stopwatch.php

См. документацию.

<?php
 
namespace Bitrix\Main\Diag;
 
class StopWatch
{
    // seconds with nanoseconds
    protected ?float $start = null;
    protected float $timer = 0.0;
    protected int $precision;
 
    public function __construct(int $precision = 6)
    {
        $this->precision = $precision;
    }
 
    public function start(): static
    {
        $this->start = hrtime(true);
 
        return $this;
    }
 
    public function stop(): float
    {
        if ($this->start !== null)
        {
            $this->timer += (hrtime(true) - $this->start)/1e+9;
            $this->start = null;
        }
 
        return $this->get();
    }
 
    public function reset(): static
    {
        return $this->set(0.0);
    }
 
    public function flyback(): float
    {
        $time = $this->stop();
        $this->reset();
        $this->start();
 
        return $time;
    }
 
    public function set(float $timer): static
    {
        $this->timer = $timer;
        $this->start = null;
 
        return $this;
    }
 
    public function get(): float
    {
        return round($this->timer, $this->precision);
    }
}