Encapsulate envlock

src/emerge.cpp

@@ -540,7 +540,7 @@ bool EmergeThread::popBlockEmerge(v3s16 *pos, BlockEmergeData *bedata)
 EmergeAction EmergeThread::getBlockOrStartGen(const v3s16 pos, bool allow_gen,
 	 const std::string *from_db, MapBlock **block, BlockMakeData *bmdata)
 {
-	MutexAutoLock envlock(m_server->m_env_mutex);
+	Server::EnvAutoLock envlock(m_server);
 
 	auto block_ok = [] (MapBlock *b) {
 		return b && b->isGenerated();
@@ -581,7 +581,7 @@ EmergeAction EmergeThread::getBlockOrStartGen(const v3s16 pos, bool allow_gen,
 MapBlock *EmergeThread::finishGen(v3s16 pos, BlockMakeData *bmdata,
 	std::map<v3s16, MapBlock *> *modified_blocks)
 {
-	MutexAutoLock envlock(m_server->m_env_mutex);
+	Server::EnvAutoLock envlock(m_server);
 	ScopeProfiler sp(g_profiler,
 		"EmergeThread: after Mapgen::makeChunk", SPT_AVG);
 
@@ -762,7 +762,7 @@ void *EmergeThread::run()
 			MapEditEvent event;
 			event.type = MEET_OTHER;
 			event.setModifiedBlocks(modified_blocks);
-			MutexAutoLock envlock(m_server->m_env_mutex);
+			Server::EnvAutoLock envlock(m_server);
 			m_map->dispatchEvent(event);
 		}
 		modified_blocks.clear();

src/script/lua_api/l_env.cpp

@@ -160,7 +160,7 @@ void LuaEmergeAreaCallback(v3s16 blockpos, EmergeAction action, void *param)
 
 	// state must be protected by envlock
 	Server *server = state->script->getServer();
-	MutexAutoLock envlock(server->m_env_mutex);
+	Server::EnvAutoLock envlock(server);
 
 	state->refcount--;
 

src/server.cpp

@@ -353,7 +353,7 @@ Server::~Server()
 		m_emerge->stopThreads();
 
 	if (m_env) {
-		MutexAutoLock envlock(m_env_mutex);
+		EnvAutoLock envlock(this);
 
 		infostream << "Server: Executing shutdown hooks" << std::endl;
 		try {
@@ -461,7 +461,7 @@ void Server::init()
 	}
 
 	//lock environment
-	MutexAutoLock envlock(m_env_mutex);
+	EnvAutoLock envlock(this);
 
 	// Create the Map (loads map_meta.txt, overriding configured mapgen params)
 	auto startup_server_map = std::make_unique<ServerMap>(m_path_world, this,
@@ -653,7 +653,7 @@ void Server::AsyncRunStep(float dtime, bool initial_step)
 	}
 
 	{
-		MutexAutoLock lock(m_env_mutex);
+		EnvAutoLock lock(this);
 		float max_lag = m_env->getMaxLagEstimate();
 		constexpr float lag_warn_threshold = 2.0f;
 
@@ -686,7 +686,7 @@ void Server::AsyncRunStep(float dtime, bool initial_step)
 	static const float map_timer_and_unload_dtime = 2.92;
 	if(m_map_timer_and_unload_interval.step(dtime, map_timer_and_unload_dtime))
 	{
-		MutexAutoLock lock(m_env_mutex);
+		EnvAutoLock lock(this);
 		// Run Map's timers and unload unused data
 		ScopeProfiler sp(g_profiler, "Server: map timer and unload");
 		m_env->getMap().timerUpdate(map_timer_and_unload_dtime,
@@ -704,7 +704,7 @@ void Server::AsyncRunStep(float dtime, bool initial_step)
 	*/
 	if (m_admin_chat) {
 		if (!m_admin_chat->command_queue.empty()) {
-			MutexAutoLock lock(m_env_mutex);
+			EnvAutoLock lock(this);
 			while (!m_admin_chat->command_queue.empty()) {
 				ChatEvent *evt = m_admin_chat->command_queue.pop_frontNoEx();
 				handleChatInterfaceEvent(evt);
@@ -725,7 +725,7 @@ void Server::AsyncRunStep(float dtime, bool initial_step)
 	{
 		m_liquid_transform_timer -= m_liquid_transform_every;
 
-		MutexAutoLock lock(m_env_mutex);
+		EnvAutoLock lock(this);
 
 		ScopeProfiler sp(g_profiler, "Server: liquid transform");
 
@@ -786,7 +786,7 @@ void Server::AsyncRunStep(float dtime, bool initial_step)
 	*/
 	{
 		//infostream<<"Server: Checking added and deleted active objects"<<std::endl;
-		MutexAutoLock envlock(m_env_mutex);
+		EnvAutoLock envlock(this);
 
 		// This guarantees that each object recomputes its cache only once per server step,
 		// unless get_effective_observers is called.
@@ -831,7 +831,7 @@ void Server::AsyncRunStep(float dtime, bool initial_step)
 		Send object messages
 	*/
 	{
-		MutexAutoLock envlock(m_env_mutex);
+		EnvAutoLock envlock(this);
 		ScopeProfiler sp(g_profiler, "Server: send SAO messages");
 
 		// Key = object id
@@ -933,7 +933,7 @@ void Server::AsyncRunStep(float dtime, bool initial_step)
 	*/
 	{
 		// We will be accessing the environment
-		MutexAutoLock lock(m_env_mutex);
+		EnvAutoLock lock(this);
 
 		// Single change sending is disabled if queue size is big
 		bool disable_single_change_sending = false;
@@ -1040,7 +1040,7 @@ void Server::AsyncRunStep(float dtime, bool initial_step)
 			g_settings->getFloat("server_map_save_interval");
 		if (counter >= save_interval) {
 			counter = 0.0;
-			MutexAutoLock lock(m_env_mutex);
+			EnvAutoLock lock(this);
 
 			ScopeProfiler sp(g_profiler, "Server: map saving (sum)");
 
@@ -1191,7 +1191,7 @@ inline void Server::handleCommand(NetworkPacket *pkt)
 void Server::ProcessData(NetworkPacket *pkt)
 {
 	// Environment is locked first.
-	MutexAutoLock envlock(m_env_mutex);
+	EnvAutoLock envlock(this);
 
 	ScopeProfiler sp(g_profiler, "Server: Process network packet (sum)");
 	u32 peer_id = pkt->getPeerId();
@@ -2363,8 +2363,7 @@ void Server::SendBlockNoLock(session_t peer_id, MapBlock *block, u8 ver,
 
 void Server::SendBlocks(float dtime)
 {
-	MutexAutoLock envlock(m_env_mutex);
-	//TODO check if one big lock could be faster then multiple small ones
+	EnvAutoLock envlock(this);
 
 	std::vector<PrioritySortedBlockTransfer> queue;
 
@@ -2695,7 +2694,7 @@ void Server::sendRequestedMedia(session_t peer_id,
 
 void Server::stepPendingDynMediaCallbacks(float dtime)
 {
-	MutexAutoLock lock(m_env_mutex);
+	EnvAutoLock lock(this);
 
 	for (auto it = m_pending_dyn_media.begin(); it != m_pending_dyn_media.end();) {
 		it->second.expiry_timer -= dtime;
@@ -2914,7 +2913,7 @@ void Server::DeleteClient(session_t peer_id, ClientDeletionReason reason)
 			}
 		}
 		{
-			MutexAutoLock env_lock(m_env_mutex);
+			EnvAutoLock envlock(this);
 			m_clients.DeleteClient(peer_id);
 		}
 	}
@@ -4107,7 +4106,7 @@ Translations *Server::getTranslationLanguage(const std::string &lang_code)
 
 std::unordered_map<std::string, std::string> Server::getMediaList()
 {
-	MutexAutoLock env_lock(m_env_mutex);
+	EnvAutoLock envlock(this);
 
 	std::unordered_map<std::string, std::string> ret;
 	for (auto &it : m_media) {

src/server.h

@@ -424,8 +424,14 @@ public:
 	// Bind address
 	Address m_bind_addr;
 
-	// Environment mutex (envlock)
-	std::mutex m_env_mutex;
+	// Public helper for taking the envlock in a scope
+	class EnvAutoLock {
+	public:
+		EnvAutoLock(Server *server): m_lock(server->m_env_mutex) {}
+
+	private:
+		MutexAutoLock m_lock;
+	};
 
 protected:
 	/* Do not add more members here, this is only required to make unit tests work. */
@@ -600,6 +606,10 @@ private:
 	/*
 		Variables
 	*/
+
+	// Environment mutex (envlock)
+	std::mutex m_env_mutex;
+
 	// World directory
 	std::string m_path_world;
 	std::string m_path_mod_data;