Support external context, heap and lcache (#1778)

JerryScript should support external context, heap and lcache,
so that it can have multiple instances and runtime configurable heap
size.

Related issue: 1746

JerryScript-DCO-1.0-Signed-off-by: Zidong Jiang zidong.jiang@intel.com

jerry-port/default/default-external-context.c

@@ -0,0 +1,43 @@
+/* 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-port.h"
+#include "jerryscript-port-default.h"
+
+/**
+ * Pointer to the current instance.
+ * Note that it is a global variable, and is not a thread safe implementation.
+ */
+static jerry_instance_t *current_instance_p = NULL;
+
+/**
+ * Set the current_instance_p as the passed pointer.
+ */
+void
+jerry_port_default_set_instance (jerry_instance_t *instance_p) /**< points to the created instance */
+{
+  current_instance_p = instance_p;
+} /* jerry_port_default_set_instance */
+
+/**
+ * Get the current instance.
+ *
+ * @return the pointer to the current instance
+ */
+jerry_instance_t *
+jerry_port_get_current_instance (void)
+{
+  return current_instance_p;
+} /* jerry_port_get_current_instance */

jerry-port/default/include/jerryscript-port-default.h

@@ -37,6 +37,8 @@ bool jerry_port_default_is_abort_on_fail (void);
 jerry_log_level_t jerry_port_default_get_log_level (void);
 void jerry_port_default_set_log_level (jerry_log_level_t level);
 
+void jerry_port_default_set_instance (jerry_instance_t *instance_p);
+
 /**
  * @}
  */