Examples when https://wiki.php.net/rfc/max_execution_wall_time would be useful

index.php

<?php

sleep(3);

timeout_curl.php

<?php

ini_set("max_execution_time", 10);

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "http://localhost/index.php");
curl_setopt($ch, CURLOPT_TIMEOUT, 1);

for ($i = 0; $i < 100; $i++) {
    curl_exec($ch);
    echo curl_error($ch);
}

// This script will run for more than 100 seconds, even though max_execution_time is 10 seconds

timeout_socket.php

<?php

ini_set("error_reporting", E_ALL);
ini_set("display_errors", 1);
ini_set("max_execution_time", 10);
ini_set("default_socket_timeout", 1);

for ($i = 0; $i < 100; $i++) {
    echo "Iteration $i\n";
    file_get_contents("http://localhost/index.php");
    echo "\n----------------\n";
}

// This script will run for more than 100 seconds, even though max_execution_time is 10 seconds