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(PHP 5 >= 5.1.0, PHP 7, PHP 8)

time_sleep_until Откладывает исполнение скрипта до заданного времени


time_sleep_until(float $timestamp): bool

Откладывает исполнение скрипта до заданной временной метки, указанной в параметре timestamp.

Список параметров


Временная метка продолжения исполнения скрипта.

Возвращаемые значения

Функция возвращает true в случае успешного выполнения или false, если возникла ошибка.


Если указанная временная метка timestamp просрочена, то функция сгенерирует E_WARNING.


Пример #1 Пример использования time_sleep_until()


//возвращает false и выводит предупреждение

// может работать только на быстродействующих компьютерах, выполнение отложено до 0.2 секунд



Замечание: Все сигналы будут доставлены после продолжения исполнения скрипта.

Смотрите также

  • sleep() - Задержка выполнения
  • usleep() - Задержка выполнения в микросекундах
  • time_nanosleep() - Задержка на заданное число секунд и наносекунд
  • set_time_limit() - Ограничивает время выполнения скрипта

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User Contributed Notes 3 notes

purdue at nc dot rr dot com
13 years ago
At least on my Windows machine, the time_sleep_until function appears to calculate the number of microseconds between now and the sleep-until timestamp, and it appears to use unsigned 32-bit math in this calculation. This roundoff leads to a maximum sleep time of just under 4295 seconds (1 hour, 11 minutes, 35 seconds). To get longer sleep times, while still using time_sleep_until to minimize processor overhead, the following loop may be some help to you:


= strtotime("tuesday 3pm");

while (
time() < $sleepuntil)

// proceed with dated processing


Of course, one could use something like "cron" instead, to avoid the script doing the extended sleep. Also note that time_nanosleep appears to do similar math, but it is somewhat more intuitive that the seconds parameter has an upper limit on what it can be. Still, both functions might report a warning when waking up prematurely due to roundoff.
rowan dot collins at cwtdigital dot com
12 years ago
Not realising that this function existed, I wrote something similar, but it has the additional facility to specify a minimum pause even if the target time has already been reached, for instance in a processor-intensive loop.

It's in seconds rather than microseconds (it's intended for heavy-duty CLI scripts), but that could easily be changed by using microtime(true) and usleep if greater granularity was required.

* Pause processing until the specified time, to avoid hammering a DB or service
* @param int $target_time Timestamp
* @param int $min_sleep Always sleep for a minimum number of seconds,
* even if the target timestamp has already passed.
* Default 0, meaning only sleep until the target timestamp is reached.
* @example <code>
while ( ! $finished )
$minimum_start_of_next_loop = time() + $min_secs_per_loop;


sleep_until( $minimum_start_of_next_loop, $min_pause_between_loops );
function sleep_until($target_time, $min_sleep = 0)
$time_now = time();

$time_to_target = $target_time - $time_now;

// If we've already reached the target time, that's fine
if ( $time_to_target <= $min_sleep )
// If required, sleep for a bit anyway
sleep( $min_sleep );
// Sleep for the number of seconds until the target time
sleep( $time_to_target );
divinity76 at gmail dot com
4 years ago
if you for some reason need a constant-time implementation of realpath(), try


function realpath_constant_time(string $path, float $target_seconds, bool &$constant_time_success = null){
$constant_time_success = @time_sleep_until($start_time+$target_seconds);

for example, a realtime that always uses exactly 1 millisecond (should be more than enough for SSD-based servers, perhaps rotating harddrive based servers may need something closer to 10 milliseconds, i don't know):


and you can use $constant_time_success to see if you needed more time (and thus failed to do realpath() in constant-time), or if you succeeded.
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