iteration counter is stored in the Bot, and incr for each evaluation

fish/src/bot.rs

@@ -16,6 +16,7 @@ pub(crate) use bumpalo::Bump as Arena;
 
 /// Encompasses an instance of the algorithm.
 pub struct Bot {
+    iters: u32,
     evaluator: Evaluator,
     algorithm: SegmentedAStar,
     // IMPORTANT: `arena` must occur after `algorithm` so that it is dropped last.
@@ -31,18 +32,36 @@ impl Bot {
         let evaluator = Evaluator::new(weights, root);
         let algorithm = SegmentedAStar::new(root);
         Self {
+            iters: 0,
             evaluator,
             algorithm,
             arena,
         }
     }
 
-    /// Perform a single "iteration" of work, which may end up improving the suggestion.
+    /// Runs the bot for up to `gas` more iterations. An "iteration" is a unit of work
-    /// What defines an iteration is vague, but similar versions of the engine should be
+    /// that is intentionally kept vague, but should be proportional to the amount CPU
-    /// deterministic, such that performing the same number of iterations gives the same
+    /// time. Iterations are deterministic, so similar versions of the engine will produce
-    /// resulting suggestion.
+    /// the same suggestions if run the for the same number of iterations.
-    pub fn think(&mut self) {
+    pub fn think_for(&mut self, gas: u32) {
-        self.algorithm.step(&self.arena, &self.evaluator);
+        // NOTICE: The actual number of iterations may slightly exceed the provided gas due to
+        // how the bot is currently structured. This shouldn't have a substantial impact over
+        // the long run since the overshoot will be very small in terms of CPU
+        // time.
+        //
+        // Runs will be deterministic as long as two runs end on the same *target*
+        // iterations on the last call to `think_for`, e.g. "bot.think_for(5000)" is the
+        // same as "bot.think_for(2500); bot.think_for(5000 - bot.iterations());"
+        let max_iters = self.iters + gas;
+        while self.iters < max_iters {
+            self.algorithm
+                .step(&self.arena, &self.evaluator, &mut self.iters);
+        }
+    }
+
+    /// Returns the number of iterations done so far.
+    pub fn iterations(&self) -> u32 {
+        self.iters
     }
 
     /// Return the current best suggested placement. Returns `None` under two possible
@@ -130,9 +149,6 @@ struct SegmentedAStar {
     best: Option<RawNodePtr>,
 }
 
-#[derive(Debug)]
-struct ShouldSelect;
-
 impl SegmentedAStar {
     fn new(root: &Node) -> Self {
         let mut open = Vec::with_capacity(root.queue().len());
@@ -149,22 +165,26 @@ impl SegmentedAStar {
         self.best.map(|node| unsafe { node.as_node() })
     }
 
-    fn step(&mut self, arena: &Arena, eval: &Evaluator) {
+    fn step(&mut self, arena: &Arena, eval: &Evaluator, iters: &mut u32) {
+        *iters += 1;
         match self.expand(arena, eval) {
-            Ok(_) => {}
+            Ok(work) => *iters += work,
-            Err(ShouldSelect) => self.select(),
+            Err(maybe_cand) => {
+                if let Some(cand) = maybe_cand {
+                    self.backup(cand, *iters);
+                }
+                self.select();
+            }
         }
     }
 
-    fn expand<'a>(&mut self, arena: &'a Arena, eval: &Evaluator) -> Result<&'a Node, ShouldSelect> {
+    fn expand<'a>(&mut self, arena: &'a Arena, eval: &Evaluator) -> Result<u32, Option<&'a Node>> {
         let open_set = self.open.get_mut(self.depth);
-        let cand = open_set.map_or(None, |set| set.pop()).ok_or(ShouldSelect)?;
+        let cand = open_set.map_or(None, |set| set.pop()).ok_or(None)?;
         let cand = unsafe { cand.0.as_node() };
 
         if cand.is_terminal() {
-            self.depth = self.open.len(); // makes expand() fail immediately
+            return Err(Some(cand));
-            self.backup(cand);
-            return Err(ShouldSelect);
         }
 
         self.depth += 1;
@@ -172,17 +192,24 @@ impl SegmentedAStar {
             self.open.resize_with(self.depth + 1, BinaryHeap::new);
         }
 
-        for suc in cand.expand(arena, |m, q| eval.evaluate(m, q)) {
+        let mut work = 0;
+        let evaluate = |mat: &Mat, queue: Queue<'_>| {
+            // each evaluated board state = +1 unit work
+            work += 1;
+            eval.evaluate(mat, queue)
+        };
+
+        for suc in cand.expand(arena, evaluate) {
             self.open[self.depth].push(suc.into());
         }
 
-        Ok(cand)
+        Ok(work)
     }
 
-    fn backup(&mut self, cand: &Node) {
+    fn backup(&mut self, cand: &Node, iters: u32) {
         if self.best().map_or(true, |best| cand.is_better(best)) {
             tracing::debug!(
-                "{} suggestion: {cand:?}",
+                "{} suggestion @ {iters}: {cand:?}",
                 self.best.map_or("1st", |_| "new")
             );
             self.best = Some(cand.into());

fish/src/bot/node.rs

@@ -94,10 +94,10 @@ impl Node {
     pub fn expand<'a, E>(
         &'a self,
         arena: &'a Arena,
-        evaluate: E,
+        mut evaluate: E,
     ) -> impl Iterator<Item = &'a Node> + 'a
     where
-        E: Fn(&Mat, Queue<'_>) -> i32 + 'a,
+        E: FnMut(&Mat, Queue<'_>) -> i32 + 'a,
     {
         let placements = self.queue().reachable().flat_map(|ty| {
             let locs = find_locations(self.matrix(), ty);

tidepool/example-configs/100L.toml

@@ -1,6 +1,3 @@
 [game]
 goal = 100
 rules = "jstris"
-
-[bot]
-iters = 9000

tidepool/example-configs/18L.toml

@@ -1,2 +1,2 @@
 game.goal = 18
-bot.iters = 5000
+bot.iters = 500_000

tidepool/src/config.rs

@@ -43,14 +43,14 @@ pub struct BotConfig {
     // TODO: algorithm
     // TODO: capabililties
     #[serde(default = "defaults::iters")]
-    pub iters: usize,
+    pub iters: u32,
     #[serde(default = "defaults::weights", deserialize_with = "de::weights")]
     pub weights: Weights,
 }
 
 impl BotConfig {
     pub const DEFAULT: Self = Self {
-        iters: 10_000,
+        iters: 100_000,
         weights: Weights::DEFAULT,
     };
 }
@@ -80,7 +80,7 @@ mod defaults {
         GameRulesConfig::JSTRIS
     }
 
-    pub const fn iters() -> usize {
+    pub const fn iters() -> u32 {
         BotConfig::DEFAULT.iters
     }
 

tidepool/src/main.rs

@@ -275,6 +275,7 @@ fn print_single_progress(
     if cleared == goal {
         writeln!(writer)
     } else {
+        write!(writer, " ")?;
         writer.flush()
     }
 }
@@ -313,6 +314,7 @@ fn print_multi_progress(
         )?;
     }
 
+    write!(writer, " ")?;
     writer.flush()
 }
 
@@ -360,11 +362,10 @@ fn run_simulation(
             mino::Queue::new(sim.queue().hold(), sim.queue().next()),
         );
 
-        for i in 0..config.bot.iters {
+        while bot.iterations() < config.bot.iters {
-            bot.think();
+            let gas = std::cmp::min(50_000, config.bot.iters - bot.iterations());
+            bot.think_for(gas);
 
-            // periodically check back with the main thread to see if we should exit
-            if i % 4096 == 4095 {
             if exit_early.load(atomic::Ordering::Relaxed) {
                 break;
             }
@@ -372,7 +373,6 @@ fn run_simulation(
                 break;
             }
         }
-        }
 
         let Some(placement) = bot.suggest() else {
             tracing::warn!("gave up :( pieces={}, id={id}", sim.pieces());