This is a simple test to show how close and kill works.

<?php
/**
 * Test close and kill
 * - main thread writes to main.log
 * - second thread writes to thread.log and shutdown.log
 * - main thread runs 10 seconds, second thread runs 20 seconds
 * - close will wait until second thread stops
 * - kill don't waits and kill immediately the second thread
 */

// main thread
logToFile("start");

// create a second thread
$thread = new parallel\Runtime();
$thread->run(function(){
    
    // what to do if thread shuts down
    register_shutdown_function ( function(){file_put_contents("shutdown.log",date('Y-m-d H:i:s') . "\t last will");} );

    // loop and count for 20 seconds
    $c=0;
    while ($c++ < 20){
        sleep(1);
        echo $c."|";
        file_put_contents("thread.log",date('Y-m-d H:i:s') . "\t" . $c.PHP_EOL, FILE_APPEND);
    }
});

// sleep 10 seconds
sleep(10);

// mainthread kills thread immediately
//$thread->kill();

// mainthread waits on thread
$thread->close();

logToFile("end");

function logToFile($msg){
    echo PHP_EOL.$msg.PHP_EOL;
    file_put_contents("main.log",date('Y-m-d H:i:s') . "\t" . $msg.PHP_EOL, FILE_APPEND);
}
?>