time_nanosleep

(PHP 5)

time_nanosleep — 延缓执行若干秒和纳秒

说明

mixed time_nanosleep ( int $seconds , int $nanoseconds )

程序延缓执行指定数量的 seconds 和 nanoseconds。

参数

seconds: 必须是一个非负整数。
nanoseconds: 必须是一个小于1亿的非负整数。

返回值

成功时返回 TRUE ，或者在失败时返回 FALSE 。

如果延迟被中断，一个关联数组会返回，内容为：

seconds - 延迟剩余未执行的秒数
nanoseconds - 延迟剩余未执行的纳秒数

更新日志

版本	说明
5.3.0	至此之后该函数在Windows平台下可用。

范例

Example #1 time_nanosleep() 的例子

  <?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." ;
}
 ?>

参见

sleep() - 延缓执行
usleep() - 以指定的微秒数延迟执行
time_sleep_until() - 使脚本睡眠到指定的时间为止。
set_time_limit() - 设置脚本最大执行时间

用户评论:

[#1] b dot andrew at shaw dot ca [2008-07-04 21:10:05]

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!

[#2] fantasysportswire at yahoo dot com [2006-12-18 15:27:02]

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 :( .....

[#3] anybody (a) emuxperts.net [2006-08-21 16:03:50]

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

Rather, "seconds" must be non-negative.

[#4] m at kufi dot net [2005-08-13 14:03:19]

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) {} 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."; ?>

[#5] tecnomaniac at ig dot com dot br [2005-07-26 15:04:58]

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) {} 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."; ?>