/* +----------------------------------------------------------------------+ | Copyright (c) The PHP Group | +----------------------------------------------------------------------+ | This source file is subject to version 2.00 of the Zend license, | | that is bundled with this package in the file LICENSE, and is | | available through the world-wide-web at the following url: | | http://www.zend.com/license/2_00.txt. | | If you did not receive a copy of the Zend license and are unable to | | obtain it through the world-wide-web, please send a note to | | license@zend.com so we can mail you a copy immediately. | +----------------------------------------------------------------------+ | Authors: krakjoe@php.net | +----------------------------------------------------------------------+ */ #include "zend.h" #include "zend_interfaces.h" #include "zend_objects_API.h" #include "zend_weakrefs.h" #include "zend_weakrefs_arginfo.h" typedef struct _zend_weakref { zend_object *referent; zend_object std; } zend_weakref; typedef struct _zend_weakmap { HashTable ht; zend_object std; } zend_weakmap; typedef struct _zend_weakmap_iterator { zend_object_iterator it; uint32_t ht_iter; } zend_weakmap_iterator; /* The EG(weakrefs) ht is a map from object address a tagged pointer, that may be one of * zend_weakref*, zend_weakmap* or HashTable*. */ #define ZEND_WEAKREF_TAG_REF 0 #define ZEND_WEAKREF_TAG_MAP 1 #define ZEND_WEAKREF_TAG_HT 2 #define ZEND_WEAKREF_GET_TAG(p) (((uintptr_t) (p)) & 3) #define ZEND_WEAKREF_GET_PTR(p) ((void *) (((uintptr_t) (p)) & ~3)) #define ZEND_WEAKREF_ENCODE(p, t) ((void *) (((uintptr_t) (p)) | (t))) zend_class_entry *zend_ce_weakref; zend_class_entry *zend_ce_weakmap; static zend_object_handlers zend_weakref_handlers; static zend_object_handlers zend_weakmap_handlers; #define zend_weakref_from(o) ((zend_weakref*)(((char*) o) - XtOffsetOf(zend_weakref, std))) #define zend_weakref_fetch(z) zend_weakref_from(Z_OBJ_P(z)) #define zend_weakmap_from(o) ((zend_weakmap*)(((char*) o) - XtOffsetOf(zend_weakmap, std))) #define zend_weakmap_fetch(z) zend_weakmap_from(Z_OBJ_P(z)) static inline void zend_weakref_unref_single( void *ptr, uintptr_t tag, zend_ulong obj_addr) { if (tag == ZEND_WEAKREF_TAG_REF) { zend_weakref *wr = ptr; wr->referent = NULL; } else { ZEND_ASSERT(tag == ZEND_WEAKREF_TAG_MAP); zend_weakmap *wm = ptr; zend_hash_index_del(&wm->ht, obj_addr); } } static void zend_weakref_unref(zend_ulong obj_addr, void *tagged_ptr) { void *ptr = ZEND_WEAKREF_GET_PTR(tagged_ptr); uintptr_t tag = ZEND_WEAKREF_GET_TAG(tagged_ptr); if (tag == ZEND_WEAKREF_TAG_HT) { HashTable *ht = ptr; ZEND_HASH_FOREACH_PTR(ht, tagged_ptr) { zend_weakref_unref_single( ZEND_WEAKREF_GET_PTR(tagged_ptr), ZEND_WEAKREF_GET_TAG(tagged_ptr), obj_addr); } ZEND_HASH_FOREACH_END(); zend_hash_destroy(ht); FREE_HASHTABLE(ht); } else { zend_weakref_unref_single(ptr, tag, obj_addr); } } static void zend_weakref_register(zend_object *object, void *payload) { GC_ADD_FLAGS(object, IS_OBJ_WEAKLY_REFERENCED); zend_ulong obj_addr = (zend_ulong) object; zval *zv = zend_hash_index_find(&EG(weakrefs), obj_addr); if (!zv) { zend_hash_index_add_new_ptr(&EG(weakrefs), obj_addr, payload); return; } void *tagged_ptr = Z_PTR_P(zv); if (ZEND_WEAKREF_GET_TAG(tagged_ptr) == ZEND_WEAKREF_TAG_HT) { HashTable *ht = ZEND_WEAKREF_GET_PTR(tagged_ptr); zend_hash_index_add_new_ptr(ht, (zend_ulong) payload, payload); return; } /* Convert simple pointer to hashtable. */ HashTable *ht = emalloc(sizeof(HashTable)); zend_hash_init(ht, 0, NULL, NULL, 0); zend_hash_index_add_new_ptr(ht, (zend_ulong) tagged_ptr, tagged_ptr); zend_hash_index_add_new_ptr(ht, (zend_ulong) payload, payload); zend_hash_index_update_ptr( &EG(weakrefs), obj_addr, ZEND_WEAKREF_ENCODE(ht, ZEND_WEAKREF_TAG_HT)); } static void zend_weakref_unregister(zend_object *object, void *payload) { zend_ulong obj_addr = (zend_ulong) object; void *tagged_ptr = zend_hash_index_find_ptr(&EG(weakrefs), obj_addr); ZEND_ASSERT(tagged_ptr && "Weakref not registered?"); void *ptr = ZEND_WEAKREF_GET_PTR(tagged_ptr); uintptr_t tag = ZEND_WEAKREF_GET_TAG(tagged_ptr); if (tag != ZEND_WEAKREF_TAG_HT) { ZEND_ASSERT(tagged_ptr == payload); zend_hash_index_del(&EG(weakrefs), obj_addr); GC_DEL_FLAGS(object, IS_OBJ_WEAKLY_REFERENCED); /* Do this last, as it may destroy the object. */ zend_weakref_unref_single(ptr, tag, obj_addr); return; } HashTable *ht = ptr; tagged_ptr = zend_hash_index_find_ptr(ht, (zend_ulong) payload); ZEND_ASSERT(tagged_ptr && "Weakref not registered?"); ZEND_ASSERT(tagged_ptr == payload); zend_hash_index_del(ht, (zend_ulong) payload); if (zend_hash_num_elements(ht) == 0) { GC_DEL_FLAGS(object, IS_OBJ_WEAKLY_REFERENCED); zend_hash_destroy(ht); FREE_HASHTABLE(ht); zend_hash_index_del(&EG(weakrefs), obj_addr); } /* Do this last, as it may destroy the object. */ zend_weakref_unref_single( ZEND_WEAKREF_GET_PTR(payload), ZEND_WEAKREF_GET_TAG(payload), obj_addr); } void zend_weakrefs_init(void) { zend_hash_init(&EG(weakrefs), 8, NULL, NULL, 0); } void zend_weakrefs_notify(zend_object *object) { /* Annoyingly we can't use the HT destructor here, because we need access to the key (which * is the object address), which is not provided to the dtor. */ zend_ulong obj_addr = (zend_ulong) object; void *tagged_ptr = zend_hash_index_find_ptr(&EG(weakrefs), obj_addr); #if ZEND_DEBUG ZEND_ASSERT(tagged_ptr && "Tracking of the IS_OBJ_WEAKLY_REFERENCE flag should be precise"); #endif if (tagged_ptr) { zend_weakref_unref(obj_addr, tagged_ptr); zend_hash_index_del(&EG(weakrefs), obj_addr); } } void zend_weakrefs_shutdown(void) { zend_ulong obj_addr; void *tagged_ptr; ZEND_HASH_FOREACH_NUM_KEY_PTR(&EG(weakrefs), obj_addr, tagged_ptr) { zend_weakref_unref(obj_addr, tagged_ptr); } ZEND_HASH_FOREACH_END(); zend_hash_destroy(&EG(weakrefs)); } static zend_object* zend_weakref_new(zend_class_entry *ce) { zend_weakref *wr = zend_object_alloc(sizeof(zend_weakref), zend_ce_weakref); zend_object_std_init(&wr->std, zend_ce_weakref); wr->std.handlers = &zend_weakref_handlers; return &wr->std; } static zend_always_inline bool zend_weakref_find(zend_object *referent, zval *return_value) { void *tagged_ptr = zend_hash_index_find_ptr(&EG(weakrefs), (zend_ulong) referent); if (!tagged_ptr) { return 0; } void *ptr = ZEND_WEAKREF_GET_PTR(tagged_ptr); uintptr_t tag = ZEND_WEAKREF_GET_TAG(tagged_ptr); if (tag == ZEND_WEAKREF_TAG_REF) { zend_weakref *wr; found_weakref: wr = ptr; RETVAL_OBJ_COPY(&wr->std); return 1; } if (tag == ZEND_WEAKREF_TAG_HT) { ZEND_HASH_FOREACH(ptr, tagged_ptr) { if (ZEND_WEAKREF_GET_TAG(tagged_ptr) == ZEND_WEAKREF_TAG_REF) { ptr = ZEND_WEAKREF_GET_PTR(tagged_ptr); goto found_weakref; } } ZEND_HASH_FOREACH_END(); } return 0; } static zend_always_inline void zend_weakref_create(zend_object *referent, zval *return_value) { zend_weakref *wr; object_init_ex(return_value, zend_ce_weakref); wr = zend_weakref_fetch(return_value); wr->referent = referent; zend_weakref_register(wr->referent, ZEND_WEAKREF_ENCODE(wr, ZEND_WEAKREF_TAG_REF)); } static zend_always_inline void zend_weakref_get(zval *weakref, zval *return_value) { zend_weakref *wr = zend_weakref_fetch(weakref); if (wr->referent) { RETVAL_OBJ_COPY(wr->referent); } } static void zend_weakref_free(zend_object *zo) { zend_weakref *wr = zend_weakref_from(zo); if (wr->referent) { zend_weakref_unregister(wr->referent, ZEND_WEAKREF_ENCODE(wr, ZEND_WEAKREF_TAG_REF)); } zend_object_std_dtor(&wr->std); } ZEND_COLD ZEND_METHOD(WeakReference, __construct) { zend_throw_error(NULL, "Direct instantiation of WeakReference is not allowed, use WeakReference::create instead"); } ZEND_METHOD(WeakReference, create) { zend_object *referent; ZEND_PARSE_PARAMETERS_START(1,1) Z_PARAM_OBJ(referent) ZEND_PARSE_PARAMETERS_END(); if (zend_weakref_find(referent, return_value)) { return; } zend_weakref_create(referent, return_value); } ZEND_METHOD(WeakReference, get) { ZEND_PARSE_PARAMETERS_NONE(); zend_weakref_get(getThis(), return_value); } static zend_object *zend_weakmap_create_object(zend_class_entry *ce) { zend_weakmap *wm = zend_object_alloc(sizeof(zend_weakmap), ce); zend_object_std_init(&wm->std, ce); wm->std.handlers = &zend_weakmap_handlers; zend_hash_init(&wm->ht, 0, NULL, ZVAL_PTR_DTOR, 0); return &wm->std; } static void zend_weakmap_free_obj(zend_object *object) { zend_weakmap *wm = zend_weakmap_from(object); zend_ulong obj_addr; ZEND_HASH_FOREACH_NUM_KEY(&wm->ht, obj_addr) { zend_weakref_unregister( (zend_object *) obj_addr, ZEND_WEAKREF_ENCODE(wm, ZEND_WEAKREF_TAG_MAP)); } ZEND_HASH_FOREACH_END(); zend_hash_destroy(&wm->ht); zend_object_std_dtor(&wm->std); } static zval *zend_weakmap_read_dimension(zend_object *object, zval *offset, int type, zval *rv) { if (offset == NULL) { zend_throw_error(NULL, "Cannot append to WeakMap"); return NULL; } if (Z_TYPE_P(offset) != IS_OBJECT) { zend_type_error("WeakMap key must be an object"); return NULL; } zend_weakmap *wm = zend_weakmap_from(object); zend_object *obj_key = Z_OBJ_P(offset); zval *zv = zend_hash_index_find(&wm->ht, (zend_ulong) obj_key); if (zv == NULL) { if (type != BP_VAR_IS) { zend_throw_error(NULL, "Object %s#%d not contained in WeakMap", ZSTR_VAL(obj_key->ce->name), obj_key->handle); return NULL; } return NULL; } if (type == BP_VAR_W || type == BP_VAR_RW) { ZVAL_MAKE_REF(zv); } return zv; } static void zend_weakmap_write_dimension(zend_object *object, zval *offset, zval *value) { if (offset == NULL) { zend_throw_error(NULL, "Cannot append to WeakMap"); return; } if (Z_TYPE_P(offset) != IS_OBJECT) { zend_type_error("WeakMap key must be an object"); return; } zend_weakmap *wm = zend_weakmap_from(object); zend_object *obj_key = Z_OBJ_P(offset); Z_TRY_ADDREF_P(value); zval *zv = zend_hash_index_find(&wm->ht, (zend_ulong) obj_key); if (zv) { zval_ptr_dtor(zv); ZVAL_COPY_VALUE(zv, value); return; } zend_weakref_register(obj_key, ZEND_WEAKREF_ENCODE(wm, ZEND_WEAKREF_TAG_MAP)); zend_hash_index_add_new(&wm->ht, (zend_ulong) obj_key, value); } /* int return and check_empty due to Object Handler API */ static int zend_weakmap_has_dimension(zend_object *object, zval *offset, int check_empty) { if (Z_TYPE_P(offset) != IS_OBJECT) { zend_type_error("WeakMap key must be an object"); return 0; } zend_weakmap *wm = zend_weakmap_from(object); zval *zv = zend_hash_index_find(&wm->ht, (zend_ulong) Z_OBJ_P(offset)); if (!zv) { return 0; } if (check_empty) { return i_zend_is_true(zv); } return Z_TYPE_P(zv) != IS_NULL; } static void zend_weakmap_unset_dimension(zend_object *object, zval *offset) { if (Z_TYPE_P(offset) != IS_OBJECT) { zend_type_error("WeakMap key must be an object"); return; } zend_weakmap *wm = zend_weakmap_from(object); zend_object *obj_key = Z_OBJ_P(offset); if (!zend_hash_index_exists(&wm->ht, (zend_ulong) Z_OBJ_P(offset))) { /* Object not in WeakMap, do nothing. */ return; } zend_weakref_unregister(obj_key, ZEND_WEAKREF_ENCODE(wm, ZEND_WEAKREF_TAG_MAP)); } static int zend_weakmap_count_elements(zend_object *object, zend_long *count) { zend_weakmap *wm = zend_weakmap_from(object); *count = zend_hash_num_elements(&wm->ht); return SUCCESS; } static HashTable *zend_weakmap_get_properties_for(zend_object *object, zend_prop_purpose purpose) { if (purpose != ZEND_PROP_PURPOSE_DEBUG) { return NULL; } zend_weakmap *wm = zend_weakmap_from(object); HashTable *ht; ALLOC_HASHTABLE(ht); zend_hash_init(ht, zend_hash_num_elements(&wm->ht), NULL, ZVAL_PTR_DTOR, 0); zend_ulong obj_addr; zval *val; ZEND_HASH_FOREACH_NUM_KEY_VAL(&wm->ht, obj_addr, val) { zend_object *obj = (zend_object*)obj_addr; zval pair; array_init(&pair); GC_ADDREF(obj); add_assoc_object(&pair, "key", obj); Z_TRY_ADDREF_P(val); add_assoc_zval(&pair, "value", val); zend_hash_next_index_insert(ht, &pair); } ZEND_HASH_FOREACH_END(); return ht; } static HashTable *zend_weakmap_get_gc(zend_object *object, zval **table, int *n) { zend_weakmap *wm = zend_weakmap_from(object); *table = NULL; *n = 0; return &wm->ht; } static zend_object *zend_weakmap_clone_obj(zend_object *old_object) { zend_object *new_object = zend_weakmap_create_object(zend_ce_weakmap); zend_weakmap *old_wm = zend_weakmap_from(old_object); zend_weakmap *new_wm = zend_weakmap_from(new_object); zend_hash_copy(&new_wm->ht, &old_wm->ht, NULL); zend_ulong obj_addr; zval *val; ZEND_HASH_FOREACH_NUM_KEY_VAL(&new_wm->ht, obj_addr, val) { zend_weakref_register( (zend_object *) obj_addr, ZEND_WEAKREF_ENCODE(new_wm, ZEND_WEAKREF_TAG_MAP)); zval_add_ref(val); } ZEND_HASH_FOREACH_END(); return new_object; } static HashPosition *zend_weakmap_iterator_get_pos_ptr(zend_weakmap_iterator *iter) { ZEND_ASSERT(iter->ht_iter != (uint32_t) -1); return &EG(ht_iterators)[iter->ht_iter].pos; } static void zend_weakmap_iterator_dtor(zend_object_iterator *obj_iter) { zend_weakmap_iterator *iter = (zend_weakmap_iterator *) obj_iter; zend_hash_iterator_del(iter->ht_iter); zval_ptr_dtor(&iter->it.data); } static int zend_weakmap_iterator_valid(zend_object_iterator *obj_iter) { zend_weakmap_iterator *iter = (zend_weakmap_iterator *) obj_iter; zend_weakmap *wm = zend_weakmap_fetch(&iter->it.data); HashPosition *pos = zend_weakmap_iterator_get_pos_ptr(iter); return zend_hash_has_more_elements_ex(&wm->ht, pos); } static zval *zend_weakmap_iterator_get_current_data(zend_object_iterator *obj_iter) { zend_weakmap_iterator *iter = (zend_weakmap_iterator *) obj_iter; zend_weakmap *wm = zend_weakmap_fetch(&iter->it.data); HashPosition *pos = zend_weakmap_iterator_get_pos_ptr(iter); return zend_hash_get_current_data_ex(&wm->ht, pos); } static void zend_weakmap_iterator_get_current_key(zend_object_iterator *obj_iter, zval *key) { zend_weakmap_iterator *iter = (zend_weakmap_iterator *) obj_iter; zend_weakmap *wm = zend_weakmap_fetch(&iter->it.data); HashPosition *pos = zend_weakmap_iterator_get_pos_ptr(iter); zend_string *string_key; zend_ulong num_key; int key_type = zend_hash_get_current_key_ex(&wm->ht, &string_key, &num_key, pos); if (key_type != HASH_KEY_IS_LONG) { ZEND_ASSERT(0 && "Must have integer key"); } ZVAL_OBJ_COPY(key, (zend_object *) num_key); } static void zend_weakmap_iterator_move_forward(zend_object_iterator *obj_iter) { zend_weakmap_iterator *iter = (zend_weakmap_iterator *) obj_iter; zend_weakmap *wm = zend_weakmap_fetch(&iter->it.data); HashPosition *pos = zend_weakmap_iterator_get_pos_ptr(iter); zend_hash_move_forward_ex(&wm->ht, pos); } static void zend_weakmap_iterator_rewind(zend_object_iterator *obj_iter) { zend_weakmap_iterator *iter = (zend_weakmap_iterator *) obj_iter; zend_weakmap *wm = zend_weakmap_fetch(&iter->it.data); HashPosition *pos = zend_weakmap_iterator_get_pos_ptr(iter); zend_hash_internal_pointer_reset_ex(&wm->ht, pos); } static const zend_object_iterator_funcs zend_weakmap_iterator_funcs = { zend_weakmap_iterator_dtor, zend_weakmap_iterator_valid, zend_weakmap_iterator_get_current_data, zend_weakmap_iterator_get_current_key, zend_weakmap_iterator_move_forward, zend_weakmap_iterator_rewind, NULL, NULL, /* get_gc */ }; /* by_ref is int due to Iterator API */ static zend_object_iterator *zend_weakmap_get_iterator( zend_class_entry *ce, zval *object, int by_ref) { zend_weakmap *wm = zend_weakmap_fetch(object); zend_weakmap_iterator *iter = emalloc(sizeof(zend_weakmap_iterator)); zend_iterator_init(&iter->it); iter->it.funcs = &zend_weakmap_iterator_funcs; ZVAL_COPY(&iter->it.data, object); iter->ht_iter = zend_hash_iterator_add(&wm->ht, 0); return &iter->it; } ZEND_METHOD(WeakMap, offsetGet) { zval *key; if (zend_parse_parameters(ZEND_NUM_ARGS(), "z", &key) == FAILURE) { return; } zval *zv = zend_weakmap_read_dimension(Z_OBJ_P(ZEND_THIS), key, BP_VAR_R, NULL); if (!zv) { return; } ZVAL_COPY(return_value, zv); } ZEND_METHOD(WeakMap, offsetSet) { zval *key, *value; if (zend_parse_parameters(ZEND_NUM_ARGS(), "zz", &key, &value) == FAILURE) { return; } zend_weakmap_write_dimension(Z_OBJ_P(ZEND_THIS), key, value); } ZEND_METHOD(WeakMap, offsetExists) { zval *key; if (zend_parse_parameters(ZEND_NUM_ARGS(), "z", &key) == FAILURE) { return; } RETURN_BOOL(zend_weakmap_has_dimension(Z_OBJ_P(ZEND_THIS), key, /* check_empty */ 0)); } ZEND_METHOD(WeakMap, offsetUnset) { zval *key; if (zend_parse_parameters(ZEND_NUM_ARGS(), "z", &key) == FAILURE) { return; } zend_weakmap_unset_dimension(Z_OBJ_P(ZEND_THIS), key); } ZEND_METHOD(WeakMap, count) { if (zend_parse_parameters_none() == FAILURE) { return; } zend_long count; zend_weakmap_count_elements(Z_OBJ_P(ZEND_THIS), &count); RETURN_LONG(count); } ZEND_METHOD(WeakMap, getIterator) { if (zend_parse_parameters_none() == FAILURE) { return; } zend_create_internal_iterator_zval(return_value, ZEND_THIS); } void zend_register_weakref_ce(void) /* {{{ */ { zend_ce_weakref = register_class_WeakReference(); zend_ce_weakref->create_object = zend_weakref_new; zend_ce_weakref->serialize = zend_class_serialize_deny; zend_ce_weakref->unserialize = zend_class_unserialize_deny; memcpy(&zend_weakref_handlers, zend_get_std_object_handlers(), sizeof(zend_object_handlers)); zend_weakref_handlers.offset = XtOffsetOf(zend_weakref, std); zend_weakref_handlers.free_obj = zend_weakref_free; zend_weakref_handlers.clone_obj = NULL; zend_ce_weakmap = register_class_WeakMap(zend_ce_arrayaccess, zend_ce_countable, zend_ce_aggregate); zend_ce_weakmap->create_object = zend_weakmap_create_object; zend_ce_weakmap->get_iterator = zend_weakmap_get_iterator; zend_ce_weakmap->serialize = zend_class_serialize_deny; zend_ce_weakmap->unserialize = zend_class_unserialize_deny; memcpy(&zend_weakmap_handlers, zend_get_std_object_handlers(), sizeof(zend_object_handlers)); zend_weakmap_handlers.offset = XtOffsetOf(zend_weakmap, std); zend_weakmap_handlers.free_obj = zend_weakmap_free_obj; zend_weakmap_handlers.read_dimension = zend_weakmap_read_dimension; zend_weakmap_handlers.write_dimension = zend_weakmap_write_dimension; zend_weakmap_handlers.has_dimension = zend_weakmap_has_dimension; zend_weakmap_handlers.unset_dimension = zend_weakmap_unset_dimension; zend_weakmap_handlers.count_elements = zend_weakmap_count_elements; zend_weakmap_handlers.get_properties_for = zend_weakmap_get_properties_for; zend_weakmap_handlers.get_gc = zend_weakmap_get_gc; zend_weakmap_handlers.clone_obj = zend_weakmap_clone_obj; } /* }}} */