Allow the JS objects to have more than one native pointer data (#2814)

Currently JS objects can only have one native pointer data which could be a limitation in special cases.
This patch allows to register multiple native infos, which can be accessed/associated with the corresponding `jerry_object_native_info_t`.

JerryScript-DCO-1.0-Signed-off-by: Robert Fancsik frobert@inf.u-szeged.hu

jerry-core/api/jerry.c

@@ -2591,9 +2591,8 @@ jerry_objects_foreach_by_native_info (const jerry_object_native_info_t *native_i
   {
     if (!ecma_is_lexical_environment (iter_p))
     {
-      native_pointer_p = ecma_get_native_pointer_value (iter_p);
+      native_pointer_p = ecma_get_native_pointer_value (iter_p, (void *) native_info_p);
       if (native_pointer_p
-          && ((const jerry_object_native_info_t *) native_pointer_p->info_p) == native_info_p
           && !foreach_p (ecma_make_object_value (iter_p), native_pointer_p->data_p, user_data_p))
       {
         return true;
@@ -2605,11 +2604,10 @@ jerry_objects_foreach_by_native_info (const jerry_object_native_info_t *native_i
 } /* jerry_objects_foreach_by_native_info */
 
 /**
- * Get native pointer and its type information, associated with specified object.
+ * Get native pointer and its type information, associated with the given native type info.
  *
  * Note:
- *  If native pointer is present, its type information is returned
- *  in out_native_pointer_p and out_native_info_p.
+ *  If native pointer is present, its type information is returned in out_native_pointer_p
  *
  * @return true - if there is an associated pointer,
  *         false - otherwise
@@ -2617,8 +2615,8 @@ jerry_objects_foreach_by_native_info (const jerry_object_native_info_t *native_i
 bool
 jerry_get_object_native_pointer (const jerry_value_t obj_val, /**< object to get native pointer from */
                                  void **out_native_pointer_p, /**< [out] native pointer */
-                                 const jerry_object_native_info_t **out_native_info_p) /**< [out] the type info
-                                                                                        *   of the native pointer */
+                                 const jerry_object_native_info_t *native_info_p) /**< the type info
+                                                                                   *   of the native pointer */
 {
   jerry_assert_api_available ();
 
@@ -2628,7 +2626,7 @@ jerry_get_object_native_pointer (const jerry_value_t obj_val, /**< object to get
   }
 
   ecma_native_pointer_t *native_pointer_p;
-  native_pointer_p = ecma_get_native_pointer_value (ecma_get_object_from_value (obj_val));
+  native_pointer_p = ecma_get_native_pointer_value (ecma_get_object_from_value (obj_val), (void *) native_info_p);
 
   if (native_pointer_p == NULL)
   {
@@ -2640,11 +2638,6 @@ jerry_get_object_native_pointer (const jerry_value_t obj_val, /**< object to get
     *out_native_pointer_p = native_pointer_p->data_p;
   }
 
-  if (out_native_info_p != NULL)
-  {
-    *out_native_info_p = (const jerry_object_native_info_t *) native_pointer_p->info_p;
-  }
-
   return true;
 } /* jerry_get_object_native_pointer */
 
@@ -2676,6 +2669,35 @@ jerry_set_object_native_pointer (const jerry_value_t obj_val, /**< object to set
   }
 } /* jerry_set_object_native_pointer */
 
+/**
+ * Delete the previously set native pointer by the native type info from the specified object.
+ *
+ * Note:
+ *      If the specified object has no matching native pointer for the given native type info
+ *      the function has no effect.
+ *
+ * Note:
+ *      This operation cannot throw an exception.
+ *
+ * @return true - if the native pointer has been deleted succesfully
+ *         false - otherwise
+ */
+bool
+jerry_delete_object_native_pointer (const jerry_value_t obj_val, /**< object to delete native pointer from */
+                                    const jerry_object_native_info_t *native_info_p) /**< object's native type info */
+{
+  jerry_assert_api_available ();
+
+  if (ecma_is_value_object (obj_val))
+  {
+    ecma_object_t *object_p = ecma_get_object_from_value (obj_val);
+
+    return ecma_delete_native_pointer_property (object_p, (void *) native_info_p);
+  }
+
+  return false;
+} /* jerry_delete_object_native_pointer */
+
 /**
  * Applies the given function to the every property in the object.
  *

jerry-core/ecma/base/ecma-gc.c

@@ -501,17 +501,24 @@ ecma_gc_free_native_pointer (ecma_property_t *property_p) /**< property */
   native_pointer_p = ECMA_GET_INTERNAL_VALUE_POINTER (ecma_native_pointer_t,
                                                       value_p->value);
 
-  if (native_pointer_p->info_p != NULL)
+  while (native_pointer_p != NULL)
   {
-    ecma_object_native_free_callback_t free_cb = native_pointer_p->info_p->free_cb;
-
-    if (free_cb != NULL)
+    if (native_pointer_p->info_p != NULL)
     {
-      free_cb (native_pointer_p->data_p);
-    }
-  }
+      ecma_object_native_free_callback_t free_cb = native_pointer_p->info_p->free_cb;
 
-  jmem_heap_free_block (native_pointer_p, sizeof (ecma_native_pointer_t));
+      if (free_cb != NULL)
+      {
+        free_cb (native_pointer_p->data_p);
+      }
+    }
+
+    ecma_native_pointer_t *next_p = native_pointer_p->next_p;
+
+    jmem_heap_free_block (native_pointer_p, sizeof (ecma_native_pointer_t));
+
+    native_pointer_p = next_p;
+  }
 } /* ecma_gc_free_native_pointer */
 
 /**

jerry-core/ecma/base/ecma-globals.h

@@ -294,10 +294,11 @@ typedef struct
 /**
  * Representation for native pointer data.
  */
-typedef struct
+typedef struct ecma_native_pointer_t
 {
   void *data_p; /**< points to the data of the object */
   ecma_object_native_info_t *info_p; /**< native info */
+  struct ecma_native_pointer_t *next_p; /**< points to the next ecma_native_pointer_t element */
 } ecma_native_pointer_t;
 
 /**

jerry-core/ecma/base/ecma-helpers-external-pointers.c

@@ -15,6 +15,7 @@
 
 #include "ecma-alloc.h"
 #include "ecma-globals.h"
+#include "ecma-objects.h"
 #include "ecma-helpers.h"
 
 /** \addtogroup ecma ECMA
@@ -42,10 +43,10 @@ ecma_create_native_pointer_property (ecma_object_t *obj_p, /**< object to create
 
   ecma_native_pointer_t *native_pointer_p;
 
-  if (is_new)
+  if (property_p == NULL)
   {
     ecma_property_value_t *value_p;
-    value_p = ecma_create_named_data_property (obj_p, name_p, ECMA_PROPERTY_FLAG_WRITABLE, &property_p);
+    value_p = ecma_create_named_data_property (obj_p, name_p, ECMA_PROPERTY_CONFIGURABLE_WRITABLE, &property_p);
 
     ECMA_CONVERT_DATA_PROPERTY_TO_INTERNAL_PROPERTY (property_p);
 
@@ -57,11 +58,37 @@ ecma_create_native_pointer_property (ecma_object_t *obj_p, /**< object to create
   {
     ecma_property_value_t *value_p = ECMA_PROPERTY_VALUE_PTR (property_p);
 
-    native_pointer_p = ECMA_GET_INTERNAL_VALUE_POINTER (ecma_native_pointer_t, value_p->value);
+    ecma_native_pointer_t *iter_p = ECMA_GET_INTERNAL_VALUE_POINTER (ecma_native_pointer_t, value_p->value);
+
+    /* There should be at least 1 native pointer in the chain */
+    JERRY_ASSERT (iter_p != NULL);
+
+    while (true)
+    {
+      if (iter_p->info_p == info_p)
+      {
+        /* The native info already exists -> update the corresponding data */
+        iter_p->data_p = native_p;
+        return false;
+      }
+
+      if (iter_p->next_p == NULL)
+      {
+        /* The native info does not exist -> append a new element to the chain */
+        break;
+      }
+
+      iter_p = iter_p->next_p;
+    }
+
+    native_pointer_p = jmem_heap_alloc_block (sizeof (ecma_native_pointer_t));
+
+    iter_p->next_p = native_pointer_p;
   }
 
   native_pointer_p->data_p = native_p;
   native_pointer_p->info_p = info_p;
+  native_pointer_p->next_p = NULL;
 
   return is_new;
 } /* ecma_create_native_pointer_property */
@@ -77,7 +104,8 @@ ecma_create_native_pointer_property (ecma_object_t *obj_p, /**< object to create
  *         NULL otherwise
  */
 ecma_native_pointer_t *
-ecma_get_native_pointer_value (ecma_object_t *obj_p) /**< object to get property value from */
+ecma_get_native_pointer_value (ecma_object_t *obj_p, /**< object to get property value from */
+                               void *info_p) /**< native pointer's type info */
 {
   ecma_string_t *name_p = ecma_get_magic_string (LIT_INTERNAL_MAGIC_STRING_NATIVE_POINTER);
   ecma_property_t *property_p = ecma_find_named_property (obj_p, name_p);
@@ -89,9 +117,94 @@ ecma_get_native_pointer_value (ecma_object_t *obj_p) /**< object to get property
 
   ecma_property_value_t *value_p = ECMA_PROPERTY_VALUE_PTR (property_p);
 
-  return ECMA_GET_INTERNAL_VALUE_POINTER (ecma_native_pointer_t, value_p->value);
+  ecma_native_pointer_t *native_pointer_p = ECMA_GET_INTERNAL_VALUE_POINTER (ecma_native_pointer_t,
+                                                                             value_p->value);
+
+  JERRY_ASSERT (native_pointer_p != NULL);
+
+  while (native_pointer_p != NULL)
+  {
+    if (native_pointer_p->info_p == info_p)
+    {
+      return native_pointer_p;
+    }
+
+    native_pointer_p = native_pointer_p->next_p;
+  }
+
+  return NULL;
 } /* ecma_get_native_pointer_value */
 
+/**
+ * Delete the previously set native pointer by the native type info from the specified object.
+ *
+ * Note:
+ *      If the specified object has no matching native pointer for the given native type info
+ *      the function has no effect.
+ *
+ * @return true - if the native pointer has been deleted succesfully
+ *         false - otherwise
+ */
+bool
+ecma_delete_native_pointer_property (ecma_object_t *obj_p, /**< object to delete property from */
+                                     void *info_p) /**< native pointer's type info */
+{
+  ecma_string_t *name_p = ecma_get_magic_string (LIT_INTERNAL_MAGIC_STRING_NATIVE_POINTER);
+  ecma_property_t *property_p = ecma_find_named_property (obj_p, name_p);
+
+  if (property_p == NULL)
+  {
+    return false;
+  }
+
+  ecma_property_value_t *value_p = ECMA_PROPERTY_VALUE_PTR (property_p);
+
+  ecma_native_pointer_t *native_pointer_p = ECMA_GET_INTERNAL_VALUE_POINTER (ecma_native_pointer_t,
+                                                                             value_p->value);
+  ecma_native_pointer_t *prev_p = NULL;
+
+  JERRY_ASSERT (native_pointer_p != NULL);
+
+  while (native_pointer_p != NULL)
+  {
+    if (native_pointer_p->info_p == info_p)
+    {
+      if (prev_p == NULL)
+      {
+        if (native_pointer_p->next_p == NULL)
+        {
+          /* Only one native pointer property exists, so the property can be deleted as well. */
+          ecma_op_object_delete (obj_p, name_p, false);
+          jmem_heap_free_block (native_pointer_p, sizeof (ecma_native_pointer_t));
+          return true;
+        }
+        else
+        {
+          /* There are at least two native pointers and the first one should be deleted.
+             In this case the second element's data is copied to the head of the chain, and freed as well. */
+          ecma_native_pointer_t *next_p = native_pointer_p->next_p;
+          memcpy (native_pointer_p, next_p, sizeof (ecma_native_pointer_t));
+          jmem_heap_free_block (next_p, sizeof (ecma_native_pointer_t));
+          return true;
+        }
+      }
+      else
+      {
+        /* There are at least two native pointers and not the first element should be deleted.
+           In this case the current element's next element reference is copied to the previous element. */
+        prev_p->next_p = native_pointer_p->next_p;
+        jmem_heap_free_block (native_pointer_p, sizeof (ecma_native_pointer_t));
+        return true;
+      }
+    }
+
+    prev_p = native_pointer_p;
+    native_pointer_p = native_pointer_p->next_p;
+  }
+
+  return false;
+} /* ecma_delete_native_pointer_property */
+
 /**
  * @}
  * @}

jerry-core/ecma/base/ecma-helpers.h

@@ -389,7 +389,8 @@ void ecma_bytecode_deref (ecma_compiled_code_t *bytecode_p);
 
 /* ecma-helpers-external-pointers.c */
 bool ecma_create_native_pointer_property (ecma_object_t *obj_p, void *native_p, void *info_p);
-ecma_native_pointer_t *ecma_get_native_pointer_value (ecma_object_t *obj_p);
+ecma_native_pointer_t *ecma_get_native_pointer_value (ecma_object_t *obj_p, void *info_p);
+bool ecma_delete_native_pointer_property (ecma_object_t *obj_p, void *info_p);
 
 /* ecma-helpers-conversion.c */
 ecma_number_t ecma_utf8_string_to_number (const lit_utf8_byte_t *str_p, lit_utf8_size_t str_size);

jerry-core/include/jerryscript-core.h

@@ -527,10 +527,12 @@ jerry_value_t jerry_set_prototype (const jerry_value_t obj_val, const jerry_valu
 
 bool jerry_get_object_native_pointer (const jerry_value_t obj_val,
                                       void **out_native_pointer_p,
-                                      const jerry_object_native_info_t **out_pointer_info_p);
+                                      const jerry_object_native_info_t *native_pointer_info_p);
 void jerry_set_object_native_pointer (const jerry_value_t obj_val,
                                       void *native_pointer_p,
                                       const jerry_object_native_info_t *native_info_p);
+bool jerry_delete_object_native_pointer (const jerry_value_t obj_val,
+                                         const jerry_object_native_info_t *native_info_p);
 
 bool jerry_objects_foreach (jerry_objects_foreach_t foreach_p,
                             void *user_data);