Object for libevent (kqueue/epoll/poll/select) library.
Usefull for getting notifications for descriptor (a socket or file) events.
Events include read (the descriptor has unread data or timeout) and write (the descriptor wrote some data or timeout).
Also, timer and signal events are supported.
addEvent(event, descriptor, eventType, timeout)
run
Runs the EventManger loop. Does not return. Private - should only be called by resumeIfNeeded.