Recovery Drain & Grace Timeout
A common criticism of strict acyclic state machines is the dead-lock hazard:
“If an agent is strictly forbidden from stepping backward ($S_{i+1} > S_i$), what happens if an oracle fails to respond at step S3? Are the agent’s funds locked forever?”
The Grace Timeout Mechanism
To eliminate deadlock while preserving mathematical acyclicity during normal operation, u64se-seu-solana includes a formal Grace Timeout / Emergency Drain Invariant (formally proven in Theorem 4).
#![allow(unused)]
fn main() {
pub const INACTIVITY_TIMEOUT_SLOTS: u16 = 100; // ~40 seconds on Solana
}The Three Strict Prerequisites for Recovery Drain
A backward transition to $S_0$ is permitted if and only if all three conditions are simultaneously satisfied:
- Temporal Expiration: $$\Delta_{\text{slot}} = \text{current_slot.wrapping_sub}(\text{anchor_slot}) > 100$$ The state machine has been completely inactive for at least 100 slots (~40 seconds).
- Authorized Role: $$\text{requested_role} = \text{ROLE_DRAIN (0x10)}$$ Only the authority holding recovery rights can trigger the drain.
- Canonical Reset Target: $$S_{i+1} = 0$$ The destination must strictly be Genesis node $0$, unlocking and refunding escrowed funds to the owner.
If an attacker attempts to call ROLE_DRAIN while $\Delta \le 100$, or attempts to drain to any node other than $0$, the attempt is blocked with FaultMask::BACKWARD_FORBIDDEN (0x10).
This guarantees that:
- Deadlock is mathematically impossible.
- Premature drainage is formally unexploitable.