why delta only include the execution time of ngx_process_events not ngx_event_process_posted (Zhang Chao) (Valentin V. Bartenev)

Valentin V. Bartenev vbart at nginx.com
Tue Nov 7 15:22:00 UTC 2017

On Tuesday, 7 November 2017 18:02:44 MSK Valentin V. Bartenev wrote:
> On Tuesday, 7 November 2017 14:36:47 MSK yang chen wrote:
> > Thank you very much, but there is another question, if delta larger than
> > 1ms, it will invole the ngx_event_expire_timers, why not 2ms or others? how
> > do you get the value?
> > if there are much events comming for 30s, and epoll_wait return quickly
> > (linux) which less than 1ms in each circle,
> > and the ngx_event_expire_timers will not be excecuted for 30s?
> > 
> ngx_event_expire_timers() doesn't care about delta at all.  It uses absolute
> time and all timers have an absolute time when they have to be triggered.
> The function triggers all the timers with absolute time less or equal than
> the current time.  This delta check is just an optimization.
> I suggest you to read the code of the function.  It's hard to understand the
> logic, if you read only the part of it and don't have the whole picture in
> the mind.

Or, maybe I misunderstand your question.

ngx_current_msec is updated once in the loop.

In short it looks like this:

    loop {
        delta = time;
        delta = time - delta;

        if (delta) {

Eventually, the time shift will be 1ms or more.

  wbr, Valentin V. Bartenev

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