hrtime

(PHP 7 >= 7.3.0, PHP 8)

hrtime — Get the system's high resolution time

Description

hrtime(bool $as_number = false): array|int|float|false

Returns the system's high resolution time, counted from an arbitrary point in time. The delivered timestamp is monotonic and can not be adjusted.

Liste de paramètres

as_number: Whether the high resolution time should be returned as array or number.

Valeurs de retour

Returns an array of integers in the form [seconds, nanoseconds], if the parameter as_number is false. Otherwise the nanoseconds are returned as int (64bit platforms) or float (32bit platforms). Returns false on failure.

Exemples

Exemple #1 hrtime() usage

<?php
echo hrtime(true), PHP_EOL;
print_r(hrtime());
?>

Résultat de l'exemple ci-dessus est similaire à :

10444739687370679
Array
(
    [0] => 10444739
    [1] => 687464812
)

Voir aussi

The High resolution timing extension
microtime() - Retourne le timestamp UNIX actuel avec les microsecondes

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User Contributed Notes 1 note

down

SenseiSimple ¶

6 years ago


This function is particularly necessary on VMs running on KVM, XEN (openstack, AWS EC2, etc) when timing execution times. 

On these platforms which lack vDSO the common method of using time() or microtime() can dramatically increase CPU/execution time due to the context switching from userland to kernel when running the `gettimeofday()` system call.

The common pattern is:
<?php
$time = -microtime(true);
sleep(5);
$end = sprintf('%f', $time += microtime(true));
?>

Substituted as:
<?php
$start=hrtime(true); 
sleep(5); 
$end=hrtime(true);
$eta=$end-$start;

echo $eta/1e+6; //nanoseconds to milliseconds
//5000.362419

//OR simply

$eta=-hrtime(true);
sleep(5);
$eta+=hrtime(true);

echo $eta/1e+6; //nanoseconds to milliseconds
//5000.088229
?>

There is also the new StopWatch class http://php.net/manual/en/class.hrtime-stopwatch.php

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