mirror of
https://github.com/matrix-construct/construct
synced 2024-10-31 02:48:58 +01:00
a5c46d31e4
Purge a lot of really old and obsolete documents, and merge some together where possible. Lots of efnet docs and the old ircd-ratbox manpage (lol) was purged. Reorganise everything nice and neatly as possible. Things describing features can be found in features/, and some more technical documents were moved to techinical/. Old credits file was consolidated into credits-past.txt, and a reference was added to it in the credits.
82 lines
2.4 KiB
Text
82 lines
2.4 KiB
Text
Overview of the event subsystem
|
|
Adrian Chadd <adrian@creative.net.au>
|
|
|
|
|
|
One of the things that immediately struck me whilst first looking at the
|
|
code was that the ircd periodically scheduled things in io_loop() but
|
|
it did them manually. This is very wasteful and very tedious.
|
|
|
|
Therefore, an event system was added to hybrid. src/event.c contains an
|
|
event system ported from the squid web cache. It is pretty self contained,
|
|
and only a few things (debugging, time resolution) needed changing.
|
|
|
|
An event is scheduled through eventAdd() or eventAddIsh() :
|
|
|
|
eventAdd(const char *name, EVH * func, void *arg, time_t when, int weight)
|
|
eventAddIsh(const char *name, EVH * func, void *arg, time_t delta_ish,
|
|
int weight)
|
|
|
|
after 'when' (or delta_ish) seconds has elapsed from the time the above
|
|
functions are called, the 'func' is called with the given data 'arg'. The
|
|
event is then deleted.
|
|
|
|
To delete an event, use eventDelete() :
|
|
|
|
eventDelete(EVH * func, void *arg)
|
|
|
|
An event is identified by its callback function and data pair.
|
|
|
|
Events are run through eventRun(). This is designed to be called *BEFORE*
|
|
your IO handlers, to let events scheduled immediately (ie a time of 0)
|
|
to initiate IO before the IO handlers are called.
|
|
|
|
(Believe me, its useful.)
|
|
|
|
|
|
|
|
Example:
|
|
|
|
Say you have something which must be called every 15 seconds.
|
|
|
|
* You would first define the callback in your module:
|
|
|
|
static EVH foo_periodic_event;
|
|
static int initialised = 0;
|
|
|
|
* You would then add the event in your initialization function:
|
|
|
|
void foo_init(void)
|
|
{
|
|
if (!initialised) {
|
|
eventAdd("foo_periodic_event", foo_periodic_event, NULL, 0, 0);
|
|
initialised = 1;
|
|
}
|
|
}
|
|
|
|
This will force the event to be called the next time eventRun() is called,
|
|
rather than waiting 15 seconds.
|
|
|
|
* You then define your event callback:
|
|
|
|
static void
|
|
foo_periodic_event(void *data)
|
|
{
|
|
/* We'd do our work here */
|
|
|
|
/* Then we'd finish */
|
|
eventAdd("foo_periodic_event", foo_periodic_event, NULL, 15, 0);
|
|
}
|
|
|
|
|
|
Notes:
|
|
|
|
* I really should change the timeout value to be in milliseconds. Squid used
|
|
a double, but Dianora had something against floating point code in the main
|
|
loop (which is understandable). If someone wants a fun task .. :-)
|
|
|
|
* Note that the 'name' parameter to eventAdd() / eventAddIsh() is a const
|
|
char *, and is *not copied* but *referenced*. Therefore, it is in your
|
|
best interest to use string constants.
|
|
|
|
* /stats E for an oper shows pending events. Thanks Diane!
|
|
|