sys_getloadavg
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!
time_nanosleep
(PHP 5)
time_nanosleep — Attendre pendant un nombre de secondes et de nanosecondes
Description
Permet d'imposer un délai d'exécution à un programme pendant un nombre de secondes seconds et un nombre de nanosecondes nanoseconds .
Liste de paramètres
- seconds
-
Doit être un entier positif.
- nanoseconds
-
Doit être un entier positif, inférieur à 1 billion.
Valeurs de retour
Cette fonction retourne TRUE en cas de succès, FALSE en cas d'échec.
Si le délai est interrompu par un signal, un tableau associatif sera retourné avec les éléments :
- seconds - nombre de secondes restantes dans le délai
- nanoseconds - nombre de nanosecondes restantes dans le délai
Exemples
Exemple #1 Exemple avec time_nanosleep()
<?php
// Attention ! Cela ne fonctionnera pas comme prévu si un tableau est retourné
if (time_nanosleep(0, 500000000)) {
echo "Dors pendant une demie seconde.\n";
}
// Ceci est meilleur :
if (time_nanosleep(0, 500000000) === true) {
echo "Dors pendant une demie seconde.\n";
}
// Et ceci est la meilleur façon :
$nano = time_nanosleep(2, 100000);
if ($nano === true) {
echo "Dors pendant 2 secondes et 100 millisecondes.\n";
} elseif ($nano === false) {
echo "Le délai a échoué.\n";
} elseif (is_array($nano)) {
$seconds = $nano['seconds'];
$nanoseconds = $nano['nanoseconds'];
echo "Interrompu par un signal.\n";
echo "Temps restant : $seconds secondes, $nanoseconds nanosecondes.";
}
?>
Notes
Note: Cette fonction n'est pas implémentée sous Windows.
Voir aussi
add a note
User Contributed Notestime_nanosleep
b dot andrew at shaw dot ca
05-Jul-2008 06:10
05-Jul-2008 06:10
fantasysportswire at yahoo dot com
19-Dec-2006 12:27
19-Dec-2006 12:27
Just glancing at this - and the note from over a year ago with a implementation for windows.. with 5.0.0 and higher it would be simplier to just do something like......
<?
if (!function_exists('time_nanosleep')) {
function time_nanosleep($seconds, $nanoseconds) {
sleep($seconds);
usleep(round($nanoseconds/100));
return true;
}
}
?>
....off the top of my head - obviously simple enough there should be no mistakes.. but those are the ones that always seem to get ya :( .....
anybody (a) emuxperts.net
22-Aug-2006 01:03
22-Aug-2006 01:03
Documentation states that "seconds" must be positive. This is not correct, 0 is possible.
Rather, "seconds" must be non-negative.
m at kufi dot net
13-Aug-2005 11:03
13-Aug-2005 11:03
You should take into account, if you use the function replacement down here, the CPU will be in use of 99% for the time of execution...
(A little bit better in this situation is to let the 'full seconds' go by a normal sleep command (makes the thread sleep!, and uses minimum cpu))
<?php
//THIS IS THE FUNCTION WE ARE TALKIN ABOUT
function timeWait($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())) < $timeLimit)
{/*DO NOTHING*/}
return(true);
}
//THIS IS HOW WE CAN USE IT
echo "Process started at " . date("H:i:s") . " and " . current(explode(" ",microtime())) . " nanoseconds.<br>";
timeWait(5.5); //With this call the system will wait 5 seconds and a half. You can use either integer or float.
echo "Process completed at " . date("H:i:s") . " and " . current(explode(" ",microtime())) . " nanoseconds.";
?>
tecnomaniac at ig dot com dot br
27-Jul-2005 12:04
27-Jul-2005 12:04
This is an alternative function to sleep_nanosecond that you can use with PHP versions below PHP 5.0. It is not very accurate if we talk about nanoseconds but the results are satisfatory. Enjoy!
<?php
//THIS IS THE FUNCTION WE ARE TALKIN ABOUT
function timeWait($microtime)
{
$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.";
?>