Note that the default maximum script execution time is 30 seconds, but you can use sleep() and usleep() to make your scripts go on for longer than that because technically PHP does not have control during the sleep operation. The above script could be rewritten like this: Using either of them is far more accurate than the previous time() loop, and they both have their advantages - sleep() is better if you do not need the accuracy, and usleep() is better if you do. Definition and Usage The sleep () function delays execution of the current script for a specified number of seconds. Even if you do sleep(60), worker processing that job will be sleeping, not your loop. The difference between sleep() and usleep() is that sleep() takes a number of seconds as its parameter, whereas usleep() takes a number of microseconds - millionths of a second - as its parameter. The loop continuously executes until the condition is false. condition - Evaluate each iteration value. The initial value of the for loop is done only once. The parameters of for loop have the following meanings: initialization - Initialize the loop counter value. A much better solution is to use the one of the two script sleep functions, sleep() and usleep(), which take the amount of time to pause execution as their only parameter. The php for loop is similar to the java/C/C++ for loop. This script goes through all active users and updates credits of each user. Schedule the execution of this script for example every 1 minute using Cron. Secondly, PHP has to sit there looping thousands of times while it waits, essentially doing nothing. Create a PHP script, which will update user's credits. You will likely find yourself using for loops a lot in PHP programming, so they are incredibly important to understand. Firstly, time() has a very low precision, only returning the number of whole seconds that have passed, which makes the whole thing quite vague. The for loop continued to iterate until it no longer matched the condition within the for loops parenthesis. How to output javascript and make sleep or wait work in foreach loop. While it does work, there are two problems with it. repeat php sleep method inside a foreach loop each iteration. Some people (thankfully very few) choose the first option and write code like this: Using mutexes is higher overhead and roughly 1/20 the performance and a lot more work for the O/S.When you want to pause execution in your script, there are two ways you can implement the code. If you doubt that, compare the performance of Mutexes and Critical sections. Polling, if done well, can be more efficient than waiting on an object (which the O/S scheduler has to pay attention to.) A good combination of SRW locks and Sleep can produce much better results than using objects to wait on. e.g, at least in Windows, you can't wait on some window that belongs to another process to finish painting itself. In addition to that, there are events for which there are no available objects that can be created to wait on. Sleep is very low overhead and lets the O/S know that for n milliseconds, the thread doesn't need any attention. One of the nice things about Sleep is that it doesn't require the application to create an object to wait on and the O/S to maintain and pay attention to it. Make sure that the displayerrors setting is turned On in your php.ini file (or use iniset() if you can't modify the file itself), and that your errorreporting() is set to EALL ESTRICT for PHP < 5.3, or EALL for PHP 5.4 (ESTRICT is part of EALL as of that version). It is written precisely for this by people who tend to be very good at their job. Even if they were launching the same number of processes, cron would be better. Sleep(n) where n > 0 is simply a mechanism to inform the scheduler the thread does not require CPU cycles. Your sleep approach, on the other hand would require your actual sleep command, your shell, your terminal, and the while (or whatever) loop to be running at the same time. I'm making a php file that will run an event after five minutes have elapsed.
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