requested = false;
+	} else if (delay < 0.0f && m_shutdown_state.isTimerRunning()) {
+		// Negative delay, cancel shutdown if requested
+		m_shutdown_state.reset();
 		std::wstringstream ws;
 
 		ws << L"*** Server shutdown canceled.";
@@ -3428,9 +3452,7 @@ void Server::requestShutdown(const std::string &msg, bool reconnect, float delay
 		SendChatMessage(PEER_ID_INEXISTENT, ws.str());
 	}
 
-	m_shutdown_timer = delay;
-	m_shutdown_msg = msg;
-	m_shutdown_ask_reconnect = reconnect;
+	m_shutdown_state.trigger(delay, msg, reconnect);
 }
 
 PlayerSAO* Server::emergePlayer(const char *name, session_t peer_id, u16 proto_version)
@@ -3518,7 +3540,7 @@ void dedicated_server_loop(Server &server, bool &kill)
 		}
 		server.step(steplen);
 
-		if (server.getShutdownRequested() || kill)
+		if (server.isShutdownRequested() || kill)
 			break;
 
 		/*
diff --git a/src/server.h b/src/server.h
index 39cf56027..02c69e491 100644
--- a/src/server.h
+++ b/src/server.h
@@ -128,6 +128,7 @@ public:
 	~Server();
 	DISABLE_CLASS_COPY(Server);
 
+	void init();
 	void start();
 	void stop();
 	// This is mainly a way to pass the time to the server.
@@ -201,7 +202,7 @@ public:
 	inline double getUptime() const { return m_uptime.m_value; }
 
 	// read shutdown state
-	inline bool getShutdownRequested() const { return m_shutdown_requested; }
+	inline bool isShutdownRequested() const { return m_shutdown_state.is_requested; }
 
 	// request server to shutdown
 	void requestShutdown(const std::string &msg, bool reconnect, float delay = 0.0f);
@@ -348,9 +349,25 @@ public:
 	std::mutex m_env_mutex;
 
 private:
-
 	friend class EmergeThread;
 	friend class RemoteClient;
+	friend class TestServerShutdownState;
+
+	struct ShutdownState {
+		friend class TestServerShutdownState;
+		public:
+			bool is_requested = false;
+			bool should_reconnect = false;
+			std::string message;
+
+			void reset();
+			void trigger(float delay, const std::string &msg, bool reconnect);
+			void tick(float dtime, Server *server);
+			std::wstring getShutdownTimerMessage() const;
+			bool isTimerRunning() const { return m_timer > 0.0f; }
+		private:
+			float m_timer = 0.0f;
+	};
 
 	void SendMovement(session_t peer_id);
 	void SendHP(session_t peer_id, u16 hp);
@@ -368,7 +385,7 @@ private:
 	void SetBlocksNotSent(std::map<v3s16, MapBlock *>& block);
 
 
-	void SendChatMessage(session_t peer_id, const ChatMessage &message);
+	virtual void SendChatMessage(session_t peer_id, const ChatMessage &message);
 	void SendTimeOfDay(session_t peer_id, u16 time, f32 time_speed);
 	void SendPlayerHP(session_t peer_id);
 
@@ -586,10 +603,7 @@ private:
 		Random stuff
 	*/
 
-	bool m_shutdown_requested = false;
-	std::string m_shutdown_msg;
-	bool m_shutdown_ask_reconnect = false;
-	float m_shutdown_timer = 0.0f;
+	ShutdownState m_shutdown_state;
 
 	ChatInterface *m_admin_chat;
 	std::string m_admin_nick;
diff --git a/src/unittest/CMakeLists.txt b/src/unittest/CMakeLists.txt
index 768959e5e..5d306ee75 100644
--- a/src/unittest/CMakeLists.txt
+++ b/src/unittest/CMakeLists.txt
@@ -20,6 +20,7 @@ set (UNITTEST_SRCS
 	${CMAKE_CURRENT_SOURCE_DIR}/test_random.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/test_schematic.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/test_serialization.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/test_server_shutdown_state.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/test_settings.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/test_socket.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/test_serveractiveobjectmap.cpp
diff --git a/src/unittest/test_server_shutdown_state.cpp b/src/unittest/test_server_shutdown_state.cpp
new file mode 100644
index 000000000..fbb76ff6a
--- /dev/null
+++ b/src/unittest/test_server_shutdown_state.cpp
@@ -0,0 +1,122 @@
+/*
+Minetest
+Copyright (C) 2018 nerzhul, Loic BLOT <loic.blot@unix-experience.fr>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include <server.h>
+#include "test.h"
+
+#include "util/string.h"
+#include "util/serialize.h"
+
+class FakeServer : public Server
+{
+public:
+	// clang-format off
+	FakeServer() : Server("fakeworld", SubgameSpec("fakespec", "fakespec"), true,
+					Address(), true, nullptr)
+	{
+	}
+	// clang-format on
+
+private:
+	void SendChatMessage(session_t peer_id, const ChatMessage &message)
+	{
+		// NOOP
+	}
+};
+
+class TestServerShutdownState : public TestBase
+{
+public:
+	TestServerShutdownState() { TestManager::registerTestModule(this); }
+	const char *getName() { return "TestServerShutdownState"; }
+
+	void runTests(IGameDef *gamedef);
+
+	void testInit();
+	void testReset();
+	void testTrigger();
+	void testTick();
+};
+
+static TestServerShutdownState g_test_instance;
+
+void TestServerShutdownState::runTests(IGameDef *gamedef)
+{
+	TEST(testInit);
+	TEST(testReset);
+	TEST(testTrigger);
+	TEST(testTick);
+}
+
+void TestServerShutdownState::testInit()
+{
+	Server::ShutdownState ss;
+	UASSERT(!ss.is_requested);
+	UASSERT(!ss.should_reconnect);
+	UASSERT(ss.message.empty());
+	UASSERT(ss.m_timer == 0.0f);
+}
+
+void TestServerShutdownState::testReset()
+{
+	Server::ShutdownState ss;
+	ss.reset();
+	UASSERT(!ss.is_requested);
+	UASSERT(!ss.should_reconnect);
+	UASSERT(ss.message.empty());
+	UASSERT(ss.m_timer == 0.0f);
+}
+
+void TestServerShutdownState::testTrigger()
+{
+	Server::ShutdownState ss;
+	ss.trigger(3.0f, "testtrigger", true);
+	UASSERT(!ss.is_requested);
+	UASSERT(ss.should_reconnect);
+	UASSERT(ss.message == "testtrigger");
+	UASSERT(ss.m_timer == 3.0f);
+}
+
+void TestServerShutdownState::testTick()
+{
+	std::unique_ptr<FakeServer> fakeServer(new FakeServer());
+	Server::ShutdownState ss;
+	ss.trigger(28.0f, "testtrigger", true);
+	ss.tick(0.0f, fakeServer.get());
+
+	// Tick with no time should not change anything
+	UASSERT(!ss.is_requested);
+	UASSERT(ss.should_reconnect);
+	UASSERT(ss.message == "testtrigger");
+	UASSERT(ss.m_timer == 28.0f);
+
+	// Tick 2 seconds
+	ss.tick(2.0f, fakeServer.get());
+	UASSERT(!ss.is_requested);
+	UASSERT(ss.should_reconnect);
+	UASSERT(ss.message == "testtrigger");
+	UASSERT(ss.m_timer == 26.0f);
+
+	// Tick remaining seconds + additional expire
+	ss.tick(26.1f, fakeServer.get());
+	UASSERT(ss.is_requested);
+	UASSERT(ss.should_reconnect);
+	UASSERT(ss.message == "testtrigger");
+	UASSERT(ss.m_timer == 0.0f);
+}