here - Stefan-Marr.de

1. Introduction
traded in for better performance, which hinders the development of domainspecific
abstractions.
An additional problem arises from the fact that the field of concurrent and
parallel programming is largely uncharted, i. e., there is no widely accepted
taxonomy that covers the wide range of different concepts. While a number
of surveys provide an overview of programming concepts and language constructs
[Briot et al., 1998; De Bosschere, 1997; Gupta et al., 2001; Skillicorn
and Talia, 1998], they are far from complete and do not cover more recent
work in the field. Thus, it is not even clear which concepts a VM should support
in order to be a viable platform for a wide range of different problems
from the field of concurrent and parallel applications. Supporting all possible
concepts directly would not be possible, because of the resulting complex feature
interactions within VMs. Since there is no one-size-fits-all solution either,
one problem this dissertation needs to solve is to identify which of all these
concepts a virtual machine should support in order to enable library and language
implementers to provide domain-specific solutions for a relevant range
of concurrent and parallel programming.
To conclude, VMs such as the JVM and the CLI lack sufficient support for
parallel and concurrent programming. The goal of this dissertation is to identify
a unifying substrate for concurrent and parallel programming that allows
efficient implementation in a VM and provides the necessary abstractions to
enable language and library implementers to implement custom abstractions.
In summary, the two problems that need to be addressed are:
Insufficient Support for Concurrent and Parallel Programming in VMs Today’s
VMs do not provide sufficient support for concurrent and parallel
programming in order to enable library and language implementers to
build domain-specific abstractions.
Set of Required Concepts Unknown Since supporting all possible concepts
is prohibitively complex, a VM needs to make abstractions of concrete
programming concepts or support a subset of them. However, the subset
of concurrent and parallel programming concepts that would enable
domain-specific solutions is currently unknown.
4