From 6bf0a5cb5034a7e684dcc3500e841785237ce2dd Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 19:32:43 +0200 Subject: Adding upstream version 1:115.7.0. Signed-off-by: Daniel Baumann --- third_party/rust/getrandom/benches/buffer.rs | 71 ++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 third_party/rust/getrandom/benches/buffer.rs (limited to 'third_party/rust/getrandom/benches') diff --git a/third_party/rust/getrandom/benches/buffer.rs b/third_party/rust/getrandom/benches/buffer.rs new file mode 100644 index 0000000000..b32be4336c --- /dev/null +++ b/third_party/rust/getrandom/benches/buffer.rs @@ -0,0 +1,71 @@ +#![feature(test, maybe_uninit_uninit_array_transpose)] +extern crate test; + +use std::mem::MaybeUninit; + +// Call getrandom on a zero-initialized stack buffer +#[inline(always)] +fn bench_getrandom() { + let mut buf = [0u8; N]; + getrandom::getrandom(&mut buf).unwrap(); + test::black_box(&buf as &[u8]); +} + +// Call getrandom_uninit on an uninitialized stack buffer +#[inline(always)] +fn bench_getrandom_uninit() { + let mut uninit = [MaybeUninit::uninit(); N]; + let buf: &[u8] = getrandom::getrandom_uninit(&mut uninit).unwrap(); + test::black_box(buf); +} + +// We benchmark using #[inline(never)] "inner" functions for two reasons: +// - Avoiding inlining reduces a source of variance when running benchmarks. +// - It is _much_ easier to get the assembly or IR for the inner loop. +// +// For example, using cargo-show-asm (https://github.com/pacak/cargo-show-asm), +// we can get the assembly for a particular benchmark's inner loop by running: +// cargo asm --bench buffer --release buffer::p384::bench_getrandom::inner +macro_rules! bench { + ( $name:ident, $size:expr ) => { + pub mod $name { + #[bench] + pub fn bench_getrandom(b: &mut test::Bencher) { + #[inline(never)] + fn inner() { + super::bench_getrandom::<{ $size }>() + } + + b.bytes = $size as u64; + b.iter(inner); + } + #[bench] + pub fn bench_getrandom_uninit(b: &mut test::Bencher) { + #[inline(never)] + fn inner() { + super::bench_getrandom_uninit::<{ $size }>() + } + + b.bytes = $size as u64; + b.iter(inner); + } + } + }; +} + +// 16 bytes (128 bits) is the size of an 128-bit AES key/nonce. +bench!(aes128, 128 / 8); + +// 32 bytes (256 bits) is the seed sized used for rand::thread_rng +// and the `random` value in a ClientHello/ServerHello for TLS. +// This is also the size of a 256-bit AES/HMAC/P-256/Curve25519 key +// and/or nonce. +bench!(p256, 256 / 8); + +// A P-384/HMAC-384 key and/or nonce. +bench!(p384, 384 / 8); + +// Initializing larger buffers is not the primary use case of this library, as +// this should normally be done by a userspace CSPRNG. However, we have a test +// here to see the effects of a lower (amortized) syscall overhead. +bench!(page, 4096); -- cgit v1.2.3