Mitigating JavaScript’s overhead with WebAssembly
Samuli Ylenius · Tampere University Institutional Repository (Tampere University) · 2020
The web and web development have evolved considerably during its short history. As a result, complex applications aren’t limited to desktop applications anymore, but many of them have found themselves in the web. While JavaScript can meet the requirements of most web applications, its performance has been deemed to be inconsistent in applications that require top performance. There have been multiple attempts to bring native speed to the web, and the most recent promising one has been the open standard, WebAssembly. In this thesis, the target was to examine WebAssembly, its design, features, background, relationship with JavaScript, and evaluate the current status of WebAssembly, and its future. Furthermore, to evaluate the overhead differences between JavaScript and WebAssembly, a Game of Life sample application was implemented in three splits, fully in JavaScript, mix of JavaScript and WebAssembly, and fully in WebAssembly. This allowed to not only compare the performance differences between JavaScript and WebAssembly but also evaluate the performance differences between different implementation splits. Based on the results, WebAssembly came ahead of JavaScript especially in terms of pure execution times, although, similar benefits were gained from asm.js, a predecessor to WebAssembly. However, WebAssembly outperformed asm.js in size and load times. In addition, there was minimal additional benefit from doing a WebAssembly-only implementation, as just porting bottleneck functions from JavaScript to WebAssembly had similar performance benefits.