Transition shape when object's capacity changes

This commit adds a `capacity` field to shapes, and adds shape transitions whenever an object's capacity changes. Objects which are allocated out of a bigger size pool will also make a transition from the root shape to the shape with the correct capacity for their size pool when they are allocated. This commit will allow us to remove numiv from objects completely, and will also mean we can guarantee that if two objects share shapes, their IVs are in the same positions (an embedded and extended object cannot share shapes). This will enable us to implement ivar sets in YJIT using object shapes. Co-Authored-By: Aaron Patterson <[email protected]>
author: Jemma Issroff <[email protected]> 2022-11-08 15:35:31 -0500
committer: Peter Zhu <[email protected]> 2022-11-10 10:11:34 -0500
commit: 5246f4027ec574e77809845e1b1f7822cc2a5cef ()
tree: a29c972df6a589c7ab8c2541ea2eea1f7caf5f70 /shape.c
parent: 9986697b621e5345177a1c395489dcc9fab8602b (diff)
1 files changed, 158 insertions, 45 deletions
@@ -1,15 +1,19 @@
 #include "vm_core.h"
 #include "vm_sync.h"
 #include "shape.h"
 #include "internal/class.h"
 #include "internal/symbol.h"
 #include "internal/variable.h"
 #include <stdbool.h>
 /*
 * Shape getters
 */
-static rb_shape_t*
 rb_shape_get_root_shape(void)
 {
 return GET_VM()->root_shape;
@@ -21,12 +25,6 @@ rb_shape_id(rb_shape_t * shape)
 return (shape_id_t)(shape - GET_VM()->shape_list);
 }
-static rb_shape_t*
-rb_shape_get_frozen_root_shape(void)
-{
- return GET_VM()->frozen_root_shape;
-}
-
 bool
 rb_shape_root_shape_p(rb_shape_t* shape)
 {
@@ -68,7 +66,7 @@ shape_id_t
 rb_shape_get_shape_id(VALUE obj)
 {
 if (RB_SPECIAL_CONST_P(obj)) {
- return FROZEN_ROOT_SHAPE_ID;
 }
 #if SHAPE_IN_BASIC_FLAGS
@@ -113,12 +111,9 @@ rb_shape_lookup_id(rb_shape_t* shape, ID id, enum shape_type shape_type)
 }
 static rb_shape_t*
-get_next_shape_internal(rb_shape_t* shape, ID id, VALUE obj, enum shape_type shape_type)
 {
 rb_shape_t *res = NULL;
-
- RUBY_ASSERT(SHAPE_FROZEN != (enum shape_type)shape->type || RB_TYPE_P(obj, T_MODULE) || RB_TYPE_P(obj, T_CLASS));
-
 RB_VM_LOCK_ENTER();
 {
 if (rb_shape_lookup_id(shape, id, shape_type)) {
@@ -142,23 +137,18 @@ get_next_shape_internal(rb_shape_t* shape, ID id, VALUE obj, enum shape_type sha
 rb_shape_t * new_shape = rb_shape_alloc(id, shape);
 new_shape->type = (uint8_t)shape_type;
 switch (shape_type) {
 case SHAPE_IVAR:
- new_shape->next_iv_index = rb_shape_get_shape_by_id(new_shape->parent_id)->next_iv_index + 1;
-
- // Check if we should update next_iv_index on the object's class
- if (BUILTIN_TYPE(obj) == T_OBJECT) {
- VALUE klass = rb_obj_class(obj);
- if (new_shape->next_iv_index > RCLASS_EXT(klass)->max_iv_count) {
- RCLASS_EXT(klass)->max_iv_count = new_shape->next_iv_index;
- }
- }
 break;
 case SHAPE_IVAR_UNDEF:
 case SHAPE_FROZEN:
- new_shape->next_iv_index = rb_shape_get_shape_by_id(new_shape->parent_id)->next_iv_index;
 break;
 case SHAPE_ROOT:
 rb_bug("Unreachable");
 break;
@@ -183,7 +173,7 @@ rb_shape_frozen_shape_p(rb_shape_t* shape)
 void
 rb_shape_transition_shape_remove_ivar(VALUE obj, ID id, rb_shape_t *shape)
 {
- rb_shape_t* next_shape = get_next_shape_internal(shape, id, obj, SHAPE_IVAR_UNDEF);
 if (shape == next_shape) {
 return;
@@ -206,16 +196,11 @@ rb_shape_transition_shape_frozen(VALUE obj)
 rb_shape_t* next_shape;
 if (shape == rb_shape_get_root_shape()) {
- next_shape = rb_shape_get_frozen_root_shape();
 }
- else {
- static ID id_frozen;
- if (!id_frozen) {
- id_frozen = rb_make_internal_id();
- }
- next_shape = get_next_shape_internal(shape, (ID)id_frozen, obj, SHAPE_FROZEN);
- }
 RUBY_ASSERT(next_shape);
 rb_shape_set_shape(obj, next_shape);
@@ -231,10 +216,39 @@ rb_shape_transition_shape(VALUE obj, ID id, rb_shape_t *shape)
 rb_shape_set_shape(obj, next_shape);
 }
-rb_shape_t*
 rb_shape_get_next(rb_shape_t* shape, VALUE obj, ID id)
 {
- return get_next_shape_internal(shape, id, obj, SHAPE_IVAR);
 }
 bool
@@ -250,11 +264,13 @@ rb_shape_get_iv_index(rb_shape_t * shape, ID id, attr_index_t *value)
 RUBY_ASSERT(shape->next_iv_index > 0);
 *value = shape->next_iv_index - 1;
 return true;
 case SHAPE_IVAR_UNDEF:
 case SHAPE_ROOT:
 return false;
 case SHAPE_FROZEN:
- rb_bug("Ivar should not exist on frozen transition\n");
 }
 }
 shape = rb_shape_get_shape_by_id(shape->parent_id);
@@ -290,9 +306,18 @@ rb_shape_alloc_with_parent_id(ID edge_name, shape_id_t parent_id)
 }
 rb_shape_t *
 rb_shape_alloc(ID edge_name, rb_shape_t * parent)
 {
- return rb_shape_alloc_with_parent_id(edge_name, rb_shape_id(parent));
 }
 MJIT_FUNC_EXPORTED void
@@ -307,6 +332,39 @@ rb_shape_flags_mask(void)
 return SHAPE_FLAG_MASK;
 }
 #if VM_CHECK_MODE > 0
 VALUE rb_cShape;
@@ -336,6 +394,14 @@ rb_shape_type(VALUE self)
 }
 static VALUE
 rb_shape_parent_id(VALUE self)
 {
 rb_shape_t * shape;
@@ -398,11 +464,16 @@ rb_shape_edge_name(VALUE self)
 rb_shape_t* shape;
 TypedData_Get_Struct(self, rb_shape_t, &shape_data_type, shape);
- if (shape->edge_name) {
- return ID2SYM(shape->edge_name);
 }
 else {
- return Qnil;
 }
 }
@@ -416,6 +487,15 @@ rb_shape_next_iv_index(VALUE self)
 }
 static VALUE
 rb_shape_export_depth(VALUE self)
 {
 rb_shape_t* shape;
@@ -454,12 +534,6 @@ rb_shape_root_shape(VALUE self)
 return rb_shape_t_to_rb_cShape(rb_shape_get_root_shape());
 }
-static VALUE
-rb_shape_frozen_root_shape(VALUE self)
-{
- return rb_shape_t_to_rb_cShape(rb_shape_get_frozen_root_shape());
-}
-
 VALUE rb_obj_shape(rb_shape_t* shape);
 static enum rb_id_table_iterator_result collect_keys_and_values(ID key, VALUE value, void *ref)
@@ -519,6 +593,43 @@ rb_shape_find_by_id(VALUE mod, VALUE id)
 #endif
 void
 Init_shape(void)
 {
 #if VM_CHECK_MODE > 0
@@ -530,21 +641,23 @@ Init_shape(void)
 rb_define_method(rb_cShape, "edges", rb_shape_edges, 0);
 rb_define_method(rb_cShape, "edge_name", rb_shape_edge_name, 0);
 rb_define_method(rb_cShape, "next_iv_index", rb_shape_next_iv_index, 0);
 rb_define_method(rb_cShape, "depth", rb_shape_export_depth, 0);
 rb_define_method(rb_cShape, "id", rb_wrapped_shape_id, 0);
 rb_define_method(rb_cShape, "type", rb_shape_type, 0);
 rb_define_const(rb_cShape, "SHAPE_ROOT", INT2NUM(SHAPE_ROOT));
 rb_define_const(rb_cShape, "SHAPE_IVAR", INT2NUM(SHAPE_IVAR));
 rb_define_const(rb_cShape, "SHAPE_IVAR_UNDEF", INT2NUM(SHAPE_IVAR_UNDEF));
 rb_define_const(rb_cShape, "SHAPE_FROZEN", INT2NUM(SHAPE_FROZEN));
 rb_define_const(rb_cShape, "SHAPE_BITS", INT2NUM(SHAPE_BITS));
 rb_define_const(rb_cShape, "SHAPE_FLAG_SHIFT", INT2NUM(SHAPE_FLAG_SHIFT));
 rb_define_singleton_method(rb_cShape, "transition_tree", shape_transition_tree, 0);
 rb_define_singleton_method(rb_cShape, "find_by_id", rb_shape_find_by_id, 1);
 rb_define_singleton_method(rb_cShape, "next_shape_id", next_shape_id, 0);
 rb_define_singleton_method(rb_cShape, "of", rb_shape_debug_shape, 1);
 rb_define_singleton_method(rb_cShape, "root_shape", rb_shape_root_shape, 0);
- rb_define_singleton_method(rb_cShape, "frozen_root_shape", rb_shape_frozen_root_shape, 0);
 #endif
 }
author	Jemma Issroff <[email protected]>	2022-11-08 15:35:31 -0500
committer	Peter Zhu <[email protected]>	2022-11-10 10:11:34 -0500
commit	5246f4027ec574e77809845e1b1f7822cc2a5cef ()
tree	a29c972df6a589c7ab8c2541ea2eea1f7caf5f70 /shape.c
parent	9986697b621e5345177a1c395489dcc9fab8602b (diff)