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javascriptjavamultithreadinggraalvmgraaljs

Graal Javascript - thread safety

What is the recommended way to use Graal.js in a multi-threaded application (such as per servlet request)? We are using Graal.js like this

jsContext = Context.newBuilder("js").allowAllAccess(true).build();
bindings = jsContext.getBindings("js");
jsContext.eval("js", jsCodeString);

Should we have a unique Context/binding for each executing thread. This can be accomplished through a pool of Context/Binding pairs or by using threadlocal. Is this the proper way to do this?

Solution

  • You should not access one Context from several threads at the same time. So, the solutions that you propose (a pool of Contexts or thread-local Contexts) are valid ways to do that.

    graalvm/graaljs repository contains some threading-related examples. You can see the usage of a thread-local Context there (in ExecutorsTest).

    FYI: There is a blog-post about multi-threading with Graal JavaScript that may clarify further questions that you may have.