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Change JSObject.weak_ref_list to use a bit and external hash table.

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1. Add a generic hashmap implementation.
2. Change Error `JSObject.is_uncatchable_error` flag to `JSObject.u.error` struct, leaving room for weak ref flag bit.
3. Compat `JSString.hash_next` to 31-bits (can be safely compat to 28-bits), leaving room for weak ref flag bit.

Save memory for each JSObject (8 bytes on 64-bit platform, 4 bytes on 32-bit platform).
This commit is contained in:
landerlyoung 2024-08-04 18:04:01 +08:00
parent 2ecaf6cf97
commit 6b073afcb9
4 changed files with 517 additions and 110 deletions
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1
TODO
View file

@ -47,7 +47,6 @@ Optimization ideas:
- add implicit numeric strings for Uint32 numbers? - add implicit numeric strings for Uint32 numbers?
- optimize `s += a + b`, `s += a.b` and similar simple expressions - optimize `s += a + b`, `s += a.b` and similar simple expressions
- ensure string canonical representation and optimise comparisons and hashes? - ensure string canonical representation and optimise comparisons and hashes?
- remove JSObject.first_weak_ref, use bit+context based hashed array for weak references
- property access optimization on the global object, functions, - property access optimization on the global object, functions,
prototypes and special non extensible objects. prototypes and special non extensible objects.
- create object literals with the correct length by backpatching length argument - create object literals with the correct length by backpatching length argument

503
quickjs.c
View file

@ -235,6 +235,10 @@ typedef struct {
int (*mul_pow10)(JSContext *ctx, JSValue *sp); int (*mul_pow10)(JSContext *ctx, JSValue *sp);
} JSNumericOperations; } JSNumericOperations;
#define JS_HASH_MAP_DEFAULT_SIZE ((size_t)4)
#define JS_HASH_MAP_DEFAULT_LOAD_FACTOR ((float)2)
#define JS_HASH_MAP_DEFAULT_SHRINK_FACTOR (1/(float)2)
struct JSRuntime { struct JSRuntime {
JSMallocFunctions mf; JSMallocFunctions mf;
JSMallocState malloc_state; JSMallocState malloc_state;
@ -304,6 +308,7 @@ struct JSRuntime {
JSNumericOperations bigdecimal_ops; JSNumericOperations bigdecimal_ops;
uint32_t operator_count; uint32_t operator_count;
#endif #endif
struct JSHashMap *weak_target_map; /* key: target object/symbol */
void *user_opaque; void *user_opaque;
}; };
@ -494,8 +499,11 @@ struct JSString {
XXX: could change encoding to have one more bit in hash */ XXX: could change encoding to have one more bit in hash */
uint32_t hash : 30; uint32_t hash : 30;
uint8_t atom_type : 2; /* != 0 if atom, JS_ATOM_TYPE_x */ uint8_t atom_type : 2; /* != 0 if atom, JS_ATOM_TYPE_x */
uint32_t hash_next; /* atom_index for JS_ATOM_TYPE_SYMBOL */ /* atom_index for JS_ATOM_TYPE_SYMBOL.
struct list_head *weak_ref_list; /* list of JSWeakRecord */ /* XXX: use a bit and an external hash table? */ must be enough to hold JS_ATOM_MAX/sizeof(JSString*)
XXX: for 64-bit platform 27 bits is enough, and 28 bits for 32-bit platform. */
uint32_t hash_next : 31;
uint8_t has_weak_ref : 1; /* if TRUE, has JSWeakRecord pointing to this object */
#ifdef DUMP_LEAKS #ifdef DUMP_LEAKS
struct list_head link; /* string list */ struct list_head link; /* string list */
#endif #endif
@ -921,7 +929,7 @@ struct JSObject {
uint8_t is_exotic : 1; /* TRUE if object has exotic property handlers */ uint8_t is_exotic : 1; /* TRUE if object has exotic property handlers */
uint8_t fast_array : 1; /* TRUE if u.array is used for get/put (for JS_CLASS_ARRAY, JS_CLASS_ARGUMENTS and typed arrays) */ uint8_t fast_array : 1; /* TRUE if u.array is used for get/put (for JS_CLASS_ARRAY, JS_CLASS_ARGUMENTS and typed arrays) */
uint8_t is_constructor : 1; /* TRUE if object is a constructor function */ uint8_t is_constructor : 1; /* TRUE if object is a constructor function */
uint8_t is_uncatchable_error : 1; /* if TRUE, error is not catchable */ uint8_t has_weak_ref : 1; /* if TRUE, has JSWeakRecord pointing to this object */
uint8_t tmp_mark : 1; /* used in JS_WriteObjectRec() */ uint8_t tmp_mark : 1; /* used in JS_WriteObjectRec() */
uint8_t is_HTMLDDA : 1; /* specific annex B IsHtmlDDA behavior */ uint8_t is_HTMLDDA : 1; /* specific annex B IsHtmlDDA behavior */
uint16_t class_id; /* see JS_CLASS_x */ uint16_t class_id; /* see JS_CLASS_x */
@ -931,8 +939,6 @@ struct JSObject {
JSShape *shape; /* prototype and property names + flag */ JSShape *shape; /* prototype and property names + flag */
JSProperty *prop; /* array of properties */ JSProperty *prop; /* array of properties */
/* byte offsets: 24/40 */ /* byte offsets: 24/40 */
struct list_head *weak_ref_list; /* list of JSWeakRecord */ /* XXX: use a bit and an external hash table? */
/* byte offsets: 28/48 */
union { union {
void *opaque; void *opaque;
struct JSBoundFunction *bound_function; /* JS_CLASS_BOUND_FUNCTION */ struct JSBoundFunction *bound_function; /* JS_CLASS_BOUND_FUNCTION */
@ -992,9 +998,14 @@ struct JSObject {
uint32_t count; /* <= 2^31-1. 0 for a detached typed array */ uint32_t count; /* <= 2^31-1. 0 for a detached typed array */
} array; /* 12/20 bytes */ } array; /* 12/20 bytes */
JSRegExp regexp; /* JS_CLASS_REGEXP: 8/16 bytes */ JSRegExp regexp; /* JS_CLASS_REGEXP: 8/16 bytes */
struct { /* JS_CLASS_ERROR 4 bytes */
uint8_t is_uncatchable_error : 1; /* if TRUE, error is not catchable */
uint32_t __unused_bits : 31;
} error;
JSValue object_data; /* for JS_SetObjectData(): 8/16/16 bytes */ JSValue object_data; /* for JS_SetObjectData(): 8/16/16 bytes */
} u; } u;
/* byte sizes: 40/48/72 */ /* byte sizes: 40/48/72 */ // TODO: update?, what is 48??? 40 is size on 32-bit platform, 64 72 on 64-bit.
/* byte sizes: 36/48/64 */
}; };
enum { enum {
@ -1043,6 +1054,26 @@ enum OPCodeEnum {
OP_TEMP_END, OP_TEMP_END,
}; };
typedef struct JSHashEntry {
struct list_head list; /* list in bucket */
} JSHashEntry;
typedef struct JSHashMap {
size_t capacity;
size_t size;
float load_factor; /* range in (0, 1] */
float shrink_factor; /* range in [0, load_factor) */
struct list_head *bucket;
void *(*get_key)(JSHashEntry *entry);
uint32_t (*key_hash)(void *key);
BOOL (*key_equals)(void *key1, void *key2);
} JSHashMap;
typedef struct JSHashMapIterator {
size_t index;
JSHashEntry *current;
} JSHashMapIterator;
static int JS_InitAtoms(JSRuntime *rt); static int JS_InitAtoms(JSRuntime *rt);
static JSAtom __JS_NewAtomInit(JSRuntime *rt, const char *str, int len, static JSAtom __JS_NewAtomInit(JSRuntime *rt, const char *str, int len,
int atom_type); int atom_type);
@ -1305,21 +1336,28 @@ static JSValue JS_InstantiateFunctionListItem2(JSContext *ctx, JSObject *p,
JSAtom atom, void *opaque); JSAtom atom, void *opaque);
static JSValue js_object_groupBy(JSContext *ctx, JSValueConst this_val, static JSValue js_object_groupBy(JSContext *ctx, JSValueConst this_val,
int argc, JSValueConst *argv, int is_map); int argc, JSValueConst *argv, int is_map);
static void js_init_weak_record(struct JSWeakRecord *wr, const struct JSWeakRecordOperations* operations);
struct list_head **js_get_target_weak_ref_list(JSContext *ctx, JSValueConst target); static void js_weak_record_init(struct JSWeakRecord *wr, const struct JSWeakRecordOperations* operations);
static BOOL js_add_weak_ref(JSContext *ctx, struct list_head **weak_ref_list, JSWeakRecord *wr); static struct JSWeakTargetRecord *js_weak_ref_obtain_target_record(JSContext *ctx, JSValueConst target);
static void js_unlink_weak_ref(JSWeakRecord *wr); static void js_weak_ref_add_record(JSContext *ctx, struct JSWeakTargetRecord *target, JSWeakRecord *wr);
static void js_reset_weak_ref(JSRuntime *rt, struct list_head **weak_ref_list); static void js_weak_ref_unlink(JSWeakRecord *wr);
static inline void js_object_reset_weak_ref(JSRuntime *rt, JSObject *p) static void js_weak_ref_reset(JSRuntime *rt, JSValueConst target);
{ static void js_weak_ref_free_runtime_map(JSRuntime *rt);
assert(p->weak_ref_list);
js_reset_weak_ref(rt, &p->weak_ref_list); static int js_hash_map_init(JSRuntime *rt, JSHashMap *map,
} size_t initial_size, /* pow of two */
static inline void js_atom_reset_weak_ref(JSRuntime *rt, JSAtomStruct *p) float load_factor, /* range in (0, +INF) */
{ float shrink_factor, /* range in [0, load_factor) */
assert(p->weak_ref_list); void *(*get_key)(JSHashEntry *entry),
js_reset_weak_ref(rt, &p->weak_ref_list); uint32_t (*key_hash)(void *key),
} BOOL (*key_equals)(void *key1, void *key2));
static void js_hash_map_release(JSRuntime *rt, JSHashMap *map,
void (*free_entry)(JSRuntime *rt, JSHashEntry *entry, void *data), void *data);
static size_t js_hash_map_size(JSHashMap *map);
static JSHashEntry *js_hash_map_find_entry(JSHashMap *map, void *key);
static int js_hash_map_add_entry(JSRuntime *rt, JSHashMap *map, JSHashEntry *entry);
static void js_hash_map_remove_entry(JSRuntime *rt, JSHashMap *map, JSHashEntry *entry);
static int js_hash_map_iterate_next_entry(JSHashMap *map, JSHashMapIterator *it);
static const JSClassExoticMethods js_arguments_exotic_methods; static const JSClassExoticMethods js_arguments_exotic_methods;
static const JSClassExoticMethods js_string_exotic_methods; static const JSClassExoticMethods js_string_exotic_methods;
@ -1723,6 +1761,7 @@ JSRuntime *JS_NewRuntime2(const JSMallocFunctions *mf, void *opaque)
JS_UpdateStackTop(rt); JS_UpdateStackTop(rt);
rt->current_exception = JS_UNINITIALIZED; rt->current_exception = JS_UNINITIALIZED;
rt->weak_target_map = NULL;
return rt; return rt;
fail: fail:
@ -1942,7 +1981,7 @@ static JSString *js_alloc_string_rt(JSRuntime *rt, int max_len, int is_wide_char
str->atom_type = 0; str->atom_type = 0;
str->hash = 0; /* optional but costless */ str->hash = 0; /* optional but costless */
str->hash_next = 0; /* optional */ str->hash_next = 0; /* optional */
str->weak_ref_list = NULL; str->has_weak_ref = 0;
#ifdef DUMP_LEAKS #ifdef DUMP_LEAKS
list_add_tail(&str->link, &rt->string_list); list_add_tail(&str->link, &rt->string_list);
#endif #endif
@ -2113,9 +2152,7 @@ void JS_FreeRuntime(JSRuntime *rt)
JSAtomStruct *p = rt->atom_array[i]; JSAtomStruct *p = rt->atom_array[i];
if (!atom_is_free(p)) { if (!atom_is_free(p)) {
/* reset weak reference */ /* reset weak reference */
if (p->weak_ref_list) { js_weak_ref_reset(rt, JS_MKPTR(JS_TAG_SYMBOL, p));
js_atom_reset_weak_ref(rt, p);
}
#ifdef DUMP_LEAKS #ifdef DUMP_LEAKS
list_del(&p->link); list_del(&p->link);
#endif #endif
@ -2125,6 +2162,10 @@ void JS_FreeRuntime(JSRuntime *rt)
js_free_rt(rt, rt->atom_array); js_free_rt(rt, rt->atom_array);
js_free_rt(rt, rt->atom_hash); js_free_rt(rt, rt->atom_hash);
js_free_rt(rt, rt->shape_hash); js_free_rt(rt, rt->shape_hash);
if (rt->weak_target_map) {
js_weak_ref_free_runtime_map(rt);
}
#ifdef DUMP_LEAKS #ifdef DUMP_LEAKS
if (!list_empty(&rt->string_list)) { if (!list_empty(&rt->string_list)) {
if (rt->rt_info) { if (rt->rt_info) {
@ -2816,7 +2857,6 @@ static JSAtom __JS_NewAtom(JSRuntime *rt, JSString *str, int atom_type)
} }
p->header.ref_count = 1; /* not refcounted */ p->header.ref_count = 1; /* not refcounted */
p->atom_type = JS_ATOM_TYPE_SYMBOL; p->atom_type = JS_ATOM_TYPE_SYMBOL;
p->weak_ref_list = NULL;
#ifdef DUMP_LEAKS #ifdef DUMP_LEAKS
list_add_tail(&p->link, &rt->string_list); list_add_tail(&p->link, &rt->string_list);
#endif #endif
@ -2850,7 +2890,7 @@ static JSAtom __JS_NewAtom(JSRuntime *rt, JSString *str, int atom_type)
p->header.ref_count = 1; p->header.ref_count = 1;
p->is_wide_char = str->is_wide_char; p->is_wide_char = str->is_wide_char;
p->len = str->len; p->len = str->len;
p->weak_ref_list = NULL; p->has_weak_ref = 0;
#ifdef DUMP_LEAKS #ifdef DUMP_LEAKS
list_add_tail(&p->link, &rt->string_list); list_add_tail(&p->link, &rt->string_list);
#endif #endif
@ -2865,7 +2905,7 @@ static JSAtom __JS_NewAtom(JSRuntime *rt, JSString *str, int atom_type)
p->header.ref_count = 1; p->header.ref_count = 1;
p->is_wide_char = 1; /* Hack to represent NULL as a JSString */ p->is_wide_char = 1; /* Hack to represent NULL as a JSString */
p->len = 0; p->len = 0;
p->weak_ref_list = NULL; p->has_weak_ref = 0;
#ifdef DUMP_LEAKS #ifdef DUMP_LEAKS
list_add_tail(&p->link, &rt->string_list); list_add_tail(&p->link, &rt->string_list);
#endif #endif
@ -2976,9 +3016,7 @@ static void JS_FreeAtomStruct(JSRuntime *rt, JSAtomStruct *p)
rt->atom_free_index = i; rt->atom_free_index = i;
/* release WeakRecord referencing to p */ /* release WeakRecord referencing to p */
if (unlikely(p->weak_ref_list)) { js_weak_ref_reset(rt, JS_MKPTR(JS_TAG_SYMBOL, p));
js_atom_reset_weak_ref(rt, p);
}
/* free the string structure */ /* free the string structure */
#ifdef DUMP_LEAKS #ifdef DUMP_LEAKS
@ -4824,10 +4862,9 @@ static JSValue JS_NewObjectFromShape(JSContext *ctx, JSShape *sh, JSClassID clas
p->is_exotic = 0; p->is_exotic = 0;
p->fast_array = 0; p->fast_array = 0;
p->is_constructor = 0; p->is_constructor = 0;
p->is_uncatchable_error = 0; p->has_weak_ref = 0;
p->tmp_mark = 0; p->tmp_mark = 0;
p->is_HTMLDDA = 0; p->is_HTMLDDA = 0;
p->weak_ref_list = NULL;
p->u.opaque = NULL; p->u.opaque = NULL;
p->shape = sh; p->shape = sh;
p->prop = js_malloc(ctx, sizeof(JSProperty) * sh->prop_size); p->prop = js_malloc(ctx, sizeof(JSProperty) * sh->prop_size);
@ -4901,6 +4938,9 @@ static JSValue JS_NewObjectFromShape(JSContext *ctx, JSShape *sh, JSClassID clas
p->u.regexp.pattern = NULL; p->u.regexp.pattern = NULL;
p->u.regexp.bytecode = NULL; p->u.regexp.bytecode = NULL;
goto set_exotic; goto set_exotic;
case JS_CLASS_ERROR:
p->u.error.is_uncatchable_error = 0;
break;
default: default:
set_exotic: set_exotic:
if (ctx->rt->class_array[class_id].exotic) { if (ctx->rt->class_array[class_id].exotic) {
@ -5516,9 +5556,7 @@ static void free_object(JSRuntime *rt, JSObject *p)
p->prop = NULL; p->prop = NULL;
/* release WeakRecord referencing to p */ /* release WeakRecord referencing to p */
if (unlikely(p->weak_ref_list)) { js_weak_ref_reset(rt, JS_MKPTR(JS_TAG_OBJECT, p));
js_object_reset_weak_ref(rt, p);
}
finalizer = rt->class_array[p->class_id].finalizer; finalizer = rt->class_array[p->class_id].finalizer;
if (finalizer) if (finalizer)
@ -9870,7 +9908,7 @@ BOOL JS_IsUncatchableError(JSContext *ctx, JSValueConst val)
if (JS_VALUE_GET_TAG(val) != JS_TAG_OBJECT) if (JS_VALUE_GET_TAG(val) != JS_TAG_OBJECT)
return FALSE; return FALSE;
p = JS_VALUE_GET_OBJ(val); p = JS_VALUE_GET_OBJ(val);
return p->class_id == JS_CLASS_ERROR && p->is_uncatchable_error; return p->class_id == JS_CLASS_ERROR && p->u.error.is_uncatchable_error;
} }
void JS_SetUncatchableError(JSContext *ctx, JSValueConst val, BOOL flag) void JS_SetUncatchableError(JSContext *ctx, JSValueConst val, BOOL flag)
@ -9880,7 +9918,7 @@ void JS_SetUncatchableError(JSContext *ctx, JSValueConst val, BOOL flag)
return; return;
p = JS_VALUE_GET_OBJ(val); p = JS_VALUE_GET_OBJ(val);
if (p->class_id == JS_CLASS_ERROR) if (p->class_id == JS_CLASS_ERROR)
p->is_uncatchable_error = flag; p->u.error.is_uncatchable_error = flag;
} }
void JS_ResetUncatchableError(JSContext *ctx) void JS_ResetUncatchableError(JSContext *ctx)
@ -47028,18 +47066,263 @@ static const JSCFunctionListEntry js_symbol_funcs[] = {
JS_CFUNC_DEF("keyFor", 1, js_symbol_keyFor ), JS_CFUNC_DEF("keyFor", 1, js_symbol_keyFor ),
}; };
/* JSObject/Atom weak support */ /* generic hash_map implementation */
static void js_init_weak_record(struct JSWeakRecord *wr, const struct JSWeakRecordOperations* operations) static int __js_hash_map_resize(JSRuntime *rt, JSHashMap *map, size_t new_size);
static size_t __js_hash_map_bucket_index(JSHashMap *map, void *key);
static int js_hash_map_init(JSRuntime *rt, JSHashMap *map,
size_t initial_size, /* must be pow of two */
float load_factor, /* range in (0, +INF) */
float shrink_factor, /* range in [0, load_factor) */
void *(*get_key)(JSHashEntry *entry),
uint32_t (*key_hash)(void *key),
BOOL (*key_equals)(void *key1, void *key2))
{ {
assert(operations); assert(load_factor > 0);
init_list_head(&wr->list); assert(shrink_factor >= 0 && shrink_factor < load_factor);
wr->operations = operations; assert(get_key && key_hash && key_equals);
map->capacity = 0;
map->size = 0;
map->bucket = NULL;
map->load_factor = load_factor;
map->shrink_factor = shrink_factor;
map->get_key = get_key;
map->key_hash = key_hash;
map->key_equals = key_equals;
if (unlikely(__js_hash_map_resize(rt, map, initial_size))) {
return -1;
}
return 0;
}
/* free hashmap internal data, doesn't free map itself */
static void js_hash_map_release(JSRuntime *rt, JSHashMap *map,
void (*free_entry)(JSRuntime *rt, JSHashEntry *entry, void *data), void *data)
{
JSHashMapIterator it = { 0 };
while(!js_hash_map_iterate_next_entry(map, &it)) {
JSHashEntry *entry = it.current;
list_del(&entry->list);
if (free_entry) {
free_entry(rt, entry, data);
}
it.current = NULL;
}
js_free_rt(rt, map->bucket);
/* fail safe */
map->capacity = 0;
map->size = 0;
map->bucket = NULL;
}
static inline size_t js_hash_map_size(JSHashMap *map)
{
return map->size;
}
static inline size_t __js_hash_map_bucket_index(JSHashMap *map, void *key)
{
uint32_t hash = map->key_hash(key);
/* spreads higher bits to lower */
hash ^= hash >> 16;
return hash & (map->capacity - 1);
}
static JSHashEntry *js_hash_map_find_entry(JSHashMap *map, void *key)
{
size_t bucket_index = __js_hash_map_bucket_index(map, key);
struct list_head *el;
struct list_head *bucket = &map->bucket[bucket_index];
list_for_each(el, bucket) {
JSHashEntry *entry = list_entry(el, JSHashEntry, list);
if (map->key_equals(map->get_key(entry), key)) {
return entry;
}
}
return NULL;
}
/* remember to init_list_head(entry->entry.list) */
static int js_hash_map_add_entry(JSRuntime *rt, JSHashMap *map, JSHashEntry *entry)
{
size_t bucket_index;
assert(entry);
assert(list_empty(&entry->list) || !entry->list.next); /* not added */
/* enlarge size */
if ((map->size + 1) > map->capacity * map->load_factor) {
if (unlikely(__js_hash_map_resize(rt, map, map->capacity << 1))) {
return -1;
}
}
bucket_index = __js_hash_map_bucket_index(map, map->get_key(entry));
list_add(&entry->list, &map->bucket[bucket_index]);
map->size++;
return 0;
}
/* remove entry from map, DOES NOT free(entry) */
static void js_hash_map_remove_entry(JSRuntime *rt, JSHashMap *map, JSHashEntry *entry)
{
map->size--;
list_del(&entry->list); /* unlink form bucket */
/* reduce size */
if (map->capacity > JS_HASH_MAP_DEFAULT_SIZE) {
float load = (map->size / (float)map->capacity);
if (load < map->shrink_factor) {
__js_hash_map_resize(rt, map, map->capacity >> 1);
}
}
}
static int __js_hash_map_resize(JSRuntime *rt, JSHashMap *map, size_t new_capacity)
{
size_t i;
size_t old_capacity;
struct list_head *el, *el1;
struct list_head *new_bucket;
struct list_head *old_bucket;
assert(new_capacity && (new_capacity & (new_capacity - 1)) == 0); /* pow of two */
if (new_capacity == map->capacity) {
return 0;
}
new_bucket = js_malloc_rt(rt, sizeof(map->bucket[0]) * new_capacity);
if (unlikely(!new_bucket)) {
return -1;
}
for (i = 0; i < new_capacity; i++) {
init_list_head(&new_bucket[i]);
}
/* add entries to new bucket */
old_capacity = map->capacity;
old_bucket = map->bucket;
map->capacity = new_capacity;
map->bucket = new_bucket;
for (i = 0; i < old_capacity; i++) {
list_for_each_safe(el, el1, &old_bucket[i]) {
JSHashEntry *entry = list_entry(el, JSHashEntry, list);
size_t new_index = __js_hash_map_bucket_index(map, map->get_key(entry));
list_del(&entry->list);
list_add(&entry->list, &new_bucket[new_index]);
}
}
js_free_rt(rt, old_bucket);
return 0;
}
/* 1. it.current == NULL returns first entry
2. when enumeration ends returns -1 and set it.current to NULL otherwise return 0.
Note: DO NOT modify hash map during iterating.
*/
static int js_hash_map_iterate_next_entry(JSHashMap *map, JSHashMapIterator *it)
{
size_t index;
struct list_head *current;
if (!map->size) {
return -1;
}
if (it->current) {
index = it->index;
current = &it->current->list;
} else {
index = 0;
current = &map->bucket[0];
}
while (index < map->capacity) {
current = current->next;
if (current != &map->bucket[index]) {
it->index = index;
it->current = list_entry(current, JSHashEntry, list);
return 0;
} else if (++index < map->capacity){
current = &map->bucket[index];
}
}
return -1;
}
/* JSObject/Atom weak support */
typedef struct JSWeakTargetRecord {
JSHashEntry entry;
void *target_ptr; /* key */
struct list_head weak_ref_list; /* value */
} JSWeakTargetRecord;
static void *__js_weak_ref_tr_get_key(JSHashEntry *entry)
{
return container_of(entry, JSWeakTargetRecord, entry)->target_ptr;
}
static uint32_t __js_weak_ref_tr_key_hash(void *key)
{
uint32_t hash;
if (sizeof(void *) == 8) {
uint64_t h = (uint64_t)(uintptr_t)key;
h ^= h >> 32;
hash = (uint32_t)h;
} else {
hash = (uint32_t)(uintptr_t)key;
}
return hash;
}
static BOOL __js_weak_ref_tr_key_equals(void *key1, void *key2)
{
return key1 == key2;
}
static JSHashMap * js_weak_ref_obtain_runtime_map(JSRuntime *rt)
{
if (!rt->weak_target_map) {
JSHashMap *weak_ref_map = js_malloc_rt(rt, sizeof(JSHashMap));
if (!weak_ref_map ||
js_hash_map_init(rt, weak_ref_map,
JS_HASH_MAP_DEFAULT_SIZE,
JS_HASH_MAP_DEFAULT_LOAD_FACTOR,
JS_HASH_MAP_DEFAULT_SHRINK_FACTOR,
__js_weak_ref_tr_get_key,
__js_weak_ref_tr_key_hash,
__js_weak_ref_tr_key_equals)) {
return NULL;
}
rt->weak_target_map = weak_ref_map;
}
return rt->weak_target_map;
}
static void js_weak_ref_free_runtime_map(JSRuntime *rt)
{
JSHashMap *map = rt->weak_target_map;
assert(rt->weak_target_map);
/* all object GCed, map should be empty */
assert(js_hash_map_size(map) == 0);
js_hash_map_release(rt, map, NULL, NULL);
js_free_rt(rt, map);
rt->weak_target_map = NULL;
} }
/* find the weak_ref_list of a Object or Symbol/Atom, /* find the weak_ref_list of a Object or Symbol/Atom,
on failure: return NULL and throw exception */ on failure: return NULL and throw exception */
struct list_head **js_get_target_weak_ref_list(JSContext *ctx, JSValueConst target) static JSWeakTargetRecord *js_weak_ref_obtain_target_record(JSContext *ctx, JSValueConst target)
{ {
JSRuntime *rt = ctx->rt;
JSHashMap *weak_ref_map;
void *target_ptr;
BOOL has_weak_ref = FALSE;
JSHashEntry *entry = NULL;
JSWeakTargetRecord *record;
/* the spec says: Thrown if target is not an object or a non-registered symbol. */ /* the spec says: Thrown if target is not an object or a non-registered symbol. */
if (JS_IsSymbol(target)) { if (JS_IsSymbol(target)) {
JSAtomStruct *p = JS_VALUE_GET_PTR(target); JSAtomStruct *p = JS_VALUE_GET_PTR(target);
@ -47047,43 +47330,108 @@ struct list_head **js_get_target_weak_ref_list(JSContext *ctx, JSValueConst targ
JS_ThrowTypeError(ctx, "registered symbol is not allowed"); JS_ThrowTypeError(ctx, "registered symbol is not allowed");
return NULL; return NULL;
} }
return &p->weak_ref_list; target_ptr = p;
has_weak_ref = p->has_weak_ref;
} else if (JS_IsObject(target)) { } else if (JS_IsObject(target)) {
JSObject *p = JS_VALUE_GET_OBJ(target); JSObject *p = JS_VALUE_GET_OBJ(target);
return &p->weak_ref_list; target_ptr = p;
has_weak_ref = p->has_weak_ref;
} else { } else {
JS_ThrowTypeError(ctx, "not a valid target"); JS_ThrowTypeError(ctx, "not a valid target");
return NULL; return NULL;
} }
weak_ref_map = js_weak_ref_obtain_runtime_map(rt);
if (unlikely(!weak_ref_map)) {
JS_ThrowOutOfMemory(ctx);
return NULL;
}
if (!has_weak_ref) {
record = js_malloc(ctx, sizeof(JSWeakTargetRecord));
if (unlikely(!record)) {
return NULL;
}
entry = &record->entry;
init_list_head(&entry->list);
record->target_ptr = target_ptr;
init_list_head(&record->weak_ref_list);
if (unlikely(js_hash_map_add_entry(rt, weak_ref_map, entry))) {
js_free(ctx, record);
JS_ThrowOutOfMemory(ctx);
return NULL;
}
/* set flag bit */
if (JS_IsObject(target)) {
((JSObject *)target_ptr)->has_weak_ref = 1;
} else if (JS_IsSymbol(target)) {
((JSAtomStruct *)target_ptr)->has_weak_ref = 1;
} else {
abort();
}
} else {
entry = js_hash_map_find_entry(weak_ref_map, target_ptr);
assert(entry);
record = container_of(entry, JSWeakTargetRecord, entry);
}
return record;
}
static void js_weak_record_init(struct JSWeakRecord *wr, const struct JSWeakRecordOperations* operations)
{
assert(operations);
init_list_head(&wr->list);
wr->operations = operations;
} }
/* Add weak record to object's weak reference list, on failure return FALSE and throw exception */ /* Add weak record to object's weak reference list, on failure return FALSE and throw exception */
static BOOL js_add_weak_ref(JSContext *ctx, struct list_head **weak_ref_list, JSWeakRecord *wr) static void js_weak_ref_add_record(JSContext *ctx, struct JSWeakTargetRecord *target, JSWeakRecord *wr)
{ {
if(likely(!*weak_ref_list)) { list_add(&wr->list, &target->weak_ref_list);
struct list_head *list = js_malloc(ctx, sizeof(*list));
if (unlikely(!list)) {
return FALSE;
}
init_list_head(list);
*weak_ref_list = list;
}
list_add(&wr->list, *weak_ref_list);
return TRUE;
} }
/* unlink the weak reference from the object weak reference list /* unlink the weak reference from the object weak reference list
eg. JSObject.u.weak_ref_list or JSString.weak_ref_list */ eg. JSWeakTargetRecord.weak_ref_list */
static void js_unlink_weak_ref(JSWeakRecord *wr) static void js_weak_ref_unlink(JSWeakRecord *wr)
{ {
list_del(&wr->list); list_del(&wr->list);
} }
/* reset object weak reference record, and do clean up */ /* reset object weak reference record, and do clean up */
static void js_reset_weak_ref(JSRuntime *rt, struct list_head **weak_ref_list)
static void js_weak_ref_reset(JSRuntime *rt, JSValueConst target)
{ {
struct list_head *list = *weak_ref_list; JSHashEntry *entry;
JSWeakTargetRecord *record;
struct list_head *list;
struct list_head *el, *el1; struct list_head *el, *el1;
void* target_ptr = NULL;
if (JS_IsObject(target)) {
JSObject *p = JS_VALUE_GET_OBJ(target);
if (p->has_weak_ref){
target_ptr = p;
}
} else if (JS_IsSymbol(target)) {
JSAtomStruct *p = JS_VALUE_GET_PTR(target);
if (p->has_weak_ref) {
target_ptr = p;
}
} else {
abort();
}
if(!target_ptr) {
return;
}
assert(rt->weak_target_map);
entry = js_hash_map_find_entry(rt->weak_target_map, target_ptr);
assert(entry);
record = container_of(entry, JSWeakTargetRecord, entry);
list = &record->weak_ref_list;
/* first pass to remove the records from the Weak... lists */ /* first pass to remove the records from the Weak... lists */
list_for_each(el, list) { list_for_each(el, list) {
@ -47102,8 +47450,8 @@ static void js_reset_weak_ref(JSRuntime *rt, struct list_head **weak_ref_list)
wr->operations->reset_weak_ref_second_pass(rt, wr); wr->operations->reset_weak_ref_second_pass(rt, wr);
} }
js_free_rt(rt, list); js_hash_map_remove_entry(rt, rt->weak_target_map, entry);
*weak_ref_list = NULL; /* fail safe */ js_free_rt(rt, record);
} }
/* WeakRef support */ /* WeakRef support */
@ -47134,10 +47482,10 @@ static const struct JSWeakRecordOperations js_weak_ref_operations = {
static JSValue js_new_weak_ref_internal(JSContext *ctx, JSValueConst ctor, JSValueConst target) static JSValue js_new_weak_ref_internal(JSContext *ctx, JSValueConst ctor, JSValueConst target)
{ {
JSValue weak_ref = JS_UNDEFINED; JSValue weak_ref = JS_UNDEFINED;
struct list_head **weak_ref_list = NULL; JSWeakTargetRecord *target_record;
weak_ref_list = js_get_target_weak_ref_list(ctx, target); target_record = js_weak_ref_obtain_target_record(ctx, target);
if (!weak_ref_list) { if (!target_record) {
goto fail; goto fail;
} }
@ -47148,14 +47496,12 @@ static JSValue js_new_weak_ref_internal(JSContext *ctx, JSValueConst ctor, JSVal
if (!ref) { if (!ref) {
goto fail; goto fail;
} }
js_init_weak_record(&ref->record, &js_weak_ref_operations); js_weak_record_init(&ref->record, &js_weak_ref_operations);
ref->this_obj = obj; ref->this_obj = obj;
ref->target = target; ref->target = target;
obj->u.weakref = ref; obj->u.weakref = ref;
if (!js_add_weak_ref(ctx, weak_ref_list, &ref->record)) { js_weak_ref_add_record(ctx, target_record, &ref->record);
goto fail;
}
} }
return weak_ref; return weak_ref;
@ -47211,7 +47557,7 @@ static void js_weakref_finalizer(JSRuntime *rt, JSValue val)
JSWeakRef *ref = p->u.weakref; JSWeakRef *ref = p->u.weakref;
if (ref) { if (ref) {
JSWeakRecord *record = &ref->record; JSWeakRecord *record = &ref->record;
js_unlink_weak_ref(record); js_weak_ref_unlink(record);
js_free_rt(rt, ref); js_free_rt(rt, ref);
} }
} }
@ -47250,7 +47596,7 @@ typedef struct JSMapRecord {
int ref_count; /* used during enumeration to avoid freeing the record */ int ref_count; /* used during enumeration to avoid freeing the record */
BOOL empty; /* TRUE if the record is deleted */ BOOL empty; /* TRUE if the record is deleted */
struct JSMapState *map; struct JSMapState *map;
JSWeakRecord weak_record; /* managed by JSObject.weak_ref_list */ JSWeakRecord weak_record; /* managed by JSWeakTargetRecord.weak_ref_list */
struct list_head link; struct list_head link;
struct list_head hash_link; struct list_head hash_link;
JSValue key; JSValue key;
@ -47499,13 +47845,14 @@ static JSMapRecord *map_add_record(JSContext *ctx, JSMapState *s,
mr->map = s; mr->map = s;
mr->empty = FALSE; mr->empty = FALSE;
if (s->is_weak) { if (s->is_weak) {
struct list_head **weak_ref_list = js_get_target_weak_ref_list(ctx, key); JSWeakTargetRecord *target_record = js_weak_ref_obtain_target_record(ctx, key);
js_init_weak_record(&mr->weak_record, &js_map_weak_operations); if (!target_record) {
/* Add the weak reference */
if (!weak_ref_list || !js_add_weak_ref(ctx, weak_ref_list, &mr->weak_record)) {
js_free(ctx, mr); js_free(ctx, mr);
return NULL; return NULL;
} }
/* Add the weak reference */
js_weak_record_init(&mr->weak_record, &js_map_weak_operations);
js_weak_ref_add_record(ctx, target_record, &mr->weak_record);
} else { } else {
JS_DupValue(ctx, key); JS_DupValue(ctx, key);
} }
@ -47526,7 +47873,7 @@ static void map_delete_record(JSRuntime *rt, JSMapState *s, JSMapRecord *mr)
return; return;
list_del(&mr->hash_link); list_del(&mr->hash_link);
if (s->is_weak) { if (s->is_weak) {
js_unlink_weak_ref(&mr->weak_record); js_weak_ref_unlink(&mr->weak_record);
} else { } else {
JS_FreeValueRT(rt, mr->key); JS_FreeValueRT(rt, mr->key);
} }
@ -47849,7 +48196,7 @@ static void js_map_finalizer(JSRuntime *rt, JSValue val)
mr = list_entry(el, JSMapRecord, link); mr = list_entry(el, JSMapRecord, link);
if (!mr->empty) { if (!mr->empty) {
if (s->is_weak) if (s->is_weak)
js_unlink_weak_ref(&mr->weak_record); js_weak_ref_unlink(&mr->weak_record);
else else
JS_FreeValueRT(rt, mr->key); JS_FreeValueRT(rt, mr->key);
JS_FreeValueRT(rt, mr->value); JS_FreeValueRT(rt, mr->value);

28
tests/microbench.js
View file

@ -1114,6 +1114,33 @@ function string_to_float(n)
return n; return n;
} }
function weakref(n)
{
var objs = new Array(n);
var weak1 = new Array(n);
var weak2 = new Array(n);
for (var i = 0; i < n; i++) {
objs[i] = { index: i };
weak1[i] = new WeakRef(objs[i]); /* init object hash table*/
weak2[i] = new WeakRef(objs[i]); /* find hsh table then add */
}
for (var i = 0; i < n; i++) {
weak1[i].deref();
weak2[i].deref();
}
for (var i = 0; i < n / 2; i++) {
objs[i] = undefined; /* release weak and hash table */
}
for (var i = 0; i < n; i++) {
weak1[i].deref();
weak2[i].deref();
}
weak1 = undefined;
weak2 = undefined;
objs = undefined;
return n * 3;
}
function load_result(filename) function load_result(filename)
{ {
var has_filename = filename; var has_filename = filename;
@ -1236,6 +1263,7 @@ function main(argc, argv, g)
float_to_string, float_to_string,
string_to_int, string_to_int,
string_to_float, string_to_float,
weakref,
]; ];
var tests = []; var tests = [];
var i, j, n, f, name, found; var i, j, n, f, name, found;

95
tests/test_builtin.js
View file

@ -794,44 +794,77 @@ function test_weak_map()
function test_weak_ref() function test_weak_ref()
{ {
var obj = {}; (function case_object() {
var ref = new WeakRef(obj); var obj = {};
var ref2 = new WeakRef(obj); var ref = new WeakRef(obj);
var ref2 = new WeakRef(obj);
assert(ref.deref(), obj); assert(ref.deref(), obj);
assert(ref2.deref(), obj); assert(ref2.deref(), obj);
obj = undefined; obj = undefined;
/* weak ref should be released */ /* weak ref should be released */
assert(ref.deref(), undefined); assert(ref.deref(), undefined);
assert(ref2.deref(), undefined); assert(ref2.deref(), undefined);
})();
// symbol (function case_symbol() {
var sym = Symbol("sym") var sym = Symbol("sym")
var ref3 = new WeakRef(sym); var ref3 = new WeakRef(sym);
assert(ref3.deref(), sym); assert(ref3.deref(), sym);
new WeakRef(Symbol.hasInstance); sym = undefined;
assert(ref3.deref(), undefined);
new WeakRef(Symbol.hasInstance);
})();
sym = undefined; (function case_bad_param() {
assert(ref3.deref(), undefined); function should_fail(block) {
try {
function should_fail(block) { block()
try { } catch (e) {
block() return
} catch (e) { }
return throw_error("weak ref should throw exception, but it not");
} }
throw_error("weak ref should throw exception, but it not");
}
should_fail(() => new WeakRef("string"));
should_fail(() => new WeakRef(/* number */0));
should_fail(() => new WeakRef(/* registered symbol */ Symbol.for("test")));
/* cyclic ref */ should_fail(() => new WeakRef("string"));
obj = {}; should_fail(() => new WeakRef(/* number */0));
ref = new WeakRef(obj); should_fail(() => new WeakRef(/* registered symbol */ Symbol.for("test")));
obj["x"] = ref; })();
(function case_cycle_ref() {
var obj = {};
var ref = new WeakRef(obj);
obj["x"] = ref;
})();
std.gc();
(function case_lots_of_weak() {
var size = 1000;
var objs = new Array(size);
var weak1 = new Array(size);
var weak2 = new Array(size);
for (var i = 0; i < size; i++) {
objs[i] = { index: i };
weak1[i] = new WeakRef(objs[i]);
weak2[i] = new WeakRef(objs[i]);
}
for (var i = 0; i < size; i++) {
assert(weak1[i].deref(), objs[i]);
assert(weak2[i].deref(), objs[i]);
}
for (var i = 0; i < size / 2; i++) {
objs[i] = undefined;
}
for (var i = 0; i < size / 2; i++) {
assert(weak1[i].deref(), undefined);
assert(weak2[i].deref(), undefined);
}
weak1 = undefined;
weak2 = undefined;
objs = undefined;
})();
} }
function test_generator() function test_generator()