tree 76603a8af4e46d247b2a9dc205fb0c772596d682
parent 71355d5dcc29b018e1d14795435fee122612d9fb
author Junxiao Shi <git@mail1.yoursunny.com> 1418014519 -0700
committer Junxiao Shi <git@mail1.yoursunny.com> 1418401556 -0700

util: Signal

Signal is an enhanced version of EventEmitter:

* only the owner can emit a signal (aka trigger an event)
* signal connection (aka event subscription) can be disconnected

EventEmitter is deprecated in favor of Signal.

refs #2279

Change-Id: I74ea5fef2e1e9b34776aa04f01170600b171152e