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.
Note: On Windows, the system may sleep longer that the given number of nanoseconds, depending on the hardware.
Returns true on success or false on failure.
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 secondssleep(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:<?phpfunction 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!