php[world] 2019 — 25 years of PHP

hrtime

(PHP 7 >= 7.3.0)

hrtimeGet the system's high resolution time

Descripción

hrtime ([ bool $get_as_number = FALSE ] ) : mixed

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

Parámetros

get_as_number

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

Valores devueltos

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

Ejemplos

Ejemplo #1 hrtime() usage

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

El resultado del ejemplo sería algo similar a:

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

Ver también

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User Contributed Notes 1 note

up
9
SenseiSimple
8 months 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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