here - Stefan-Marr.de

6.4. Comparing Implementation Size
sends and channels entail more than these semantics, the OMOP supports
only one important aspect, and thus, these concepts are partially supported.
Managed State and Managed Execution The remaining three concepts of
replication, and speculative execution could benefit from the available tracking
of state mutation and method invocation. For instance, the implementation
of replication with a certain consistency guarantee needs reliable tracking of
all state changes, which can be realized similarly to how the OMOP is used
for an STM implementation. Speculative execution has similar requirements
and can be realized with some variation of STM semantics to enable a clean
abort of a speculatively executed computational branch. However, the OMOP
provides support for only one of the important aspects of these concepts and
beyond that the concepts are largely orthogonal to the concerns handled by
the OMOP.
6.3.3. Conclusion
This section discussed how the OMOP facilitates the implementation of the
concepts identified in Sec. 3.2. For all 18 concepts that require VM support
to enforce their semantics, the OMOP either provides full support or simplifies
the implementation substantially. It does that by providing flexible mechanisms
to realize managed state, managed execution, ownership,
and controlled enforcement.
Language implementers benefit substantially from this support, because for
all evaluated concepts it addresses challenges such as immutability, isolation,
custom execution policies, and custom state access policies (cf. Tab. 6.1).
6.4. Comparing Implementation Size
This section argues that the OMOP provides an abstraction that has a positive
impact on the implementation size for concurrent programming concepts. It
demonstrates this by showing that the OMOP-based implementations of AmbientTalkST
and LRSTM are smaller than their ad hoc counterparts. In addition,
it argues that the OMOP-based implementations of active objects, and
CSP are sufficiently concise, i. e., have small implementations as well. This
section first details the used metrics and then discusses the three case studies,
i. e., the implementation of Clojure agents, LRSTM, and AmbientTalkST.
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