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    time_nanosleep

    (PHP 5, PHP 7, PHP 8)

    time_nanosleep — 延缓执行若干秒和纳秒

    说明

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

    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。

    注意: 在 Windows 上，系统的睡眠时间可能会超过指定的纳秒数，具体取决于硬件。

    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

    示例

    示例 #1 time_nanosleep() 示例

    <?php
    // 小心！如果返回数组，将无法按照预期工作
    if (time_nanosleep(0, 500000000)) {
    echo     "Slept for half a second.\n";
    }

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

    // 这个最好：
    $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

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    用户贡献的备注 4 notes

    up
    7
    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.";
    ?>
    up
    6
    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.
    up
    5
    fantasysportswire at yahoo dot com
    17 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 :( .....
    up
    2
    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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