Tick

Ticks are events that occur for a group of N statements, executed by PHP.

Ticks are started within the declare block.

Ticks are deprecated since PHP 5.3. They might entirely disappear in PHP 9.0.

<?php

declare(ticks=1);

// A function called on each tick event
function tick_handler()
{
    echo 'tick_handler() called'.PHP_EOL;
}

register_tick_function('tick_handler'); // causes a tick event

$a = 1; // causes a tick event

if ($a > 0) {
    $a += 2; // causes a tick event
    print($a); // causes a tick event
}

?>

Documentation

See also The declare() function and ticks, PHP RFC: Deprecate ticks

Related : declare()