1 /*
2 +----------------------------------------------------------------------+
3 | Copyright (c) The PHP Group |
4 +----------------------------------------------------------------------+
5 | This source file is subject to version 2.00 of the Zend license, |
6 | that is bundled with this package in the file LICENSE, and is |
7 | available through the world-wide-web at the following url: |
8 | http://www.zend.com/license/2_00.txt. |
9 | If you did not receive a copy of the Zend license and are unable to |
10 | obtain it through the world-wide-web, please send a note to |
11 | license@zend.com so we can mail you a copy immediately. |
12 +----------------------------------------------------------------------+
13 | Authors: krakjoe@php.net |
14 +----------------------------------------------------------------------+
15 */
16
17 #ifndef ZEND_WEAKREFS_H
18 #define ZEND_WEAKREFS_H
19
20 #include "zend_alloc.h"
21
22 BEGIN_EXTERN_C()
23
24 extern ZEND_API zend_class_entry *zend_ce_weakref;
25
26 void zend_register_weakref_ce(void);
27
28 void zend_weakrefs_init(void);
29 void zend_weakrefs_shutdown(void);
30
31 ZEND_API void zend_weakrefs_notify(zend_object *object);
32
33 ZEND_API zval *zend_weakrefs_hash_add(HashTable *ht, zend_object *key, zval *pData);
34 ZEND_API zend_result zend_weakrefs_hash_del(HashTable *ht, zend_object *key);
zend_weakrefs_hash_add_ptr(HashTable * ht,zend_object * key,void * ptr)35 static zend_always_inline void *zend_weakrefs_hash_add_ptr(HashTable *ht, zend_object *key, void *ptr) {
36 zval tmp, *zv;
37 ZVAL_PTR(&tmp, ptr);
38 if ((zv = zend_weakrefs_hash_add(ht, key, &tmp))) {
39 return Z_PTR_P(zv);
40 } else {
41 return NULL;
42 }
43 }
44
45 /* Because php uses the raw numbers as a hash function, raw pointers will lead to hash collisions.
46 * We have a guarantee that the lowest ZEND_MM_ALIGNED_OFFSET_LOG2 bits of a pointer are zero.
47 *
48 * E.g. On most 64-bit platforms, pointers are aligned to 8 bytes, so the least significant 3 bits are always 0 and can be discarded.
49 *
50 * NOTE: This function is only used for EG(weakrefs) and zend_weakmap->ht.
51 * It is not used for the HashTable instances associated with ZEND_WEAKREF_TAG_HT tags (created in zend_weakref_register, which uses ZEND_WEAKREF_ENCODE instead).
52 * The ZEND_WEAKREF_TAG_HT instances are used to disambiguate between multiple weak references to the same zend_object.
53 */
zend_object_to_weakref_key(const zend_object * object)54 static zend_always_inline zend_ulong zend_object_to_weakref_key(const zend_object *object)
55 {
56 ZEND_ASSERT(((uintptr_t)object) % ZEND_MM_ALIGNMENT == 0);
57 return ((uintptr_t) object) >> ZEND_MM_ALIGNMENT_LOG2;
58 }
59
zend_weakref_key_to_object(zend_ulong key)60 static zend_always_inline zend_object *zend_weakref_key_to_object(zend_ulong key)
61 {
62 return (zend_object *) (((uintptr_t) key) << ZEND_MM_ALIGNMENT_LOG2);
63 }
64
65 HashTable *zend_weakmap_get_gc(zend_object *object, zval **table, int *n);
66 HashTable *zend_weakmap_get_key_entry_gc(zend_object *object, zval **table, int *n);
67 HashTable *zend_weakmap_get_entry_gc(zend_object *object, zval **table, int *n);
68 HashTable *zend_weakmap_get_object_key_entry_gc(zend_object *object, zval **table, int *n);
69 HashTable *zend_weakmap_get_object_entry_gc(zend_object *object, zval **table, int *n);
70
71 END_EXTERN_C()
72
73 #endif
74
75
