Add helper APIs for get_gc implementations

get_gc() implementations that need to explore heterogeneous data
currently work by computing how many GC entries they need,
allocating a buffer for that and storing it on the object. This
is inefficient and wastes memory, because the buffer is retained
after the GC run.

This commit adds an API for a single global GC buffer, which can
be reused by get_gc implementations (as only one get_gc call is
ever active at the same time). The GC buffer will automatically
grow during the GC run and be discarded at the end.

2 files changed, 7 insertions, 33 deletions

diff --git a/ext/spl/spl_dllist.c b/ext/spl/spl_dllist.c
index 306aefa5d8..ef0e5b60ff 100644
--- a/ext/spl/spl_dllist.c
+++ b/ext/spl/spl_dllist.c
@@ -91,8 +91,6 @@ struct _spl_dllist_object {
 	zend_function         *fptr_offset_del;
 	zend_function         *fptr_count;
 	zend_class_entry      *ce_get_iterator;
-	zval                  *gc_data;
-	int                    gc_data_count;
 	zend_object            std;
 };
 
@@ -356,10 +354,6 @@ static void spl_dllist_object_free_storage(zend_object *object) /* {{{ */
 		zval_ptr_dtor(&tmp);
 	}
 
-	if (intern->gc_data != NULL) {
-		efree(intern->gc_data);
-	};
-
 	spl_ptr_llist_destroy(intern->llist);
 	SPL_LLIST_CHECK_DELREF(intern->traverse_pointer);
 }
@@ -534,21 +528,15 @@ static inline HashTable* spl_dllist_object_get_debug_info(zend_object *obj) /* {
 static HashTable *spl_dllist_object_get_gc(zend_object *obj, zval **gc_data, int *gc_data_count) /* {{{ */
 {
 	spl_dllist_object *intern = spl_dllist_from_obj(obj);
+	zend_get_gc_buffer *gc_buffer = zend_get_gc_buffer_create();
 	spl_ptr_llist_element *current = intern->llist->head;
-	int i = 0;
-
-	if (intern->gc_data_count < intern->llist->count) {
-		intern->gc_data_count = intern->llist->count;
-		intern->gc_data = safe_erealloc(intern->gc_data, intern->gc_data_count, sizeof(zval), 0);
-	}
 
 	while (current) {
-		ZVAL_COPY_VALUE(&intern->gc_data[i++], &current->data);
+		zend_get_gc_buffer_add_zval(gc_buffer, &current->data);
 		current = current->next;
 	}
 
-	*gc_data = intern->gc_data;
-	*gc_data_count = i;
+	zend_get_gc_buffer_use(gc_buffer, gc_data, gc_data_count);
 	return zend_std_get_properties(obj);
 }
 /* }}} */
diff --git a/ext/spl/spl_observer.c b/ext/spl/spl_observer.c
index 09f27595d9..bcf3a39535 100644
--- a/ext/spl/spl_observer.c
+++ b/ext/spl/spl_observer.c
@@ -50,8 +50,6 @@ typedef struct _spl_SplObjectStorage { /* {{{ */
 	HashPosition      pos;
 	zend_long         flags;
 	zend_function    *fptr_get_hash;
-	zval             *gcdata;
-	size_t            gcdata_num;
 	zend_object       std;
 } spl_SplObjectStorage; /* }}} */
 
@@ -75,11 +73,6 @@ void spl_SplObjectStorage_free_storage(zend_object *object) /* {{{ */
 	zend_object_std_dtor(&intern->std);
 
 	zend_hash_destroy(&intern->storage);
-
-	if (intern->gcdata != NULL) {
-		efree(intern->gcdata);
-	}
-
 } /* }}} */
 
 static int spl_object_storage_get_hash(zend_hash_key *key, spl_SplObjectStorage *intern, zval *obj) {
@@ -285,23 +278,16 @@ static inline HashTable* spl_object_storage_debug_info(zend_object *obj) /* {{{
 /* overridden for garbage collection */
 static HashTable *spl_object_storage_get_gc(zend_object *obj, zval **table, int *n) /* {{{ */
 {
-	int i = 0;
 	spl_SplObjectStorage *intern = spl_object_storage_from_obj(obj);
 	spl_SplObjectStorageElement *element;
-
-	if (intern->storage.nNumOfElements * 2 > intern->gcdata_num) {
-		intern->gcdata_num = intern->storage.nNumOfElements * 2;
-		intern->gcdata = (zval*)erealloc(intern->gcdata, sizeof(zval) * intern->gcdata_num);
-	}
+	zend_get_gc_buffer *gc_buffer = zend_get_gc_buffer_create();
 
 	ZEND_HASH_FOREACH_PTR(&intern->storage, element) {
-		ZVAL_COPY_VALUE(&intern->gcdata[i++], &element->obj);
-		ZVAL_COPY_VALUE(&intern->gcdata[i++], &element->inf);
+		zend_get_gc_buffer_add_zval(gc_buffer, &element->obj);
+		zend_get_gc_buffer_add_zval(gc_buffer, &element->inf);
 	} ZEND_HASH_FOREACH_END();
 
-	*table = intern->gcdata;
-	*n = i;
-
+	zend_get_gc_buffer_use(gc_buffer, table, n);
 	return zend_std_get_properties(obj);
 }
 /* }}} */