Benchmark internals

Author: nvzqz

.github/workflows/ci.yml

@@ -138,3 +138,26 @@ jobs:
             target
           key: examples-bench-${{ runner.os }}
       - run: cargo bench -p examples --all-features
+
+  # Run `internal_benches/` directory as benchmarks.
+  internals-bench:
+    name: Internals Bench
+    runs-on: ${{ matrix.os }}
+    env:
+      # Run each benchmark within 2 seconds.
+      DIVAN_MAX_TIME: 2
+    strategy:
+      matrix:
+        os:
+          - ubuntu-latest
+          - macos-latest
+          - windows-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/[email protected]
+        with:
+          path: |
+            ${{ env.CARGO_HOME }}
+            target
+          key: internals-bench-${{ runner.os }}
+      - run: cargo bench -p internal_benches --all-features

Cargo.toml

@@ -29,8 +29,11 @@ default = ["wrap_help"]
 help = ["clap/help"]
 wrap_help = ["help", "clap/wrap_help"]
 
+# Benchmark internals. Not meant for public use.
+internal_benches = []
+
 [workspace]
-members = ["macros", "examples"]
+members = ["macros", "examples", "internal_benches"]
 
 [workspace.dependencies]
 divan = { path = "." }

internal_benches/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "internal_benches"
+version = "0.0.0"
+edition = "2021"
+authors = ["Nikolai Vazquez"]
+license = "MIT OR Apache-2.0"
+description = "Internal benchmarks for Divan, a comfy benchmarking framework."
+readme = "../README.md"
+publish = false
+
+[dependencies]
+divan = { workspace = true, features = ["internal_benches"] }
+
+[[bench]]
+name = "internals"
+harness = false

internal_benches/README.md

@@ -0,0 +1,27 @@
+# Divan Internal Benchmarks
+
+This crate demonstrates how to use [Divan] to benchmark internals of a crate by
+benchmarking the internals of Divan.
+
+These can be benchmarked locally by running:
+
+```sh
+git clone https://github.com/nvzqz/divan.git
+cd divan
+
+cargo bench -q -p internal_benches
+```
+
+As of this writing, the output on my machine is:
+
+```txt
+divan                             fastest  │ slowest  │ median   │ mean     │ samples │ iters
+╰─ time                                    │          │          │          │         │
+   ╰─ timer                                │          │          │          │         │
+      ├─ get_tsc                  0.158 ns │ 0.202 ns │ 0.161 ns │ 0.162 ns │ 100     │ 1638400
+      ╰─ measure                           │          │          │          │         │
+         ├─ precision             89.58 µs │ 221.5 µs │ 201.9 µs │ 184.5 µs │ 100     │ 100
+         ╰─ sample_loop_overhead  314.2 µs │ 342.5 µs │ 314.5 µs │ 317.1 µs │ 100     │ 100
+```
+
+[divan]: https://github.com/nvzqz/divan

internal_benches/benches/internals.rs

@@ -0,0 +1,3 @@
+fn main() {
+    divan::main();
+}

src/time/timer.rs

@@ -172,3 +172,25 @@ pub(crate) enum TimerKind {
     /// CPU timestamp counter.
     Tsc,
 }
+
+#[cfg(feature = "internal_benches")]
+#[crate::bench(crate = crate)]
+fn get_tsc() -> Result<Timer, TscUnavailable> {
+    Timer::get_tsc()
+}
+
+#[cfg(feature = "internal_benches")]
+mod measure {
+    use super::*;
+
+    #[crate::bench(crate = crate)]
+    fn precision() -> FineDuration {
+        Timer::Os.measure_precision()
+    }
+
+    #[cfg(feature = "internal_benches")]
+    #[crate::bench(crate = crate)]
+    fn sample_loop_overhead() -> FineDuration {
+        Timer::Os.measure_sample_loop_overhead()
+    }
+}