An Orchestration Language for Parallel Objects
Authors:
L. V. Kale, Mark Hills, Chao Huang
Parallel Programming Laboratory, Department of Computer Science, University
of Illinois at Urbana-Champaign
Proceeding of Seventh Workshop on Languages, Compilers, and Run-time Support for Scalable Systems (LCR 04)
Charm++, a parallel object language based on the idea of virtual processors, has attained significant success in efficient parallelization of applications. Requiring the user to only decompose the computation into a large number of objects ("virtual processors" or VPs), Charm++ empowers its intelligent adaptive runtime system to assign and reassign the objects to processors at runtime. This facility is used to optimize execution, including via dynamic load balancing. Having multiple sets of VPs for distinct parts of a simulation leads to improved modularity and performance. However, it also tends to obscure the global flow of control: One must look at the code of multiple objects to discern how the sets of objects are orchestrated in a given application. In this paper, we present an orchestration notation that allows expression of Charm++ functionality without its fragmented flow of control.