Merge pull request #6215 from odin-lang/bill/fix-data-races-2026-02

Fix numerous data races

12 files changed, 92 insertions, 57 deletions

diff --git a/src/check_builtin.cpp b/src/check_builtin.cpp
index e732d8ec3..e2428576e 100644
--- a/src/check_builtin.cpp
+++ b/src/check_builtin.cpp
@@ -534,12 +534,12 @@ gb_internal bool check_builtin_objc_procedure(CheckerContext *c, Operand *operan
 				return false;
 			}
 
-			if (ident.entity->kind != Entity_Procedure) {
+			if (ident.entity.load()->kind != Entity_Procedure) {
 				gbString e = expr_to_string(handler_node);
 
 				ERROR_BLOCK();
 				error(handler.expr, "'%.*s' expected a direct reference to a procedure", LIT(builtin_name));
-				if(ident.entity->kind == Entity_Variable) {
+				if(ident.entity.load()->kind == Entity_Variable) {
 					error_line("\tSuggestion: Variables referencing a procedure are not allowed, they are not a direct procedure reference.");
 				} else {
 					error_line("\tSuggestion: Ensure '%s' is not a runtime-evaluated expression.", e); // NOTE(harold): Is this case possible to hit?
diff --git a/src/check_decl.cpp b/src/check_decl.cpp
index 8019d00c3..22a74f370 100644
--- a/src/check_decl.cpp
+++ b/src/check_decl.cpp
@@ -2155,7 +2155,7 @@ gb_internal bool check_proc_body(CheckerContext *ctx_, Token token, DeclInfo *de
 	rw_mutex_unlock(&ctx->scope->mutex);
 
 
-	bool where_clause_ok = evaluate_where_clauses(ctx, nullptr, decl->scope, &decl->proc_lit->ProcLit.where_clauses, !decl->where_clauses_evaluated);
+	bool where_clause_ok = evaluate_where_clauses(ctx, nullptr, decl->scope, &decl->proc_lit->ProcLit.where_clauses, !decl->where_clauses_evaluated.load(std::memory_order_relaxed));
 	if (!where_clause_ok) {
 		// NOTE(bill, 2019-08-31): Don't check the body as the where clauses failed
 		return false;
@@ -2173,15 +2173,15 @@ gb_internal bool check_proc_body(CheckerContext *ctx_, Token token, DeclInfo *de
 		}
 
 		GB_ASSERT(decl->proc_checked_state != ProcCheckedState_Checked);
-		if (decl->defer_use_checked) {
+		if (decl->defer_use_checked.load(std::memory_order_relaxed)) {
 			GB_ASSERT(is_type_polymorphic(type, true));
 			error(token, "Defer Use Checked: %.*s", LIT(decl->entity.load()->token.string));
-			GB_ASSERT(decl->defer_use_checked == false);
+			GB_ASSERT(decl->defer_use_checked.load(std::memory_order_relaxed) == false);
 		}
 
 		check_stmt_list(ctx, bs->stmts, Stmt_CheckScopeDecls);
 
-		decl->defer_use_checked = true;
+		decl->defer_use_checked.store(true, std::memory_order_relaxed);
 
 		for (Ast *stmt : bs->stmts) {
 			if (stmt->kind == Ast_ValueDecl) {
diff --git a/src/checker.cpp b/src/checker.cpp
index 453f3e241..9568b8cfa 100644
--- a/src/checker.cpp
+++ b/src/checker.cpp
@@ -1792,7 +1792,22 @@ gb_internal void add_untyped(CheckerContext *c, Ast *expr, AddressingMode mode,
 	check_set_expr_info(c, expr, mode, type, value);
 }
 
-gb_internal void add_type_and_value(CheckerContext *ctx, Ast *expr, AddressingMode mode, Type *type, ExactValue const &value, bool use_mutex) {
+struct alignas(GB_CACHE_LINE_SIZE) TypeAndValueMutexStripes {
+	BlockingMutex mutex;
+	u8 padding[GB_CACHE_LINE_SIZE - gb_size_of(BlockingMutex)];
+};
+
+enum { TypeAndValueMutexStripes_COUNT = 128 };
+gb_global TypeAndValueMutexStripes tav_mutex_stripes[TypeAndValueMutexStripes_COUNT];
+
+gb_internal BlockingMutex *tav_mutex_for_node(Ast *node) {
+	GB_ASSERT(node != nullptr);
+	uintptr h = cast(uintptr)node;
+	h ^= h >> 6;
+	return &tav_mutex_stripes[h % TypeAndValueMutexStripes_COUNT].mutex;
+}
+
+gb_internal void add_type_and_value(CheckerContext *ctx, Ast *expr, AddressingMode mode, Type *type, ExactValue const &value) {
 	if (expr == nullptr) {
 		return;
 	}
@@ -1803,14 +1818,18 @@ gb_internal void add_type_and_value(CheckerContext *ctx, Ast *expr, AddressingMo
 		return;
 	}
 
-	BlockingMutex *mutex = &ctx->info->type_and_value_mutex;
-	if (ctx->decl) {
-		mutex = &ctx->decl->type_and_value_mutex;
-	} else if (ctx->pkg) {
-		mutex = &ctx->pkg->type_and_value_mutex;
-	}
+	BlockingMutex *mutex = tav_mutex_for_node(expr);
+
+	/* Previous logic:
+		BlockingMutex *mutex = &ctx->info->type_and_value_mutex;
+		if (ctx->decl) {
+			mutex = &ctx->decl->type_and_value_mutex;
+		} else if (ctx->pkg) {
+			mutex = &ctx->pkg->type_and_value_mutex;
+		}
+	*/
 
-	if (use_mutex) mutex_lock(mutex);
+	mutex_lock(mutex);
 	Ast *prev_expr = nullptr;
 	while (prev_expr != expr) {
 		prev_expr = expr;
@@ -1835,7 +1854,7 @@ gb_internal void add_type_and_value(CheckerContext *ctx, Ast *expr, AddressingMo
 			break;
 		};
 	}
-	if (use_mutex) mutex_unlock(mutex);
+	mutex_unlock(mutex);
 }
 
 gb_internal void add_entity_definition(CheckerInfo *i, Ast *identifier, Entity *entity) {
diff --git a/src/checker.hpp b/src/checker.hpp
index f9c279a51..374aaf10d 100644
--- a/src/checker.hpp
+++ b/src/checker.hpp
@@ -221,14 +221,14 @@ struct DeclInfo {
 
 	Entity *     para_poly_original;
 
-	bool          is_using;
-	bool          where_clauses_evaluated;
-	bool          foreign_require_results;
+	bool                          is_using;
+	bool                          foreign_require_results;
+	std::atomic<bool>             where_clauses_evaluated;
 	std::atomic<ProcCheckedState> proc_checked_state;
 
-	BlockingMutex proc_checked_mutex;
-	isize         defer_used;
-	bool          defer_use_checked;
+	BlockingMutex     proc_checked_mutex;
+	isize             defer_used;
+	std::atomic<bool> defer_use_checked;
 
 	CommentGroup *comment;
 	CommentGroup *docs;
@@ -631,7 +631,7 @@ gb_internal void    scope_lookup_parent (Scope *s, String const &name, Scope **s
 gb_internal Entity *scope_insert (Scope *s, Entity *entity);
 
 
-gb_internal void      add_type_and_value      (CheckerContext *c, Ast *expression, AddressingMode mode, Type *type, ExactValue const &value, bool use_mutex=true);
+gb_internal void      add_type_and_value      (CheckerContext *c, Ast *expression, AddressingMode mode, Type *type, ExactValue const &value);
 gb_internal ExprInfo *check_get_expr_info     (CheckerContext *c, Ast *expr);
 gb_internal void      add_untyped             (CheckerContext *c, Ast *expression, AddressingMode mode, Type *basic_type, ExactValue const &value);
 gb_internal void      add_entity_use          (CheckerContext *c, Ast *identifier, Entity *entity);
diff --git a/src/entity.cpp b/src/entity.cpp
index 55aca8069..070b05462 100644
--- a/src/entity.cpp
+++ b/src/entity.cpp
@@ -170,7 +170,7 @@ struct Entity {
 	Type *      type;
 	std::atomic<Ast *> identifier; // Can be nullptr
 	DeclInfo *  decl_info;
-	DeclInfo *  parent_proc_decl; // nullptr if in file/global scope
+	std::atomic<DeclInfo *> parent_proc_decl; // nullptr if in file/global scope
 	AstFile *   file;
 	AstPackage *pkg;
 
@@ -181,11 +181,11 @@ struct Entity {
 	Entity *    aliased_of;
 
 	union {
-		struct lbModule *code_gen_module;
+		std::atomic<struct lbModule *> code_gen_module;
 		struct cgModule *cg_module;
 	};
 	union {
-		struct lbProcedure *code_gen_procedure;
+		std::atomic<struct lbProcedure *> code_gen_procedure;
 		struct cgProcedure *cg_procedure;
 	};
 
@@ -370,7 +370,7 @@ gb_internal Entity *alloc_entity_using_variable(Entity *parent, Token token, Typ
 	token.pos = parent->token.pos;
 	Entity *entity = alloc_entity(Entity_Variable, parent->scope, token, type);
 	entity->using_parent = parent;
-	entity->parent_proc_decl = parent->parent_proc_decl;
+	entity->parent_proc_decl.store(parent->parent_proc_decl, std::memory_order_relaxed);
 	entity->using_expr = using_expr;
 	entity->flags |= EntityFlag_Using;
 	entity->flags |= EntityFlag_Used;
diff --git a/src/llvm_backend_proc.cpp b/src/llvm_backend_proc.cpp
index 07b1870f0..b596f15ef 100644
--- a/src/llvm_backend_proc.cpp
+++ b/src/llvm_backend_proc.cpp
@@ -676,7 +676,7 @@ gb_internal void lb_begin_procedure_body(lbProcedure *p) {
 
 					lbAddr res = {};
 					if (p->entity && p->entity->decl_info &&
-					    p->entity->decl_info->defer_use_checked &&
+					    p->entity->decl_info->defer_use_checked.load(std::memory_order_relaxed) &&
 					    p->entity->decl_info->defer_used == 0) {
 
 						// NOTE(bill): this is a bodge to get around the issue of the problem BELOW
@@ -2217,8 +2217,10 @@ gb_internal lbValue lb_build_builtin_proc(lbProcedure *p, Ast *expr, TypeAndValu
 				Entity *e = entity_of_node(ident);
 				GB_ASSERT(e != nullptr);
 
-				if (e->parent_proc_decl != nullptr && e->parent_proc_decl->entity != nullptr) {
-					procedure = e->parent_proc_decl->entity.load()->token.string;
+				DeclInfo *parent_proc_decl = e->parent_proc_decl.load(std::memory_order_relaxed);
+				if (parent_proc_decl != nullptr &&
+				    parent_proc_decl->entity != nullptr) {
+					procedure = parent_proc_decl->entity.load()->token.string;
 				} else {
 					procedure = str_lit("");
 				}
diff --git a/src/llvm_backend_utility.cpp b/src/llvm_backend_utility.cpp
index 929239486..367e7be75 100644
--- a/src/llvm_backend_utility.cpp
+++ b/src/llvm_backend_utility.cpp
@@ -2419,7 +2419,7 @@ gb_internal lbValue lb_handle_objc_block(lbProcedure *p, Ast *expr) {
 
 	Ast *proc_lit = unparen_expr(ce->args[capture_arg_count]);
 	if (proc_lit->kind == Ast_Ident) {
-		proc_lit = proc_lit->Ident.entity->decl_info->proc_lit;
+		proc_lit = proc_lit->Ident.entity.load()->decl_info->proc_lit;
 	}
 	GB_ASSERT(proc_lit->kind == Ast_ProcLit);
 
diff --git a/src/name_canonicalization.cpp b/src/name_canonicalization.cpp
index f1dccb182..d3faefed7 100644
--- a/src/name_canonicalization.cpp
+++ b/src/name_canonicalization.cpp
@@ -559,8 +559,8 @@ gb_internal void write_canonical_parent_prefix(TypeWriter *w, Entity *e) {
 			// no prefix
 			return;
 		}
-		if (e->parent_proc_decl) {
-			Entity *p = e->parent_proc_decl->entity;
+		if (e->parent_proc_decl.load(std::memory_order_relaxed)) {
+			Entity *p = e->parent_proc_decl.load(std::memory_order_relaxed)->entity;
 			write_canonical_parent_prefix(w, p);
 			type_writer_append(w, p->token.string.text, p->token.string.len);
 			if (is_type_polymorphic(p->type)) {
diff --git a/src/parser.hpp b/src/parser.hpp
index 39f56ffae..1026433d0 100644
--- a/src/parser.hpp
+++ b/src/parser.hpp
@@ -425,7 +425,7 @@ struct AstSplitArgs {
 #define AST_KINDS \
 	AST_KIND(Ident,          "identifier",      struct { \
 		Token   token;  \
-		Entity *entity; \
+		std::atomic<Entity *> entity; \
 		u32     hash;   \
 	}) \
 	AST_KIND(Implicit,       "implicit",        Token) \
@@ -856,19 +856,19 @@ gb_global isize const ast_variant_sizes[] = {
 };
 
 struct AstCommonStuff {
-	AstKind      kind; // u16
-	u8           state_flags;
-	u8           viral_state_flags;
-	i32          file_id;
-	TypeAndValue tav; // NOTE(bill): Making this a pointer is slower
+	AstKind         kind; // u16
+	u8              state_flags;
+	std::atomic<u8> viral_state_flags;
+	i32             file_id;
+	TypeAndValue    tav; // NOTE(bill): Making this a pointer is slower
 };
 
 struct Ast {
-	AstKind      kind; // u16
-	u8           state_flags;
-	u8           viral_state_flags;
-	i32          file_id;
-	TypeAndValue tav; // NOTE(bill): Making this a pointer is slower
+	AstKind         kind; // u16
+	u8              state_flags;
+	std::atomic<u8> viral_state_flags;
+	i32             file_id;
+	TypeAndValue    tav; // NOTE(bill): Making this a pointer is slower
 
 	// IMPORTANT NOTE(bill): This must be at the end since the AST is allocated to be size of the variant
 	union {
diff --git a/src/thread_pool.cpp b/src/thread_pool.cpp
index ca6483fd9..a0afbd269 100644
--- a/src/thread_pool.cpp
+++ b/src/thread_pool.cpp
@@ -1,5 +1,15 @@
 // thread_pool.cpp
 
+// TODO(bill): make work on MSVC
+// #if defined(__SANITIZE_THREAD__) || (defined(__has_feature) && __has_feature(thread_sanitizer))
+// #include <sanitizer/tsan_interface.h>
+// #define TSAN_RELEASE(addr) __tsan_release(addr)
+// #define TSAN_ACQUIRE(addr) __tsan_acquire(addr)
+// #else
+#define TSAN_RELEASE(addr)
+#define TSAN_ACQUIRE(addr)
+// #endif
+
 struct WorkerTask;
 struct ThreadPool;
 
@@ -88,6 +98,7 @@ void thread_pool_queue_push(Thread *thread, WorkerTask task) {
 	}
 
 	cur_ring->buffer[bot % cur_ring->size] = task;
+	TSAN_RELEASE(cur_ring->buffer[bot % cur_ring->size]);
 	std::atomic_thread_fence(std::memory_order_release);
 	thread->queue.bottom.store(bot + 1, std::memory_order_relaxed);
 
@@ -108,6 +119,7 @@ GrabState thread_pool_queue_take(Thread *thread, WorkerTask *task) {
 	if (top <= bot) {
 
 		// Queue is not empty
+		TSAN_ACQUIRE(cur_ring->buffer[bot % cur_ring->size]);
 		*task = cur_ring->buffer[bot % cur_ring->size];
 		if (top == bot) {
 			// Only one entry left in queue
@@ -139,6 +151,8 @@ GrabState thread_pool_queue_steal(Thread *thread, WorkerTask *task) {
 	if (top < bot) {
 		// Queue is not empty
 		TaskRingBuffer *cur_ring = thread->queue.ring.load(std::memory_order_consume);
+
+		TSAN_ACQUIRE(&cur_ring->buffer[top % cur_ring->size]);
 		*task = cur_ring->buffer[top % cur_ring->size];
 
 		if (!thread->queue.top.compare_exchange_strong(top, top + 1, std::memory_order_seq_cst, std::memory_order_relaxed)) {
diff --git a/src/threading.cpp b/src/threading.cpp
index 02e6de14b..d8ae321f5 100644
--- a/src/threading.cpp
+++ b/src/threading.cpp
@@ -375,8 +375,8 @@ gb_internal void semaphore_wait(Semaphore *s) {
 	}
 	gb_internal bool mutex_try_lock(BlockingMutex *m) {
 		ANNOTATE_LOCK_PRE(m, 1);
-		i32 v = m->state().exchange(Internal_Mutex_State_Locked, std::memory_order_acquire);
-		if (v == Internal_Mutex_State_Unlocked) {
+		i32 expected = Internal_Mutex_State_Unlocked;
+		if (m->state().compare_exchange_strong(expected, Internal_Mutex_State_Locked, std::memory_order_acquire)) {
 			ANNOTATE_LOCK_POST(m);
 			return true;
 		}
diff --git a/src/types.cpp b/src/types.cpp
index a7f2bfda2..9ecdf5cdd 100644
--- a/src/types.cpp
+++ b/src/types.cpp
@@ -170,21 +170,21 @@ struct TypeStruct {
 };
 
 struct TypeUnion {
-	Slice<Type *> variants;
+	Slice<Type *>    variants;
 
-	Ast *         node;
-	Scope *       scope;
+	Ast *            node;
+	Scope *          scope;
 
-	i64           variant_block_size;
-	i64           custom_align;
-	Type *        polymorphic_params; // Type_Tuple
-	Type *        polymorphic_parent;
-	Wait_Signal   polymorphic_wait_signal;
+	std::atomic<i64> variant_block_size;
+	i64              custom_align;
+	Type *           polymorphic_params; // Type_Tuple
+	Type *           polymorphic_parent;
+	Wait_Signal      polymorphic_wait_signal;
 
-	i16           tag_size;
-	bool          is_polymorphic;
-	bool          is_poly_specialized;
-	UnionTypeKind kind;
+	std::atomic<i16> tag_size;
+	bool             is_polymorphic;
+	bool             is_poly_specialized;
+	UnionTypeKind    kind;
 };
 
 struct TypeProc {