streams/library/symfony/process/Pipes/AbstractPipes.php

<?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;
    }
}