File size: 5,449 Bytes
1d3f990 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 | //! SUBLEQ Virtual Machine — Core execution engine
use crate::memory::{Memory, Address};
use crate::checkpoint::{Checkpoint, CheckpointManager};
use crate::telemetry::{TelemetryEmitter, MutationDelta};
use anyhow::{Result, Context};
use parking_lot::RwLock;
use std::sync::Arc;
use tracing::{trace, debug, warn};
/// SUBLEQ Instruction: M[b] ← M[b] - M[a]; if M[b] ≤ 0 then IP ← c
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct Instruction {
pub a: Address,
pub b: Address,
pub c: Address,
}
impl Instruction {
pub const SIZE: usize = 3;
pub fn from_memory(mem: &Memory, ip: Address) -> Option<Self> {
let a = mem.read(ip)? as Address;
let b = mem.read(ip + 1)? as Address;
let c = mem.read(ip + 2)? as Address;
Some(Self { a, b, c })
}
}
/// Execution modes for the VM
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ExecMode {
/// Standard execution with mutation logging
Standard,
/// Proof validation mode
Verified,
/// Dry-run for invariant extraction
Analysis,
}
/// High-performance SUBLEQ VM with self-modification tracking
pub struct SubleqVM {
memory: Arc<RwLock<Memory>>,
ip: Address,
mode: ExecMode,
mutation_log: Vec<MutationDelta>,
checkpoint_mgr: CheckpointManager,
telemetry: Option<Arc<TelemetryEmitter>>,
step_count: u64,
max_steps: Option<u64>,
}
impl SubleqVM {
pub fn new(memory: Memory, mode: ExecMode) -> Self {
let mem = Arc::new(RwLock::new(memory));
Self {
memory: mem.clone(),
ip: 0,
mode,
mutation_log: Vec::new(),
checkpoint_mgr: CheckpointManager::new(mem),
telemetry: None,
step_count: 0,
max_steps: None,
}
}
pub fn with_telemetry(mut self, emitter: Arc<TelemetryEmitter>) -> Self {
self.telemetry = Some(emitter);
self
}
pub fn with_max_steps(mut self, max: u64) -> Self {
self.max_steps = Some(max);
self
}
/// Execute a single SUBLEQ instruction
pub fn step(&mut self) -> Result<Option<bool>> {
if let Some(max) = self.max_steps {
if self.step_count >= max {
return Ok(None);
}
}
let mem = self.memory.read();
let instr = Instruction::from_memory(&mem, self.ip)
.context("Instruction fetch failed: IP out of bounds")?;
drop(mem);
trace!(ip = self.ip, ?instr, "Executing SUBLEQ");
// Fetch operands
let (val_a, val_b) = {
let mem = self.memory.read();
let val_a = mem.read(instr.a).unwrap_or(0);
let val_b = mem.read(instr.b).unwrap_or(0);
(val_a, val_b)
};
// Perform subtraction
let res = val_b.wrapping_sub(val_a);
// Write result + log mutation
{
let mut mem = self.memory.write();
mem.write(instr.b, res)?;
self.mutation_log.push(MutationDelta {
address: instr.b,
old_value: val_b,
new_value: res,
ip: self.ip,
step: self.step_count,
});
}
// Emit telemetry
if let Some(ref tel) = self.telemetry {
tel.emit(MutationDelta {
address: instr.b,
old_value: val_b,
new_value: res,
ip: self.ip,
step: self.step_count,
});
}
// Branch logic
let branched = res <= 0;
if branched {
self.ip = instr.c;
} else {
self.ip += Instruction::SIZE;
}
self.step_count += 1;
Ok(Some(branched))
}
/// Run until halt or max steps
pub fn run(&mut self) -> Result<()> {
while self.step()?.is_some() {}
Ok(())
}
/// Create WORM checkpoint
pub fn checkpoint(&mut self) -> Checkpoint {
self.checkpoint_mgr.create(self.ip, self.step_count, self.mutation_log.len())
}
/// Rollback to checkpoint
pub fn rollback(&mut self, checkpoint: &Checkpoint) -> Result<()> {
self.checkpoint_mgr.restore(checkpoint, &mut self.memory.write())?;
self.ip = checkpoint.ip;
self.step_count = checkpoint.step_count;
self.mutation_log.truncate(checkpoint.mutation_log_len);
warn!(?checkpoint, "Rolled back");
Ok(())
}
pub fn mutation_log(&self) -> &[MutationDelta] {
&self.mutation_log
}
pub fn ip(&self) -> Address {
self.ip
}
pub fn steps(&self) -> u64 {
self.step_count
}
pub fn memory(&self) -> Arc<RwLock<Memory>> {
self.memory.clone()
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_basic_subleq() {
let mut mem = Memory::new(1024);
mem.write(0, 1).unwrap();
mem.write(1, 5).unwrap();
mem.write(2, 6).unwrap();
mem.write(3, 0).unwrap();
let mut vm = SubleqVM::new(mem, ExecMode::Standard);
vm.run().unwrap();
let final_mem = vm.memory.read();
assert_eq!(final_mem.read(2), Some(1));
}
}
|