PocketMine-MP/src/GarbageCollectorManager.php
Dylan K. Taylor 8b57e9007a
👺
2025-03-15 01:33:29 +00:00

115 lines
3.6 KiB
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\timings\TimingsHandler;
use function gc_collect_cycles;
use function gc_disable;
use function gc_status;
use function hrtime;
use function max;
use function min;
use function number_format;
use function sprintf;
/**
* Allows threads to manually trigger the cyclic garbage collector using a threshold like PHP's own garbage collector,
* but triggered at a time that suits the thread instead of in random code pathways.
*
* The GC trigger behaviour in this class was adapted from Zend/zend_gc.c as of PHP 8.3.14.
*/
final class GarbageCollectorManager{
//TODO: These values could be adjusted to better suit PM, but for now we just want to mirror PHP GC to minimize
//behavioural changes.
private const GC_THRESHOLD_TRIGGER = 100;
private const GC_THRESHOLD_MAX = 1_000_000_000;
private const GC_THRESHOLD_DEFAULT = 10_001;
private const GC_THRESHOLD_STEP = 10_000;
private int $threshold = self::GC_THRESHOLD_DEFAULT;
private int $collectionTimeTotalNs = 0;
private int $runs = 0;
private \Logger $logger;
private TimingsHandler $timings;
public function __construct(
\Logger $logger,
?TimingsHandler $parentTimings,
){
gc_disable();
$this->logger = new \PrefixedLogger($logger, "Cyclic Garbage Collector");
$this->timings = new TimingsHandler("Cyclic Garbage Collector", $parentTimings);
}
private function adjustGcThreshold(int $cyclesCollected, int $rootsAfterGC) : void{
//TODO Very simple heuristic for dynamic GC buffer resizing:
//If there are "too few" collections, increase the collection threshold
//by a fixed step
//Adapted from zend_gc.c/gc_adjust_threshold() as of PHP 8.3.14
if($cyclesCollected < self::GC_THRESHOLD_TRIGGER || $rootsAfterGC >= $this->threshold){
$this->threshold = min(self::GC_THRESHOLD_MAX, $this->threshold + self::GC_THRESHOLD_STEP);
}elseif($this->threshold > self::GC_THRESHOLD_DEFAULT){
$this->threshold = max(self::GC_THRESHOLD_DEFAULT, $this->threshold - self::GC_THRESHOLD_STEP);
}
}
public function getThreshold() : int{ return $this->threshold; }
public function getCollectionTimeTotalNs() : int{ return $this->collectionTimeTotalNs; }
public function maybeCollectCycles() : int{
$rootsBefore = gc_status()["roots"];
if($rootsBefore < $this->threshold){
return 0;
}
$this->timings->startTiming();
$start = hrtime(true);
$cycles = gc_collect_cycles();
$end = hrtime(true);
$rootsAfter = gc_status()["roots"];
$this->adjustGcThreshold($cycles, $rootsAfter);
$this->timings->stopTiming();
$time = $end - $start;
$this->collectionTimeTotalNs += $time;
$this->runs++;
$this->logger->info(sprintf(
"Run #%d took %s ms (%s -> %s roots, %s cycles collected) - cumulative GC time: %s ms",
$this->runs,
number_format($time / 1_000_000, 2),
$rootsBefore,
$rootsAfter,
$cycles,
number_format($this->collectionTimeTotalNs / 1_000_000, 2)
));
return $cycles;
}
}