Update to drupal 8.0.0-rc1. For more information, see https://www.drupal.org/node/2582663

vendor/symfony/process/Pipes/AbstractPipes.php

@@ -0,0 +1,74 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Process\Pipes;
+
+/**
+ * @author Romain Neutron <imprec@gmail.com>
+ *
+ * @internal
+ */
+abstract class AbstractPipes implements PipesInterface
+{
+    /** @var array */
+    public $pipes = array();
+
+    /** @var string */
+    protected $inputBuffer = '';
+    /** @var resource|null */
+    protected $input;
+
+    /** @var bool */
+    private $blocked = true;
+
+    /**
+     * {@inheritdoc}
+     */
+    public function close()
+    {
+        foreach ($this->pipes as $pipe) {
+            fclose($pipe);
+        }
+        $this->pipes = array();
+    }
+
+    /**
+     * Returns true if a system call has been interrupted.
+     *
+     * @return bool
+     */
+    protected function hasSystemCallBeenInterrupted()
+    {
+        $lastError = error_get_last();
+
+        // stream_select returns false when the `select` system call is interrupted by an incoming signal
+        return isset($lastError['message']) && false !== stripos($lastError['message'], 'interrupted system call');
+    }
+
+    /**
+     * Unblocks streams.
+     */
+    protected function unblock()
+    {
+        if (!$this->blocked) {
+            return;
+        }
+
+        foreach ($this->pipes as $pipe) {
+            stream_set_blocking($pipe, 0);
+        }
+        if (null !== $this->input) {
+            stream_set_blocking($this->input, 0);
+        }
+
+        $this->blocked = false;
+    }
+}