Re: [Libevent-users] API compatibility (was Re: patch to use different return value for event_base_loop())
On Tue, Sep 29, 2009 at 11:39:59AM -0700, Ka-Hing Cheung wrote: > On Sun, 2009-08-16 at 10:39 -0700, Nick Mathewson wrote: > > > but I am willing to submit another patch (the one with > > > accessor to base->event_gotterm/event_break) if you think that's the > > > better way to do it. > > > > Probably. > > Sorry for taking so long. Attached is the promised patch which adds > accessors to base->event_gotterm/event_break, as well as modifying when > they are reset in event_base_loop(). Applied; thanks! -- Nick ___ Libevent-users mailing list Libevent-users@monkey.org http://lists.monkey.org:8080/listinfo/libevent-users
Re: [Libevent-users] API compatibility (was Re: patch to use different return value for event_base_loop())
On Sun, 2009-08-16 at 10:39 -0700, Nick Mathewson wrote:
> > but I am willing to submit another patch (the one with
> > accessor to base->event_gotterm/event_break) if you think that's the
> > better way to do it.
>
> Probably.
Sorry for taking so long. Attached is the promised patch which adds
accessors to base->event_gotterm/event_break, as well as modifying when
they are reset in event_base_loop().
-khc
Index: include/event2/event.h
===
--- include/event2/event.h (revision 1437)
+++ include/event2/event.h (working copy)
@@ -300,6 +300,28 @@
*/
int event_base_loopbreak(struct event_base *);
+/**
+ Checks if the event loop was told to exit
+
+ @param eb the event_base structure returned by event_init()
+ @return true if event_base_loopexit() was called on this event base,
+or 0 otherwise
+ @see event_base_loopexit
+ @see event_base_got_break
+ */
+int event_base_got_exit(struct event_base *);
+
+/**
+ Checks if the event loop was told to abort immediately.
+
+ @param eb the event_base structure returned by event_init()
+ @return true if event_base_loopbreak() was called on this event base,
+or 0 otherwise
+ @see event_base_loopbreak
+ @see event_base_got_exit
+ */
+int event_base_got_break(struct event_base *);
+
/* Flags to pass to event_set(), event_new(), event_assign(),
* event_pending(), and anything else with an argument of the form
* "short events" */
Index: event.c
===
--- event.c (revision 1437)
+++ event.c (working copy)
@@ -830,8 +830,20 @@
}
}
+int
+event_base_got_break(struct event_base *event_base)
+{
+return event_base->event_break;
+}
+int
+event_base_got_exit(struct event_base *event_base)
+{
+return event_base->event_gotterm;
+}
+
+
/* not thread safe */
int
@@ -859,15 +871,15 @@
base->th_owner_id = EVTHREAD_GET_ID();
#endif
+base->event_gotterm = base->event_break = 0;
+
while (!done) {
/* Terminate the loop if we have been asked to */
if (base->event_gotterm) {
- base->event_gotterm = 0;
break;
}
if (base->event_break) {
- base->event_break = 0;
break;
}
___
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[Libevent-users] API compatibility (was Re: patch to use different return value for event_base_loop())
On Thu, Aug 13, 2009 at 11:04:52AM -0700, Ka-Hing Cheung wrote: > On Thu, 2009-08-13 at 09:16 -0700, Nick Mathewson wrote: > > On Wed, Aug 12, 2009 at 11:42:47AM -0700, Ka-Hing Cheung wrote: > > [...] > > > I do realize that this breaks existing assumptions about return values. > > > What if instead of using a different return value, we don't reset > > > base->event_gotterm and base->event_break when triggered? We can reset > > > them at the beginning of event_base_loop() instead. > > > > How would you inspect them? The event_base structure isn't exposed in > > any public headers. I suppose we could add a new accessor function. > > Right. > > > I like the idea of the original patch, but I'm also concerned about > > return values. If anyone has written code like > > "if (event_base_loop(base,0)<0)" or "if (event_base_loop(base,0)==-1)", > > they'll get unexpected results. > > Yes I like that too. I don't know how strict the api compatibility > requirement is, The foremost API requirement is: we don't want to break source compatibility for existing correct programs. Breaking existing programs annoys developers, and prevents distributors from upgrading to new Libevent versions[*]. Since the return values for event_base_loop() and friends have been documented and relied upon for a while, I don't think that we can change them safely. > but I am willing to submit another patch (the one with > accessor to base->event_gotterm/event_break) if you think that's the > better way to do it. Probably. yrs, -- Nick ___ Libevent-users mailing list Libevent-users@monkey.org http://monkeymail.org/mailman/listinfo/libevent-users
