functions to be used

http://tdistler.com/2010/06/27/high-performance-timing-on-linux-windows


linux: int clock_gettime(clockid_t clock_id, struct timespec *tp);
http://pubs.opengroup.org/onlinepubs/000095399/functions/clock_getres.html

windows: BOOL WINAPI QueryPerformanceCounter(LARGE_INTEGER lpPerformanceCount);
http://msdn.microsoft.com/en-us/library/ms644904(v=VS.85).aspx

example with linux clock_gettime

https://github.com/php/php-src/blob/128eda843f7dff487fff529a384fee3c5494e0f6/sapi/fpm/fpm/fpm_clock.c

please try http://pecl.php.net/hrtime

I don't think an extension solves this feature request. We need a monotonic time function in core, otherwise NTP and leap seconds will be a problem for event loops and others that rely on the elapsed time.

Of course, feel free to reopen this and discuss on internals. Portable parts of the hrtime ext can be reused for the implementation in the core, or hrtime could be taken in. Otherwise, the ticket is closed, because there's actually no functionality in the core, that would require monotonic time.

I can also add, that every library you base your loop on, usually provides its own timer APIs. Take libuv or libevent as a ref, best way should be to rely on their routines. The core time functions use gettimeofday() or reimplement it, it is a known fact. It doesn't hurt to have monotonic time in the core, though preferable are probably the timers provided by the base libs. Except you implement the event loop in pure PHP ofc, which is likely not the case.

Thanks.

I can't reopen it, as I don't have a php.net account.

> I can also add, that every library you base your loop on, usually provides its own timer APIs. [...] Except you implement the event loop in pure PHP ofc, which is likely not the case.

Right, those provide their own APIs, but PHP does not. Implementing an event loop in pure PHP isn't that uncommon:

 - https://github.com/amphp/loop/blob/master/lib/NativeLoop.php
 - https://github.com/reactphp/event-loop/blob/master/src/StreamSelectLoop.php

What you link is a compatibility shim. It's unlikely one would want to run a pure PHP implementation in production, and for development it doesn't matter much. Nevertheless, some monotonic timer implementation in the core could be pursued. To workout the best course of action the topic should be to discussed on internals.

Thanks.

Running a stream-select loop in production is actually pretty fine, as long as you don't have thousands of concurrent streams.

I'll post to internals soon.

Here's an example what problems you might encounter when language of your choice doesn't have monotonic time functions. https://blog.cloudflare.com/how-and-why-the-leap-second-affected-cloudflare-dns/

I already sent a mail to internals that mentions that one, but mail distribution seems broken currently.

http://news.php.net/php.internals/97502