Using an ExecEnvPool allows you to cache transformation module bytecode and metamodels.

// pool init, called at init time of my tool
Metamodel metamodel = EmftvmFactory.eINSTANCE.createMetamodel();
metamodel.setResource(EcorePackage.eINSTANCE.eResource());
// pool (first used bellow) is an attribute of the class; the object is a singleton
pool.registerMetaModel("ECORE", metamodel);



// use pool, potentially multi-threaded
ExecEnv env = pool.getExecEnv(); // a new env object is created in each thread using this call??
ModuleResolver mr = new DefaultModuleResolver("platform:/plugin/my.plugin.id/transformations/", new ResourceSetImpl());
TimingData td = new TimingData();
env.loadModule(mr, "Module");
td.finishLoading();
env.run(td);

pool.returnExecEnv(env);

Hi Dennis,

thanks a lot for your answer, it took me some time before to answer because I wanted to experiment a bit the ExecEnv option you mentionned:

Quote:

Using an ExecEnvPool allows you to cache transformation module bytecode and metamodels.

I tried it. Initially, I did not go for this solution because I do not always have the same set of transformation modules, and in some cases I need to load modules dynamically. In order to see if it reduces the init time, I gave a try to this option. Indeed, the init time is significantly reduced (or at least transferred to the initialisation phase of my tool).

However, I also wanted to know if this solution is thread-safe?

Another question I have is: is it thread safe if I load metamodel using the pool but load modules using the exec env? Like this for instance:

// pool init, called at init time of my tool
Metamodel metamodel = EmftvmFactory.eINSTANCE.createMetamodel();
metamodel.setResource(EcorePackage.eINSTANCE.eResource());
// pool (first used bellow) is an attribute of the class; the object is a singleton
pool.registerMetaModel("ECORE", metamodel);



// use pool, potentially multi-threaded
ExecEnv env = pool.getExecEnv(); // a new env object is created in each thread using this call??
ModuleResolver mr = new DefaultModuleResolver("platform:/plugin/my.plugin.id/transformations/", new ResourceSetImpl());
TimingData td = new TimingData();
env.loadModule(mr, "Module");
td.finishLoading();
env.run(td);

pool.returnExecEnv(env);

Using such a setting, launching several transfo in different threads, I experienced difficulties (typically some memory over consumption).

Regarding model loading, I load models using resources obtained from an xtext-based parser. Not sure if it answers your questions.
Best regards and thanks for your help!
Etienne.