guzzletest.php

#!/usr/bin/php
<?php

use GuzzleHttp\Client;
use GuzzleHttp\Handler\CurlHandler;
use GuzzleHttp\HandlerStack;
use Psr\Http\Message\ResponseInterface;

error_reporting(E_ALL);
ini_set('display_errors', 1);
ini_set('error_log', null); // error_log to stderr

require_once 'vendor/autoload.php';
require_once 'MyCurlFactory.php';

function output_file_descriptors(string $label)
{
    usleep(50000);
    $pid = getmypid();

    if (is_dir('/Applications')) {
        // rudimentary macOS system check
        $files = trim(shell_exec('lsof -p ' . intval($pid)));
        $files = explode("\n", $files);
    } else {
        $dir = sprintf('/proc/%d/fd/*', $pid);
        $files = glob($dir);
    }
    error_log(sprintf("*** IN %s: OPEN FDs %d", $label, count($files)));
    usleep(50000);
}

/**
 * Make a bunch of concurrent curl requests to a single domain on different paths
 * @return array Map on responses
 */
function run_script_chunk()
{
    $curl_factory = new MyCurlFactory(3);
    $handler = new CurlHandler([
        'handle_factory' => $curl_factory,
    ]);
    $client = new Client([
        'base_uri' => 'https://66.media.tumblr.com/',
        'proxy' => null,
        'handler' => HandlerStack::create($handler),
    ]);

    $paths = [
        '/ca13692b4d21ac673e6c4eea232ceee1/tumblr_pm43a9jP7o1thjq1e_640.jpg',
        '/4ceb016f5174868bf90ce97ed80a979e/tumblr_po9kpyv1Zc1xoyw8po1_640.jpg',
        '/605dfc39f03599e04a05d6bee72da699/tumblr_poa05jz0CB1w7u8nmo1_1280.jpg',
        '/11e37ea7e1be01f08fcccb859a1076f6/tumblr_pirts4a9HG1sn3ne4o1_1280.jpg',
        '/077b41778bceaebe5e4c15f48be65677/tumblr_po9vj74Irk1rsezm9o1_1280.jpg',
        '/6ec1d80af8c181d3e597f1b1b0ae681f/tumblr_po9zb72brS1r7b7ly_540.jpg',
        '/e869e2e1ab780e9a39b297f4ff08d3e5/tumblr_po9zkwyoTB1vz5npso1_1280.png',
        '/cbba1fb23610cca96275c4d3f4719f6c/tumblr_pk4pwgvPyU1qbtrumo1_1280.jpg',
        '/c7e0b3c226674c2381f9494761a2834c/tumblr_pjyk879oq91qdj91io2_540.png',
        '/c7e0b3c2266731194761a2834c/tumblr_pjyk879oq91qdj91io2_540.png', // Causes a 4XX HTTP Exception!
        '/a08955930aed7ab081700efc44a26b05/tumblr_pllaadvGbz1thzx08o1_500.gif',
        '/98e382314d57a49380bac5662d9b6e18/tumblr_po9pul2Iyv1xoyw8po1_1280.png',
        '/8830736f845a7ce0d0e6f46c73fe77df/tumblr_osw9itaD1n1tyhiwmo1_1280.png',
        '/b5ba6a7e12b6c2e76431e8fd47d08a8e/tumblr_poa8cf4rwS1y72ak6o1_540.gif',
        '/82929a643f1c31b8e9b32781fa06d25a/tumblr_po6gt1nw331r3yybh_400.jpg',
        '/0ba4821cb51a7bac6a9e388014a7f879/tumblr_pmtv2w62hP1r4q6y5_400.jpg',
        '/2c95416f8ac98e0f83ca780afdb9ec59/tumblr_pmy0n9bqwL1qjhjrd_400.jpg',
    ];

    $promises = [];

    foreach ($paths as $index => $path) {
        // Initiate each request but do not block
        $promises['image' . $index] = $client->requestAsync('GET', $path)->then(
            function (ResponseInterface $res) {
                echo 'Got response! Code ' . $res->getStatusCode() . PHP_EOL;
            },
            function (\GuzzleHttp\Exception\RequestException $exception) {
                echo 'Got exception: ' . $exception->getMessage() . PHP_EOL;
            }
        );
    }

    // $results = \GuzzleHttp\Promise\unwrap($promises);
    $results = \GuzzleHttp\Promise\settle($promises)->wait();

    $curl_factory->cleanup();

    return $results;
}

function run_outer_loop()
{
    $responses = run_script_chunk();
}

// MAIN *******

output_file_descriptors('BEGIN');

// Run the complete thing a few times
foreach (range(1, 4) as $iter) {
    run_outer_loop();
    output_file_descriptors("LOOP");
}

output_file_descriptors('FINAL');

MyCurlFactory.php

<?php

use GuzzleHttp\Handler\EasyHandle;

/**
 * Extends Guzzle's CurlFactory package to enable better control of garbage collection after connections
 * are no longer needed.
 */
class MyCurlFactory extends \GuzzleHttp\Handler\CurlFactory
{
    /** @var resource[] References to all curl connections */
    protected $all_handles = [];

    /**
     * Manually cleanup and close all curl handles that may still be open
     * @return void
     */
    public function cleanup()
    {
        foreach ($this->all_handles as $curl_handle) {
            if (isset($curl_handle) && is_resource($curl_handle)) {
                curl_close($curl_handle);
            }
        }
        $this->all_handles = [];
    }

    /**
     * @inheritDoc
     */
    public function release(EasyHandle $easy)
    {
        // Reference the curl resource for later cleanup
        $this->all_handles[] = $easy->handle;
        parent::release($easy);
    }
}