Event Timers and RB trees

[agentzh]

On Sat, Jan 2, 2010 at 12:29 AM, test guy <testguy103 at gmail.com> wrote:
>
> I have been looking through the nginx source code and cannot figure out how event timers are used (and their purpose). Can somebody shed some light on this for me please?
>

Timers are usually used to implement the timeout mechanism for
non-blocking I/O operations in nginx. But it is also used to implement
non-blocking sleep in the ngx_chunkin module. Logically, a timer is
usually associated with an ngx_event_t object, and at any one time,
only one timer is allowed for one ngx_event_t object.

Two functions are often used to handle timers, ngx_add_timer and ngx_del_timer.

> Also, I noticed a red/black tree is used somehow with event timers, and I also do not understand this.
>

It's used to store the timers themselves. It's the implementation
details already, I think ;)

Cheers,
-agentzh