In the context of multi-core processors and the trend toward many-core, dataflow programming can be used as a solu- tion to the parallelization problem. By decoupling computa- tion from communication, this paradigm naturally exposes parallelism in several ways. In this work we propose lan- guage extensions for expressing throughput properties over dataflow programs together with a run-time mechanism for the observation of events meaningful to compute the effec- tive throughput. We show the limited impact of such mech- anisms on the application overall performances. We also review existing run-time adaptation mechanisms that may be used in a dataflow context to satisfy throughput require- ments.