Re-add Shared Pointer Class into platform features

TESTS/mbed_platform/SharedPtr/main.cpp

@@ -0,0 +1,128 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2018 ARM Limited
+ *
+ * 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 "mbed.h"
+#include "greentea-client/test_env.h"
+#include "utest/utest.h"
+#include "unity/unity.h"
+
+#include "platform/SharedPtr.h"
+
+using utest::v1::Case;
+
+struct TestStruct {
+    TestStruct()
+    {
+        s_count++;
+        value = 42;
+    }
+
+    ~TestStruct()
+    {
+        s_count--;
+        value = 0;
+    }
+
+    int value;
+    static int s_count;
+};
+
+int TestStruct::s_count = 0;
+
+/**
+ * Test that a shared pointer correctly manages the lifetime of the underlying raw pointer
+ */
+void test_single_sharedptr_lifetime()
+{
+    // Sanity-check value of counter
+    TEST_ASSERT_EQUAL(0, TestStruct::s_count);
+
+    // Create and destroy shared pointer in given scope
+    {
+        SharedPtr<TestStruct> s_ptr(new TestStruct);
+        TEST_ASSERT_EQUAL(1, TestStruct::s_count);
+    }
+
+    // Destroy shared pointer
+    TEST_ASSERT_EQUAL(0, TestStruct::s_count);
+}
+
+/**
+ * Test that multiple instances of shared pointers correctly manage the reference count
+ * to release the object at the correct point
+ */
+void test_instance_sharing()
+{
+    SharedPtr<TestStruct> s_ptr1(NULL);
+
+    // Sanity-check value of counter
+    TEST_ASSERT_EQUAL(0, TestStruct::s_count);
+
+    // Create and destroy shared pointer in given scope
+    {
+        SharedPtr<TestStruct> s_ptr2(new TestStruct);
+        TEST_ASSERT_EQUAL(1, TestStruct::s_count);
+        s_ptr1 = s_ptr2;
+        TEST_ASSERT_EQUAL(1, TestStruct::s_count);
+    }
+
+    TEST_ASSERT_EQUAL(1, TestStruct::s_count);
+
+    s_ptr1 = NULL;
+
+    // Destroy shared pointer
+    TEST_ASSERT_EQUAL(0, TestStruct::s_count);
+}
+
+/**
+ * Test whether comparison operators operate as expected, both between
+ * shared pointers managing the same object,
+ * and a shared pointer and underlying raw pointer
+ */
+void test_equality_comparators()
+{
+    TestStruct *raw_ptr1 = new TestStruct;
+    TestStruct *raw_ptr2 = new TestStruct;
+    SharedPtr<TestStruct> s_ptr1_1(raw_ptr1);
+    SharedPtr<TestStruct> s_ptr1_2 = s_ptr1_1;
+    SharedPtr<TestStruct> s_ptr2(raw_ptr2);
+
+    // Pointers that should be deemed equal
+    TEST_ASSERT_TRUE(s_ptr1_1 == raw_ptr1); // Shared pointer / Raw pointer
+    TEST_ASSERT_TRUE(s_ptr1_1 == s_ptr1_2); // Shared pointer / Shared pointer
+
+    // Pointers that should be deemed different
+    TEST_ASSERT_TRUE(s_ptr1_1 != raw_ptr2); // Shared pointer / Raw pointer
+    TEST_ASSERT_TRUE(s_ptr1_1 != s_ptr2); // Shared pointer / Shared pointer
+}
+
+utest::v1::status_t test_setup(const size_t number_of_cases)
+{
+    GREENTEA_SETUP(10, "default_auto");
+    return utest::v1::verbose_test_setup_handler(number_of_cases);
+}
+
+Case cases[] = {
+    Case("Test single shared pointer instance", test_single_sharedptr_lifetime),
+    Case("Test instance sharing across multiple shared pointers", test_instance_sharing),
+    Case("Test equality comparators", test_equality_comparators)
+};
+
+utest::v1::Specification specification(test_setup, cases);
+
+int main()
+{
+    return !utest::v1::Harness::run(specification);
+}