S418 · CPU0 partial-state reconciliation

#![allow(unexpected_cfgs)]

//! S418 CPU0 stale partial-state reconciliation.
//!
//! Before another attempt, CPU0 inspects the mutually exclusive S409 receipt,
//! S410 candidate, and S411 admission slots. A value bound to the active S247
//! token is preserved. A value whose lease has ended (or whose token differs
//! from the current lease) is taken and dropped exactly once. The successful
//! S243/S187 handoff slot is never inspected or consumed here.

use crate::g8l_target_dispatch_scheduler_owner_scheduler_mutation_production_migration_lifecycle_s417_handshake_attempt_reconciliation::{
    S417_DIRECT_SCHEDULER_ACCESS_SITES, S417_PRODUCTION_GUARDED_DIRECT_ACCESS_SITES,
    S417_SOURCE_AUDIT_UNITS, S417_SOURCE_MODEL_COVERED_DIRECT_ACCESS_SITES,
    S417_UNROUTED_DIRECT_ACCESS_SITES,
};

pub const S418_SOURCE_AUDIT_UNITS: usize = S417_SOURCE_AUDIT_UNITS;
pub const S418_DIRECT_SCHEDULER_ACCESS_SITES: usize = S417_DIRECT_SCHEDULER_ACCESS_SITES;
pub const S418_SOURCE_MODEL_COVERED_DIRECT_ACCESS_SITES: usize =
    S417_SOURCE_MODEL_COVERED_DIRECT_ACCESS_SITES;
pub const S418_PRODUCTION_GUARDED_DIRECT_ACCESS_SITES: usize =
    S417_PRODUCTION_GUARDED_DIRECT_ACCESS_SITES;
pub const S418_UNROUTED_DIRECT_ACCESS_SITES: usize = S417_UNROUTED_DIRECT_ACCESS_SITES;
pub const S418_RECONCILED_PARTIAL_STAGE_COUNT: usize = 3;
pub const S418_PRODUCTION_RECONCILIATION_CALLSITES: usize = 1;
pub const S418_CPU0_PARTIAL_STATE_RECONCILIATION_COMPLETE: bool = true;
pub const S418_S243_S187_HANDOFF_PRESERVED: bool = true;
pub const S418_CPU1_S187_HANDOFF_CONSUMPTION_COMPLETE: bool = false;

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum G8lS418Cpu0PartialStage {
    S409DeliveryReceipt,
    S410Candidate,
    S411Admission,
}

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub struct G8lS418Cpu0PartialStateView {
    pub stage: G8lS418Cpu0PartialStage,
    pub attempt_id: u64,
    pub provider_request_id: u64,
    pub exclusive_token: u64,
}

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum G8lS418Cpu0PartialStateReconciliationOutcome {
    Clean,
    HandshakeActive(G8lS418Cpu0PartialStateView),
    DiscardStale(G8lS418Cpu0PartialStateView),
    Discarded(G8lS418Cpu0PartialStateView),
}

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum G8lS418Cpu0PartialStateReconciliationError {
    WrongCpu,
    MultiplePendingStages,
    BindingDrift,
    UpstreamInspection,
    TakeDisappeared,
    TakeDrift,
}

pub fn preflight_s418_cpu0_partial_state_reconciliation(
    caller_cpu: usize,
    active_exclusive_token: Option<u64>,
    delivery: Option<G8lS418Cpu0PartialStateView>,
    candidate: Option<G8lS418Cpu0PartialStateView>,
    admission: Option<G8lS418Cpu0PartialStateView>,
) -> Result<G8lS418Cpu0PartialStateReconciliationOutcome, G8lS418Cpu0PartialStateReconciliationError>
{
    if caller_cpu != 0 {
        return Err(G8lS418Cpu0PartialStateReconciliationError::WrongCpu);
    }
    let pending_count =
        delivery.is_some() as usize + candidate.is_some() as usize + admission.is_some() as usize;
    if pending_count > 1 {
        return Err(G8lS418Cpu0PartialStateReconciliationError::MultiplePendingStages);
    }
    let Some(partial) = delivery.or(candidate).or(admission) else {
        return Ok(G8lS418Cpu0PartialStateReconciliationOutcome::Clean);
    };
    if partial.attempt_id == 0 || partial.provider_request_id == 0 || partial.exclusive_token == 0 {
        return Err(G8lS418Cpu0PartialStateReconciliationError::BindingDrift);
    }
    if active_exclusive_token == Some(partial.exclusive_token) {
        Ok(G8lS418Cpu0PartialStateReconciliationOutcome::HandshakeActive(partial))
    } else {
        Ok(G8lS418Cpu0PartialStateReconciliationOutcome::DiscardStale(
            partial,
        ))
    }
}

#[cfg(all(target_arch = "aarch64", target_os = "none", feature = "board-rpi5"))]
pub fn service_s418_cpu0_partial_state_reconciliation_on_cpu0(
) -> Result<G8lS418Cpu0PartialStateReconciliationOutcome, G8lS418Cpu0PartialStateReconciliationError>
{
    use crate::g8l_runtime_contract::CPU0;
    if crate::percpu::try_current_cpu_id() != Some(CPU0) {
        return Err(G8lS418Cpu0PartialStateReconciliationError::WrongCpu);
    }
    let delivery = crate::g8l_target_dispatch_scheduler_owner_scheduler_mutation_production_migration_lifecycle_s409_live_offer_sgi_delivery::inspect_s409_live_offer_sgi_delivery_receipt_on_cpu0()
        .map_err(|_| G8lS418Cpu0PartialStateReconciliationError::UpstreamInspection)?
        .map(|view| G8lS418Cpu0PartialStateView {
            stage: G8lS418Cpu0PartialStage::S409DeliveryReceipt,
            attempt_id: view.attempt_id(),
            provider_request_id: view.provider_request_id(),
            exclusive_token: view.exclusive_token(),
        });
    let candidate = crate::g8l_target_dispatch_scheduler_owner_scheduler_mutation_production_migration_lifecycle_s410_exclusion_admission_candidate_publication::inspect_s410_exclusion_admission_candidate_on_cpu0()
        .map_err(|_| G8lS418Cpu0PartialStateReconciliationError::UpstreamInspection)?
        .map(|view| G8lS418Cpu0PartialStateView {
            stage: G8lS418Cpu0PartialStage::S410Candidate,
            attempt_id: view.attempt_id,
            provider_request_id: view.provider_request_id,
            exclusive_token: view.exclusive_token,
        });
    let admission = crate::g8l_target_dispatch_scheduler_owner_scheduler_mutation_production_migration_lifecycle_s411_ephemeral_exclusion_admission_constructor::inspect_s411_ephemeral_exclusion_admission_on_cpu0()
        .map_err(|_| G8lS418Cpu0PartialStateReconciliationError::UpstreamInspection)?
        .map(|view| G8lS418Cpu0PartialStateView {
            stage: G8lS418Cpu0PartialStage::S411Admission,
            attempt_id: view.attempt_id,
            provider_request_id: view.provider_request_id,
            exclusive_token: view.exclusive_token,
        });
    let active_token = crate::g8l_target_dispatch_scheduler_owner_scheduler_mutation_production_migration_lifecycle_s246_whole_scheduler_read_access_guard::S247_PRODUCTION_WHOLE_SCHEDULER_ACCESS_GATE
        .active_exclusive_token();
    let outcome = preflight_s418_cpu0_partial_state_reconciliation(
        CPU0,
        active_token,
        delivery,
        candidate,
        admission,
    )?;
    let G8lS418Cpu0PartialStateReconciliationOutcome::DiscardStale(expected) = outcome else {
        return Ok(outcome);
    };
    let taken = match expected.stage {
        G8lS418Cpu0PartialStage::S409DeliveryReceipt => {
            let value = crate::g8l_target_dispatch_scheduler_owner_scheduler_mutation_production_migration_lifecycle_s409_live_offer_sgi_delivery::take_s409_live_offer_sgi_delivery_receipt_on_cpu0()
                .map_err(|_| G8lS418Cpu0PartialStateReconciliationError::UpstreamInspection)?
                .ok_or(G8lS418Cpu0PartialStateReconciliationError::TakeDisappeared)?;
            G8lS418Cpu0PartialStateView {
                stage: expected.stage,
                attempt_id: value.attempt_id(),
                provider_request_id: value.provider_request_id(),
                exclusive_token: value.exclusive_token(),
            }
        }
        G8lS418Cpu0PartialStage::S410Candidate => {
            let value = crate::g8l_target_dispatch_scheduler_owner_scheduler_mutation_production_migration_lifecycle_s410_exclusion_admission_candidate_publication::take_s410_exclusion_admission_candidate_on_cpu0()
                .map_err(|_| G8lS418Cpu0PartialStateReconciliationError::UpstreamInspection)?
                .ok_or(G8lS418Cpu0PartialStateReconciliationError::TakeDisappeared)?;
            G8lS418Cpu0PartialStateView {
                stage: expected.stage,
                attempt_id: value.attempt_id(),
                provider_request_id: value.provider_request_id(),
                exclusive_token: value.exclusive_token(),
            }
        }
        G8lS418Cpu0PartialStage::S411Admission => {
            let value = crate::g8l_target_dispatch_scheduler_owner_scheduler_mutation_production_migration_lifecycle_s411_ephemeral_exclusion_admission_constructor::take_s411_ephemeral_exclusion_admission_on_cpu0()
                .map_err(|_| G8lS418Cpu0PartialStateReconciliationError::UpstreamInspection)?
                .ok_or(G8lS418Cpu0PartialStateReconciliationError::TakeDisappeared)?;
            G8lS418Cpu0PartialStateView {
                stage: expected.stage,
                attempt_id: value.attempt_id(),
                provider_request_id: value.provider_request_id(),
                exclusive_token: value.exclusive_token(),
            }
        }
    };
    if taken != expected {
        return Err(G8lS418Cpu0PartialStateReconciliationError::TakeDrift);
    }
    Ok(G8lS418Cpu0PartialStateReconciliationOutcome::Discarded(
        taken,
    ))
}

use aselsan_microkernel_simulation::g8l_target_dispatch_scheduler_owner_scheduler_mutation_production_migration_lifecycle_s418_cpu0_partial_state_reconciliation::*;

fn view(stage: G8lS418Cpu0PartialStage, token: u64) -> G8lS418Cpu0PartialStateView {
    G8lS418Cpu0PartialStateView {
        stage,
        attempt_id: 7,
        provider_request_id: 8,
        exclusive_token: token,
    }
}

#[test]
fn constants_limit_cleanup_to_pre_s243_partial_states() {
    assert_eq!(S418_RECONCILED_PARTIAL_STAGE_COUNT, 3);
    assert_eq!(S418_PRODUCTION_RECONCILIATION_CALLSITES, 1);
    assert!(S418_CPU0_PARTIAL_STATE_RECONCILIATION_COMPLETE);
    assert!(S418_S243_S187_HANDOFF_PRESERVED);
    assert!(!S418_CPU1_S187_HANDOFF_CONSUMPTION_COMPLETE);
}

#[test]
fn empty_partial_surfaces_are_clean() {
    assert_eq!(
        preflight_s418_cpu0_partial_state_reconciliation(0, None, None, None, None),
        Ok(G8lS418Cpu0PartialStateReconciliationOutcome::Clean)
    );
}

#[test]
fn live_matching_partial_state_is_preserved() {
    let admission = view(G8lS418Cpu0PartialStage::S411Admission, 9);
    assert_eq!(
        preflight_s418_cpu0_partial_state_reconciliation(0, Some(9), None, None, Some(admission)),
        Ok(G8lS418Cpu0PartialStateReconciliationOutcome::HandshakeActive(admission))
    );
}

#[test]
fn released_token_marks_each_possible_stage_for_exact_discard() {
    for stage in [
        G8lS418Cpu0PartialStage::S409DeliveryReceipt,
        G8lS418Cpu0PartialStage::S410Candidate,
        G8lS418Cpu0PartialStage::S411Admission,
    ] {
        let partial = view(stage, 9);
        let args = match stage {
            G8lS418Cpu0PartialStage::S409DeliveryReceipt => (Some(partial), None, None),
            G8lS418Cpu0PartialStage::S410Candidate => (None, Some(partial), None),
            G8lS418Cpu0PartialStage::S411Admission => (None, None, Some(partial)),
        };
        assert_eq!(
            preflight_s418_cpu0_partial_state_reconciliation(0, None, args.0, args.1, args.2),
            Ok(G8lS418Cpu0PartialStateReconciliationOutcome::DiscardStale(
                partial
            ))
        );
    }
}

#[test]
fn multiple_pending_stages_fail_closed() {
    assert_eq!(
        preflight_s418_cpu0_partial_state_reconciliation(
            0,
            None,
            Some(view(G8lS418Cpu0PartialStage::S409DeliveryReceipt, 9)),
            Some(view(G8lS418Cpu0PartialStage::S410Candidate, 9)),
            None,
        ),
        Err(G8lS418Cpu0PartialStateReconciliationError::MultiplePendingStages)
    );
}

#[test]
fn invalid_binding_and_wrong_cpu_fail_closed() {
    assert_eq!(
        preflight_s418_cpu0_partial_state_reconciliation(
            0,
            None,
            None,
            Some(view(G8lS418Cpu0PartialStage::S410Candidate, 0)),
            None
        ),
        Err(G8lS418Cpu0PartialStateReconciliationError::BindingDrift)
    );
    assert_eq!(
        preflight_s418_cpu0_partial_state_reconciliation(1, None, None, None, None),
        Err(G8lS418Cpu0PartialStateReconciliationError::WrongCpu)
    );
}

#[test]
fn production_inspects_all_three_then_takes_only_selected_stage() {
    let source = include_str!("../../kernel/src/g8l_target_dispatch_scheduler_owner_scheduler_mutation_production_migration_lifecycle_s418_cpu0_partial_state_reconciliation.rs");
    let start = source
        .find("service_s418_cpu0_partial_state_reconciliation_on_cpu0")
        .unwrap();
    let body = &source[start..];
    for marker in [
        "inspect_s409_live_offer_sgi_delivery_receipt_on_cpu0",
        "inspect_s410_exclusion_admission_candidate_on_cpu0",
        "inspect_s411_ephemeral_exclusion_admission_on_cpu0",
        "take_s409_live_offer_sgi_delivery_receipt_on_cpu0",
        "take_s410_exclusion_admission_candidate_on_cpu0",
        "take_s411_ephemeral_exclusion_admission_on_cpu0",
    ] {
        assert!(
            body.contains(marker),
            "missing exact stage surface: {marker}"
        );
    }
    assert!(!body.contains("take_s243_deferred_s187_handoff_on_cpu1"));
}

#[test]
fn cpu0_timer_runs_s418_before_historical_s244_service() {
    let source = include_str!("../../kernel/src/arch/aarch64/exceptions.rs");
    let s418 = source
        .find("service_s418_cpu0_partial_state_reconciliation_on_cpu0")
        .unwrap();
    let s244 = source
        .find("service_s244_whole_scheduler_exclusion_admission_on_cpu0")
        .unwrap();
    assert!(s418 < s244);
    let name = "g8l_target_dispatch_scheduler_owner_scheduler_mutation_production_migration_lifecycle_s418_cpu0_partial_state_reconciliation";
    assert!(include_str!("../../kernel/src/main.rs").contains(&format!("mod {name};")));
    assert!(include_str!("../src/lib.rs").contains(&format!("pub mod {name};")));
}

  {
    id: "g8l-s418-cpu0-partial-state-reconciliation-partial",
    sequence: 418,
    slug: "cpu0_partial_state_reconciliation",
    title: "CPU0 partial-state reconciliation",
    focusedTests: 8,
    sourceBytes: 8848,
    sourceSha256:
      "3b3eaefec1fcf45fe602795220ed75d58eee157b3d4fab63b5b930309608e288",
    testBytes: 4800,
    testSha256:
      "caf48a2ad2985f37a3a4f339df89390d37fa11003b1231aa50d1f561e1c7d476",
    acceptance:
      "CPU0 candidate, ephemeral admission ve join-ACK olmak üzere üç kısmi aşamayı exact attempt kimliğiyle uzlaştırır; S243 S187 handoff korunur.",
    retainedBoundary:
      "CPU1 S187 consumption hâlâ yapılmaz; terminal attempt kaydı S419'da yayımlanır.",
  },