Diff: mbed-cloud-client/mbed-client/source/include/smartpointer.h

Revision:

0:276e7a263c35

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-cloud-client/mbed-client/source/include/smartpointer.h	Mon Jul 02 06:30:39 2018 +0000
@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 2015 ARM Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ * 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.
+ */
+#ifndef SMART_POINTER_H
+#define SMART_POINTER_H
+
+class ReferenceCount
+{
+private:
+
+    int _count; // Reference count
+
+public:
+
+void add_ref()
+{
+    // Increment the reference count
+    _count++;
+}
+
+int release()
+{
+    // Decrement the reference count and
+    // return the reference count.
+    return --_count;
+}
+};
+
+template < typename T > class SmartPointer
+{
+private:
+
+    T                   *_data;         // Generic pointer to be stored
+    ReferenceCount      *_reference;    // Reference count
+
+
+public:
+
+SmartPointer()
+: _data(0), _reference(0)
+{
+    // Create a new reference
+    _reference = new ReferenceCount();
+    // Increment the reference count
+    _reference->add_ref();
+}
+
+SmartPointer(T* value)
+: _data(value), _reference(0)
+{
+    // Create a new reference
+    _reference = new ReferenceCount();
+    // Increment the reference count
+    _reference->add_ref();
+}
+
+SmartPointer(const SmartPointer<T>& smart_pointer)
+: _data(smart_pointer._data), reference(smart_pointer._reference)
+{
+    // Copy constructor
+    // Copy the data and reference pointer
+    // and increment the reference count
+    _reference->add_ref();
+}
+
+~SmartPointer()
+{
+    if(_reference->release() == 0) {
+        delete _data;
+        delete _reference;
+    }
+}
+
+T& operator* ()
+{
+    return *_data;
+}
+
+T* operator-> ()
+{
+    return _data;
+}
+
+SmartPointer<T>& operator = (const SmartPointer<T>& smart_pointer)
+{
+    // Assignment operator
+    if (this != &SmartPointer) { // Avoid self assignment
+        // Decrement the old reference count
+        // if reference become zero delete the old data
+        if(_reference->release() == 0) {
+           delete _data;
+           delete _reference;
+        }
+
+        // Copy the data and reference pointer
+        // and increment the reference count
+        _data = SmartPointer._data;
+        _reference = SmartPointer._reference;
+        _reference->add_ref();
+    }
+    return *this;
+}
+
+};
+
+#endif // SMART_POINTER_H