time_nanosleep

(PHP 5, PHP 7, PHP 8)

time_nanosleep — Delay for a number of seconds and nanoseconds

Descrizione

time_nanosleep(int $seconds, int $nanoseconds): array|bool

Delays program execution for the given number of seconds and nanoseconds.

Elenco dei parametri

seconds: Must be a non-negative integer.
nanoseconds: Must be a non-negative integer less than 1 billion.

Nota: On Windows, the system may sleep longer that the given number of nanoseconds, depending on the hardware.

Valori restituiti

Restituisce true in caso di successo, false in caso di fallimento.

If the delay was interrupted by a signal, an associative array will be returned with the components:

seconds - number of seconds remaining in the delay
nanoseconds - number of nanoseconds remaining in the delay

Esempi

Example #1 time_nanosleep() example

<?php
// Careful! This won't work as expected if an array is returned
if (time_nanosleep(0, 500000000)) {
    echo "Slept for half a second.\n";
}

// This is better:
if (time_nanosleep(0, 500000000) === true) {
    echo "Slept for half a second.\n";
}

// And this is the best:
$nano = time_nanosleep(2, 100000);

if ($nano === true) {
    echo "Slept for 2 seconds, 100 microseconds.\n";
} elseif ($nano === false) {
    echo "Sleeping failed.\n";
} elseif (is_array($nano)) {
    $seconds = $nano['seconds'];
    $nanoseconds = $nano['nanoseconds'];
    echo "Interrupted by a signal.\n";
    echo "Time remaining: $seconds seconds, $nanoseconds nanoseconds.";
}
?>

Vedere anche:

sleep() - Pausa dell'esecuzione
usleep() - Ritarda l'esecuzione in micro-secondi
time_sleep_until() - Make the script sleep until the specified time
set_time_limit() - Limita il tempo massimo di esecuzione

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User Contributed Notes 4 notes

down

m at kufi dot net ¶

19 years ago

You should take into account, if you use the function replacement down here, the CPU will be in use of 99% for the time of execution...

(A little bit better in this situation is to let the 'full seconds' go by a normal sleep command (makes the thread sleep!, and uses minimum cpu))

<?php
    //THIS IS THE FUNCTION WE ARE TALKIN ABOUT
    function timeWait($microtime)
    {
//optimizations added by me [start]
//sleep the full seconds
sleep(intval($microtime));
//set the microtime to only resleep the last part of the nanos
$microtime = $microtime - intval($microtime);
//optimizations added by me [end]

        $timeLimit = $microtime + array_sum(explode(" ",microtime()));
        while(array_sum(explode(" ",microtime())) < $timeLimit)
        {/*DO NOTHING*/}
        return(true);
    }
 
    //THIS IS HOW WE CAN USE IT
    echo "Process started at " . date("H:i:s") . " and " . current(explode(" ",microtime())) . " nanoseconds.<br>";
    timeWait(5.5); //With this call the system will wait 5 seconds and a half. You can use either integer or float.
    echo "Process completed at " . date("H:i:s") . " and " . current(explode(" ",microtime())) . " nanoseconds.";
 ?>

down

anybody (a) emuxperts.net ¶

18 years ago

Documentation states that "seconds" must be positive. This is not correct, 0 is possible.

Rather, "seconds" must be non-negative.

down

fantasysportswire at yahoo dot com ¶

18 years ago

Just glancing at this - and the note from over a year ago with a implementation for windows.. with 5.0.0 and higher it would be simplier to just do something like......



<?php



if (!function_exists('time_nanosleep')) {



function time_nanosleep($seconds, $nanoseconds) {



sleep($seconds);

usleep(round($nanoseconds/100));



return true;



}



}



?>



....off the top of my head - obviously simple enough there should be no mistakes.. but those are the ones that always seem to get ya :( .....

down

b dot andrew at shaw dot ca ¶

16 years ago

A response to the note below:

Your function is also useless, as the WinNT 32 kernel only functions at a minimum of about 10+ ms (1,000 us), rendering usleep() useless, because usleep uses the C function which is provided by the system (in this case, kernel32.dll).

You'll want to use a function that does not rely on the kernel, but rather something made for precise measurement:

<?php
function usleep_win( $micro_seconds )
{
    if ( @function_exists( "socket_create" ) && @function_exists( "socket_select" ) )
    {
        $false = NULL;
        $socket = array( socket_create( AF_INET, SOCK_RAW, $false ) );
        socket_select( $false, $false, $socket, 0, $micro_seconds );
        return true;
    }
    else
    {
        return false;
    }
}
?>

This function will allow to you sleep for a specified microsecond, although I have measured it to be off by ~5 us.

Again, most of this depends on the hardware in your system. If you _REALLY_ need to be precise to < 10 us, you shouldn't be using WinNT anyways!

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