ruby/shape.c

1343 строки
40 KiB
C

#include "vm_core.h"
#include "vm_sync.h"
#include "shape.h"
#include "symbol.h"
#include "id_table.h"
#include "internal/class.h"
#include "internal/error.h"
#include "internal/gc.h"
#include "internal/object.h"
#include "internal/symbol.h"
#include "internal/variable.h"
#include "variable.h"
#include <stdbool.h>
#ifndef _WIN32
#include <sys/mman.h>
#endif
#ifndef SHAPE_DEBUG
#define SHAPE_DEBUG (VM_CHECK_MODE > 0)
#endif
#if SIZEOF_SHAPE_T == 4
#if RUBY_DEBUG
#define SHAPE_BUFFER_SIZE 0x8000
#else
#define SHAPE_BUFFER_SIZE 0x80000
#endif
#else
#define SHAPE_BUFFER_SIZE 0x8000
#endif
#define REDBLACK_CACHE_SIZE (SHAPE_BUFFER_SIZE * 32)
/* This depends on that the allocated memory by Ruby's allocator or
* mmap is not located at an odd address. */
#define SINGLE_CHILD_TAG 0x1
#define TAG_SINGLE_CHILD(x) (struct rb_id_table *)((uintptr_t)(x) | SINGLE_CHILD_TAG)
#define SINGLE_CHILD_MASK (~((uintptr_t)SINGLE_CHILD_TAG))
#define SINGLE_CHILD_P(x) ((uintptr_t)(x) & SINGLE_CHILD_TAG)
#define SINGLE_CHILD(x) (rb_shape_t *)((uintptr_t)(x) & SINGLE_CHILD_MASK)
#define ANCESTOR_CACHE_THRESHOLD 10
#define MAX_SHAPE_ID (SHAPE_BUFFER_SIZE - 1)
#define ANCESTOR_SEARCH_MAX_DEPTH 2
static ID id_frozen;
static ID id_t_object;
#define LEAF 0
#define BLACK 0x0
#define RED 0x1
static redblack_node_t *
redblack_left(redblack_node_t * node)
{
if (node->l == LEAF) {
return LEAF;
}
else {
RUBY_ASSERT(node->l < GET_SHAPE_TREE()->cache_size);
redblack_node_t * left = &GET_SHAPE_TREE()->shape_cache[node->l - 1];
return left;
}
}
static redblack_node_t *
redblack_right(redblack_node_t * node)
{
if (node->r == LEAF) {
return LEAF;
}
else {
RUBY_ASSERT(node->r < GET_SHAPE_TREE()->cache_size);
redblack_node_t * right = &GET_SHAPE_TREE()->shape_cache[node->r - 1];
return right;
}
}
static redblack_node_t *
redblack_find(redblack_node_t * tree, ID key)
{
if (tree == LEAF) {
return LEAF;
}
else {
RUBY_ASSERT(redblack_left(tree) == LEAF || redblack_left(tree)->key < tree->key);
RUBY_ASSERT(redblack_right(tree) == LEAF || redblack_right(tree)->key > tree->key);
if (tree->key == key) {
return tree;
}
else {
if (key < tree->key) {
return redblack_find(redblack_left(tree), key);
}
else {
return redblack_find(redblack_right(tree), key);
}
}
}
}
static inline rb_shape_t *
redblack_value(redblack_node_t * node)
{
// Color is stored in the bottom bit of the shape pointer
// Mask away the bit so we get the actual pointer back
return (rb_shape_t *)((uintptr_t)node->value & ~(uintptr_t)1);
}
#ifdef HAVE_MMAP
static inline char
redblack_color(redblack_node_t * node)
{
return node && ((uintptr_t)node->value & RED);
}
static inline bool
redblack_red_p(redblack_node_t * node)
{
return redblack_color(node) == RED;
}
static redblack_id_t
redblack_id_for(redblack_node_t * node)
{
RUBY_ASSERT(node || node == LEAF);
if (node == LEAF) {
return 0;
}
else {
redblack_node_t * redblack_nodes = GET_SHAPE_TREE()->shape_cache;
redblack_id_t id = (redblack_id_t)(node - redblack_nodes);
return id + 1;
}
}
static redblack_node_t *
redblack_new(char color, ID key, rb_shape_t * value, redblack_node_t * left, redblack_node_t * right)
{
if (GET_SHAPE_TREE()->cache_size + 1 >= REDBLACK_CACHE_SIZE) {
// We're out of cache, just quit
return LEAF;
}
RUBY_ASSERT(left == LEAF || left->key < key);
RUBY_ASSERT(right == LEAF || right->key > key);
redblack_node_t * redblack_nodes = GET_SHAPE_TREE()->shape_cache;
redblack_node_t * node = &redblack_nodes[(GET_SHAPE_TREE()->cache_size)++];
node->key = key;
node->value = (rb_shape_t *)((uintptr_t)value | color);
node->l = redblack_id_for(left);
node->r = redblack_id_for(right);
return node;
}
static redblack_node_t *
redblack_balance(char color, ID key, rb_shape_t * value, redblack_node_t * left, redblack_node_t * right)
{
if (color == BLACK) {
ID new_key, new_left_key, new_right_key;
rb_shape_t *new_value, *new_left_value, *new_right_value;
redblack_node_t *new_left_left, *new_left_right, *new_right_left, *new_right_right;
if (redblack_red_p(left) && redblack_red_p(redblack_left(left))) {
new_right_key = key;
new_right_value = value;
new_right_right = right;
new_key = left->key;
new_value = redblack_value(left);
new_right_left = redblack_right(left);
new_left_key = redblack_left(left)->key;
new_left_value = redblack_value(redblack_left(left));
new_left_left = redblack_left(redblack_left(left));
new_left_right = redblack_right(redblack_left(left));
}
else if (redblack_red_p(left) && redblack_red_p(redblack_right(left))) {
new_right_key = key;
new_right_value = value;
new_right_right = right;
new_left_key = left->key;
new_left_value = redblack_value(left);
new_left_left = redblack_left(left);
new_key = redblack_right(left)->key;
new_value = redblack_value(redblack_right(left));
new_left_right = redblack_left(redblack_right(left));
new_right_left = redblack_right(redblack_right(left));
}
else if (redblack_red_p(right) && redblack_red_p(redblack_left(right))) {
new_left_key = key;
new_left_value = value;
new_left_left = left;
new_right_key = right->key;
new_right_value = redblack_value(right);
new_right_right = redblack_right(right);
new_key = redblack_left(right)->key;
new_value = redblack_value(redblack_left(right));
new_left_right = redblack_left(redblack_left(right));
new_right_left = redblack_right(redblack_left(right));
}
else if (redblack_red_p(right) && redblack_red_p(redblack_right(right))) {
new_left_key = key;
new_left_value = value;
new_left_left = left;
new_key = right->key;
new_value = redblack_value(right);
new_left_right = redblack_left(right);
new_right_key = redblack_right(right)->key;
new_right_value = redblack_value(redblack_right(right));
new_right_left = redblack_left(redblack_right(right));
new_right_right = redblack_right(redblack_right(right));
}
else {
return redblack_new(color, key, value, left, right);
}
RUBY_ASSERT(new_left_key < new_key);
RUBY_ASSERT(new_right_key > new_key);
RUBY_ASSERT(new_left_left == LEAF || new_left_left->key < new_left_key);
RUBY_ASSERT(new_left_right == LEAF || new_left_right->key > new_left_key);
RUBY_ASSERT(new_left_right == LEAF || new_left_right->key < new_key);
RUBY_ASSERT(new_right_left == LEAF || new_right_left->key < new_right_key);
RUBY_ASSERT(new_right_left == LEAF || new_right_left->key > new_key);
RUBY_ASSERT(new_right_right == LEAF || new_right_right->key > new_right_key);
return redblack_new(
RED, new_key, new_value,
redblack_new(BLACK, new_left_key, new_left_value, new_left_left, new_left_right),
redblack_new(BLACK, new_right_key, new_right_value, new_right_left, new_right_right));
}
return redblack_new(color, key, value, left, right);
}
static redblack_node_t *
redblack_insert_aux(redblack_node_t * tree, ID key, rb_shape_t * value)
{
if (tree == LEAF) {
return redblack_new(RED, key, value, LEAF, LEAF);
}
else {
redblack_node_t *left, *right;
if (key < tree->key) {
left = redblack_insert_aux(redblack_left(tree), key, value);
RUBY_ASSERT(left != LEAF);
right = redblack_right(tree);
RUBY_ASSERT(right == LEAF || right->key > tree->key);
}
else if (key > tree->key) {
left = redblack_left(tree);
RUBY_ASSERT(left == LEAF || left->key < tree->key);
right = redblack_insert_aux(redblack_right(tree), key, value);
RUBY_ASSERT(right != LEAF);
}
else {
return tree;
}
return redblack_balance(
redblack_color(tree),
tree->key,
redblack_value(tree),
left,
right
);
}
}
static redblack_node_t *
redblack_force_black(redblack_node_t * node)
{
node->value = redblack_value(node);
return node;
}
static redblack_node_t *
redblack_insert(redblack_node_t * tree, ID key, rb_shape_t * value)
{
redblack_node_t * root = redblack_insert_aux(tree, key, value);
if (redblack_red_p(root)) {
return redblack_force_black(root);
}
else {
return root;
}
}
#endif
rb_shape_tree_t *rb_shape_tree_ptr = NULL;
/*
* Shape getters
*/
rb_shape_t *
rb_shape_get_root_shape(void)
{
return GET_SHAPE_TREE()->root_shape;
}
shape_id_t
rb_shape_id(rb_shape_t * shape)
{
return (shape_id_t)(shape - GET_SHAPE_TREE()->shape_list);
}
void
rb_shape_each_shape(each_shape_callback callback, void *data)
{
rb_shape_t *cursor = rb_shape_get_root_shape();
rb_shape_t *end = rb_shape_get_shape_by_id(GET_SHAPE_TREE()->next_shape_id);
while (cursor < end) {
callback(cursor, data);
cursor += 1;
}
}
RUBY_FUNC_EXPORTED rb_shape_t *
rb_shape_get_shape_by_id(shape_id_t shape_id)
{
RUBY_ASSERT(shape_id != INVALID_SHAPE_ID);
rb_shape_t *shape = &GET_SHAPE_TREE()->shape_list[shape_id];
return shape;
}
rb_shape_t *
rb_shape_get_parent(rb_shape_t * shape)
{
return rb_shape_get_shape_by_id(shape->parent_id);
}
#if !SHAPE_IN_BASIC_FLAGS
shape_id_t rb_generic_shape_id(VALUE obj);
#endif
RUBY_FUNC_EXPORTED shape_id_t
rb_shape_get_shape_id(VALUE obj)
{
if (RB_SPECIAL_CONST_P(obj)) {
return SPECIAL_CONST_SHAPE_ID;
}
#if SHAPE_IN_BASIC_FLAGS
return RBASIC_SHAPE_ID(obj);
#else
switch (BUILTIN_TYPE(obj)) {
case T_OBJECT:
return ROBJECT_SHAPE_ID(obj);
break;
case T_CLASS:
case T_MODULE:
return RCLASS_SHAPE_ID(obj);
default:
return rb_generic_shape_id(obj);
}
#endif
}
size_t
rb_shape_depth(rb_shape_t * shape)
{
size_t depth = 1;
while (shape->parent_id != INVALID_SHAPE_ID) {
depth++;
shape = rb_shape_get_parent(shape);
}
return depth;
}
rb_shape_t*
rb_shape_get_shape(VALUE obj)
{
return rb_shape_get_shape_by_id(rb_shape_get_shape_id(obj));
}
static rb_shape_t *
shape_alloc(void)
{
shape_id_t shape_id = GET_SHAPE_TREE()->next_shape_id;
GET_SHAPE_TREE()->next_shape_id++;
if (shape_id == (MAX_SHAPE_ID + 1)) {
// TODO: Make an OutOfShapesError ??
rb_bug("Out of shapes");
}
return &GET_SHAPE_TREE()->shape_list[shape_id];
}
static rb_shape_t *
rb_shape_alloc_with_parent_id(ID edge_name, shape_id_t parent_id)
{
rb_shape_t * shape = shape_alloc();
shape->edge_name = edge_name;
shape->next_iv_index = 0;
shape->parent_id = parent_id;
shape->edges = NULL;
return shape;
}
static rb_shape_t *
rb_shape_alloc(ID edge_name, rb_shape_t * parent, enum shape_type type)
{
rb_shape_t * shape = rb_shape_alloc_with_parent_id(edge_name, rb_shape_id(parent));
shape->type = (uint8_t)type;
shape->heap_index = parent->heap_index;
shape->capacity = parent->capacity;
shape->edges = 0;
return shape;
}
#ifdef HAVE_MMAP
static redblack_node_t *
redblack_cache_ancestors(rb_shape_t * shape)
{
if (!(shape->ancestor_index || shape->parent_id == INVALID_SHAPE_ID)) {
redblack_node_t * parent_index;
parent_index = redblack_cache_ancestors(rb_shape_get_parent(shape));
if (shape->type == SHAPE_IVAR) {
shape->ancestor_index = redblack_insert(parent_index, shape->edge_name, shape);
#if RUBY_DEBUG
if (shape->ancestor_index) {
redblack_node_t *inserted_node = redblack_find(shape->ancestor_index, shape->edge_name);
RUBY_ASSERT(inserted_node);
RUBY_ASSERT(redblack_value(inserted_node) == shape);
}
#endif
}
else {
shape->ancestor_index = parent_index;
}
}
return shape->ancestor_index;
}
#else
static redblack_node_t *
redblack_cache_ancestors(rb_shape_t * shape)
{
return LEAF;
}
#endif
static rb_shape_t *
rb_shape_alloc_new_child(ID id, rb_shape_t * shape, enum shape_type shape_type)
{
rb_shape_t * new_shape = rb_shape_alloc(id, shape, shape_type);
switch (shape_type) {
case SHAPE_IVAR:
if (UNLIKELY(shape->next_iv_index >= shape->capacity)) {
RUBY_ASSERT(shape->next_iv_index == shape->capacity);
new_shape->capacity = (uint32_t)rb_malloc_grow_capa(shape->capacity, sizeof(VALUE));
}
RUBY_ASSERT(new_shape->capacity > shape->next_iv_index);
new_shape->next_iv_index = shape->next_iv_index + 1;
if (new_shape->next_iv_index > ANCESTOR_CACHE_THRESHOLD) {
redblack_cache_ancestors(new_shape);
}
break;
case SHAPE_FROZEN:
new_shape->next_iv_index = shape->next_iv_index;
break;
case SHAPE_OBJ_TOO_COMPLEX:
case SHAPE_ROOT:
case SHAPE_T_OBJECT:
rb_bug("Unreachable");
break;
}
return new_shape;
}
static rb_shape_t*
get_next_shape_internal(rb_shape_t * shape, ID id, enum shape_type shape_type, bool * variation_created, bool new_variations_allowed)
{
rb_shape_t *res = NULL;
// There should never be outgoing edges from "too complex"
RUBY_ASSERT(rb_shape_id(shape) != OBJ_TOO_COMPLEX_SHAPE_ID);
*variation_created = false;
RB_VM_LOCK_ENTER();
{
// If the current shape has children
if (shape->edges) {
// Check if it only has one child
if (SINGLE_CHILD_P(shape->edges)) {
rb_shape_t * child = SINGLE_CHILD(shape->edges);
// If the one child has a matching edge name, then great,
// we found what we want.
if (child->edge_name == id) {
res = child;
}
}
else {
// If it has more than one child, do a hash lookup to find it.
VALUE lookup_result;
if (rb_id_table_lookup(shape->edges, id, &lookup_result)) {
res = (rb_shape_t *)lookup_result;
}
}
}
// If we didn't find the shape we're looking for we create it.
if (!res) {
// If we're not allowed to create a new variation, of if we're out of shapes
// we return TOO_COMPLEX_SHAPE.
if (!new_variations_allowed || GET_SHAPE_TREE()->next_shape_id > MAX_SHAPE_ID) {
res = rb_shape_get_shape_by_id(OBJ_TOO_COMPLEX_SHAPE_ID);
}
else {
rb_shape_t * new_shape = rb_shape_alloc_new_child(id, shape, shape_type);
if (!shape->edges) {
// If the shape had no edge yet, we can directly set the new child
shape->edges = TAG_SINGLE_CHILD(new_shape);
}
else {
// If the edge was single child we need to allocate a table.
if (SINGLE_CHILD_P(shape->edges)) {
rb_shape_t * old_child = SINGLE_CHILD(shape->edges);
shape->edges = rb_id_table_create(2);
rb_id_table_insert(shape->edges, old_child->edge_name, (VALUE)old_child);
}
rb_id_table_insert(shape->edges, new_shape->edge_name, (VALUE)new_shape);
*variation_created = true;
}
res = new_shape;
}
}
}
RB_VM_LOCK_LEAVE();
return res;
}
int
rb_shape_frozen_shape_p(rb_shape_t* shape)
{
return SHAPE_FROZEN == (enum shape_type)shape->type;
}
static rb_shape_t *
remove_shape_recursive(rb_shape_t *shape, ID id, rb_shape_t **removed_shape)
{
if (shape->parent_id == INVALID_SHAPE_ID) {
// We've hit the top of the shape tree and couldn't find the
// IV we wanted to remove, so return NULL
return NULL;
}
else {
if (shape->type == SHAPE_IVAR && shape->edge_name == id) {
*removed_shape = shape;
return rb_shape_get_parent(shape);
}
else {
// This isn't the IV we want to remove, keep walking up.
rb_shape_t *new_parent = remove_shape_recursive(rb_shape_get_parent(shape), id, removed_shape);
// We found a new parent. Create a child of the new parent that
// has the same attributes as this shape.
if (new_parent) {
if (UNLIKELY(new_parent->type == SHAPE_OBJ_TOO_COMPLEX)) {
return new_parent;
}
bool dont_care;
rb_shape_t *new_child = get_next_shape_internal(new_parent, shape->edge_name, shape->type, &dont_care, true);
if (UNLIKELY(new_child->type == SHAPE_OBJ_TOO_COMPLEX)) {
return new_child;
}
RUBY_ASSERT(new_child->capacity <= shape->capacity);
return new_child;
}
else {
// We went all the way to the top of the shape tree and couldn't
// find an IV to remove, so return NULL
return NULL;
}
}
}
}
bool
rb_shape_transition_shape_remove_ivar(VALUE obj, ID id, rb_shape_t *shape, VALUE *removed)
{
if (UNLIKELY(shape->type == SHAPE_OBJ_TOO_COMPLEX)) {
return false;
}
rb_shape_t *removed_shape = NULL;
rb_shape_t *new_shape = remove_shape_recursive(shape, id, &removed_shape);
if (new_shape) {
RUBY_ASSERT(removed_shape != NULL);
if (UNLIKELY(new_shape->type == SHAPE_OBJ_TOO_COMPLEX)) {
return false;
}
RUBY_ASSERT(new_shape->next_iv_index == shape->next_iv_index - 1);
VALUE *ivptr;
switch(BUILTIN_TYPE(obj)) {
case T_CLASS:
case T_MODULE:
ivptr = RCLASS_IVPTR(obj);
break;
case T_OBJECT:
ivptr = ROBJECT_IVPTR(obj);
break;
default: {
struct gen_ivtbl *ivtbl;
rb_gen_ivtbl_get(obj, id, &ivtbl);
ivptr = ivtbl->as.shape.ivptr;
break;
}
}
*removed = ivptr[removed_shape->next_iv_index - 1];
memmove(&ivptr[removed_shape->next_iv_index - 1], &ivptr[removed_shape->next_iv_index],
((new_shape->next_iv_index + 1) - removed_shape->next_iv_index) * sizeof(VALUE));
// Re-embed objects when instances become small enough
// This is necessary because YJIT assumes that objects with the same shape
// have the same embeddedness for efficiency (avoid extra checks)
if (BUILTIN_TYPE(obj) == T_OBJECT &&
!RB_FL_TEST_RAW(obj, ROBJECT_EMBED) &&
rb_obj_embedded_size(new_shape->next_iv_index) <= rb_gc_obj_slot_size(obj)) {
RB_FL_SET_RAW(obj, ROBJECT_EMBED);
memcpy(ROBJECT_IVPTR(obj), ivptr, new_shape->next_iv_index * sizeof(VALUE));
xfree(ivptr);
}
rb_shape_set_shape(obj, new_shape);
}
return true;
}
rb_shape_t *
rb_shape_transition_shape_frozen(VALUE obj)
{
rb_shape_t* shape = rb_shape_get_shape(obj);
RUBY_ASSERT(shape);
RUBY_ASSERT(RB_OBJ_FROZEN(obj));
if (rb_shape_frozen_shape_p(shape) || rb_shape_obj_too_complex(obj)) {
return shape;
}
rb_shape_t* next_shape;
if (shape == rb_shape_get_root_shape()) {
return rb_shape_get_shape_by_id(SPECIAL_CONST_SHAPE_ID);
}
bool dont_care;
next_shape = get_next_shape_internal(shape, (ID)id_frozen, SHAPE_FROZEN, &dont_care, true);
RUBY_ASSERT(next_shape);
return next_shape;
}
/*
* This function is used for assertions where we don't want to increment
* max_iv_count
*/
rb_shape_t *
rb_shape_get_next_iv_shape(rb_shape_t* shape, ID id)
{
RUBY_ASSERT(!is_instance_id(id) || RTEST(rb_sym2str(ID2SYM(id))));
bool dont_care;
return get_next_shape_internal(shape, id, SHAPE_IVAR, &dont_care, true);
}
static inline rb_shape_t *
shape_get_next(rb_shape_t *shape, VALUE obj, ID id, bool emit_warnings)
{
RUBY_ASSERT(!is_instance_id(id) || RTEST(rb_sym2str(ID2SYM(id))));
if (UNLIKELY(shape->type == SHAPE_OBJ_TOO_COMPLEX)) {
return shape;
}
#if RUBY_DEBUG
attr_index_t index;
if (rb_shape_get_iv_index(shape, id, &index)) {
rb_bug("rb_shape_get_next: trying to create ivar that already exists at index %u", index);
}
#endif
bool allow_new_shape = true;
if (BUILTIN_TYPE(obj) == T_OBJECT) {
VALUE klass = rb_obj_class(obj);
allow_new_shape = RCLASS_EXT(klass)->variation_count < SHAPE_MAX_VARIATIONS;
}
bool variation_created = false;
rb_shape_t *new_shape = get_next_shape_internal(shape, id, SHAPE_IVAR, &variation_created, allow_new_shape);
// Check if we should update max_iv_count 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;
}
if (variation_created) {
RCLASS_EXT(klass)->variation_count++;
if (emit_warnings && rb_warning_category_enabled_p(RB_WARN_CATEGORY_PERFORMANCE)) {
if (RCLASS_EXT(klass)->variation_count >= SHAPE_MAX_VARIATIONS) {
rb_category_warn(
RB_WARN_CATEGORY_PERFORMANCE,
"The class %"PRIsVALUE" reached %d shape variations, instance variables accesses will be slower and memory usage increased.\n"
"It is recommended to define instance variables in a consistent order, for instance by eagerly defining them all in the #initialize method.",
rb_class_path(klass),
SHAPE_MAX_VARIATIONS
);
}
}
}
}
return new_shape;
}
rb_shape_t *
rb_shape_get_next(rb_shape_t *shape, VALUE obj, ID id)
{
return shape_get_next(shape, obj, id, true);
}
rb_shape_t *
rb_shape_get_next_no_warnings(rb_shape_t *shape, VALUE obj, ID id)
{
return shape_get_next(shape, obj, id, false);
}
// Same as rb_shape_get_iv_index, but uses a provided valid shape id and index
// to return a result faster if branches of the shape tree are closely related.
bool
rb_shape_get_iv_index_with_hint(shape_id_t shape_id, ID id, attr_index_t *value, shape_id_t *shape_id_hint)
{
attr_index_t index_hint = *value;
rb_shape_t *shape = rb_shape_get_shape_by_id(shape_id);
rb_shape_t *initial_shape = shape;
if (*shape_id_hint == INVALID_SHAPE_ID) {
*shape_id_hint = shape_id;
return rb_shape_get_iv_index(shape, id, value);
}
rb_shape_t * shape_hint = rb_shape_get_shape_by_id(*shape_id_hint);
// We assume it's likely shape_id_hint and shape_id have a close common
// ancestor, so we check up to ANCESTOR_SEARCH_MAX_DEPTH ancestors before
// eventually using the index, as in case of a match it will be faster.
// However if the shape doesn't have an index, we walk the entire tree.
int depth = INT_MAX;
if (shape->ancestor_index && shape->next_iv_index >= ANCESTOR_CACHE_THRESHOLD) {
depth = ANCESTOR_SEARCH_MAX_DEPTH;
}
while (depth > 0 && shape->next_iv_index > index_hint) {
while (shape_hint->next_iv_index > shape->next_iv_index) {
shape_hint = rb_shape_get_parent(shape_hint);
}
if (shape_hint == shape) {
// We've found a common ancestor so use the index hint
*value = index_hint;
*shape_id_hint = rb_shape_id(shape);
return true;
}
if (shape->edge_name == id) {
// We found the matching id before a common ancestor
*value = shape->next_iv_index - 1;
*shape_id_hint = rb_shape_id(shape);
return true;
}
shape = rb_shape_get_parent(shape);
depth--;
}
// If the original shape had an index but its ancestor doesn't
// we switch back to the original one as it will be faster.
if (!shape->ancestor_index && initial_shape->ancestor_index) {
shape = initial_shape;
}
*shape_id_hint = shape_id;
return rb_shape_get_iv_index(shape, id, value);
}
static bool
shape_get_iv_index(rb_shape_t *shape, ID id, attr_index_t *value)
{
while (shape->parent_id != INVALID_SHAPE_ID) {
if (shape->edge_name == id) {
enum shape_type shape_type;
shape_type = (enum shape_type)shape->type;
switch (shape_type) {
case SHAPE_IVAR:
RUBY_ASSERT(shape->next_iv_index > 0);
*value = shape->next_iv_index - 1;
return true;
case SHAPE_ROOT:
case SHAPE_T_OBJECT:
return false;
case SHAPE_OBJ_TOO_COMPLEX:
case SHAPE_FROZEN:
rb_bug("Ivar should not exist on transition");
}
}
shape = rb_shape_get_parent(shape);
}
return false;
}
static bool
shape_cache_get_iv_index(rb_shape_t *shape, ID id, attr_index_t *value)
{
if (shape->ancestor_index && shape->next_iv_index >= ANCESTOR_CACHE_THRESHOLD) {
redblack_node_t *node = redblack_find(shape->ancestor_index, id);
if (node) {
rb_shape_t *shape = redblack_value(node);
*value = shape->next_iv_index - 1;
#if RUBY_DEBUG
attr_index_t shape_tree_index;
RUBY_ASSERT(shape_get_iv_index(shape, id, &shape_tree_index));
RUBY_ASSERT(shape_tree_index == *value);
#endif
return true;
}
/* Verify the cache is correct by checking that this instance variable
* does not exist in the shape tree either. */
RUBY_ASSERT(!shape_get_iv_index(shape, id, value));
}
return false;
}
bool
rb_shape_get_iv_index(rb_shape_t *shape, ID id, attr_index_t *value)
{
// It doesn't make sense to ask for the index of an IV that's stored
// on an object that is "too complex" as it uses a hash for storing IVs
RUBY_ASSERT(rb_shape_id(shape) != OBJ_TOO_COMPLEX_SHAPE_ID);
if (!shape_cache_get_iv_index(shape, id, value)) {
// If it wasn't in the ancestor cache, then don't do a linear search
if (shape->ancestor_index && shape->next_iv_index >= ANCESTOR_CACHE_THRESHOLD) {
return false;
}
else {
return shape_get_iv_index(shape, id, value);
}
}
return true;
}
void
rb_shape_set_shape(VALUE obj, rb_shape_t* shape)
{
rb_shape_set_shape_id(obj, rb_shape_id(shape));
}
int32_t
rb_shape_id_offset(void)
{
return sizeof(uintptr_t) - SHAPE_ID_NUM_BITS / sizeof(uintptr_t);
}
rb_shape_t *
rb_shape_traverse_from_new_root(rb_shape_t *initial_shape, rb_shape_t *dest_shape)
{
RUBY_ASSERT(initial_shape->type == SHAPE_T_OBJECT);
rb_shape_t *next_shape = initial_shape;
if (dest_shape->type != initial_shape->type) {
next_shape = rb_shape_traverse_from_new_root(initial_shape, rb_shape_get_parent(dest_shape));
if (!next_shape) {
return NULL;
}
}
switch ((enum shape_type)dest_shape->type) {
case SHAPE_IVAR:
case SHAPE_FROZEN:
if (!next_shape->edges) {
return NULL;
}
VALUE lookup_result;
if (SINGLE_CHILD_P(next_shape->edges)) {
rb_shape_t * child = SINGLE_CHILD(next_shape->edges);
if (child->edge_name == dest_shape->edge_name) {
return child;
}
else {
return NULL;
}
}
else {
if (rb_id_table_lookup(next_shape->edges, dest_shape->edge_name, &lookup_result)) {
next_shape = (rb_shape_t *)lookup_result;
}
else {
return NULL;
}
}
break;
case SHAPE_ROOT:
case SHAPE_T_OBJECT:
break;
case SHAPE_OBJ_TOO_COMPLEX:
rb_bug("Unreachable");
break;
}
return next_shape;
}
rb_shape_t *
rb_shape_rebuild_shape(rb_shape_t * initial_shape, rb_shape_t * dest_shape)
{
RUBY_ASSERT(rb_shape_id(initial_shape) != OBJ_TOO_COMPLEX_SHAPE_ID);
RUBY_ASSERT(rb_shape_id(dest_shape) != OBJ_TOO_COMPLEX_SHAPE_ID);
rb_shape_t * midway_shape;
RUBY_ASSERT(initial_shape->type == SHAPE_T_OBJECT);
if (dest_shape->type != initial_shape->type) {
midway_shape = rb_shape_rebuild_shape(initial_shape, rb_shape_get_parent(dest_shape));
if (UNLIKELY(rb_shape_id(midway_shape) == OBJ_TOO_COMPLEX_SHAPE_ID)) {
return midway_shape;
}
}
else {
midway_shape = initial_shape;
}
switch ((enum shape_type)dest_shape->type) {
case SHAPE_IVAR:
midway_shape = rb_shape_get_next_iv_shape(midway_shape, dest_shape->edge_name);
break;
case SHAPE_ROOT:
case SHAPE_FROZEN:
case SHAPE_T_OBJECT:
break;
case SHAPE_OBJ_TOO_COMPLEX:
rb_bug("Unreachable");
break;
}
return midway_shape;
}
RUBY_FUNC_EXPORTED bool
rb_shape_obj_too_complex(VALUE obj)
{
return rb_shape_get_shape_id(obj) == OBJ_TOO_COMPLEX_SHAPE_ID;
}
size_t
rb_shape_edges_count(rb_shape_t *shape)
{
if (shape->edges) {
if (SINGLE_CHILD_P(shape->edges)) {
return 1;
}
else {
return rb_id_table_size(shape->edges);
}
}
return 0;
}
size_t
rb_shape_memsize(rb_shape_t *shape)
{
size_t memsize = sizeof(rb_shape_t);
if (shape->edges && !SINGLE_CHILD_P(shape->edges)) {
memsize += rb_id_table_memsize(shape->edges);
}
return memsize;
}
#if SHAPE_DEBUG
/*
* Exposing Shape to Ruby via RubyVM.debug_shape
*/
/* :nodoc: */
static VALUE
rb_shape_too_complex(VALUE self)
{
rb_shape_t * shape;
shape = rb_shape_get_shape_by_id(NUM2INT(rb_struct_getmember(self, rb_intern("id"))));
if (rb_shape_id(shape) == OBJ_TOO_COMPLEX_SHAPE_ID) {
return Qtrue;
}
else {
return Qfalse;
}
}
static VALUE
parse_key(ID key)
{
if (is_instance_id(key)) {
return ID2SYM(key);
}
return LONG2NUM(key);
}
static VALUE rb_shape_edge_name(rb_shape_t * shape);
static VALUE
rb_shape_t_to_rb_cShape(rb_shape_t *shape)
{
VALUE rb_cShape = rb_const_get(rb_cRubyVM, rb_intern("Shape"));
VALUE obj = rb_struct_new(rb_cShape,
INT2NUM(rb_shape_id(shape)),
INT2NUM(shape->parent_id),
rb_shape_edge_name(shape),
INT2NUM(shape->next_iv_index),
INT2NUM(shape->heap_index),
INT2NUM(shape->type),
INT2NUM(shape->capacity));
rb_obj_freeze(obj);
return obj;
}
static enum rb_id_table_iterator_result
rb_edges_to_hash(ID key, VALUE value, void *ref)
{
rb_hash_aset(*(VALUE *)ref, parse_key(key), rb_shape_t_to_rb_cShape((rb_shape_t*)value));
return ID_TABLE_CONTINUE;
}
/* :nodoc: */
static VALUE
rb_shape_edges(VALUE self)
{
rb_shape_t* shape;
shape = rb_shape_get_shape_by_id(NUM2INT(rb_struct_getmember(self, rb_intern("id"))));
VALUE hash = rb_hash_new();
if (shape->edges) {
if (SINGLE_CHILD_P(shape->edges)) {
rb_shape_t * child = SINGLE_CHILD(shape->edges);
rb_edges_to_hash(child->edge_name, (VALUE)child, &hash);
}
else {
rb_id_table_foreach(shape->edges, rb_edges_to_hash, &hash);
}
}
return hash;
}
static VALUE
rb_shape_edge_name(rb_shape_t * shape)
{
if (shape->edge_name) {
if (is_instance_id(shape->edge_name)) {
return ID2SYM(shape->edge_name);
}
return INT2NUM(shape->capacity);
}
return Qnil;
}
/* :nodoc: */
static VALUE
rb_shape_export_depth(VALUE self)
{
rb_shape_t* shape;
shape = rb_shape_get_shape_by_id(NUM2INT(rb_struct_getmember(self, rb_intern("id"))));
return SIZET2NUM(rb_shape_depth(shape));
}
/* :nodoc: */
static VALUE
rb_shape_parent(VALUE self)
{
rb_shape_t * shape;
shape = rb_shape_get_shape_by_id(NUM2INT(rb_struct_getmember(self, rb_intern("id"))));
if (shape->parent_id != INVALID_SHAPE_ID) {
return rb_shape_t_to_rb_cShape(rb_shape_get_parent(shape));
}
else {
return Qnil;
}
}
/* :nodoc: */
static VALUE
rb_shape_debug_shape(VALUE self, VALUE obj)
{
return rb_shape_t_to_rb_cShape(rb_shape_get_shape(obj));
}
/* :nodoc: */
static VALUE
rb_shape_root_shape(VALUE self)
{
return rb_shape_t_to_rb_cShape(rb_shape_get_root_shape());
}
/* :nodoc: */
static VALUE
rb_shape_shapes_available(VALUE self)
{
return INT2NUM(MAX_SHAPE_ID - (GET_SHAPE_TREE()->next_shape_id - 1));
}
/* :nodoc: */
static VALUE
rb_shape_exhaust(int argc, VALUE *argv, VALUE self)
{
rb_check_arity(argc, 0, 1);
int offset = argc == 1 ? NUM2INT(argv[0]) : 0;
GET_SHAPE_TREE()->next_shape_id = MAX_SHAPE_ID - offset + 1;
return Qnil;
}
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)
{
rb_hash_aset(*(VALUE *)ref, parse_key(key), rb_obj_shape((rb_shape_t*)value));
return ID_TABLE_CONTINUE;
}
static VALUE edges(struct rb_id_table* edges)
{
VALUE hash = rb_hash_new();
if (SINGLE_CHILD_P(edges)) {
rb_shape_t * child = SINGLE_CHILD(edges);
collect_keys_and_values(child->edge_name, (VALUE)child, &hash);
}
else {
rb_id_table_foreach(edges, collect_keys_and_values, &hash);
}
return hash;
}
/* :nodoc: */
VALUE
rb_obj_shape(rb_shape_t* shape)
{
VALUE rb_shape = rb_hash_new();
rb_hash_aset(rb_shape, ID2SYM(rb_intern("id")), INT2NUM(rb_shape_id(shape)));
rb_hash_aset(rb_shape, ID2SYM(rb_intern("edges")), edges(shape->edges));
if (shape == rb_shape_get_root_shape()) {
rb_hash_aset(rb_shape, ID2SYM(rb_intern("parent_id")), INT2NUM(ROOT_SHAPE_ID));
}
else {
rb_hash_aset(rb_shape, ID2SYM(rb_intern("parent_id")), INT2NUM(shape->parent_id));
}
rb_hash_aset(rb_shape, ID2SYM(rb_intern("edge_name")), rb_id2str(shape->edge_name));
return rb_shape;
}
/* :nodoc: */
static VALUE
shape_transition_tree(VALUE self)
{
return rb_obj_shape(rb_shape_get_root_shape());
}
/* :nodoc: */
static VALUE
rb_shape_find_by_id(VALUE mod, VALUE id)
{
shape_id_t shape_id = NUM2UINT(id);
if (shape_id >= GET_SHAPE_TREE()->next_shape_id) {
rb_raise(rb_eArgError, "Shape ID %d is out of bounds\n", shape_id);
}
return rb_shape_t_to_rb_cShape(rb_shape_get_shape_by_id(shape_id));
}
#endif
#ifdef HAVE_MMAP
#include <sys/mman.h>
#endif
void
Init_default_shapes(void)
{
rb_shape_tree_ptr = xcalloc(1, sizeof(rb_shape_tree_t));
#ifdef HAVE_MMAP
rb_shape_tree_ptr->shape_list = (rb_shape_t *)mmap(NULL, rb_size_mul_or_raise(SHAPE_BUFFER_SIZE, sizeof(rb_shape_t), rb_eRuntimeError),
PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (GET_SHAPE_TREE()->shape_list == MAP_FAILED) {
GET_SHAPE_TREE()->shape_list = 0;
}
#else
GET_SHAPE_TREE()->shape_list = xcalloc(SHAPE_BUFFER_SIZE, sizeof(rb_shape_t));
#endif
if (!GET_SHAPE_TREE()->shape_list) {
rb_memerror();
}
id_frozen = rb_make_internal_id();
id_t_object = rb_make_internal_id();
#ifdef HAVE_MMAP
rb_shape_tree_ptr->shape_cache = (redblack_node_t *)mmap(NULL, rb_size_mul_or_raise(REDBLACK_CACHE_SIZE, sizeof(redblack_node_t), rb_eRuntimeError),
PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
rb_shape_tree_ptr->cache_size = 0;
// If mmap fails, then give up on the redblack tree cache.
// We set the cache size such that the redblack node allocators think
// the cache is full.
if (GET_SHAPE_TREE()->shape_cache == MAP_FAILED) {
GET_SHAPE_TREE()->shape_cache = 0;
GET_SHAPE_TREE()->cache_size = REDBLACK_CACHE_SIZE;
}
#endif
// Root shape
rb_shape_t *root = rb_shape_alloc_with_parent_id(0, INVALID_SHAPE_ID);
root->capacity = 0;
root->type = SHAPE_ROOT;
root->heap_index = 0;
GET_SHAPE_TREE()->root_shape = root;
RUBY_ASSERT(rb_shape_id(GET_SHAPE_TREE()->root_shape) == ROOT_SHAPE_ID);
bool dont_care;
// Special const shape
#if RUBY_DEBUG
rb_shape_t *special_const_shape =
#endif
get_next_shape_internal(root, (ID)id_frozen, SHAPE_FROZEN, &dont_care, true);
RUBY_ASSERT(rb_shape_id(special_const_shape) == SPECIAL_CONST_SHAPE_ID);
RUBY_ASSERT(SPECIAL_CONST_SHAPE_ID == (GET_SHAPE_TREE()->next_shape_id - 1));
RUBY_ASSERT(rb_shape_frozen_shape_p(special_const_shape));
rb_shape_t *too_complex_shape = rb_shape_alloc_with_parent_id(0, ROOT_SHAPE_ID);
too_complex_shape->type = SHAPE_OBJ_TOO_COMPLEX;
too_complex_shape->heap_index = 0;
RUBY_ASSERT(OBJ_TOO_COMPLEX_SHAPE_ID == (GET_SHAPE_TREE()->next_shape_id - 1));
RUBY_ASSERT(rb_shape_id(too_complex_shape) == OBJ_TOO_COMPLEX_SHAPE_ID);
// Make shapes for T_OBJECT
size_t *sizes = rb_gc_heap_sizes();
for (int i = 0; sizes[i] > 0; i++) {
rb_shape_t *t_object_shape = rb_shape_alloc_with_parent_id(0, INVALID_SHAPE_ID);
t_object_shape->type = SHAPE_T_OBJECT;
t_object_shape->heap_index = i;
t_object_shape->capacity = (uint32_t)((sizes[i] - offsetof(struct RObject, as.ary)) / sizeof(VALUE));
t_object_shape->edges = rb_id_table_create(0);
t_object_shape->ancestor_index = LEAF;
RUBY_ASSERT(rb_shape_id(t_object_shape) == (shape_id_t)(i + FIRST_T_OBJECT_SHAPE_ID));
}
}
void
Init_shape(void)
{
#if SHAPE_DEBUG
VALUE rb_cShape = rb_struct_define_under(rb_cRubyVM, "Shape",
"id",
"parent_id",
"edge_name",
"next_iv_index",
"heap_index",
"type",
"capacity",
NULL);
rb_define_method(rb_cShape, "parent", rb_shape_parent, 0);
rb_define_method(rb_cShape, "edges", rb_shape_edges, 0);
rb_define_method(rb_cShape, "depth", rb_shape_export_depth, 0);
rb_define_method(rb_cShape, "too_complex?", rb_shape_too_complex, 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_T_OBJECT", INT2NUM(SHAPE_T_OBJECT));
rb_define_const(rb_cShape, "SHAPE_FROZEN", INT2NUM(SHAPE_FROZEN));
rb_define_const(rb_cShape, "SHAPE_ID_NUM_BITS", INT2NUM(SHAPE_ID_NUM_BITS));
rb_define_const(rb_cShape, "SHAPE_FLAG_SHIFT", INT2NUM(SHAPE_FLAG_SHIFT));
rb_define_const(rb_cShape, "SPECIAL_CONST_SHAPE_ID", INT2NUM(SPECIAL_CONST_SHAPE_ID));
rb_define_const(rb_cShape, "OBJ_TOO_COMPLEX_SHAPE_ID", INT2NUM(OBJ_TOO_COMPLEX_SHAPE_ID));
rb_define_const(rb_cShape, "FIRST_T_OBJECT_SHAPE_ID", INT2NUM(FIRST_T_OBJECT_SHAPE_ID));
rb_define_const(rb_cShape, "SHAPE_MAX_VARIATIONS", INT2NUM(SHAPE_MAX_VARIATIONS));
rb_define_const(rb_cShape, "SIZEOF_RB_SHAPE_T", INT2NUM(sizeof(rb_shape_t)));
rb_define_const(rb_cShape, "SIZEOF_REDBLACK_NODE_T", INT2NUM(sizeof(redblack_node_t)));
rb_define_const(rb_cShape, "SHAPE_BUFFER_SIZE", INT2NUM(sizeof(rb_shape_t) * SHAPE_BUFFER_SIZE));
rb_define_const(rb_cShape, "REDBLACK_CACHE_SIZE", INT2NUM(sizeof(redblack_node_t) * REDBLACK_CACHE_SIZE));
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, "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, "shapes_available", rb_shape_shapes_available, 0);
rb_define_singleton_method(rb_cShape, "exhaust_shapes", rb_shape_exhaust, -1);
#endif
}