From 1e17d86421ed26b71cced6ab4126540fb562dbcb Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <dktapps@pmmp.io>
Date: Fri, 13 Jan 2023 16:03:15 +0000
Subject: [PATCH] Constify server TPS and server tick time this makes it
 significantly easier to perform experiments involving the server TPS.

---
 src/Server.php | 41 +++++++++++++++++++++++++++++------------
 1 file changed, 29 insertions(+), 12 deletions(-)

diff --git a/src/Server.php b/src/Server.php
index 6d762d538..3b1c22a32 100644
--- a/src/Server.php
+++ b/src/Server.php
@@ -181,6 +181,21 @@ class Server{
 	public const DEFAULT_PORT_IPV6 = 19133;
 	public const DEFAULT_MAX_VIEW_DISTANCE = 16;
 
+	/**
+	 * Worlds, network, commands and most other things are polled this many times per second on average.
+	 * Between ticks, the server will sleep to ensure that the average tick rate is maintained.
+	 * It may wake up between ticks if a Snooze notification source is triggered (e.g. to process network packets).
+	 */
+	public const TARGET_TICKS_PER_SECOND = 20;
+	/**
+	 * The average time between ticks, in seconds.
+	 */
+	public const TARGET_SECONDS_PER_TICK = 1 / self::TARGET_TICKS_PER_SECOND;
+	/**
+	 * The TPS threshold below which the server will generate log warnings.
+	 */
+	public const TPS_OVERLOAD_WARNING_THRESHOLD = self::TARGET_TICKS_PER_SECOND * 0.6;
+
 	private static ?Server $instance = null;
 
 	private SleeperHandler $tickSleeper;
@@ -199,7 +214,7 @@ class Server{
 
 	private PluginManager $pluginManager;
 
-	private float $profilingTickRate = 20;
+	private float $profilingTickRate = self::TARGET_TICKS_PER_SECOND;
 
 	private UpdateChecker $updater;
 
@@ -209,10 +224,10 @@ class Server{
 	private int $tickCounter = 0;
 	private float $nextTick = 0;
 	/** @var float[] */
-	private array $tickAverage = [20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20];
+	private array $tickAverage;
 	/** @var float[] */
-	private array $useAverage = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];
-	private float $currentTPS = 20;
+	private array $useAverage;
+	private float $currentTPS = self::TARGET_TICKS_PER_SECOND;
 	private float $currentUse = 0;
 	private float $startTime;
 
@@ -750,6 +765,8 @@ class Server{
 		}
 		self::$instance = $this;
 		$this->startTime = microtime(true);
+		$this->tickAverage = array_fill(0, self::TARGET_TICKS_PER_SECOND, self::TARGET_TICKS_PER_SECOND);
+		$this->useAverage = array_fill(0, self::TARGET_TICKS_PER_SECOND, 0);
 
 		$this->tickSleeper = new SleeperHandler();
 
@@ -933,7 +950,7 @@ class Server{
 
 			Timings::init();
 			TimingsHandler::setEnabled($this->configGroup->getPropertyBool("settings.enable-profiling", false));
-			$this->profilingTickRate = $this->configGroup->getPropertyInt("settings.profile-report-trigger", 20);
+			$this->profilingTickRate = $this->configGroup->getPropertyInt("settings.profile-report-trigger", self::TARGET_TICKS_PER_SECOND);
 
 			DefaultPermissions::registerCorePermissions();
 
@@ -1793,11 +1810,11 @@ class Server{
 		$this->network->tick();
 		Timings::$connection->stopTiming();
 
-		if(($this->tickCounter % 20) === 0){
+		if(($this->tickCounter % self::TARGET_TICKS_PER_SECOND) === 0){
 			if($this->doTitleTick){
 				$this->titleTick();
 			}
-			$this->currentTPS = 20;
+			$this->currentTPS = self::TARGET_TICKS_PER_SECOND;
 			$this->currentUse = 0;
 
 			$queryRegenerateEvent = new QueryRegenerateEvent(new QueryInfo($this));
@@ -1818,7 +1835,7 @@ class Server{
 				$world->clearCache();
 			}
 
-			if($this->getTicksPerSecondAverage() < 12){
+			if($this->getTicksPerSecondAverage() < self::TPS_OVERLOAD_WARNING_THRESHOLD){
 				$this->logger->warning($this->getLanguage()->translate(KnownTranslationFactory::pocketmine_server_tickOverload()));
 			}
 		}
@@ -1837,19 +1854,19 @@ class Server{
 		Timings::$serverTick->stopTiming();
 
 		$now = microtime(true);
-		$this->currentTPS = min(20, 1 / max(0.001, $now - $tickTime));
-		$this->currentUse = min(1, ($now - $tickTime) / 0.05);
+		$this->currentTPS = min(self::TARGET_TICKS_PER_SECOND, 1 / max(0.001, $now - $tickTime));
+		$this->currentUse = min(1, ($now - $tickTime) / self::TARGET_SECONDS_PER_TICK);
 
 		TimingsHandler::tick($this->currentTPS <= $this->profilingTickRate);
 
-		$idx = $this->tickCounter % 20;
+		$idx = $this->tickCounter % self::TARGET_TICKS_PER_SECOND;
 		$this->tickAverage[$idx] = $this->currentTPS;
 		$this->useAverage[$idx] = $this->currentUse;
 
 		if(($this->nextTick - $tickTime) < -1){
 			$this->nextTick = $tickTime;
 		}else{
-			$this->nextTick += 0.05;
+			$this->nextTick += self::TARGET_SECONDS_PER_TICK;
 		}
 	}
 }