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Appendix B. Appendix: Performance Evaluation
additional overhead and the penalty for the subtraction in the Int Loop
loop.
Local vs. Remote Sends for AmbientTalkST The benchmarks for local and
remote sends between actors are meant to measure cost of asynchronous
message sends for the two AmbientTalkST implementations. The three
benchmarks do local sends to a counter, remote sends to a counter in
another actor, and remote sends with ten arguments. They each execute
a tight loop which sends a message to increase the counter that is kept
in a separate object. In the local version, the send ideally results only
in the creation of a context object in which the counter’s object field is
read and modified, while in the remote version a message object has
to be created that is enqueued in the actor’s message inbox and then
processed as soon as the receiving actor is scheduled.
B.1.2. Kernel Benchmarks
The used kernel benchmarks are collection from different sources, most notably
the Computer Language Benchmark Game. We adapted them for our
experiments with LRSTM and AmbientTalkST, but did not change the underlying
algorithms or functionality.
Compiler We chose the compiler benchmark as a sufficiently complex processes,
exercising a wide range of aspects of the system. The benchmark
compiles a Smalltalk method of 11 lines of code, which include tests,
loops, and a variety of message sends. The compiler will first construct
an AST from the source code and then produce a CompiledMethod from
this AST, which contains the final bytecode sequence. In the process, it
creates and traverses the AST, uses a variety of collections, does string
processing, and uses the stream facilities.
Slopstone and Smopstone These benchmarks 1 are collections of Smalltalk
microbenchmarks and kernel benchmarks. The Slopstone microbenchmark
collection tests integer addition, float addition, character access
on strings, object creation, object cloning, reflective method invocation
with #perform:, and block evaluation. We include this benchmark since
the structure is different from our benchmarks. It does not use a tight
loop but performs a larger number of operations directly in sequence.
1 According to the source comment, they have been authored by Bruce Samuelson in 1993.
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