Use a `RwMutex` instead of `BlockingMutex`

src/check_expr.cpp

@@ -5101,7 +5101,6 @@ gb_internal ExactValue get_constant_field_single(CheckerContext *c, ExactValue v
 					ast_node(fv, FieldValue, elem);
 					String name = fv->field->Ident.token.string;
 					Selection sub_sel = lookup_field(node->tav.type, name, false);
-					defer (array_free(&sub_sel.index));
 					if (sub_sel.index.count > 0 &&
 					    sub_sel.index[0] == index) {
 						value = fv->value->tav.value;
@@ -7885,9 +7884,9 @@ gb_internal CallArgumentError check_polymorphic_record_type(CheckerContext *c, O
 	{
 		GenTypesData *found_gen_types = ensure_polymorphic_record_entity_has_gen_types(c, original_type);
 
-		mutex_lock(&found_gen_types->mutex);
+		rw_mutex_shared_lock(&found_gen_types->mutex);
 		Entity *found_entity = find_polymorphic_record_entity(found_gen_types, param_count, ordered_operands);
-		mutex_unlock(&found_gen_types->mutex);
+		rw_mutex_shared_unlock(&found_gen_types->mutex);
 
 		if (found_entity) {
 			operand->mode = Addressing_Type;

src/check_type.cpp

@@ -321,8 +321,8 @@ gb_internal void add_polymorphic_record_entity(CheckerContext *ctx, Ast *node, T
 	e->TypeName.objc_metadata = original_type->Named.type_name->TypeName.objc_metadata;
 
 	auto *found_gen_types = ensure_polymorphic_record_entity_has_gen_types(ctx, original_type);
-	mutex_lock(&found_gen_types->mutex);
-	defer (mutex_unlock(&found_gen_types->mutex));
+	rw_mutex_lock(&found_gen_types->mutex);
+	defer (rw_mutex_unlock(&found_gen_types->mutex));
 
 	for (Entity *prev : found_gen_types->types) {
 		if (prev == e) {

src/checker.hpp

@@ -417,7 +417,7 @@ struct GenProcsData {
 
 struct GenTypesData {
 	Array<Entity *> types;
-	BlockingMutex   mutex;
+	RwMutex         mutex;
 };
 
 struct Defineable {

src/llvm_backend_expr.cpp

@@ -2563,10 +2563,11 @@ gb_internal lbValue lb_emit_conv(lbProcedure *p, lbValue value, Type *t) {
 
 		Type *dt = t;
 
+		TEMPORARY_ALLOCATOR_GUARD();
+
 		GB_ASSERT(is_type_struct(st) || is_type_raw_union(st));
 		Selection sel = {};
-		sel.index.allocator = heap_allocator();
-		defer (array_free(&sel.index));
+		sel.index.allocator = temporary_allocator();
 		if (lookup_subtype_polymorphic_selection(t, src_type, &sel)) {
 			if (sel.entity == nullptr) {
 				GB_PANIC("invalid subtype cast  %s -> ", type_to_string(src_type), type_to_string(t));

src/types.cpp

@@ -435,11 +435,8 @@ gb_internal Selection make_selection(Entity *entity, Array<i32> index, bool indi
 }
 
 gb_internal void selection_add_index(Selection *s, isize index) {
-	// IMPORTANT NOTE(bill): this requires a stretchy buffer/dynamic array so it requires some form
-	// of heap allocation
-	// TODO(bill): Find a way to use a backing buffer for initial use as the general case is probably .count<3
 	if (s->index.data == nullptr) {
-		array_init(&s->index, heap_allocator());
+		array_init(&s->index, permanent_allocator());
 	}
 	array_add(&s->index, cast(i32)index);
 }
@@ -447,7 +444,7 @@ gb_internal void selection_add_index(Selection *s, isize index) {
 gb_internal Selection selection_combine(Selection const &lhs, Selection const &rhs) {
 	Selection new_sel = lhs;
 	new_sel.indirect = lhs.indirect || rhs.indirect;
-	new_sel.index = array_make<i32>(heap_allocator(), lhs.index.count+rhs.index.count);
+	new_sel.index = array_make<i32>(permanent_allocator(), lhs.index.count+rhs.index.count);
 	array_copy(&new_sel.index, lhs.index, 0);
 	array_copy(&new_sel.index, rhs.index, lhs.index.count);
 	return new_sel;
@@ -3958,7 +3955,7 @@ gb_internal i64 type_size_of(Type *t) {
 		TypePath path{};
 		type_path_init(&path);
 		{
-			MUTEX_GUARD(&g_type_mutex);
+			// MUTEX_GUARD(&g_type_mutex);
 			size = type_size_of_internal(t, &path);
 			t->cached_size.store(size);
 		}
@@ -3978,7 +3975,7 @@ gb_internal i64 type_align_of(Type *t) {
 	TypePath path{};
 	type_path_init(&path);
 	{
-		MUTEX_GUARD(&g_type_mutex);
+		// MUTEX_GUARD(&g_type_mutex);
 		t->cached_align.store(type_align_of_internal(t, &path));
 	}
 	type_path_free(&path);
@@ -4704,7 +4701,7 @@ gb_internal Type *alloc_type_tuple_from_field_types(Type **field_types, isize fi
 	}
 
 	Type *t = alloc_type_tuple();
-	t->Tuple.variables = slice_make<Entity *>(heap_allocator(), field_count);
+	t->Tuple.variables = slice_make<Entity *>(permanent_allocator(), field_count);
 
 	Scope *scope = nullptr;
 	for_array(i, t->Tuple.variables) {