53606de634
The mixed `number | bigint` representation was useful optimization for pointers. Now, pointers are represented as V8 externals. As part of the FFI stabilization effort we want to make `bigint` the only representation for `u64` and `i64`. BigInt representation performance is almost on par with mixed representation with the added benefit that its less confusing and users don't need manual checks and conversions for doing operations on the value. ``` cpu: AMD Ryzen 5 7530U with Radeon Graphics runtime: deno 1.43.6+92a8d09 (x86_64-unknown-linux-gnu) file:///home/divy/gh/ffi/main.ts benchmark time (avg) iter/s (min … max) p75 p99 p995 -------------------------------------------------------------------------- ----------------------------- nop 4.01 ns/iter 249,533,690.5 (3.97 ns … 10.8 ns) 3.97 ns 4.36 ns 9.03 ns ret bigint 7.74 ns/iter 129,127,186.8 (7.72 ns … 10.46 ns) 7.72 ns 8.11 ns 8.82 ns ret i32 7.81 ns/iter 128,087,100.5 (7.77 ns … 12.72 ns) 7.78 ns 8.57 ns 9.75 ns ret bigint (add op) 15.02 ns/iter 66,588,253.2 (14.64 ns … 24.99 ns) 14.76 ns 19.13 ns 19.44 ns ret i32 (add op) 12.02 ns/iter 83,209,131.8 (11.95 ns … 18.18 ns) 11.98 ns 13.11 ns 14.5 ns ``` |
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.. | ||
00_ffi.js | ||
call.rs | ||
callback.rs | ||
Cargo.toml | ||
dlfcn.rs | ||
ir.rs | ||
lib.rs | ||
README.md | ||
repr.rs | ||
static.rs | ||
symbol.rs | ||
turbocall.rs |
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:
target/release/deno bench --allow-ffi --allow-read --unstable-ffi ./tests/ffi/tests/bench.js