At a high level, the Cilk Plus and Cilk++ schedulers operate using the same algorithms as MIT Cilk. Here is a list of some of the original research papers which describes some of the relevant concepts.
Analysis of work-stealing algorithms, applicable to MIT Cilk:
http://dx.doi.org/10.1145/324133.324234
Description of MIT Cilk implementation:
http://dx.doi.org/10.1145/277650.277725
The description of the implementation of reducers, introduced by Cilk++:
http://dx.doi.org/10.1145/1583991.1584017
These documents may or may not tell you what you are interested in, depending on what you are looking for.
Cheers,
Jim
