AsyncWorker: Use statics for thread-local worker storage instead of globals

src/pocketmine/scheduler/AsyncTask.php

@@ -126,29 +126,29 @@ abstract class AsyncTask extends Collectable{
 	}
 
 	/**
-	 * Gets something into the local thread store.
-	 * You have to initialize this in some way from the task on run
+	 * @see AsyncWorker::getFromThreadStore()
 	 *
 	 * @param string $identifier
 	 * @return mixed
 	 */
 	public function getFromThreadStore(string $identifier){
-		global $store;
-		return ($this->isGarbage() or !isset($store[$identifier])) ? null : $store[$identifier];
+		if($this->worker === null or $this->isGarbage()){
+			throw new \BadMethodCallException("Objects stored in AsyncWorker thread-local storage can only be retrieved during task execution");
+		}
+		return $this->worker->getFromThreadStore($identifier);
 	}
 
 	/**
-	 * Saves something into the local thread store.
-	 * This might get deleted at any moment.
+	 * @see AsyncWorker::saveToThreadStore()
 	 *
 	 * @param string $identifier
 	 * @param mixed  $value
 	 */
 	public function saveToThreadStore(string $identifier, $value){
-		global $store;
-		if(!$this->isGarbage()){
-			$store[$identifier] = $value;
+		if($this->worker === null or $this->isGarbage()){
+			throw new \BadMethodCallException("Objects can only be added to AsyncWorker thread-local storage during task execution");
 		}
+		$this->worker->saveToThreadStore($identifier, $value);
 	}
 
 	/**

src/pocketmine/scheduler/AsyncWorker.php

@@ -26,6 +26,8 @@ namespace pocketmine\scheduler;
 use pocketmine\Worker;
 
 class AsyncWorker extends Worker{
+	/** @var mixed[] */
+	private static $store = [];
 
 	private $logger;
 	private $id;
@@ -53,9 +55,6 @@ class AsyncWorker extends Worker{
 			ini_set('memory_limit', '-1');
 			$this->logger->debug("No memory limit set");
 		}
-
-		global $store;
-		$store = [];
 	}
 
 	public function getLogger() : \ThreadedLogger{
@@ -73,4 +72,30 @@ class AsyncWorker extends Worker{
 	public function getAsyncWorkerId() : int{
 		return $this->id;
 	}
+
+	/**
+	 * Saves mixed data into the worker's thread-local object store. This can be used to store objects which you
+	 * want to use on this worker thread from multiple AsyncTasks.
+	 *
+	 * @param string $identifier
+	 * @param mixed  $value
+	 */
+	public function saveToThreadStore(string $identifier, $value) : void{
+		self::$store[$identifier] = $value;
+	}
+
+	/**
+	 * Retrieves mixed data from the worker's thread-local object store.
+	 *
+	 * Note that the thread-local object store could be cleared and your data might not exist, so your code should
+	 * account for the possibility that what you're trying to retrieve might not exist.
+	 *
+	 * Objects stored in this storage may ONLY be retrieved while the task is running.
+	 *
+	 * @param string $identifier
+	 * @return mixed
+	 */
+	public function getFromThreadStore(string $identifier){
+		return self::$store[$identifier] ?? null;
+	}
 }

src/pocketmine/scheduler/DumpWorkerMemoryTask.php

@@ -48,10 +48,8 @@ class DumpWorkerMemoryTask extends AsyncTask{
 	}
 
 	public function onRun(){
-		global $store;
-
 		MemoryManager::dumpMemory(
-			["worker" => $this->worker, "store" => $store],
+			$this->worker,
 			$this->outputFolder . DIRECTORY_SEPARATOR . "AsyncWorker#" . $this->worker->getAsyncWorkerId(),
 			$this->maxNesting,
 			$this->maxStringSize,