(8) feat(dpdk): test EAL harness (with_eal macro + const fn)#1572
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daniel-noland wants to merge 2 commits into
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(8) feat(dpdk): test EAL harness (with_eal macro + const fn)#1572daniel-noland wants to merge 2 commits into
daniel-noland wants to merge 2 commits into
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Lets callers derive the rte_acl input-buffer size requirement from a const FIELD_DEFS array at compile time -- useful for feeding into a const generic (e.g. the STRIDE on a DPDK-backed Lookup type alias) rather than rediscovering it at runtime. The runtime path through AclBuildConfig::new still calls into the same helper and caches the result; only the surface broadens from fn to const fn (with the for-loop rewritten as a while-let-i index walk that const-fn-eval can chew on). Existing FieldExtentOverflow validation is preserved; in a const context overflow becomes a compile error instead of UB. Adds one test exercising the const path: const MIN_INPUT_SIZE = AclBuildConfig::compute_min_input_size(&DEFS); plus the assertion that the runtime path returns the same value. just fmt; cargo check -p dataplane-dpdk --all-targets passes.
Introduces shared EAL test scaffolding for downstream crates that
need to exercise rte_acl, mempools, or any other DPDK runtime under
`#[test]`. Two pieces, both behind the new dpdk `test` feature so
production builds remain unchanged:
- dpdk-test-macros: proc-macro crate exposing #[with_eal], which
injects `let _eal = <dpdk_crate>::test_support::start_eal();` at
the top of a #[test] function. Resolves the dpdk crate's path via
proc-macro-crate so the macro works in-tree (`crate`), under the
workspace alias (`::dpdk`), or with the canonical name
(`::dataplane_dpdk`).
- dpdk::test_support: hosts a shared OnceLock<Eal> initialized with
--no-huge / --no-pci / --in-memory and the cpu-affinity-aware
--lcores derivation that was previously inline in acl/mod.rs.
Once-per-process by construction; safe under nextest's per-test
forking and single-process runners alike.
dpdk/src/acl/mod.rs picks up the new macro: every test in the module
loses its `let _eal = start_eal();` prologue and gains a #[with_eal]
attribute above #[test]. The inline start_eal helper and the
module-scoped OnceLock<Eal> static go away.
dpdk/Cargo.toml grows the `test` feature (turns on dpdk-test-macros
plus the id and nix runtime helpers that test_support needs) and a
self-referencing dev-dep `dataplane-dpdk = { path = ".", features =
["test"] }` so dpdk's own tests see the macro surface.
just fmt; cargo check --workspace --all-targets passes.
This was referenced May 31, 2026
daniel-noland
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Pull request overview
Adds shared DPDK EAL initialization support for tests (via a start_eal() helper and a #[with_eal] proc-macro), and refactors an ACL helper to be usable in const contexts.
Changes:
- Introduces
dpdk::test_support::start_eal()(OnceLock-backed) to initialize EAL once per process with test-friendly flags. - Adds
dataplane-dpdk-test-macrosproviding#[with_eal], and wires it intodataplane-dpdkbehind atestfeature. - Refactors
AclBuildConfig::compute_min_input_sizeto aconst fnand adds a const-context unit test; updates ACL tests to use the macro and simplifies some call sites.
Reviewed changes
Copilot reviewed 8 out of 9 changed files in this pull request and generated 1 comment.
Show a summary per file
| File | Description |
|---|---|
| dpdk/src/test_support.rs | New shared EAL init helper for tests. |
| dpdk/src/lib.rs | Exposes test_support in tests / test feature; re-exports #[with_eal] under feature = "test". |
| dpdk/src/acl/mod.rs | Updates ACL unit tests to use #[with_eal]; minor doc/example tweak. |
| dpdk/src/acl/config.rs | Makes compute_min_input_size const-friendly and adds a const-context test. |
| dpdk/Cargo.toml | Adds test feature and optional deps/macro wiring for test harness support. |
| dpdk-test-macros/src/lib.rs | Implements the #[with_eal] attribute macro. |
| dpdk-test-macros/Cargo.toml | New proc-macro crate manifest. |
| Cargo.toml | Adds new workspace member + workspace dependency entry. |
| Cargo.lock | Locks new proc-macro crate and updated dependency graph. |
Comment on lines
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| /// Compute DPDK's minimum input buffer size. | ||
| /// | ||
| /// See [`min_input_size`][AclBuildConfig::min_input_size] for the | ||
| /// formula and rationale. Factored out so that `new` can call it | ||
| /// once and cache the result; the public accessor returns the cached | ||
| /// value. | ||
| /// | ||
| /// Precondition: all fields' `offset + 4` fit in `u32`. This is | ||
| /// guaranteed by the `FieldExtentOverflow` check in | ||
| /// [`new`][AclBuildConfig::new], so the plain `+` below cannot | ||
| /// overflow. | ||
| fn compute_min_input_size(field_defs: &[FieldDef; N]) -> usize { | ||
| /// `offset + 4` must fit in `u32`; [`AclBuildConfig::new`] validates this. | ||
| #[must_use] | ||
| pub const fn compute_min_input_size(field_defs: &[FieldDef; N]) -> usize { | ||
| let mut max_load_end: u32 = 0; |
mvachhar
approved these changes
Jun 1, 2026
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Stack (8). Base:
pr/daniel-noland/threading-rewrite.DPDK test plumbing that the rest of the ACL stack relies on, kept separate so it
reviews on its own:
refactor(dpdk/acl): makecompute_min_input_sizeaconst fn.feat(dpdk):test_support::start_eal+#[with_eal]attribute macro(
dpdk-test-macros), so EAL-dependent tests can opt in declaratively.No new abstractions, no behavior change to shipping code.
Review stack (merge bottom -> top):