Partially revert "ConsoleReaderChildProcess: Commit suicide in more cases"

This reverts commit cbe0f44c4f7bc3715acbf148f981bd93111c4c8f.

This achieves the same result as the reverted commit wrt. process in the
same manner (writing a keepalive into the socket and checking if it
failed to send). However, it does _not_ allow the process to die on
reaching pipe EOF, since this can cause many spams of subprocesses when
stdin is actually not a tty (e.g. in a Docker container).

src/console/ConsoleReader.php

@@ -23,38 +23,49 @@ declare(strict_types=1);
 
 namespace pocketmine\console;
 
-use pocketmine\utils\AssumptionFailedError;
 use function fclose;
 use function fgets;
 use function fopen;
+use function is_resource;
 use function stream_select;
 use function trim;
+use function usleep;
 
 final class ConsoleReader{
 	/** @var resource */
 	private $stdin;
 
 	public function __construct(){
-		$stdin = fopen("php://stdin", "r");
-		if($stdin === false) throw new AssumptionFailedError("Opening stdin should never fail");
-		$this->stdin = $stdin;
+		$this->initStdin();
+	}
+
+	private function initStdin() : void{
+		if(is_resource($this->stdin)){
+			fclose($this->stdin);
+		}
+
+		$this->stdin = fopen("php://stdin", "r");
 	}
 
 	/**
 	 * Reads a line from the console and adds it to the buffer. This method may block the thread.
-	 * @throws ConsoleReaderException
 	 */
 	public function readLine() : ?string{
+		if(!is_resource($this->stdin)){
+			$this->initStdin();
+		}
+
 		$r = [$this->stdin];
 		$w = $e = null;
 		if(($count = stream_select($r, $w, $e, 0, 200000)) === 0){ //nothing changed in 200000 microseconds
 			return null;
 		}elseif($count === false){ //stream error
-			throw new ConsoleReaderException("Unexpected EOF on select()");
+			return null;
 		}
 
 		if(($raw = fgets($this->stdin)) === false){ //broken pipe or EOF
-			throw new ConsoleReaderException("Unexpected EOF on fgets()");
+			usleep(200000); //prevent CPU waste if it's end of pipe
+			return null; //loop back round
 		}
 
 		$line = trim($raw);

src/console/ConsoleReaderChildProcess.php

@@ -45,14 +45,7 @@ if($socket === false){
 }
 $consoleReader = new ConsoleReader();
 while(!feof($socket)){
-	try{
-		$line = $consoleReader->readLine();
-	}catch(ConsoleReaderException $e){
-		//Encountered unexpected EOF. This might be because the user did something stupid, or because the parent process
-		//has died. In either case, commit suicide. If the parent process is still alive, it will start a new console
-		//reader.
-		break;
-	}
+	$line = $consoleReader->readLine();
 	if(@fwrite($socket, ($line ?? "") . "\n") === false){
 		//Always send even if there's no line, to check if the parent is alive
 		//If the parent process was terminated forcibly, it won't close the connection properly, so feof() will return

src/console/ConsoleReaderException.php

@@ -1,28 +0,0 @@
-<?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;
-
-final class ConsoleReaderException extends \RuntimeException{
-
-}