Initial version of a Model Execution Protocol framework for GEMOC

[dvojtise]

This PR contributes some reusable elements to implement a Model Execution Protocol (Debug Adapter Protocol) in GEMOC

This first PR adds:

• a plugin offering a printstream that allow to redirect the stream if it comes from a given thread (note: this should be used later in the messaging system too)
• a maven project (org.eclipse.gemoc.executionframework.mep) providing the base classes of a MEP server. It mainly provides abstract classes that specific engines must implement.
  This project is intended to run in a pure maven build. It uses maven dependencies instead of plugin/manifest (ie. it doesn't use tycho) as tycho dependencies and maven dependencies cannot be built in the same reactor, the pom are in specific folders (named pomfirst)

This PR comes with eclipse-gemoc/gemoc-studio#207 and eclipse-gemoc/gemoc-studio-execution-java#7

[ebousse]

very nice!

Question: how does an engine have to deal with this novelty? Looking at the diff I see a new launcher and a server, which I suppose will start a chosen execution engine and await orders from an MEP client. But what are these "abstract classes that specific engines must implement"?

[dvojtise]

Other PR are on the way with an example for K3 FSM 😉
roughly: every engine offering such protocol need a special implementation. Currently, this is not fully aligned with existing engine (pb with eclipse extension point and how to offer the "debugger addon" in pure java application).

This work is a starting point for further discussions (about deployment, pure java vs eclipse based app, addons via extension point or another dependency injection, some concern about required/important addons (debug, trace that are useful/required on the server side) versus optional addons (most of the time on the client side)) this should probably be discussed on the dev mailing list...

[dvojtise]

• a subset of GEMOC project now have a "pomfirst" subfolder that allows to recreate a more reliable dependency tree using maven dependencies (it recreates the dependencies between gemoc projects)

[dvojtise]

for archive:
here is an overview of the current state in this PR (actually, I plan many changes in order to move multidimentional trace view in a web page)