here - Stefan-Marr.de

1.4. Dissertation Outline
programming concepts. The third part of the chapter identifies common
problems in implementing concurrent programming concepts on top
of today’s VMs. Based on survey results and identified problems, this
chapter concludes with requirements for comprehensive VM support
for concurrent programming.
Chapter 4: Experimentation Platform
This chapter discusses the motivation and choices for the platforms used
for experiments and evaluation. First, it introduces SOM (Simple Object
Machine), a minimal Smalltalk dialect, which is used throughout this
dissertation for code examples and the discussion of the OMOP’s semantics.
This section includes an introduction to general Smalltalk syntax
and its semantics. Second, it motivates the choice of Smalltalk as
platform for this research. Finally, it discusses RoarVM as a choice for
the VM implementation experiments and detailed its implementation.
Chapter 5: An Ownership-based MOP to Express Concurrency Abstractions
This chapter introduce this dissertation’s main contribution, an ownership-based
metaobject protocol (OMOP). The OMOP is a unifying
substrate for the implementation of concurrent programming concepts.
First, the chapter discusses the foundational notions of open implementations
and metaobject protocols. Second, it presents the OMOP itself.
Third, it discusses examples of how to apply the OMOP to enforce immutability
and how to implement Clojure agents with it. Finally, the
chapter defines the OMOP’s semantics based on SOM’s bytecode interpreter
and discusses the OMOP in the context of related work.
Chapter 6: Evaluation – The OMOP as Unifying Substrate
In order to evaluate the OMOP, this chapter discusses how it fulfills the
identified requirements. First, the chapter discusses the evaluation criteria.
Second, it examines the case studies implementing Clojure agents,
software transactional memory (STM), and AmbientTalk actors. Third,
the chapter discusses concepts identified in Chapter 3 and argues that
the OMOP supports all of the concepts that require VM support for
guaranteeing correct semantics. Fourth, the chapter shows that the using
OMOP does not have a negative impact on the implementation size
of agents, actors, and STM, by comparing their OMOP-based implementations
against their ad hoc implementations. Finally, the limitations of
the OMOP are discussed.
7