Use thread_local instead from some static settings (#5955)

thread_local permits to limit variable lifetime to thread duration. Use it on each setting place which uses static to cache variable result only for thread lifetime. This permits to keep the same performance level & reconfigure server from MT gui in those various variables places.

Add thread_local to undersampling calculation too.

8 files changed, 22 insertions, 16 deletions

diff --git a/src/drawscene.cpp b/src/drawscene.cpp
index 59f9b8375..2cf9689a8 100644
--- a/src/drawscene.cpp
+++ b/src/drawscene.cpp
@@ -474,7 +474,7 @@ void draw_plain(Camera &camera, bool show_hud,
 	// Undersampling-specific stuff
 	static video::ITexture *image = NULL;
 	static v2u32 last_pixelated_size = v2u32(0, 0);
-	int undersampling = g_settings->getU16("undersampling");
+	static thread_local int undersampling = g_settings->getU16("undersampling");
 	v2u32 pixelated_size;
 	v2u32 dest_size;
 	if (undersampling > 0) {
diff --git a/src/game.cpp b/src/game.cpp
index ed7316a4d..c32ab6f30 100644
--- a/src/game.cpp
+++ b/src/game.cpp
@@ -3637,7 +3637,7 @@ PointedThing Game::updatePointedThing(
 	std::vector<aabb3f> *selectionboxes = hud->getSelectionBoxes();
 	selectionboxes->clear();
 	hud->setSelectedFaceNormal(v3f(0.0, 0.0, 0.0));
-	static const bool show_entity_selectionbox = g_settings->getBool(
+	static thread_local const bool show_entity_selectionbox = g_settings->getBool(
 		"show_entity_selectionbox");
 
 	ClientMap &map = client->getEnv().getClientMap();
@@ -3980,7 +3980,7 @@ void Game::handleDigging(const PointedThing &pointed, const v3s16 &nodepos,
 		bool is_valid_position;
 		MapNode wasnode = map.getNodeNoEx(nodepos, &is_valid_position);
 		if (is_valid_position) {
-			if (client->moddingEnabled() && 
+			if (client->moddingEnabled() &&
 			    		client->getScript()->on_dignode(nodepos, wasnode)) {
 				return;
 			}
diff --git a/src/hud.cpp b/src/hud.cpp
index a2f031b4c..6bdbafc06 100644
--- a/src/hud.cpp
+++ b/src/hud.cpp
@@ -639,7 +639,7 @@ void drawItemStack(video::IVideoDriver *driver,
 		ItemRotationKind rotation_kind)
 {
 	static MeshTimeInfo rotation_time_infos[IT_ROT_NONE];
-	static bool enable_animations =
+	static thread_local bool enable_animations =
 		g_settings->getBool("inventory_items_animations");
 
 	if (item.empty()) {
diff --git a/src/mapblock_mesh.cpp b/src/mapblock_mesh.cpp
index 6781f21af..4fcdaaa57 100644
--- a/src/mapblock_mesh.cpp
+++ b/src/mapblock_mesh.cpp
@@ -271,7 +271,7 @@ static u16 getSmoothLightCombined(v3s16 p, MeshMakeData *data)
 
 	if (ambient_occlusion > 4)
 	{
-		static const float ao_gamma = rangelim(
+		static thread_local const float ao_gamma = rangelim(
 			g_settings->getFloat("ambient_occlusion_gamma"), 0.25, 4.0);
 
 		// Table of gamma space multiply factors.
diff --git a/src/network/serverpackethandler.cpp b/src/network/serverpackethandler.cpp
index f33b1a523..6c766a37a 100644
--- a/src/network/serverpackethandler.cpp
+++ b/src/network/serverpackethandler.cpp
@@ -1380,7 +1380,9 @@ void Server::handleCommand_Interact(NetworkPacket* pkt)
 		Check that target is reasonably close
 		(only when digging or placing things)
 	*/
-	static const bool enable_anticheat = !g_settings->getBool("disable_anticheat");
+	static thread_local const bool enable_anticheat =
+			!g_settings->getBool("disable_anticheat");
+
 	if ((action == 0 || action == 2 || action == 3 || action == 4) &&
 			(enable_anticheat && !isSingleplayer())) {
 		float d = player_pos.getDistanceFrom(pointed_pos_under);
diff --git a/src/particles.cpp b/src/particles.cpp
index e89e182e6..fe681fe6c 100644
--- a/src/particles.cpp
+++ b/src/particles.cpp
@@ -294,7 +294,7 @@ void ParticleSpawner::step(float dtime, ClientEnvironment* env)
 {
 	m_time += dtime;
 
-	static const float radius =
+	static thread_local const float radius =
 			g_settings->getS16("max_block_send_distance") * MAP_BLOCKSIZE;
 
 	bool unloaded = false;
diff --git a/src/server.cpp b/src/server.cpp
index 5911bbaf1..a6af742a5 100644
--- a/src/server.cpp
+++ b/src/server.cpp
@@ -638,14 +638,15 @@ void Server::AsyncRunStep(bool initial_step)
 		ScopeProfiler sp(g_profiler, "Server: checking added and deleted objs");
 
 		// Radius inside which objects are active
-		static const s16 radius =
+		static thread_local const s16 radius =
 			g_settings->getS16("active_object_send_range_blocks") * MAP_BLOCKSIZE;
 
 		// Radius inside which players are active
-		static const bool is_transfer_limited =
+		static thread_local const bool is_transfer_limited =
 			g_settings->exists("unlimited_player_transfer_distance") &&
 			!g_settings->getBool("unlimited_player_transfer_distance");
-		static const s16 player_transfer_dist = g_settings->getS16("player_transfer_distance") * MAP_BLOCKSIZE;
+		static thread_local const s16 player_transfer_dist =
+			g_settings->getS16("player_transfer_distance") * MAP_BLOCKSIZE;
 		s16 player_radius = player_transfer_dist;
 		if (player_radius == 0 && is_transfer_limited)
 			player_radius = radius;
@@ -982,7 +983,7 @@ void Server::AsyncRunStep(bool initial_step)
 	{
 		float &counter = m_savemap_timer;
 		counter += dtime;
-		static const float save_interval =
+		static thread_local const float save_interval =
 			g_settings->getFloat("server_map_save_interval");
 		if (counter >= save_interval) {
 			counter = 0.0;
@@ -1684,7 +1685,7 @@ void Server::SendSpawnParticle(u16 peer_id, u16 protocol_version,
 				const struct TileAnimationParams &animation, u8 glow)
 {
 	DSTACK(FUNCTION_NAME);
-	static const float radius =
+	static thread_local const float radius =
 			g_settings->getS16("max_block_send_distance") * MAP_BLOCKSIZE * BS;
 
 	if (peer_id == PEER_ID_INEXISTENT) {
@@ -3676,8 +3677,9 @@ void dedicated_server_loop(Server &server, bool &kill)
 
 	IntervalLimiter m_profiler_interval;
 
-	static const float steplen = g_settings->getFloat("dedicated_server_step");
-	static const float profiler_print_interval =
+	static thread_local const float steplen =
+			g_settings->getFloat("dedicated_server_step");
+	static thread_local const float profiler_print_interval =
 			g_settings->getFloat("profiler_print_interval");
 
 	for(;;) {
diff --git a/src/serverenvironment.cpp b/src/serverenvironment.cpp
index 7be958920..161b24fd4 100644
--- a/src/serverenvironment.cpp
+++ b/src/serverenvironment.cpp
@@ -1169,7 +1169,8 @@ void ServerEnvironment::step(float dtime)
 	// Update this one
 	// NOTE: This is kind of funny on a singleplayer game, but doesn't
 	// really matter that much.
-	static const float server_step = g_settings->getFloat("dedicated_server_step");
+	static thread_local const float server_step =
+			g_settings->getFloat("dedicated_server_step");
 	m_recommended_send_interval = server_step;
 
 	/*
@@ -1230,7 +1231,8 @@ void ServerEnvironment::step(float dtime)
 		/*
 			Update list of active blocks, collecting changes
 		*/
-		static const s16 active_block_range = g_settings->getS16("active_block_range");
+		static thread_local const s16 active_block_range =
+				g_settings->getS16("active_block_range");
 		std::set<v3s16> blocks_removed;
 		std::set<v3s16> blocks_added;
 		m_active_blocks.update(players_blockpos, active_block_range,