* Consume fuel during function execution
This commit adds codegen infrastructure necessary to instrument wasm
code to consume fuel as it executes. Currently nothing is really done
with the fuel, but that'll come in later commits.
The focus of this commit is to implement the codegen infrastructure
necessary to consume fuel and account for fuel consumed correctly.
* Periodically check remaining fuel in wasm JIT code
This commit enables wasm code to periodically check to see if fuel has
run out. When fuel runs out an intrinsic is called which can do what it
needs to do in the result of fuel running out. For now a trap is thrown
to have at least some semantics in synchronous stores, but another
planned use for this feature is for asynchronous stores to periodically
yield back to the host based on fuel running out.
Checks for remaining fuel happen in the same locations as interrupt
checks, which is to say the start of the function as well as loop
headers.
* Improve codegen by caching `*const VMInterrupts`
The location of the shared interrupt value and fuel value is through a
double-indirection on the vmctx (load through the vmctx and then load
through that pointer). The second pointer in this chain, however, never
changes, so we can alter codegen to account for this and remove some
extraneous load instructions and hopefully reduce some register
pressure even maybe.
* Add tests fuel can abort infinite loops
* More fuzzing with fuel
Use fuel to time out modules in addition to time, using fuzz input to
figure out which.
* Update docs on trapping instructions
* Fix doc links
* Fix a fuzz test
* Change setting fuel to adding fuel
* Fix a doc link
* Squelch some rustdoc warnings
cargo-deny tells us that we should upgrade raw-cpuid to v9.0.0. This
new version also seems to lack the `nightly` feature (perhaps it has
been incorporated into the base functionality) so I had to remove this
feature selector to build.
* Add support for the experimental wasi-crypto APIs
The sole purpose of the implementation is to allow bindings and
application developers to test the proposed APIs.
Rust and AssemblyScript bindings are also available as examples.
Like `wasi-nn`, it is currently disabled by default, and requires
the `wasi-crypto` feature flag to be compiled in.
* Rename the wasi-crypto/spec submodule
* Add a path dependency into the submodule for wasi-crypto
* Tell the publish script to vendor wasi-crypto
This commit goes through the dependencies that wasmtime has and updates
versions where possible. This notably brings in a wasmparser/wast update
which has some simd spec changes with new instructions. Otherwise most
of these are just routine updates.
This commit updates the various tooling used by wasmtime which has new
updates to the module linking proposal. This is done primarily to sync
with WebAssembly/module-linking#26. The main change implemented here is
that wasmtime now supports creating instances from a set of values, nott
just from instantiating a module. Additionally subtyping handling of
modules with respect to imports is now properly handled by desugaring
two-level imports to imports of instances.
A number of small refactorings are included here as well, but most of
them are in accordance with the changes to `wasmparser` and the updated
binary format for module linking.
This helps us avoid measurement bias due to accidental locality of unrelated
heap objects. See *Stabilizer: Statistically Sound Performance Evaluation* by
Curtsinger and Berger for details (although Stabilizer deals with much more than
just the location of heap allocations):
https://people.cs.umass.edu/~emery/pubs/stabilizer-asplos13.pdf
