Overview

Libevent is used for our event notification system. You can look at documentation on Libevent at http://monkey.org/~provos/libevent/ or http://www.wangafu.net/~nickm/libevent-book/

In CoreJS we use it in two different ways:

• Socket Communication
• Cross Thread Communication

The Very General Flow Of Libevent

• Create a new base to add all of our events to.
  *

struct event_base *base = event_base_new(); 

• Create a new event *

struct event * event_new(struct event_base *base, evutil_socket_t fd, short what, event_callback_fn cb,  void *arg);

• Add the event to the event_base *

event_add(struct event * ev, NULL);

• Start the loop to begin listening for the added events *

	event_base_dispatch(event_base);

How We Use It

We wanted to be able to have event notification across threads so we create a single instance of libevent's event_base. We created a singleton class called BaseEvent that contains this event_base. All events are added to this base.