MemoryManager.php

<?php
 
/*
 *
 *  ____            _        _   __  __ _                  __  __ ____
 * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
 * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
 * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
 * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
 *
 * 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 3 of the License, or
 * (at your option) any later version.
 *
 * @author PocketMine Team
 * @link http://www.pocketmine.net/
 *
 *
 */
 
declare(strict_types=1);
 
namespace pocketmine;
 
use pocketmine\event\server\LowMemoryEvent;
use pocketmine\network\mcpe\cache\ChunkCache;
use pocketmine\scheduler\DumpWorkerMemoryTask;
use pocketmine\scheduler\GarbageCollectionTask;
use pocketmine\timings\Timings;
use pocketmine\utils\Process;
use pocketmine\YmlServerProperties as Yml;
use function gc_collect_cycles;
use function gc_mem_caches;
use function ini_set;
use function intdiv;
use function mb_strtoupper;
use function min;
use function preg_match;
use function round;
use function sprintf;
 
class MemoryManager{
    private const DEFAULT_CHECK_RATE = Server::TARGET_TICKS_PER_SECOND;
    private const DEFAULT_CONTINUOUS_TRIGGER_RATE = Server::TARGET_TICKS_PER_SECOND * 2;
    private const DEFAULT_TICKS_PER_GC = 30 * 60 * Server::TARGET_TICKS_PER_SECOND;
 
    private GarbageCollectorManager $cycleGcManager;
 
    private int $memoryLimit;
    private int $globalMemoryLimit;
    private int $checkRate;
    private int $checkTicker = 0;
    private bool $lowMemory = false;
 
    private bool $continuousTrigger = true;
    private int $continuousTriggerRate;
    private int $continuousTriggerCount = 0;
    private int $continuousTriggerTicker = 0;
 
    private int $garbageCollectionPeriod;
    private int $garbageCollectionTicker = 0;
 
    private int $lowMemChunkRadiusOverride;
 
    private bool $dumpWorkers = true;
 
    private \Logger $logger;
 
    public function __construct(
        private Server $server
    ){
        $this->logger = new \PrefixedLogger($server->getLogger(), "Memory Manager");
        $this->cycleGcManager = new GarbageCollectorManager($this->logger, Timings::$memoryManager);
 
        $this->init($server->getConfigGroup());
    }
 
    private function init(ServerConfigGroup $config) : void{
        $this->memoryLimit = $config->getPropertyInt(Yml::MEMORY_MAIN_LIMIT, 0) * 1024 * 1024;
 
        $defaultMemory = 1024;
 
        if(preg_match("/([0-9]+)([KMGkmg])/", $config->getConfigString("memory-limit", ""), $matches) > 0){
            $m = (int) $matches[1];
            if($m <= 0){
                $defaultMemory = 0;
            }else{
                $defaultMemory = match(mb_strtoupper($matches[2])){
                    "K" => intdiv($m, 1024),
                    "M" => $m,
                    "G" => $m * 1024,
                    default => $m,
                };
            }
        }
 
        $hardLimit = $config->getPropertyInt(Yml::MEMORY_MAIN_HARD_LIMIT, $defaultMemory);
 
        if($hardLimit <= 0){
            ini_set("memory_limit", '-1');
        }else{
            ini_set("memory_limit", $hardLimit . "M");
        }
 
        $this->globalMemoryLimit = $config->getPropertyInt(Yml::MEMORY_GLOBAL_LIMIT, 0) * 1024 * 1024;
        $this->checkRate = $config->getPropertyInt(Yml::MEMORY_CHECK_RATE, self::DEFAULT_CHECK_RATE);
        $this->continuousTrigger = $config->getPropertyBool(Yml::MEMORY_CONTINUOUS_TRIGGER, true);
        $this->continuousTriggerRate = $config->getPropertyInt(Yml::MEMORY_CONTINUOUS_TRIGGER_RATE, self::DEFAULT_CONTINUOUS_TRIGGER_RATE);
 
        $this->garbageCollectionPeriod = $config->getPropertyInt(Yml::MEMORY_GARBAGE_COLLECTION_PERIOD, self::DEFAULT_TICKS_PER_GC);
 
        $this->lowMemChunkRadiusOverride = $config->getPropertyInt(Yml::MEMORY_MAX_CHUNKS_CHUNK_RADIUS, 4);
 
        $this->dumpWorkers = $config->getPropertyBool(Yml::MEMORY_MEMORY_DUMP_DUMP_ASYNC_WORKER, true);
    }
 
    public function isLowMemory() : bool{
        return $this->lowMemory;
    }
 
    public function getGlobalMemoryLimit() : int{
        return $this->globalMemoryLimit;
    }
 
    public function getViewDistance(int $distance) : int{
        return ($this->lowMemory && $this->lowMemChunkRadiusOverride > 0) ? min($this->lowMemChunkRadiusOverride, $distance) : $distance;
    }
 
    public function trigger(int $memory, int $limit, bool $global = false, int $triggerCount = 0) : void{
        $this->logger->debug(sprintf("%sLow memory triggered, limit %gMB, using %gMB",
            $global ? "Global " : "", round(($limit / 1024) / 1024, 2), round(($memory / 1024) / 1024, 2)));
        foreach($this->server->getWorldManager()->getWorlds() as $world){
            $world->clearCache(true);
        }
        ChunkCache::pruneCaches();
 
        foreach($this->server->getWorldManager()->getWorlds() as $world){
            $world->doChunkGarbageCollection();
        }
 
        $ev = new LowMemoryEvent($memory, $limit, $global, $triggerCount);
        $ev->call();
 
        $cycles = $this->triggerGarbageCollector();
 
        $this->logger->debug(sprintf("Freed %gMB, $cycles cycles", round(($ev->getMemoryFreed() / 1024) / 1024, 2)));
    }
 
    public function check() : void{
        Timings::$memoryManager->startTiming();
 
        if(($this->memoryLimit > 0 || $this->globalMemoryLimit > 0) && ++$this->checkTicker >= $this->checkRate){
            $this->checkTicker = 0;
            $memory = Process::getAdvancedMemoryUsage();
            $trigger = false;
            if($this->memoryLimit > 0 && $memory[0] > $this->memoryLimit){
                $trigger = 0;
            }elseif($this->globalMemoryLimit > 0 && $memory[1] > $this->globalMemoryLimit){
                $trigger = 1;
            }
 
            if($trigger !== false){
                if($this->lowMemory && $this->continuousTrigger){
                    if(++$this->continuousTriggerTicker >= $this->continuousTriggerRate){
                        $this->continuousTriggerTicker = 0;
                        $this->trigger($memory[$trigger], $this->memoryLimit, $trigger > 0, ++$this->continuousTriggerCount);
                    }
                }else{
                    $this->lowMemory = true;
                    $this->continuousTriggerCount = 0;
                    $this->trigger($memory[$trigger], $this->memoryLimit, $trigger > 0);
                }
            }else{
                $this->lowMemory = false;
            }
        }
 
        if($this->garbageCollectionPeriod > 0 && ++$this->garbageCollectionTicker >= $this->garbageCollectionPeriod){
            $this->garbageCollectionTicker = 0;
            $this->triggerGarbageCollector();
        }else{
            $this->cycleGcManager->maybeCollectCycles();
        }
 
        Timings::$memoryManager->stopTiming();
    }
 
    public function triggerGarbageCollector() : int{
        Timings::$garbageCollector->startTiming();
 
        $pool = $this->server->getAsyncPool();
        if(($w = $pool->shutdownUnusedWorkers()) > 0){
            $this->logger->debug("Shut down $w idle async pool workers");
        }
        foreach($pool->getRunningWorkers() as $i){
            $pool->submitTaskToWorker(new GarbageCollectionTask(), $i);
        }
 
        $cycles = gc_collect_cycles();
        gc_mem_caches();
 
        Timings::$garbageCollector->stopTiming();
 
        return $cycles;
    }
 
    public function dumpServerMemory(string $outputFolder, int $maxNesting, int $maxStringSize) : void{
        $logger = new \PrefixedLogger($this->server->getLogger(), "Memory Dump");
        $logger->notice("After the memory dump is done, the server might crash");
        MemoryDump::dumpMemory($this->server, $outputFolder, $maxNesting, $maxStringSize, $logger);
 
        if($this->dumpWorkers){
            $pool = $this->server->getAsyncPool();
            foreach($pool->getRunningWorkers() as $i){
                $pool->submitTaskToWorker(new DumpWorkerMemoryTask($outputFolder, $maxNesting, $maxStringSize), $i);
            }
        }
    }
}