Understanding GraalWasm – the WASM Truffle interpreter

GraalVM provides an interpreter and compiler for WASM code called GraalWasm. GraalWasm opens up possibilities of building polyglot web applications that perform close to natively. Before we get into the details of GraalWasm, let's have a quick overview of WASM.

Understanding WASM

WASM is a binary format that can run on most modern browsers at near-native speeds. Web applications have become more and more sophisticated and demand a high-performance, near-native experience. JavaScript can only get to a certain level, and we have seen a lot of very good applications built on JavaScript that provide almost native experience. WASM augments JavaScript and other technologies to allow us to compile C, C++, and Rust programs on the web. The following figure shows a very simple pipeline of building WASM applications:

Figure 9.5 – WASM compilation pipeline flow

In the preceding figure, we...