1 files changed, 96 insertions, 33 deletions

diff --git a/ai/src/transposition_table.rs b/ai/src/transposition_table.rs
index b801789..2b56a66 100644
--- a/ai/src/transposition_table.rs
+++ b/ai/src/transposition_table.rs
@@ -1,49 +1,44 @@
 use crate::CheckersBitBoard;
-
-#[cfg(debug_assertions)]
-const TABLE_SIZE: usize = 1_000_000 / std::mem::size_of::<TranspositionTableEntry>();
-
-#[cfg(not(debug_assertions))]
-const TABLE_SIZE: usize = 10_000_000 / std::mem::size_of::<TranspositionTableEntry>();
-
-const EMPTY_ENTRY: Option<TranspositionTableEntry> = None;
-static mut REPLACE_TABLE: [Option<TranspositionTableEntry>; TABLE_SIZE] = [EMPTY_ENTRY; TABLE_SIZE];
-static mut DEPTH_TABLE: [Option<TranspositionTableEntry>; TABLE_SIZE] = [EMPTY_ENTRY; TABLE_SIZE];
+use parking_lot::RwLock;
+use std::num::NonZeroU8;
 
 #[derive(Copy, Clone, Debug)]
 struct TranspositionTableEntry {
 	board: CheckersBitBoard,
 	eval: f32,
-	depth: u8,
-}
-
-pub struct TranspositionTableReference {
-	replace_table: &'static mut [Option<TranspositionTableEntry>; TABLE_SIZE],
-	depth_table: &'static mut [Option<TranspositionTableEntry>; TABLE_SIZE],
+	depth: NonZeroU8,
 }
 
 impl TranspositionTableEntry {
-	const fn new(board: CheckersBitBoard, eval: f32, depth: u8) -> Self {
+	const fn new(board: CheckersBitBoard, eval: f32, depth: NonZeroU8) -> Self {
 		Self { board, eval, depth }
 	}
 }
 
-impl TranspositionTableReference {
-	pub fn new() -> Self {
-		Self {
-			replace_table: unsafe { &mut REPLACE_TABLE },
-			depth_table: unsafe { &mut DEPTH_TABLE },
-		}
-	}
+pub struct TranspositionTable {
+	replace_table: Box<[RwLock<Option<TranspositionTableEntry>>]>,
+	depth_table: Box<[RwLock<Option<TranspositionTableEntry>>]>,
+}
 
+#[derive(Copy, Clone, Debug)]
+pub struct TranspositionTableRef<'a> {
+	replace_table: &'a [RwLock<Option<TranspositionTableEntry>>],
+	depth_table: &'a [RwLock<Option<TranspositionTableEntry>>],
+}
+
+impl<'a> TranspositionTableRef<'a> {
 	pub fn get(self, board: CheckersBitBoard, depth: u8) -> Option<f32> {
+		let table_len = self.replace_table.as_ref().len();
+
 		// try the replace table
 		let entry = unsafe {
 			self.replace_table
-				.get_unchecked(board.hash_code() as usize % TABLE_SIZE)
+				.as_ref()
+				.get_unchecked(board.hash_code() as usize % table_len)
+				.read()
 		};
 		if let Some(entry) = *entry {
-			if entry.board == board && entry.depth >= depth {
+			if entry.board == board && entry.depth.get() >= depth {
 				return Some(entry.eval);
 			}
 		}
@@ -51,12 +46,14 @@ impl TranspositionTableReference {
 		// try the depth table
 		let entry = unsafe {
 			self.depth_table
-				.get_unchecked(board.hash_code() as usize % TABLE_SIZE)
+				.as_ref()
+				.get_unchecked(board.hash_code() as usize % table_len)
+				.read()
 		};
 		match *entry {
 			Some(entry) => {
 				if entry.board == board {
-					if entry.depth >= depth {
+					if entry.depth.get() >= depth {
 						Some(entry.eval)
 					} else {
 						None
@@ -69,18 +66,57 @@ impl TranspositionTableReference {
 		}
 	}
 
-	pub fn insert(self, board: CheckersBitBoard, eval: f32, depth: u8) {
-		// insert to the replace table
+	pub fn get_any_depth(self, board: CheckersBitBoard) -> Option<f32> {
+		let table_len = self.replace_table.as_ref().len();
+
+		// try the depth table
 		let entry = unsafe {
+			self.depth_table
+				.as_ref()
+				.get_unchecked(board.hash_code() as usize % table_len)
+				.read()
+		};
+		if let Some(entry) = *entry {
+			if entry.board == board {
+				return Some(entry.eval);
+			}
+		}
+
+		// try the replace table
+		let entry = unsafe {
+			self.replace_table
+				.as_ref()
+				.get_unchecked(board.hash_code() as usize % table_len)
+				.read()
+		};
+		match *entry {
+			Some(entry) => {
+				if entry.board == board {
+					Some(entry.eval)
+				} else {
+					None
+				}
+			}
+			None => None,
+		}
+	}
+
+	pub fn insert(&self, board: CheckersBitBoard, eval: f32, depth: NonZeroU8) {
+		let table_len = self.replace_table.as_ref().len();
+
+		// insert to the replace table
+		let mut entry = unsafe {
 			self.replace_table
-				.get_unchecked_mut(board.hash_code() as usize % TABLE_SIZE)
+				.get_unchecked(board.hash_code() as usize % table_len)
+				.write()
 		};
 		*entry = Some(TranspositionTableEntry::new(board, eval, depth));
 
 		// insert to the depth table, only if the new depth is higher
-		let entry = unsafe {
+		let mut entry = unsafe {
 			self.depth_table
-				.get_unchecked_mut(board.hash_code() as usize % TABLE_SIZE)
+				.get_unchecked(board.hash_code() as usize % table_len)
+				.write()
 		};
 		match *entry {
 			Some(entry_val) => {
@@ -92,3 +128,30 @@ impl TranspositionTableReference {
 		}
 	}
 }
+
+impl TranspositionTable {
+	pub fn new(table_size: usize) -> Self {
+		let mut replace_table = Box::new_uninit_slice(table_size / 2);
+		let mut depth_table = Box::new_uninit_slice(table_size / 2);
+
+		for entry in replace_table.iter_mut() {
+			entry.write(RwLock::new(None));
+		}
+
+		for entry in depth_table.iter_mut() {
+			entry.write(RwLock::new(None));
+		}
+
+		Self {
+			replace_table: unsafe { replace_table.assume_init() },
+			depth_table: unsafe { depth_table.assume_init() },
+		}
+	}
+
+	pub fn mut_ref(&mut self) -> TranspositionTableRef {
+		TranspositionTableRef {
+			replace_table: &self.replace_table,
+			depth_table: &self.depth_table,
+		}
+	}
+}