hrtime

    (PHP 7 >= 7.3.0, PHP 8)

    hrtime — Get the system's high resolution time

    Beschreibung

    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.

    Parameter-Liste

    as_number

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

    Rückgabewerte

    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.

    Beispiele

    Beispiel #1 hrtime() usage

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

    Das oben gezeigte Beispiel erzeugt eine ähnliche Ausgabe wie:

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

    Siehe auch

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    User Contributed Notes 1 note

    up
    65
    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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