Claude (sandbox)
0ee3fe7330
GPU sweep decomposed the ~23ms/700ms @50 injection deficit: every
ledger bucket is ~zero (drop park 0, discards 0, drop yield ~0.3ms),
books balance at absorbed+forgiven = 4x injected in all 48 cells, and
the 0%-cell contamination signature is absent. The probe pins the
residual: eff 0.933-0.943, a constant 22-27µs missing per site entry
= ~4.9 slice-expiry yields/entry x ~5.6µs runqueue wait. The
"deficit" is runnable off-CPU time inside the site — wall time the
probe's ground truth counts but on-CPU attribution correctly skips
(Coz model: speeding the site's code does not shrink queue-wait).
Measure-only reclassification, no behaviour change: a yield in the
target site stashes (tsc, experiment epoch) on the slot; the next
on_resume counts the gap into OFFCPU_IN_SITE_{CYCLES,N} (would-be
delta terms, MAX_SAMPLE_CYCLES-capped) iff the epoch still matches
and the word is live — a gap straddling end()/a same-word begin()
(live in the probe's 50,50 schedule) is dropped, never a leaked
cooldown. Parks excluded: blocked time is forgiveness territory.
New offcpu column in render_ledger_audit; LedgerCounters and
ExperimentResult grow the two fields. Fidelity footer now states
the on-CPU basis (deliberate wording change to the pinned summary;
the substring pin test still holds). +2 tests (counted gap; epoch
straddle) + render assert.
980 lines
37 KiB
Rust
980 lines
37 KiB
Rust
//! Integration tests for `smarm-causal` — native causal profiling (RFC 007).
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//!
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//! Gated on the feature; run with:
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//! cargo test --test causal --features smarm-causal
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#![cfg(feature = "smarm-causal")]
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use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
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use std::sync::Arc;
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use std::time::Duration;
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/// Progress points count, and snapshots expose deltas by name.
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#[test]
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fn progress_point_counts() {
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smarm::init(smarm::Config::exact(1)).run(|| {
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let before = smarm::causal::progress_snapshot();
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let h = smarm::spawn(|| {
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for _ in 0..100 {
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smarm::progress!("units-a");
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}
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for _ in 0..7 {
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smarm::progress!("units-b");
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}
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});
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h.join().unwrap();
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let after = smarm::causal::progress_snapshot();
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let delta = |name: &str| {
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after.iter().find(|(n, _)| n == name).map(|(_, c)| *c).unwrap()
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- before
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.iter()
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.find(|(n, _)| n == name)
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.map(|(_, c)| *c)
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.unwrap_or(0)
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};
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assert_eq!(delta("units-a"), 100);
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assert_eq!(delta("units-b"), 7);
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});
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}
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/// Site guards nest and restore, and site identity is per-actor: observable
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/// from inside the actor and gone once the guard drops.
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#[test]
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fn site_guard_nesting_restores() {
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smarm::init(smarm::Config::exact(1)).run(|| {
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let h = smarm::spawn(|| {
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assert_eq!(smarm::causal::current_site_name(), None);
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{
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let _outer = smarm::causal_site!("outer");
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assert_eq!(
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smarm::causal::current_site_name().as_deref(),
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Some("outer")
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);
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{
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let _inner = smarm::causal_site!("inner");
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assert_eq!(
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smarm::causal::current_site_name().as_deref(),
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Some("inner")
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);
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}
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assert_eq!(
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smarm::causal::current_site_name().as_deref(),
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Some("outer")
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);
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}
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assert_eq!(smarm::causal::current_site_name(), None);
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});
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h.join().unwrap();
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});
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}
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/// The core Coz transposition: while an experiment targets site S with a
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/// nonzero speedup, work inside S grows the global delay ledger and credits
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/// itself; an actor *outside* S absorbs the difference (its per-actor ledger
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/// catches up to the global one) instead of running delay-free.
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#[test]
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fn virtual_speedup_ledger() {
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let _s = serial();
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let global_out = Arc::new(AtomicU64::new(0));
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let absorbed_out = Arc::new(AtomicU64::new(0));
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let g_out = global_out.clone();
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let a_out = absorbed_out.clone();
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smarm::init(smarm::Config::exact(2)).run(move || {
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let stop = Arc::new(AtomicBool::new(false));
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// Bystander: never in the target site; must absorb injected delay.
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let stop2 = stop.clone();
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let out2 = a_out.clone();
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let bystander = smarm::spawn(move || {
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while !stop2.load(Ordering::Relaxed) {
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smarm::check!();
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out2.store(
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smarm::causal::my_absorbed_delay_cycles(),
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Ordering::Relaxed,
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);
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}
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});
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// Target: spins inside the experiment's site.
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let stop3 = stop.clone();
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let target = smarm::spawn(move || {
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let _g = smarm::causal_site!("hot-site");
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while !stop3.load(Ordering::Relaxed) {
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smarm::check!();
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}
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});
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let base = smarm::causal::global_delay_cycles();
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smarm::causal::begin_experiment_for_test("hot-site", 50);
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smarm::sleep(Duration::from_millis(200));
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g_out.store(
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smarm::causal::global_delay_cycles() - base,
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Ordering::Relaxed,
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);
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smarm::causal::end_experiment_for_test();
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stop.store(true, Ordering::Relaxed);
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bystander.join().unwrap();
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target.join().unwrap();
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});
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let global = global_out.load(Ordering::Relaxed);
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let absorbed = absorbed_out.load(Ordering::Relaxed);
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// The target's site work must have grown the ledger…
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assert!(global > 0, "global delay ledger never grew");
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// …and the bystander must have absorbed a meaningful share of it (it can
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// lag by a few check intervals; require half to be robust).
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assert!(
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absorbed >= global / 2,
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"bystander absorbed {absorbed} of {global} global delay cycles"
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);
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}
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/// The forgiveness rule must not leak: delay is forgiven on resume from a
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/// *park* (Coz's blocked-thread rule), but an actor that merely yields on
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/// timeslice expiry stays runnable and must PAY — its work rate has to drop
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/// while an experiment targets someone else. (Regression: forgiving on every
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/// resume made all bystanders delay-immune, so experiments moved nothing.)
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#[test]
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fn runnable_bystander_pays_delay() {
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let _s = serial();
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let baseline = Arc::new(AtomicU64::new(0));
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let during = Arc::new(AtomicU64::new(0));
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let b_out = baseline.clone();
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let d_out = during.clone();
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smarm::init(smarm::Config::exact(1)).run(move || {
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let stop = Arc::new(AtomicBool::new(false));
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// Target: in-site spinner; grows the ledger while the experiment runs.
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let stop_t = stop.clone();
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let target = smarm::spawn(move || {
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let _g = smarm::causal_site!("pay-site");
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while !stop_t.load(Ordering::Relaxed) {
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smarm::check!();
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}
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});
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// Bystander: pure check!-loop — yields on slice expiry, never parks.
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let stop_b = stop.clone();
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let iters = Arc::new(AtomicU64::new(0));
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let iters2 = iters.clone();
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let absorbed = Arc::new(AtomicU64::new(0));
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let absorbed2 = absorbed.clone();
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let bystander = smarm::spawn(move || {
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while !stop_b.load(Ordering::Relaxed) {
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iters2.fetch_add(1, Ordering::Relaxed);
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smarm::check!();
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absorbed2.store(
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smarm::causal::my_absorbed_delay_cycles(),
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Ordering::Relaxed,
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);
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}
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});
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let window = |out: &AtomicU64| {
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let i0 = iters.load(Ordering::Relaxed);
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let t = std::time::Instant::now();
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smarm::sleep(Duration::from_millis(150));
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let rate =
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(iters.load(Ordering::Relaxed) - i0) as f64 / t.elapsed().as_secs_f64();
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out.store(rate as u64, Ordering::Relaxed);
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};
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window(&b_out);
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let d0 = smarm::causal::global_delay_cycles();
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smarm::causal::begin_experiment_for_test("pay-site", 50);
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window(&d_out);
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smarm::causal::end_experiment_for_test();
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let injected = smarm::causal::global_delay_cycles() - d0;
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stop.store(true, Ordering::Relaxed);
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target.join().unwrap();
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bystander.join().unwrap();
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// The never-parking bystander's ledger can only advance by actually
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// spinning (forgiveness requires a real park), so this is no longer
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// vacuous: most of the injected delay must have been paid for real.
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let a = absorbed.load(Ordering::Relaxed);
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assert!(injected > 0, "experiment injected nothing");
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assert!(
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a >= injected / 2,
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"bystander spun off {a} of {injected} injected cycles"
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);
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});
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let b = baseline.load(Ordering::Relaxed) as f64;
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let d = during.load(Ordering::Relaxed) as f64;
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// Time-shared single scheduler: target is on-CPU ~50% of wall, so a 50%
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// virtual speedup injects ~25% of wall — expected slowdown ×0.8 (measured
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// exactly that live); on real parallelism it's ×0.67. Either way <0.9.
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assert!(b > 0.0, "bystander never ran");
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assert!(
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d < b * 0.9,
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"runnable bystander did not pay: baseline {b:.0}/s, during experiment {d:.0}/s"
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);
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}
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/// A zero-percent experiment must inject nothing: the null experiment is the
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/// baseline Coz relies on, and it doubles as the overhead sanity check.
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#[test]
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fn zero_speedup_injects_nothing() {
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let _s = serial();
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smarm::init(smarm::Config::exact(2)).run(|| {
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let stop = Arc::new(AtomicBool::new(false));
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let stop2 = stop.clone();
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let worker = smarm::spawn(move || {
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let _g = smarm::causal_site!("zero-site");
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while !stop2.load(Ordering::Relaxed) {
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smarm::check!();
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}
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});
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let before = smarm::causal::global_delay_cycles();
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smarm::causal::begin_experiment_for_test("zero-site", 0);
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smarm::sleep(Duration::from_millis(50));
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smarm::causal::end_experiment_for_test();
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let after = smarm::causal::global_delay_cycles();
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stop.store(true, Ordering::Relaxed);
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worker.join().unwrap();
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assert_eq!(after, before, "0% speedup must not grow the delay ledger");
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});
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}
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/// `impact_pct` computes the normalized throughput impact of a (site,
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/// speedup) cell against that site's own 0% baseline: injected virtual delay
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/// is removed from the divisor (Coz's normalization), so a bottleneck site
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/// shows positive impact and a fully-overlapped one shows ~zero.
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#[test]
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fn impact_from_synthetic_results() {
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use smarm::causal::{impact_pct, tsc_hz, ExperimentResult};
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let hz = tsc_hz();
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let secs = |s: f64| Duration::from_secs_f64(s);
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let cycles = |s: f64| (s * hz) as u64;
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let results = vec![
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// Baseline: 1000 units in 1s, nothing injected.
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ExperimentResult {
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site: "bottleneck".into(),
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speedup_pct: 0,
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duration: secs(1.0),
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deltas: vec![("units".into(), 1000)],
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injected_cycles: 0,
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..Default::default()
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},
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// Bottleneck at 50%: raw count unchanged, 0.5s injected
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// -> rate 1000/0.5 = 2x baseline -> +100%.
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ExperimentResult {
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site: "bottleneck".into(),
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speedup_pct: 50,
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duration: secs(1.0),
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deltas: vec![("units".into(), 1000)],
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injected_cycles: cycles(0.5),
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..Default::default()
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},
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ExperimentResult {
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site: "overlapped".into(),
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speedup_pct: 0,
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duration: secs(1.0),
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deltas: vec![("units".into(), 1000)],
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injected_cycles: 0,
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..Default::default()
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},
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// Overlapped at 50%: everyone else (incl. the real bottleneck)
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// slowed, count drops with the divisor -> ~0% impact.
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ExperimentResult {
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site: "overlapped".into(),
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speedup_pct: 50,
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duration: secs(1.0),
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deltas: vec![("units".into(), 500)],
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injected_cycles: cycles(0.5),
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..Default::default()
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},
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];
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let bn = impact_pct(&results, "bottleneck", 50, "units").unwrap();
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assert!((bn - 100.0).abs() < 5.0, "bottleneck impact: {bn}");
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let ov = impact_pct(&results, "overlapped", 50, "units").unwrap();
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assert!(ov.abs() < 5.0, "overlapped impact: {ov}");
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// Missing cells yield None, not garbage.
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assert!(impact_pct(&results, "nosuch", 50, "units").is_none());
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assert!(impact_pct(&results, "bottleneck", 50, "nosuch").is_none());
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}
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/// End-to-end controller pass over a toy workload: the report must contain a
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/// human summary naming every (site × speedup) cell and a Coz-compatible
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/// section with experiment / throughput-point lines.
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#[test]
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fn controller_produces_report() {
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let _s = serial();
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smarm::init(smarm::Config::exact(2)).run(|| {
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let stop = Arc::new(AtomicBool::new(false));
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let stop2 = stop.clone();
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let worker = smarm::spawn(move || {
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while !stop2.load(Ordering::Relaxed) {
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{
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let _g = smarm::causal_site!("stage-x");
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for _ in 0..50 {
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smarm::check!();
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}
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}
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smarm::progress!("items");
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}
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});
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let results = smarm::causal::run_experiments(&smarm::causal::ExperimentPlan {
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speedups_pct: vec![0, 50],
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experiment: Duration::from_millis(60),
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cooldown: Duration::from_millis(20),
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});
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stop.store(true, Ordering::Relaxed);
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worker.join().unwrap();
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assert!(!results.is_empty());
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let summary = smarm::causal::render_summary(&results);
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assert!(summary.contains("stage-x"), "summary: {summary}");
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assert!(summary.contains("items"), "summary: {summary}");
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assert!(
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summary.contains("impacts are lower bounds"),
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"fidelity footer missing: {summary}"
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);
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let coz = smarm::causal::render_coz(&results);
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assert!(coz.contains("experiment\tselected=stage-x"), "coz: {coz}");
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assert!(coz.contains("throughput-point\tname=items"), "coz: {coz}");
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});
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}
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/// A target-site entry that never hits a cold causal check must still be
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/// attributed: the guard boundaries flush the pending interval on exit and
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/// re-arm the clock on entry. Without the exit flush, in-site time between
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/// the last check and guard drop is silently discarded — measured live at
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/// ~6-7% of all target time (eff 0.93), under-reporting every impact
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/// (+83.5% where theory says +100%).
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#[test]
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fn site_boundaries_flush_tail() {
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let _s = serial();
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fn tsc() -> u64 {
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// SAFETY: rdtsc has no preconditions on x86_64.
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unsafe { core::arch::x86_64::_rdtsc() }
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}
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let injected = Arc::new(AtomicU64::new(0));
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let spent = Arc::new(AtomicU64::new(0));
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let inj_out = injected.clone();
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let spent_out = spent.clone();
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smarm::init(smarm::Config::exact(1)).run(move || {
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// Experiment is live before the actor ever enters the site.
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smarm::causal::begin_experiment_for_test("tail-site", 50);
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let base = smarm::causal::global_delay_cycles();
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let a = smarm::spawn(move || {
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let t0 = tsc();
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{
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let _g = smarm::causal_site!("tail-site");
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// Burn ~20M cycles with no allocations and no `check!()`:
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// the amortised cold check can never fire, so only the
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// guard-boundary flush can attribute this time.
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let start = tsc();
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while tsc().wrapping_sub(start) < 20_000_000 {
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core::hint::spin_loop();
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}
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}
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spent_out.store(tsc().wrapping_sub(t0), Ordering::Relaxed);
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});
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a.join().unwrap();
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smarm::causal::end_experiment_for_test();
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inj_out.store(
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smarm::causal::global_delay_cycles() - base,
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Ordering::Relaxed,
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);
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});
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let injected = injected.load(Ordering::Relaxed);
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let spent = spent.load(Ordering::Relaxed);
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// At 50% the flush should attribute ≈ half the in-guard time; allow a
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// generous band for guard overhead and clock skew.
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assert!(
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injected >= spent * 40 / 100 && injected <= spent * 60 / 100,
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"boundary flush attributed {injected} of {spent} spent cycles (want ~50%)"
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);
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}
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// ---------------------------------------------------------------------------
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// RFC 007 timer virtual time: injected delay dilates virtual time for
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// everyone, so a pending timer's *effective* deadline is its raw deadline
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// plus whatever delay was injected while it was armed. Without this, a
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// sleep or receive-timeout fires "early" in virtual terms and timeout-driven
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// behaviour speeds up relative to the dilated world.
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//
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// These tests (and every ledger-delta test above) share the process-global
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// delay ledger, so they serialize on `serial()`.
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// ---------------------------------------------------------------------------
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fn serial() -> std::sync::MutexGuard<'static, ()> {
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static M: std::sync::Mutex<()> = std::sync::Mutex::new(());
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M.lock().unwrap_or_else(std::sync::PoisonError::into_inner)
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}
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/// A pending timer must not fire at its raw deadline if delay was injected
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/// after it was armed; it fires once wall time covers raw + injected.
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#[test]
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fn timer_deadline_shifts_with_injected_delay() {
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let _s = serial();
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use smarm::pid::Pid;
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use smarm::timer::Timers;
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use std::time::Instant;
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let hz = smarm::causal::tsc_hz();
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let mut t = Timers::new();
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let now = Instant::now();
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t.insert_sleep(now + Duration::from_millis(50), Pid::new(0, 0), 1);
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// 100ms of debt lands while the timer is pending.
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smarm::causal::inject_delay_cycles_for_test((hz * 0.100) as u64);
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// Raw deadline passed, effective deadline not: nothing fires, entry kept.
|
||
assert!(t.pop_due(now + Duration::from_millis(60)).is_empty());
|
||
assert!(!t.is_empty(), "shifted entry must be re-queued, not dropped");
|
||
|
||
// Past raw + injected (with margin) it must fire. Chase in case a
|
||
// parallel test injected more debt meanwhile.
|
||
let mut fire_at = now + Duration::from_millis(170);
|
||
let mut fired = false;
|
||
for _ in 0..40 {
|
||
if !t.pop_due(fire_at).is_empty() {
|
||
fired = true;
|
||
break;
|
||
}
|
||
fire_at += Duration::from_millis(50);
|
||
}
|
||
assert!(fired, "timer never fired after covering injected delay");
|
||
}
|
||
|
||
/// With no debt accrued since insertion, behaviour is byte-identical to
|
||
/// before: due entries fire at their raw deadline.
|
||
#[test]
|
||
fn timer_zero_debt_pops_at_raw_deadline() {
|
||
let _s = serial();
|
||
use smarm::pid::Pid;
|
||
use smarm::timer::Timers;
|
||
use std::time::Instant;
|
||
|
||
let mut t = Timers::new();
|
||
let now = Instant::now();
|
||
t.insert_sleep(now - Duration::from_millis(1), Pid::new(0, 0), 1);
|
||
assert_eq!(t.pop_due(now).len(), 1);
|
||
assert!(t.is_empty());
|
||
}
|
||
|
||
/// A wall-anchored timer (RFC 007 controller fix) fires at its raw deadline
|
||
/// regardless of injected delay, while a virtual sibling in the same heap
|
||
/// still shifts. This is what keeps the causal controller's experiment
|
||
/// windows a fixed wall length even under heavy injection.
|
||
#[test]
|
||
fn wall_timer_ignores_injected_delay() {
|
||
let _s = serial();
|
||
use smarm::pid::Pid;
|
||
use smarm::timer::Timers;
|
||
use std::time::Instant;
|
||
|
||
let hz = smarm::causal::tsc_hz();
|
||
let mut t = Timers::new();
|
||
let now = Instant::now();
|
||
t.insert_sleep_wall(now + Duration::from_millis(50), Pid::new(0, 0), 1);
|
||
t.insert_sleep(now + Duration::from_millis(50), Pid::new(1, 0), 1);
|
||
|
||
// 100ms of debt lands while both are pending.
|
||
smarm::causal::inject_delay_cycles_for_test((hz * 0.100) as u64);
|
||
|
||
// Just past the raw deadline: the wall entry fires, the virtual one is
|
||
// re-queued at its shifted deadline.
|
||
let due = t.pop_due(now + Duration::from_millis(60));
|
||
assert_eq!(due.len(), 1, "exactly the wall entry must fire at raw deadline");
|
||
assert_eq!(due[0].pid, Pid::new(0, 0));
|
||
assert!(!t.is_empty(), "virtual sibling must remain queued, shifted");
|
||
}
|
||
|
||
/// Re-queueing a shifted entry must preserve its identity: a `send_after`
|
||
/// cancelled *after* being shifted past its raw deadline must still cancel
|
||
/// (return true) and must never deliver.
|
||
#[test]
|
||
fn send_after_cancel_survives_reheap() {
|
||
let _s = serial();
|
||
use smarm::pid::Pid;
|
||
use smarm::timer::Timers;
|
||
use std::sync::atomic::AtomicBool;
|
||
use std::time::Instant;
|
||
|
||
let hz = smarm::causal::tsc_hz();
|
||
let mut t = Timers::new();
|
||
let now = Instant::now();
|
||
let delivered = Arc::new(AtomicBool::new(false));
|
||
let d2 = delivered.clone();
|
||
let id = t.insert_send(
|
||
now + Duration::from_millis(20),
|
||
Pid::new(0, 0),
|
||
Box::new(move || d2.store(true, Ordering::Relaxed)),
|
||
);
|
||
|
||
smarm::causal::inject_delay_cycles_for_test((hz * 0.100) as u64);
|
||
|
||
// Raw deadline passed: shifted, not fired.
|
||
assert!(t.pop_due(now + Duration::from_millis(30)).is_empty());
|
||
// Cancellation still works on the re-queued entry.
|
||
assert!(t.cancel(id), "cancel lost track of a re-queued send_after");
|
||
// Even far past the effective deadline nothing is delivered.
|
||
for e in t.pop_due(now + Duration::from_secs(3600)) {
|
||
if let smarm::timer::Reason::Send { fire } = e.reason {
|
||
fire();
|
||
}
|
||
}
|
||
assert!(
|
||
!delivered.load(Ordering::Relaxed),
|
||
"cancelled send_after delivered after re-heap"
|
||
);
|
||
}
|
||
|
||
/// End-to-end through the runtime: an actor mid-`sleep` pays delay injected
|
||
/// while it is parked by sleeping *longer* — which is exactly what makes the
|
||
/// park-gated resume-credit fast-forward correct rather than forgiving.
|
||
#[test]
|
||
fn sleeping_actor_pays_injected_delay() {
|
||
let _s = serial();
|
||
use std::time::Instant;
|
||
|
||
let slept = Arc::new(AtomicU64::new(0));
|
||
let s_out = slept.clone();
|
||
|
||
smarm::init(smarm::Config::exact(1)).run(move || {
|
||
let hz = smarm::causal::tsc_hz();
|
||
let s2 = s_out.clone();
|
||
let sleeper = smarm::spawn(move || {
|
||
let t0 = Instant::now();
|
||
smarm::sleep(Duration::from_millis(50));
|
||
s2.store(t0.elapsed().as_millis() as u64, Ordering::Relaxed);
|
||
});
|
||
|
||
// Let the sleeper arm its timer, then inject 150ms of debt from a
|
||
// plain OS thread — no slot, so nothing spin-absorbs it here and the
|
||
// only path by which it can slow the sleeper is the timer shift.
|
||
smarm::sleep(Duration::from_millis(10));
|
||
std::thread::spawn(move || {
|
||
smarm::causal::inject_delay_cycles_for_test((hz * 0.150) as u64);
|
||
})
|
||
.join()
|
||
.unwrap();
|
||
|
||
sleeper.join().unwrap();
|
||
});
|
||
|
||
let ms = slept.load(Ordering::Relaxed);
|
||
// Raw sleep 50ms + ~150ms debt injected mid-sleep => ~200ms effective.
|
||
// Loose lower bound; the pre-fix behaviour is ~50ms.
|
||
assert!(
|
||
ms >= 150,
|
||
"sleeper paid nothing: slept {ms}ms, expected >= 150ms (raw 50 + injected 150)"
|
||
);
|
||
}
|
||
|
||
/// RFC 007 user-facing opt-out: a wall-anchored `send_after` entry fires at
|
||
/// its raw deadline while a virtual sibling armed at the same instant is
|
||
/// shifted by injected delay — the `Send`-reason mirror of
|
||
/// `wall_timer_ignores_injected_delay`.
|
||
#[test]
|
||
fn wall_send_after_ignores_injected_delay() {
|
||
let _s = serial();
|
||
use smarm::pid::Pid;
|
||
use smarm::timer::Timers;
|
||
use std::time::Instant;
|
||
|
||
let hz = smarm::causal::tsc_hz();
|
||
let mut t = Timers::new();
|
||
let now = Instant::now();
|
||
let wall_fired = Arc::new(AtomicBool::new(false));
|
||
let virt_fired = Arc::new(AtomicBool::new(false));
|
||
let (w2, v2) = (wall_fired.clone(), virt_fired.clone());
|
||
let _wid = t.insert_send_wall(
|
||
now + Duration::from_millis(50),
|
||
Pid::new(0, 0),
|
||
Box::new(move || w2.store(true, Ordering::Relaxed)),
|
||
);
|
||
let _vid = t.insert_send(
|
||
now + Duration::from_millis(50),
|
||
Pid::new(1, 0),
|
||
Box::new(move || v2.store(true, Ordering::Relaxed)),
|
||
);
|
||
|
||
// 100ms of debt lands while both are pending.
|
||
smarm::causal::inject_delay_cycles_for_test((hz * 0.100) as u64);
|
||
|
||
// Just past the raw deadline: only the wall send pops; run its thunk.
|
||
let due = t.pop_due(now + Duration::from_millis(60));
|
||
assert_eq!(due.len(), 1, "exactly the wall send must fire at raw deadline");
|
||
for e in due {
|
||
if let smarm::timer::Reason::Send { fire } = e.reason {
|
||
fire();
|
||
}
|
||
}
|
||
assert!(wall_fired.load(Ordering::Relaxed), "wall send must deliver");
|
||
assert!(!virt_fired.load(Ordering::Relaxed), "virtual send must not");
|
||
assert!(!t.is_empty(), "virtual sibling must remain queued, shifted");
|
||
}
|
||
|
||
/// `cancel` is anchor-agnostic: a wall-anchored `send_after` cancels exactly
|
||
/// like a virtual one and never delivers, even with delay debt outstanding.
|
||
#[test]
|
||
fn wall_send_after_cancels() {
|
||
let _s = serial();
|
||
use smarm::pid::Pid;
|
||
use smarm::timer::Timers;
|
||
use std::time::Instant;
|
||
|
||
let hz = smarm::causal::tsc_hz();
|
||
let mut t = Timers::new();
|
||
let now = Instant::now();
|
||
let delivered = Arc::new(AtomicBool::new(false));
|
||
let d2 = delivered.clone();
|
||
let id = t.insert_send_wall(
|
||
now + Duration::from_millis(20),
|
||
Pid::new(0, 0),
|
||
Box::new(move || d2.store(true, Ordering::Relaxed)),
|
||
);
|
||
|
||
smarm::causal::inject_delay_cycles_for_test((hz * 0.100) as u64);
|
||
|
||
assert!(t.cancel(id), "cancel must find the wall-anchored send");
|
||
for e in t.pop_due(now + Duration::from_secs(3600)) {
|
||
if let smarm::timer::Reason::Send { fire } = e.reason {
|
||
fire();
|
||
}
|
||
}
|
||
assert!(
|
||
!delivered.load(Ordering::Relaxed),
|
||
"cancelled wall send_after delivered"
|
||
);
|
||
}
|
||
|
||
// ---------------------------------------------------------------------------
|
||
// Ledger audit (RFC 007 deficit hunt) — measure-only counters that decompose
|
||
// where injected delay is born, paid, forgiven, and where would-be
|
||
// attribution is silently lost. Behaviour under test is accounting only:
|
||
// none of these tests assert a change in injection or absorption itself.
|
||
// ---------------------------------------------------------------------------
|
||
|
||
/// A never-parking bystander's spin absorption lands in the audit's
|
||
/// `spin_absorbed_cycles` — the "paid for real" bucket.
|
||
#[test]
|
||
fn audit_counts_spin_absorption() {
|
||
let _s = serial();
|
||
smarm::init(smarm::Config::exact(1)).run(|| {
|
||
let stop = Arc::new(AtomicBool::new(false));
|
||
let stop_t = stop.clone();
|
||
let target = smarm::spawn(move || {
|
||
let _g = smarm::causal_site!("audit-spin-site");
|
||
while !stop_t.load(Ordering::Relaxed) {
|
||
smarm::check!();
|
||
}
|
||
});
|
||
let stop_b = stop.clone();
|
||
let bystander = smarm::spawn(move || {
|
||
while !stop_b.load(Ordering::Relaxed) {
|
||
smarm::check!();
|
||
}
|
||
});
|
||
let c0 = smarm::causal::ledger_counters();
|
||
let g0 = smarm::causal::global_delay_cycles();
|
||
smarm::causal::begin_experiment_for_test("audit-spin-site", 50);
|
||
smarm::sleep(Duration::from_millis(150));
|
||
smarm::causal::end_experiment_for_test();
|
||
let injected = smarm::causal::global_delay_cycles() - g0;
|
||
let c1 = smarm::causal::ledger_counters();
|
||
stop.store(true, Ordering::Relaxed);
|
||
target.join().unwrap();
|
||
bystander.join().unwrap();
|
||
|
||
let spun = c1.spin_absorbed_cycles - c0.spin_absorbed_cycles;
|
||
assert!(injected > 0, "experiment injected nothing");
|
||
assert!(
|
||
spun >= injected / 2,
|
||
"audit missed spin absorption: {spun} of {injected} injected"
|
||
);
|
||
// Payers are bounded by the debt that exists; 2x headroom covers the
|
||
// main actor's incidental checkpoint payments.
|
||
assert!(
|
||
spun <= injected.saturating_mul(2),
|
||
"audit over-counted spin: {spun} of {injected} injected"
|
||
);
|
||
});
|
||
}
|
||
|
||
/// A wake after a real park waives the sleeper's accrued debt; the waiver is
|
||
/// tallied in `park_forgiven_cycles` (Coz's blocked-thread rule, now visible).
|
||
#[test]
|
||
fn audit_counts_park_forgiveness() {
|
||
let _s = serial();
|
||
smarm::init(smarm::Config::exact(1)).run(|| {
|
||
let stop = Arc::new(AtomicBool::new(false));
|
||
let stop_t = stop.clone();
|
||
let target = smarm::spawn(move || {
|
||
let _g = smarm::causal_site!("audit-forgive-site");
|
||
while !stop_t.load(Ordering::Relaxed) {
|
||
smarm::check!();
|
||
}
|
||
});
|
||
// Parks across the whole injection window; owes everything at wake.
|
||
let sleeper = smarm::spawn(|| smarm::sleep(Duration::from_millis(120)));
|
||
|
||
let c0 = smarm::causal::ledger_counters();
|
||
let g0 = smarm::causal::global_delay_cycles();
|
||
smarm::causal::begin_experiment_for_test("audit-forgive-site", 50);
|
||
smarm::sleep(Duration::from_millis(60));
|
||
smarm::causal::end_experiment_for_test();
|
||
let injected = smarm::causal::global_delay_cycles() - g0;
|
||
sleeper.join().unwrap();
|
||
let c1 = smarm::causal::ledger_counters();
|
||
stop.store(true, Ordering::Relaxed);
|
||
target.join().unwrap();
|
||
|
||
let forgiven = c1.park_forgiven_cycles - c0.park_forgiven_cycles;
|
||
assert!(injected > 0, "experiment injected nothing");
|
||
assert!(
|
||
forgiven >= injected / 2,
|
||
"audit missed park forgiveness: {forgiven} of {injected} injected"
|
||
);
|
||
});
|
||
}
|
||
|
||
/// Parking while *inside* the target site drops the sample tail
|
||
/// `[last sample -> park]` — nothing flushes it, and `on_resume` re-arms the
|
||
/// clock. The audit counts that loss without changing it.
|
||
#[test]
|
||
fn audit_counts_park_drop_inside_target_site() {
|
||
let _s = serial();
|
||
smarm::init(smarm::Config::exact(1)).run(|| {
|
||
smarm::causal::begin_experiment_for_test("audit-park-drop-site", 50);
|
||
let c0 = smarm::causal::ledger_counters();
|
||
let h = smarm::spawn(|| {
|
||
let _g = smarm::causal_site!("audit-park-drop-site");
|
||
smarm::check!(); // arm an in-site sample interval
|
||
smarm::sleep(Duration::from_millis(20)); // real park, in-guard
|
||
});
|
||
h.join().unwrap();
|
||
let c1 = smarm::causal::ledger_counters();
|
||
smarm::causal::end_experiment_for_test();
|
||
|
||
assert!(
|
||
c1.drop_park_n > c0.drop_park_n,
|
||
"in-site park recorded no drop event"
|
||
);
|
||
assert!(
|
||
c1.drop_park_cycles > c0.drop_park_cycles,
|
||
"in-site park drop carried no cycles"
|
||
);
|
||
});
|
||
}
|
||
|
||
/// An explicit yield inside the target site loses its tail the same way; it
|
||
/// lands in the separate yield bucket so park- and yield-losses stay apart.
|
||
#[test]
|
||
fn audit_counts_yield_drop_inside_target_site() {
|
||
let _s = serial();
|
||
smarm::init(smarm::Config::exact(1)).run(|| {
|
||
smarm::causal::begin_experiment_for_test("audit-yield-drop-site", 50);
|
||
let c0 = smarm::causal::ledger_counters();
|
||
let h = smarm::spawn(|| {
|
||
let _g = smarm::causal_site!("audit-yield-drop-site");
|
||
smarm::check!(); // arm an in-site sample interval
|
||
smarm::yield_now();
|
||
smarm::check!();
|
||
});
|
||
h.join().unwrap();
|
||
let c1 = smarm::causal::ledger_counters();
|
||
smarm::causal::end_experiment_for_test();
|
||
|
||
assert!(
|
||
c1.drop_yield_n > c0.drop_yield_n,
|
||
"in-site yield recorded no drop event"
|
||
);
|
||
assert!(
|
||
c1.drop_yield_cycles > c0.drop_yield_cycles,
|
||
"in-site yield drop carried no cycles"
|
||
);
|
||
});
|
||
}
|
||
|
||
/// A single in-site interval past MAX_SAMPLE_CYCLES is discarded by the
|
||
/// TSC-weirdness clamp; the audit counts the discard instead of losing it
|
||
/// silently.
|
||
#[test]
|
||
fn audit_counts_overmax_discard() {
|
||
let _s = serial();
|
||
smarm::init(smarm::Config::exact(1)).run(|| {
|
||
smarm::causal::begin_experiment_for_test("audit-overmax-site", 50);
|
||
let c0 = smarm::causal::ledger_counters();
|
||
let h = smarm::spawn(|| {
|
||
let _g = smarm::causal_site!("audit-overmax-site");
|
||
// Stay in-site past MAX_SAMPLE_CYCLES (~33ms at 3GHz) without a
|
||
// single checkpoint: no allocs, no check!. The guard-drop flush
|
||
// then sees one huge interval and must discard it.
|
||
let t0 = std::time::Instant::now();
|
||
while t0.elapsed() < Duration::from_millis(60) {
|
||
std::hint::spin_loop();
|
||
}
|
||
});
|
||
h.join().unwrap();
|
||
let c1 = smarm::causal::ledger_counters();
|
||
smarm::causal::end_experiment_for_test();
|
||
|
||
assert!(
|
||
c1.discard_overmax_n > c0.discard_overmax_n,
|
||
"overmax interval recorded no discard event"
|
||
);
|
||
assert!(
|
||
c1.discard_overmax_cycles > c0.discard_overmax_cycles,
|
||
"overmax discard carried no cycles"
|
||
);
|
||
});
|
||
}
|
||
|
||
/// Debt left outstanding when a window ends is paid during the NEXT active
|
||
/// experiment — including a 0% baseline cell, whose bystander-chase branch is
|
||
/// live at pct=0. Synthesized deterministically: grow the ledger with no
|
||
/// experiment active (nobody pays), then watch a 0% window absorb it.
|
||
#[test]
|
||
fn audit_zero_pct_window_absorbs_leftover_debt() {
|
||
let _s = serial();
|
||
smarm::init(smarm::Config::exact(1)).run(|| {
|
||
let hz = smarm::causal::tsc_hz();
|
||
let stop = Arc::new(AtomicBool::new(false));
|
||
let stop_b = stop.clone();
|
||
let bystander = smarm::spawn(move || {
|
||
while !stop_b.load(Ordering::Relaxed) {
|
||
smarm::check!();
|
||
}
|
||
});
|
||
|
||
// No experiment active: checks early-return, debt sits unpaid.
|
||
let debt = (hz * 0.020) as u64; // ~20ms
|
||
smarm::causal::inject_delay_cycles_for_test(debt);
|
||
smarm::sleep(Duration::from_millis(30));
|
||
|
||
let c0 = smarm::causal::ledger_counters();
|
||
let g0 = smarm::causal::global_delay_cycles();
|
||
smarm::causal::begin_experiment_for_test("audit-zero-pct-site", 0);
|
||
smarm::sleep(Duration::from_millis(60));
|
||
smarm::causal::end_experiment_for_test();
|
||
let c1 = smarm::causal::ledger_counters();
|
||
stop.store(true, Ordering::Relaxed);
|
||
bystander.join().unwrap();
|
||
|
||
assert_eq!(
|
||
smarm::causal::global_delay_cycles(),
|
||
g0,
|
||
"a 0% window must inject nothing"
|
||
);
|
||
let spun = c1.spin_absorbed_cycles - c0.spin_absorbed_cycles;
|
||
assert!(
|
||
spun >= debt / 2,
|
||
"leftover debt not absorbed in the 0% window: {spun} of {debt}"
|
||
);
|
||
});
|
||
}
|
||
|
||
/// The audit render lists one line per cell with the ledger columns.
|
||
#[test]
|
||
fn ledger_audit_renders_per_cell() {
|
||
use smarm::causal::{render_ledger_audit, ExperimentResult};
|
||
let results = vec![ExperimentResult {
|
||
site: "audit-render-site".into(),
|
||
speedup_pct: 50,
|
||
duration: Duration::from_secs(1),
|
||
deltas: vec![("units".into(), 10)],
|
||
injected_cycles: 1_000_000,
|
||
spin_absorbed_cycles: 900_000,
|
||
park_forgiven_cycles: 50_000,
|
||
drop_park_cycles: 30_000,
|
||
drop_park_n: 2,
|
||
drop_yield_cycles: 10_000,
|
||
drop_yield_n: 1,
|
||
discard_overmax_cycles: 5_000,
|
||
discard_overmax_n: 1,
|
||
discard_unarmed_n: 0,
|
||
offcpu_in_site_cycles: 20_000,
|
||
offcpu_in_site_n: 3,
|
||
}];
|
||
let s = render_ledger_audit(&results);
|
||
assert!(s.contains("ledger audit"), "missing header: {s}");
|
||
assert!(s.contains("audit-render-site"), "missing site line: {s}");
|
||
assert!(s.contains("absorbed"), "missing absorbed column: {s}");
|
||
assert!(s.contains("forgiven"), "missing forgiven column: {s}");
|
||
assert!(s.contains("offcpu"), "missing offcpu column: {s}");
|
||
}
|
||
|
||
/// A runnable (yield) deschedule inside the target site opens an off-CPU
|
||
/// gap; the resume closing it lands in the same experiment window, so the
|
||
/// audit counts it. RFC 007: this is the located @50 deficit — runnable
|
||
/// queue-wait is real wall time in-site that on-CPU attribution correctly
|
||
/// skips; the bucket exists so the books close instead of leaving a
|
||
/// silent ~7% residual.
|
||
#[test]
|
||
fn audit_counts_offcpu_runnable_gap_in_target_site() {
|
||
let _s = serial();
|
||
smarm::init(smarm::Config::exact(1)).run(|| {
|
||
smarm::causal::begin_experiment_for_test("audit-offcpu-site", 50);
|
||
let c0 = smarm::causal::ledger_counters();
|
||
let h = smarm::spawn(|| {
|
||
let _g = smarm::causal_site!("audit-offcpu-site");
|
||
smarm::check!(); // arm
|
||
smarm::yield_now(); // runnable gap: deschedule -> resume
|
||
smarm::check!();
|
||
});
|
||
h.join().unwrap();
|
||
let c1 = smarm::causal::ledger_counters();
|
||
smarm::causal::end_experiment_for_test();
|
||
|
||
assert!(
|
||
c1.offcpu_in_site_n > c0.offcpu_in_site_n,
|
||
"in-site runnable gap recorded no offcpu event"
|
||
);
|
||
assert!(
|
||
c1.offcpu_in_site_cycles > c0.offcpu_in_site_cycles,
|
||
"in-site runnable gap carried no cycles"
|
||
);
|
||
});
|
||
}
|
||
|
||
/// An off-CPU gap that straddles `end()` — even into a later window with
|
||
/// an identical site+pct word (live in the attrib probe's 50,50 schedule)
|
||
/// — is dropped, not counted: the stash carries the experiment *epoch*,
|
||
/// so a straddling resume can never leak a cooldown across windows.
|
||
#[test]
|
||
fn audit_offcpu_gap_across_windows_not_counted() {
|
||
let _s = serial();
|
||
smarm::init(smarm::Config::exact(1)).run(|| {
|
||
smarm::causal::begin_experiment_for_test("audit-offcpu-straddle", 50);
|
||
let c0 = smarm::causal::ledger_counters();
|
||
let h = smarm::spawn(|| {
|
||
let _g = smarm::causal_site!("audit-offcpu-straddle");
|
||
smarm::check!();
|
||
smarm::yield_now(); // stash carries window A's epoch
|
||
smarm::check!();
|
||
});
|
||
// FIFO on exact(1): let h run to its yield, then close window A and
|
||
// open a same-word window B before h resumes.
|
||
smarm::yield_now();
|
||
smarm::causal::end_experiment_for_test();
|
||
smarm::causal::begin_experiment_for_test("audit-offcpu-straddle", 50);
|
||
h.join().unwrap();
|
||
let c1 = smarm::causal::ledger_counters();
|
||
smarm::causal::end_experiment_for_test();
|
||
|
||
assert_eq!(
|
||
c1.offcpu_in_site_n, c0.offcpu_in_site_n,
|
||
"gap straddling windows must not be counted"
|
||
);
|
||
});
|
||
}
|