mirror of
https://github.com/denoland/deno.git
synced 2024-12-24 16:19:12 -05:00
25 lines
945 B
Markdown
25 lines
945 B
Markdown
# deno_ffi
|
|
|
|
This crate implements dynamic library ffi.
|
|
|
|
## Performance
|
|
|
|
Deno FFI calls have extremely low overhead (~1ns on M1 16GB RAM) and perform on
|
|
par with native code. Deno leverages V8 fast api calls and JIT compiled bindings
|
|
to achieve these high speeds.
|
|
|
|
`Deno.dlopen` generates an optimized and a fallback path. Optimized paths are
|
|
triggered when V8 decides to optimize the function, hence call through the Fast
|
|
API. Fallback paths handle types like function callbacks and implement proper
|
|
error handling for unexpected types, that is not supported in Fast calls.
|
|
|
|
Optimized calls enter a JIT compiled function "trampoline" that translates Fast
|
|
API values directly for symbol calls. JIT compilation itself is super fast,
|
|
thanks to `tinycc`. Currently, the optimized path is only supported on Linux and
|
|
MacOS.
|
|
|
|
To run benchmarks:
|
|
|
|
```bash
|
|
target/release/deno bench --allow-ffi --allow-read --unstable-ffi ./tests/ffi/tests/bench.js
|
|
```
|