Asynchronous Operations with WASM
Implement asynchronous patterns to handle long-running tasks in WASM without blocking the main thread, using promises and async/await.
Why Asynchronous WASM?
When a WebAssembly module performs a complex calculation or a long task, it can freeze your web page. This is because JavaScript is single-threaded, and most direct WASM calls are synchronous.
Asynchronous WASM patterns allow these tasks to run without completely blocking the main browser thread, keeping your UI responsive.
WASM's Synchronous Nature
When JavaScript calls an exported WASM function, that function executes entirely before JavaScript regains control. If the WASM function takes a long time, the browser's main thread will be blocked.
This means no UI updates, no user input processing, making the page appear frozen. True parallel execution for WASM often involves Web Workers, which is covered in another lesson.
All lessons in this course
- Asynchronous Operations with WASM
- Custom JavaScript Callbacks
- Error Handling & Exceptions
- Sharing Memory and Typed Arrays Across the JS/WASM Boundary