Event potential concurrency issues#5

Merged

jdantonio merged 2 commits intoruby-concurrency:masterfrom

mighe:master

Jan 20, 2014

Commits on Jan 18, 2014

Event#set? changed to ensure visibility
mighe
committed

Commits on Jan 19, 2014

added: ImmediateExecutor, a simple executor where tasks are executed by thread that posted them
mighe
committed