--- libev/ev.html 2007/11/12 08:47:14 1.17 +++ libev/ev.html 2007/11/12 09:01:12 1.21 @@ -6,7 +6,7 @@ - +
@@ -19,7 +19,8 @@Libev represents time as a single floating point number, representing the
(fractional) number of seconds since the (POSIX) epoch (somewhere near
the beginning of 1970, details are complicated, don't ask). This type is
called ev_tstamp
, which is what you should use too. It usually aliases
to the double type in C.
These functions can be called anytime, even before initialising the +library in any way.
If you use threads, a common model is to run the default event loop -in your main thread (or in a separate thrad) and for each thread you +in your main thread (or in a separate thread) and for each thread you create, you also create another event loop. Libev itself does no locking whatsoever, so if you mix calls to the same event loop in different threads, make sure you lock (this is usually a bad idea, though, even if @@ -564,11 +571,10 @@ ignored. Instead, each time the periodic watcher gets scheduled, the reschedule callback will be called with the watcher as first, and the current time as second argument.
-NOTE: This callback MUST NOT stop or destroy the periodic or any other
-periodic watcher, ever, or make any event loop modifications. If you need
-to stop it, return now + 1e30
(or so, fudge fudge) and stop it afterwards.
Also, this callback must always return a time that is later than the
-passed now
value. Not even now
itself will be ok.
NOTE: This callback MUST NOT stop or destroy any periodic watcher,
+ever, or make any event loop modifications. If you need to stop it,
+return now + 1e30
(or so, fudge fudge) and stop it afterwards (e.g. by
+starting a prepare watcher).
Its prototype is ev_tstamp (*reschedule_cb)(struct ev_periodic *w,
ev_tstamp now)
, e.g.:
static ev_tstamp my_rescheduler (struct ev_periodic *w, ev_tstamp now) @@ -581,6 +587,8 @@ (that is, the lowest time value larger than to the second argument). It will usually be called just before the callback will be triggered, but might be called at other times, too. +NOTE: This callback must always return a time that is later than the +passed
now
value. Not evennow
itself will do, it must be larger.This can be used to create very complex timers, such as a timer that triggers on each midnight, local time. To do this, you would calculate the next midnight after
now
and return the timestamp value for this. How you do this