Prevent blocking empty fread()

[divinity76]

There is an issue where this fread can block up to 5 seconds when there is nothing to read.

Fix it by not issuing fread() if stream_select() say there is nothing to read.

Also encountered a strange issue on PHP8.4.12 Ubuntu24.04 where stream_select() would incorrectly return 0 if we had never ran fread() on the socket, so made a workaround to always call fread the first time, even if stream_select() say there is nothing to read.

• resolves performance issue with Page::getCurentUrl() chrome#711

• resolves PageNavigation constructor: 2 seconds delay BEFORE sending the Page.navigate message to the browser (keepAlive problem?) chrome#646

• probably resolves Timeout issues when setting cookies chrome#704

• probably resolves Operation timed out after 5s chrome#710

• probably resolves Exception: OperationTimedOut on Chrome 131.0.6778.109 chrome#669

Reproduce script:

<?php

declare(strict_types=1);
require_once(__DIR__ . '/vendor/autoload.php');
$chromeBinary = "/snap/bin/chromium";
$browser_factory = new \HeadlessChromium\BrowserFactory($chromeBinary);
$browser_factory->setOptions([
    "headless" => true,
    "noSandbox" => true,
    'customFlags' => [
        // docker ...
        '--disable-dev-shm-usage',
    ]
]);
$browser = $browser_factory->createBrowser();
$page = $browser->createPage();
$highscore = -INF;
$page->navigate("http://example.com")->waitForNavigation();

for ($i = 0; $i < 100; ++$i) {
$t = microtime(true);
$url = $page->getCurrentUrl();
$t = microtime(true) - $t;
if ($t > $highscore) {
    echo "New highscore: $t seconds for $url\n";
    $highscore = $t;
}
}

output before this patch:

hans@DESKTOP-EE15SLU:~/projects/chrome/hans$ php reproduce.php 
New highscore: 1.0967254638672E-5 seconds for getCurrentUrl() on https://example.com/
New highscore: 0.0005338191986084 seconds for getCurrentUrl() on https://example.com/
New highscore: 0.021073818206787 seconds for getCurrentUrl() on https://example.com/
New highscore: 0.96735405921936 seconds for getCurrentUrl() on https://example.com/
New highscore: 3.1658289432526 seconds for getCurrentUrl() on https://example.com/
New highscore: 5.0055141448975 seconds for getCurrentUrl() on https://example.com/
New highscore: 5.0062091350555 seconds for getCurrentUrl() on https://example.com/
New highscore: 5.0073070526123 seconds for getCurrentUrl() on https://example.com/
New highscore: 5.0073978900909 seconds for getCurrentUrl() on https://example.com/
New highscore: 5.0115480422974 seconds for getCurrentUrl() on https://example.com/
^C

(Had to ctrl+c cancel it because it was taking so long...)
Output after this patch:

hans@DESKTOP-EE15SLU:~/projects/chrome/hans$ php reproduce.php 
New highscore: 9.0599060058594E-6 seconds for getCurrentUrl() on https://example.com/
hans@DESKTOP-EE15SLU:~/projects/chrome/hans$ php reproduce.php 
New highscore: 5.9604644775391E-6 seconds for getCurrentUrl() on https://example.com/
hans@DESKTOP-EE15SLU:~/projects/chrome/hans$ php reproduce.php 
New highscore: 1.0967254638672E-5 seconds for getCurrentUrl() on https://example.com/
New highscore: 2.0027160644531E-5 seconds for getCurrentUrl() on https://example.com/
hans@DESKTOP-EE15SLU:~/projects/chrome/hans$ 

• Consistently execute in a fraction of a second 👍