Questions about non-atomic instructions like `i32.store`
Nobody has claimed this yet.
Assessment
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Newbie friendliness
- 25/100
- Issue type
- Documentation
- Clarity
- Mostly clear
- Activity status
- Stale
- Tech stack
- wasm
- Domain
- compilers
Research direction
Start with the WebAssembly Threads specification sections linked in the issue, especially the instruction and runtime event definitions. Compare the stated behavior of shared-memory i32.store with i32.atomic.rmw.cmpxchg and the mutex pattern described; done means resolving the interpretation and recording a clear specification answer.
Written by the indexing model from the issue text.
Description
when i32.store writes data to a shared memory, it's performed with an wr action. (https://webassembly.github.io/threads/core/exec/instructions.html#t-mathsf-xref-syntax-instructions-syntax-instr-memory-mathsf-store-n-xref-syntax-instructions-syntax-memarg-mathit-memarg)
those events are atomically performed according to https://webassembly.github.io/threads/core/exec/runtime.html#events.
thus, if a runtime implements atomic instructions like i32.atomic.rmw.cmpxchg via a lock, non-atomic instructions like i32.store should take the lock too, at least when operating on a shared memory.
is it the correct reading of the spec?
background:
some applications (eg. musl) implements a mutex with atomic cmpxchg for lock and ordinary store + barrier for unlock. as far as i know, it's fine for eg. x86. however, a naive porting to wasm might or might not cause problems.
- Dominant language
- WebAssembly
- Stars
- 767
- Forks
- 54
- PR merge metrics
- No merged PRs in 30d
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
More from WebAssembly/threads
-
Difficulty 2/5 1-3 hours Newbie friendliness 68/100
WebAssembly/threads#254 ·
-
Difficulty 5/5 Over a week Newbie friendliness 30/100
WebAssembly/threads#253 · 6 comments ·
-
Difficulty 4/5 3-5 days Newbie friendliness 35/100
WebAssembly/threads#245 · 1 reaction ·
-
Difficulty 4/5 3-5 days Newbie friendliness 35/100
WebAssembly/threads#240 ·
-
Branch renaming Open
Difficulty 1/5 Under an hour Newbie friendliness 20/100
WebAssembly/threads#237 ·
All issues in WebAssembly/threads
Similar issues
-
Difficulty 2/5 1-3 hours Newbie friendliness 75/100
objectionary/eo#8923 ·
-
Difficulty 2/5 1-3 hours Newbie friendliness 75/100
-
Coarray integration tests carry no LABELS, so run_tests.py silently skips them under every backend Opencoarray
Difficulty 2/5 1-3 hours Newbie friendliness 70/100
-
Difficulty 2/5 1-3 hours Newbie friendliness 75/100
-
internal.h中，漏掉了1个定义。 Open
Difficulty 1/5 Under an hour Newbie friendliness 95/100