rfcs / PR #11 RFC: Redesign Wasmtime's API · rfc-notifications

Stream: rfc-notifications

Topic: rfcs / PR #11 RFC: Redesign Wasmtime's API

RFC notifications bot (May 04 2021 at 15:30):

alexcrichton opened PR #11 from new-api to main:

Rendered

Overhaul the wasmtime crate's API to improve it along a number of vectors:

Greatly improve the multithreading story in all languages (Rust, C, Go, ...),
namely enabling safe usage of wasmtime in multithreaded server runtimes
where wasm objects can migrate between threads.

Leverage mutability in Rust to allow &mut access to user-defined state
instead of requiring users to use interior mutability.

Simplify memory management in the C API and embeddings.

The only major cost relative to today's API is that ExternRef will move to
atomic reference counting and will require T: Send + Sync on constructors.

RFC notifications bot (May 06 2021 at 13:40):

bnjbvr submitted PR Review.

RFC notifications bot (May 06 2021 at 13:40):

bnjbvr submitted PR Review.

RFC notifications bot (May 06 2021 at 13:40):

bnjbvr created PR Review Comment:

self`. The reason for this is that everything is effectively behind an `Rc`

RFC notifications bot (May 06 2021 at 13:40):

bnjbvr created PR Review Comment:

Above it is suggested that having the Store be Send + Sync is optional and depends on T being Send + Sync too; so is this a strong requirement, even when the embedder doesn't need a Send + Sync Store?

RFC notifications bot (May 06 2021 at 13:40):

bnjbvr created PR Review Comment:

Should the first parameter be cx: impl AsContextMut here?

RFC notifications bot (May 06 2021 at 13:40):

bnjbvr created PR Review Comment:

Are these two functions doing more than what the AsContext/Mut trait methods provide?

RFC notifications bot (May 06 2021 at 13:40):

bnjbvr created PR Review Comment:

* Management of memory in the API can sometimes be confusing. Additionally for C

RFC notifications bot (May 06 2021 at 15:18):

alexcrichton submitted PR Review.

RFC notifications bot (May 06 2021 at 15:18):

alexcrichton created PR Review Comment:

That's correct, regardless of whether the embedder needs Send and Sync host functions will always be required to be Send and Sync. This is thought to be ok, though, because most host state should be stored in T rather than in the funtion itself, and it's expected that the majority of host functions are simply 0-sized closures that are just code and no data.

RFC notifications bot (May 06 2021 at 15:19):

alexcrichton submitted PR Review.

RFC notifications bot (May 06 2021 at 15:19):

alexcrichton created PR Review Comment:

Nah they're just explicitly named so if users want to call them they don't have to import the trait. I'm not sure if this makes sense but it's always an option we can have of course!

RFC notifications bot (May 06 2021 at 15:19):

alexcrichton updated PR #11 from new-api to main.

RFC notifications bot (May 10 2021 at 12:52):

alexcrichton updated PR #11 from new-api to main.

RFC notifications bot (May 10 2021 at 23:03):

alexcrichton updated PR #11 from new-api to main.

RFC notifications bot (May 11 2021 at 08:33):

bjorn3 created PR Review Comment:

  it's simply an index into the `Store`. This implementation detail is how the

RFC notifications bot (May 11 2021 at 08:33):

bjorn3 submitted PR Review.

RFC notifications bot (May 12 2021 at 15:44):

alexcrichton updated PR #11 from new-api to main.

RFC notifications bot (May 24 2021 at 18:13):

pchickey submitted PR review.

RFC notifications bot (May 24 2021 at 18:14):

peterhuene submitted PR review.

RFC notifications bot (May 24 2021 at 18:30):

jedisct1 submitted PR review.

RFC notifications bot (May 24 2021 at 18:43):

sunfishcode submitted PR review.

RFC notifications bot (May 24 2021 at 18:43):

sunfishcode submitted PR review.

RFC notifications bot (May 24 2021 at 18:43):

sunfishcode created PR review comment:

`wasm.h` which does not have any sort of context handle passed around anywhere.

RFC notifications bot (May 24 2021 at 18:51):

alexcrichton updated PR #11 from new-api to main.

RFC notifications bot (May 24 2021 at 19:14):

bjorn3 submitted PR review.

RFC notifications bot (May 24 2021 at 22:48):

radu-matei submitted PR review.

RFC notifications bot (May 25 2021 at 15:59):

abrown submitted PR review.

RFC notifications bot (May 25 2021 at 16:01):

thomastaylor312 submitted PR review.

RFC notifications bot (May 25 2021 at 16:18):

bacongobbler submitted PR review.

RFC notifications bot (Jun 02 2021 at 16:35):

bnjbvr submitted PR review.

RFC notifications bot (Jun 03 2021 at 14:09):

alexcrichton merged PR #11.

Last updated: Dec 06 2025 at 06:05 UTC