Re: [Libevent-users] event_priority_set() function and some questions about event priority and

[Nick Mathewson <nickm@xxxxxxxxxxxxx>]

On Wed, Jun 19, 2013 at 8:19 AM, liu lily <politoesolve@xxxxxxxxx> wrote:

I have some questions on libevent event priority 1 what is the priority number range?

That's a property of the event_base, and is configured by event_base_priority_init() when you're constructing the event_base.

 

2 in the mannual, it says By default, libevent assigns the middle priority to all events unless their priority is explicitly set. so what is the exact default priority number?

It's the maximum priority value plus one, divided by 2. 

3 when priority is higher, the number is smaller or larger?

Numerically lower priority values are more high-priority.

 

4 There are two functions which are related to event priority in libevent. event_priority_init() and event_priority_set, what are the differences between them?

event_base_priority_init() sets up priorities in an event_base.  event_priority_set() changes the priority of an event.  event_priority_init() is deprecated.

 

5 what are return values for event_priority_set(struct event *ev, int pri)? I notice an article says something like: when an event is ready, it can't be set and calling of this function returns -1. I really don't understand what does this mean? can anyone explain a bit? thanks!

I don't know what article you're talking about. Try looking at the reference manual at http://www.wangafu.net/~nickm/libevent-book/ and at the documentation in the header files.