pcntl_alarm.php

<?php

declare(ticks = 1);

class TimeoutException extends Exception {};

function signal_handler($signal) {
    throw new TimeoutException();
}

pcntl_signal(SIGALRM, "signal_handler", true);
pcntl_alarm(1);

try {
    // simulate long executing block
    while(1) sleep(30);
} catch(TimeoutException $e) {
    echo "Timeout exceeded";
}

echo "done";