4 ms·

For folks looking to learn more, the Component Model documentation is pretty good! I like this excerpt for explaining the core vs component split: > components

For folks looking to learn more, the Component Model documentation is pretty good! I like this excerpt for explaining the core vs component split: > components interact only through the Canonical ABI. Specifically, unlike core modules, components may not export Wasm memory. This not only reinforces sandboxing, but enables interoperation between languages that make different assumptions about memory - for example, allowing a component that relies on Wasm GC (garbage collected) memory to collaborate with one that uses conventional linear memory. Link: https://component-model.bytecodealliance.org/design/why-component-model.html https://component-model.bytecodealliance.org/design/why-comp...

flohofwoe 3y ago
Hopefully it's trivial to push C structs around by value if poking around in other instances memory isn't allowed. Otherwise it sounds like a lot of hassle just to appease "fringe languages" ( ;P ) that don't have a linear memory model. This sort of "directly reading and writing the WASM heap" is quite essential for JS code that sits between a WASM instance and a web API for instance (in the "WASM in browsers" scenario). ...for instance how do you share large amounts of data between components then, there must be some sort of cheap way to safely share portions of memory between components right? Because there are situations where multiple copy steps are simply out of question.
- boomskats 3y ago
  If you watch the video I linked to in the sibling comment, Luke addresses that exact question around 21 minutes in. The WIT spec I also linked to talks about resources and handles in some depth.
boomskats 3y ago
I thought this keynote presentation[0] by Luke Wagner at Wasmcon was great and covered it very well. I also found the WIT Format design doc[1] in the component model repo to be the most complete explanation of how it's all going to hang together. [0]: https://www.youtube.com/watch?v=tAACYA1Mwv4 https://www.youtube.com/watch?v=tAACYA1Mwv4 [1]: https://github.com/WebAssembly/component-model/blob/main/design/mvp/WIT.md https://github.com/WebAssembly/component-model/blob/main/des...

flohofwoe 3y ago

Hopefully it's trivial to push C structs around by value if poking around in other instances memory isn't allowed. Otherwise it sounds like a lot of hassle just to appease "fringe languages" ( ;P ) that don't have a linear memory model. This sort of "directly reading and writing the WASM heap" is quite essential for JS code that sits between a WASM instance and a web API for instance (in the "WASM in browsers" scenario). ...for instance how do you share large amounts of data between components then, there must be some sort of cheap way to safely share portions of memory between components right? Because there are situations where multiple copy steps are simply out of question.

boomskats 3y ago
If you watch the video I linked to in the sibling comment, Luke addresses that exact question around 21 minutes in. The WIT spec I also linked to talks about resources and handles in some depth.

boomskats 3y ago

I thought this keynote presentation[0] by Luke Wagner at Wasmcon was great and covered it very well. I also found the WIT Format design doc[1] in the component model repo to be the most complete explanation of how it's all going to hang together. [0]: https://www.youtube.com/watch?v=tAACYA1Mwv4 https://www.youtube.com/watch?v=tAACYA1Mwv4 [1]: https://github.com/WebAssembly/component-model/blob/main/design/mvp/WIT.md https://github.com/WebAssembly/component-model/blob/main/des...