Use a subprocess for reading lines from STDIN (#4332)

this FINALLY provides us with a way to deal with Windows without needing to forcibly terminate the entire server on shutdown.

src/console/ConsoleReaderChildProcess.php

@@ -0,0 +1,49 @@
+<?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\console;
+
+use function cli_set_process_title;
+use function count;
+use function dirname;
+use function fwrite;
+use function stream_socket_client;
+
+require dirname(__DIR__, 2) . '/vendor/autoload.php';
+
+if(count($argv) !== 2){
+	die("Please provide a server to connect to");
+}
+
+@cli_set_process_title('PocketMine-MP Console Reader');
+$socket = stream_socket_client($argv[1]);
+if($socket === false){
+	throw new \RuntimeException("Failed to connect to server process");
+}
+$consoleReader = new ConsoleReader();
+while(true){
+	$line = $consoleReader->readLine();
+	if($line !== null){
+		fwrite($socket, $line . "\n");
+	}
+}

src/console/ConsoleReaderThread.php

@@ -25,10 +25,21 @@ namespace pocketmine\console;
 
 use pocketmine\snooze\SleeperNotifier;
 use pocketmine\thread\Thread;
-use pocketmine\thread\ThreadException;
-use function microtime;
+use pocketmine\utils\AssumptionFailedError;
+use Webmozart\PathUtil\Path;
+use function fgets;
+use function fopen;
 use function preg_replace;
-use function usleep;
+use function proc_open;
+use function proc_terminate;
+use function sprintf;
+use function stream_select;
+use function stream_socket_accept;
+use function stream_socket_get_name;
+use function stream_socket_server;
+use function stream_socket_shutdown;
+use const PHP_BINARY;
+use const STREAM_SHUT_RDWR;
 
 final class ConsoleReaderThread extends Thread{
 	private \Threaded $buffer;
@@ -45,35 +56,69 @@ final class ConsoleReaderThread extends Thread{
 		$this->shutdown = true;
 	}
 
-	public function quit() : void{
-		$wait = microtime(true) + 0.5;
-		while(microtime(true) < $wait){
-			if($this->isRunning()){
-				usleep(100000);
-			}else{
-				parent::quit();
-				return;
-			}
-		}
-
-		throw new ThreadException("CommandReader is stuck in a blocking STDIN read");
-	}
-
 	protected function onRun() : void{
 		$buffer = $this->buffer;
 		$notifier = $this->notifier;
 
-		$reader = new ConsoleReader();
-		while(!$this->shutdown){
-			$line = $reader->readLine();
+		/*
+		 * This pile of shit exists because PHP on Windows is broken, and can't handle stream_select() on stdin or pipes
+		 * properly - stdin native triggers stream_select() when a key is pressed, causing it to get stuck in fgets()
+		 * waiting for a line that might never come (and Windows doesn't support character-based reading either), and
+		 * pipes just constantly trigger stream_select() instead of only when data is returned, rendering it useless.
+		 *
+		 * This results in whichever process reads stdin getting stuck on shutdown, which previously forced us to kill
+		 * the entire server process to make it go away.
+		 *
+		 * To get around this problem, we delegate the responsibility of reading stdin to a subprocess, which we can
+		 * then brutally murder when the server shuts down, without killing the entire server process.
+		 * Thankfully, stream_select() actually works properly on sockets, so we can use them for inter-process
+		 * communication.
+		 */
 
-			if($line !== null){
-				$buffer[] = preg_replace("#\\x1b\\x5b([^\\x1b]*\\x7e|[\\x40-\\x50])#", "", $line);
+		$server = stream_socket_server("tcp://127.0.0.1:0");
+		if($server === false){
+			throw new \RuntimeException("Failed to open console reader socket server");
+		}
+		$address = stream_socket_get_name($server, false);
+		if($address === false) throw new AssumptionFailedError("stream_socket_get_name() shouldn't return false here");
+
+		$sub = proc_open(
+			[PHP_BINARY, '-r', sprintf('require "%s";', Path::join(__DIR__, 'ConsoleReaderChildProcess.php')), $address],
+			[
+				2 => fopen("php://stderr", "w"),
+			],
+			$pipes
+		);
+		if($sub === false){
+			throw new AssumptionFailedError("Something has gone horribly wrong");
+		}
+		$client = stream_socket_accept($server);
+		if($client === false){
+			throw new AssumptionFailedError("stream_socket_accept() returned false");
+		}
+		stream_socket_shutdown($server, STREAM_SHUT_RDWR);
+		while(!$this->shutdown){
+			$r = [$client];
+			$w = null;
+			$e = null;
+			if(stream_select($r, $w, $e, 0, 200000) === 1){
+				$command = fgets($client);
+				if($command === false){
+					throw new AssumptionFailedError("Something has gone horribly wrong");
+				}
+
+				$buffer[] = preg_replace("#\\x1b\\x5b([^\\x1b]*\\x7e|[\\x40-\\x50])#", "", $command);
 				if($notifier !== null){
 					$notifier->wakeupSleeper();
 				}
 			}
 		}
+
+		//we have no way to signal to the subprocess to shut down gracefully; besides, Windows sucks, and the subprocess
+		//gets stuck in a blocking fgets() read because stream_select() is a hunk of junk (hence the separate process in
+		//the first place).
+		proc_terminate($sub);
+		stream_socket_shutdown($client, STREAM_SHUT_RDWR);
 	}
 
 	public function getThreadName() : string{

tests/phpstan/configs/phpstan-bugs.neon

@@ -10,6 +10,11 @@ parameters:
 			count: 2
 			path: ../../../src/console/ConsoleReader.php
 
+		-
+			message: "#^Parameter \\#1 \\$command of function proc_open expects string, array\\<int, string\\> given\\.$#"
+			count: 1
+			path: ../../../src/console/ConsoleReaderThread.php
+
 		-
 			message: "#^Method pocketmine\\\\crafting\\\\CraftingManager\\:\\:getDestructorCallbacks\\(\\) should return pocketmine\\\\utils\\\\ObjectSet\\<Closure\\(\\)\\: void\\> but returns pocketmine\\\\utils\\\\ObjectSet\\<Closure\\(\\)\\: void\\>\\|pocketmine\\\\utils\\\\ObjectSet\\<object\\>\\.$#"
 			count: 1