WebAssembly and Friends Roadmap

Wasm SIMD (prototype)

• Adds support for SIMD (vector math) operations to WebAssembly.
• Wasm SIMD will have support for roughly the portable set of SIMD operations originally planned for SIMD.js.
• NOTE: This feature does not yet have widespread support from all Wasm
• implementors and may change significantly. This time estimate mainly relates to
• prototype support in Chrome, behind a flag.

Wasm - Threads

• Add WebAssembly support for shared memory threads.
• We're actively working to standardize SharedArrayBuffer compatible threads for WebAssembly. As this extension to WebAssembly has not yet been standardized, this is a general estimate.

Wasm - postMessage

• Adds the ability to postMessage a WebAssembly.Module to Web Workers.
• Our M57 Wasm launch did not include support for this aspect of the WebAssembly Web embedding.
• This is one of the requirements for multi-threaded Wasm.

Wasm - IndexedDB

• Adds the ability to serialize a WebAssembly.Module to IndexedDB.
• Our M57 Wasm launch did not include support for this aspect of the WebAssembly Web embedding.
• This feature enables explicit caching in IDB.

Wasm - OOB Traps

Linux

• Optimization allowing 64-bit systems to avoid performing Out-Of-Bounds checks by using hardware fault handling in combination with clever memory layout.
• Improves performance of applications by 10-25%.

Wasm - Streaming Compile

• Allows WebAssembly to compile while still being downloaded.
• Building on the WebAssembly Response based API, WebAssembly will be able to compile while still being downloaded, with the granularity of individual functions.
• This will allow applications to hide the cost of compilation behind download costs.

Wasm - Shared Code

• Make WebAssembly threads use substantially less memory.
• By making WebAssembly module generated code less content dependent, multiple Web Workers will be able to share a single copy of the underlying machine code.

Wasm - Execute from Cache

• Allow cached WebAssembly code to start faster with less resident memory.
• By enabling Chrome's storage layer to memory map cached WebAssembly code, enable quick, lazy load of WebAssembly cached code, comparable to how native applications start.

Wasm - CSP Support

• Allows pages that have locked down security policies to use WebAssembly.
• A Content Security Policy can be used to limit the scripting resources used by your Web App. The Response based API will allow WebAssembly to run inside a strict CSP that forbids "unsafe-eval".

Wasm - OOB Traps

Windows

• Optimization allowing 64-bit systems to avoid performing Out-Of-Bounds checks by using hardware fault handling in combination with clever memory layout.
• Improves performance of applications by 10-25%.

Wasm - Exceptions

• Add support for fast exception handling to WebAssembly.
• This feature has not yet been standardized, but there is growing consensus.
• Proposal

Wasm - OOB Traps

OSX

• Optimization allowing 64-bit systems to avoid performing Out-Of-Bounds checks by using hardware fault handling in combination with clever memory layout.
• Improves performance of applications by 10-25%.

WebGL 2

• WebGL 2.0 shipped in Chrome M56.

WebAssembly MVP

• WebAssembly shipped in Chrome M57, bringing a same, fast, and efficient low level code format to the Web.
• Implementations are in development in all major engines.
• Intent to Implement
• Intent to Ship

SharedArrayBuffer

• SharedArrayBuffers bring shared memory to JavaScript.
• Opens the door to new synchronization patterns in the browser. Worker threads are allowed to block waiting for data from other threads.
• SharedArrayBuffers pave the way for WebAssembly threads, which will be inter-operable.
• Documentation
• Intent to Implement
• Intent to Ship

asm.js -> WebAssembly

• One of the precursors of WebAssembly, asm.js, embeds machine level code in subset of JavaScript.
• Explicit validation of asm.js code and conversion to WebAssembly will offer more consistent asm.js performance, and a path to support this content during the transition to WebAssembly.
• asm.js Spec

Wasm True-Async

• Allows WebAssembly compilation to happen in the background.
• Our M57 Wasm launch provided an asynchronous API for compiling and instantiating WebAssembly code. Unfortunately, our implementation in Chrome M57 - M59 does not actually perform these actions in the background. Starting in M61, the correct performance behavior will occur, preventing janky behavior when compiling Wasm.

Wasm Response

• Adds an API to compile directly from a fetched URL.
• Browsers have agreed on an extension to the Web embedding on WebAssembly that provides a Response object based way to compile and instantiate Wasm code. The Response object (a promise for which is returned by the fetch API), is origin bound.
• This will allow CSP based applications to function when using WebAssembly (even with unsafe-eval disallowed).
• Additionally, this API will seamlessly support streaming compilation when it becomes available.
• Web Embedding