Allow thread errors and their traces to be properly recorded in crashdumps (#5910)

until now, any thread crash would show as a generic crash since we aren't able to get the trace from the crashed thread directly. This uses some dirty tricks to export a partially serialized stack trace to the main thread, where it can be written into a crashdump.
This enables us to see proper crash information for async tasks in the crash archive (finally!!!) as well as being able to capture RakLib errors properly.

src/thread/CommonThreadPartsTrait.php

@@ -26,7 +26,10 @@ namespace pocketmine\thread;
 use pmmp\thread\ThreadSafeArray;
 use pocketmine\errorhandler\ErrorToExceptionHandler;
 use pocketmine\Server;
+use function error_get_last;
 use function error_reporting;
+use function register_shutdown_function;
+use function set_exception_handler;
 
 trait CommonThreadPartsTrait{
 	/**
@@ -38,6 +41,8 @@ trait CommonThreadPartsTrait{
 
 	protected bool $isKilled = false;
 
+	private ?ThreadCrashInfo $crashInfo = null;
+
 	/**
 	 * @return ThreadSafeClassLoader[]
 	 */
@@ -88,12 +93,48 @@ trait CommonThreadPartsTrait{
 		}
 	}
 
+	public function getCrashInfo() : ?ThreadCrashInfo{ return $this->crashInfo; }
+
 	final public function run() : void{
 		error_reporting(-1);
 		$this->registerClassLoaders();
 		//set this after the autoloader is registered
 		ErrorToExceptionHandler::set();
+
+		//this permits adding extra functionality to the exception and shutdown handlers via overriding
+		set_exception_handler($this->onUncaughtException(...));
+		register_shutdown_function($this->onShutdown(...));
+
 		$this->onRun();
+		$this->isKilled = true;
+	}
+
+	/**
+	 * Called by set_exception_handler() when an uncaught exception is thrown.
+	 */
+	protected function onUncaughtException(\Throwable $e) : void{
+		$this->synchronized(function() use ($e) : void{
+			$this->crashInfo = ThreadCrashInfo::fromThrowable($e, $this->getThreadName());
+		});
+	}
+
+	/**
+	 * Called by register_shutdown_function() when the thread shuts down. This may be because of a benign shutdown, or
+	 * because of a fatal error. Use isKilled to determine which.
+	 */
+	protected function onShutdown() : void{
+		$this->synchronized(function() : void{
+			if(!$this->isKilled && $this->crashInfo === null){
+				$last = error_get_last();
+				if($last !== null){
+					//fatal error
+					$this->crashInfo = ThreadCrashInfo::fromLastErrorInfo($last, $this->getThreadName());
+				}else{
+					//probably misused exit()
+					$this->crashInfo = ThreadCrashInfo::fromThrowable(new \RuntimeException("Thread crashed without an error - perhaps exit() was called?"), $this->getThreadName());
+				}
+			}
+		});
 	}
 
 	/**

src/thread/ThreadCrashException.php

@@ -0,0 +1,38 @@
+<?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\thread;
+
+final class ThreadCrashException extends ThreadException{
+
+	private ThreadCrashInfo $crashInfo;
+
+	public function __construct(string $message, ThreadCrashInfo $crashInfo){
+		parent::__construct($message);
+		$this->crashInfo = $crashInfo;
+	}
+
+	public function getCrashInfo() : ThreadCrashInfo{
+		return $this->crashInfo;
+	}
+}

src/thread/ThreadCrashInfo.php

@@ -0,0 +1,89 @@
+<?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\thread;
+
+use pmmp\thread\ThreadSafe;
+use pmmp\thread\ThreadSafeArray;
+use pocketmine\errorhandler\ErrorTypeToStringMap;
+use pocketmine\utils\Filesystem;
+use pocketmine\utils\Utils;
+use function get_class;
+use function sprintf;
+
+final class ThreadCrashInfo extends ThreadSafe{
+
+	/** @phpstan-var ThreadSafeArray<int, ThreadCrashInfoFrame> */
+	private ThreadSafeArray $trace;
+
+	/**
+	 * @param ThreadCrashInfoFrame[] $trace
+	 */
+	public function __construct(
+		private string $type,
+		private string $message,
+		private string $file,
+		private int $line,
+		array $trace,
+		private string $threadName
+	){
+		$this->trace = ThreadSafeArray::fromArray($trace);
+	}
+
+	public static function fromThrowable(\Throwable $e, string $threadName) : self{
+		return new self(get_class($e), $e->getMessage(), $e->getFile(), $e->getLine(), Utils::printableTraceWithMetadata($e->getTrace()), $threadName);
+	}
+
+	/**
+	 * @phpstan-param array{type: int, message: string, file: string, line: int} $info
+	 */
+	public static function fromLastErrorInfo(array $info, string $threadName) : self{
+		try{
+			$class = ErrorTypeToStringMap::get($info["type"]);
+		}catch(\InvalidArgumentException){
+			$class = "Unknown error type (" . $info["type"] . ")";
+		}
+		return new self($class, $info["message"], $info["file"], $info["line"], Utils::printableTraceWithMetadata(Utils::currentTrace()), $threadName);
+	}
+
+	public function getType() : string{ return $this->type; }
+
+	public function getMessage() : string{ return $this->message; }
+
+	public function getFile() : string{ return $this->file; }
+
+	public function getLine() : int{ return $this->line; }
+
+	/**
+	 * @return ThreadCrashInfoFrame[]
+	 */
+	public function getTrace() : array{
+		return (array) $this->trace;
+	}
+
+	public function getThreadName() : string{ return $this->threadName; }
+
+	public function makePrettyMessage() : string{
+		return sprintf("%s: \"%s\" in \"%s\" on line %d", $this->type ?? "Fatal error", $this->message, Filesystem::cleanPath($this->file), $this->line);
+	}
+}

src/thread/ThreadCrashInfoFrame.php

@@ -0,0 +1,41 @@
+<?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\thread;
+
+use pmmp\thread\ThreadSafe;
+
+final class ThreadCrashInfoFrame extends ThreadSafe{
+
+	public function __construct(
+		private string $printableFrame,
+		private ?string $file,
+		private int $line,
+	){}
+
+	public function getPrintableFrame() : string{ return $this->printableFrame; }
+
+	public function getFile() : ?string{ return $this->file; }
+
+	public function getLine() : int{ return $this->line; }
+}