Allow API usage in native_free_callbacks (#3515)

This patch allows the use of API functions in native_free_callbacks for native pointers once again.

JerryScript-DCO-1.0-Signed-off-by: Daniel Balla dballa@inf.u-szeged.hu

Author: Daniel Balla

docs/02.API-REFERENCE.md

@@ -447,7 +447,7 @@ typedef jerry_value_t (*jerry_external_handler_t) (const jerry_value_t function_
 Native free callback of an object. It is used in `jerry_object_native_info_t` and for external Array buffers.
 
 *Note*:
- - This callback method **must not** call any JerryScript API methods.
+ - Referred values by this method must have at least 1 reference. (Correct API usage satisfies this condition)
 
 **Prototype**
 
@@ -456,6 +456,7 @@ typedef void (*jerry_object_native_free_callback_t) (void *native_p);
 ```
 
 *New in version 2.0*: Renamed from `jerry_object_free_callback_t`.
+*Changed in version 2.2*: API calls are once again allowed. (See note)
 
 **See also**
 
@@ -6145,7 +6146,7 @@ You can get them by calling [jerry_get_object_native_pointer](#jerry_get_object_
    it will be called by the garbage collector when the object is freed.
  - If the object is only referenced via the "global" object (or one of it's "child"),
    the free callback will be invoked during the execution of `jerry_cleanup`.
- - The free callback **must not** invoke API functions.
+ - The free callback can invoke API functions.
 
 *Note*: If possible do not store API values in native pointers, rather check
         [jerry_set_internal_property](#jerry_set_internal_property).

jerry-core/api/jerry.c

@@ -2956,7 +2956,7 @@ jerry_get_object_native_pointer (const jerry_value_t obj_val, /**< object to get
  * Note:
  *      If a non-NULL free callback is specified in the native type info,
  *      it will be called by the garbage collector when the object is freed.
- *      This callback **must not** invoke API functions.
+ *      Referred values by this method must have at least 1 reference. (Correct API usage satisfies this condition)
  *      The type info always overwrites the previous value, so passing
  *      a NULL value deletes the current type info.
  */

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

@@ -700,10 +700,6 @@ 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);
 
-#ifndef JERRY_NDEBUG
-  JERRY_CONTEXT (status_flags) &= (uint32_t) ~ECMA_STATUS_API_AVAILABLE;
-#endif /* !JERRY_NDEBUG */
-
   while (native_pointer_p != NULL)
   {
     if (native_pointer_p->info_p != NULL)
@@ -722,10 +718,6 @@ ecma_gc_free_native_pointer (ecma_property_t *property_p) /**< property */
 
     native_pointer_p = next_p;
   }
-
-#ifndef JERRY_NDEBUG
-  JERRY_CONTEXT (status_flags) |= ECMA_STATUS_API_AVAILABLE;
-#endif /* !JERRY_NDEBUG */
 } /* ecma_gc_free_native_pointer */
 
 /**
@@ -1405,6 +1397,7 @@ ecma_gc_run (void)
   while (marked_anything_during_current_iteration);
 
   black_end_p->gc_next_cp = JMEM_CP_NULL;
+  JERRY_CONTEXT (ecma_gc_objects_cp) = black_list_head.gc_next_cp;
 
   /* Sweep objects that are currently unmarked. */
   obj_iter_cp = white_gray_list_head.gc_next_cp;
@@ -1420,8 +1413,6 @@ ecma_gc_run (void)
     obj_iter_cp = obj_next_cp;
   }
 
-  JERRY_CONTEXT (ecma_gc_objects_cp) = black_list_head.gc_next_cp;
-
 #if ENABLED (JERRY_BUILTIN_REGEXP)
   /* Free RegExp bytecodes stored in cache */
   re_cache_gc_run ();

jerry-core/ecma/base/ecma-init-finalize.c

@@ -29,6 +29,11 @@
  * @{
  */
 
+/**
+ * Maximum number of GC loops on cleanup.
+ */
+#define JERRY_GC_LOOP_LIMIT 100
+
 /**
  * Initialize ECMA components
  */
@@ -73,8 +78,17 @@ ecma_finalize (void)
 #endif /* ENABLED (JERRY_ES2015) */
 
   ecma_finalize_global_lex_env ();
-  ecma_finalize_builtins ();
-  ecma_gc_run ();
+  uint8_t runs = 0;
+  do
+  {
+    ecma_finalize_builtins ();
+    ecma_gc_run ();
+    if (++runs >= JERRY_GC_LOOP_LIMIT)
+    {
+      jerry_fatal (ERR_UNTERMINATED_GC_LOOPS);
+    }
+  }
+  while (JERRY_CONTEXT (ecma_gc_new_objects) != 0);
   ecma_finalize_lit_storage ();
 } /* ecma_finalize */
 

jerry-core/include/jerryscript-port.h

@@ -51,6 +51,7 @@ typedef enum
   ERR_OUT_OF_MEMORY = 10,
   ERR_REF_COUNT_LIMIT = 12,
   ERR_DISABLED_BYTE_CODE = 13,
+  ERR_UNTERMINATED_GC_LOOPS = 14,
   ERR_FAILED_INTERNAL_ASSERTION = 120
 } jerry_fatal_code_t;
 

jerry-core/jrt/jrt-fatals.c

@@ -42,6 +42,11 @@ jerry_fatal (jerry_fatal_code_t code) /**< status code */
       JERRY_ERROR_MSG ("Error: ERR_REF_COUNT_LIMIT\n");
       break;
     }
+    case ERR_UNTERMINATED_GC_LOOPS:
+    {
+      JERRY_ERROR_MSG ("Error: ERR_UNTERMINATED_GC_LOOPS\n");
+      break;
+    }
     case ERR_DISABLED_BYTE_CODE:
     {
       JERRY_ERROR_MSG ("Error: ERR_DISABLED_BYTE_CODE\n");

tests/unit-core/test-native-callback-nested.c

@@ -0,0 +1,69 @@
+/* Copyright JS Foundation and other contributors, http://js.foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+#include "jerryscript.h"
+#include "jerryscript-port.h"
+#include "jerryscript-port-default.h"
+#include "test-common.h"
+
+static void native_cb2 (void)
+{
+  jerry_value_t array = jerry_create_array (100);
+  jerry_release_value (array);
+} /* native_cb2 */
+
+static const jerry_object_native_info_t native_info2 =
+{
+  .free_cb = (jerry_object_native_free_callback_t) native_cb2
+};
+
+static void native_cb (void)
+{
+  jerry_value_t array = jerry_create_array (100);
+
+  jerry_set_object_native_pointer (array, NULL, &native_info2);
+
+  jerry_release_value (array);
+} /* native_cb */
+
+static const jerry_object_native_info_t native_info =
+{
+  .free_cb = (jerry_object_native_free_callback_t) native_cb
+};
+
+static void *
+context_alloc_fn (size_t size, void *cb_data)
+{
+  (void) cb_data;
+  return malloc (size);
+} /* context_alloc_fn */
+
+int
+main (void)
+{
+  jerry_context_t *ctx_p = jerry_create_context (1024, context_alloc_fn, NULL);
+  jerry_port_default_set_current_context (ctx_p);
+  jerry_init (JERRY_INIT_EMPTY);
+
+  jerry_value_t obj = jerry_create_object ();
+
+  jerry_set_object_native_pointer (obj, NULL, &native_info);
+  jerry_release_value (obj);
+
+  jerry_cleanup ();
+  free (ctx_p);
+  return 0;
+} /* main */