Documentation states that "seconds" must be positive. This is not correct, 0 is possible.
Rather, "seconds" must be non-negative.
(PHP 5, PHP 7, PHP 8)
time_nanosleep — Delay for a number of seconds and nanoseconds
Delays program execution for the given number of
seconds and nanoseconds.
secondsMust be a non-negative integer.
nanosecondsMust 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.
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
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, $nanoseconds nanoseconds.";
}
?>
Documentation states that "seconds" must be positive. This is not correct, 0 is possible.
Rather, "seconds" must be non-negative.You should take into account, if you use the function replacement down here, the CPU will be in use of 99% for the time of execution...
(A little bit better in this situation is to let the 'full seconds' go by a normal sleep command (makes the thread sleep!, and uses minimum cpu))
<?php
//THIS IS THE FUNCTION WE ARE TALKIN ABOUT
function timeWait($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())) < $timeLimit)
{/*DO NOTHING*/}
return(true);
}
//THIS IS HOW WE CAN USE IT
echo "Process started at " . date("H:i:s") . " and " . current(explode(" ",microtime())) . " nanoseconds.<br>";
timeWait(5.5); //With this call the system will wait 5 seconds and a half. You can use either integer or float.
echo "Process completed at " . date("H:i:s") . " and " . current(explode(" ",microtime())) . " nanoseconds.";
?>Just glancing at this - and the note from over a year ago with a implementation for windows.. with 5.0.0 and higher it would be simplier to just do something like......
<?php
if (!function_exists('time_nanosleep')) {
function time_nanosleep($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 :( .....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!