Have a function timeout on itself

test.php

<?php

try {
    test();
} catch (TimeoutException $e) {
    $e->handle();
} catch (Throwable $t) {
    printf('Some other error occured. %s', $t->getMessage());
}

class Timer
{

    public function setTimeout($seconds)
    {
        declare(ticks = 1);
        pcntl_signal(SIGALRM, array($this, 'handler'), true);
        pcntl_alarm($seconds);
    }

    public function handler(int $signal)
    {
        throw new \TimeoutException(sprintf("Received Timeout Signal: %d\n", $signal));
    }
}

class TimeoutException extends \RuntimeException
{
    public function handle()
    {
        print $this->getMessage();
    }
}

function test($timeout = 5, $length = 100)
{
    $timer = new Timer();
    printf("Timeout: %d, Length: %d\n", $timeout, $length);
    $timer->setTimeout($timeout);
    for($i=0;$i<=$length;$i++)
    {
        printf("%d\n", fibonacci($i));
    }
}

function fibonacci($n) {
    //make it look like we are working.
    usleep(150000);
    return round(pow((sqrt(5)+1)/2, $n) / sqrt(5));
}