Add a test to check for init race conditions

Test SingletonPtr initailization along the with lazy initailization
that is built into the C++ language itself.

TESTS/mbed_drivers/race_test/main.cpp

@@ -0,0 +1,134 @@
+/*
+ * Copyright (c) 2016-2016, 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.
+ */
+#include "mbed.h"
+#include "rtos.h"
+#include "greentea-client/test_env.h"
+#include "unity/unity.h"
+#include "utest/utest.h"
+#include "SingletonPtr.h"
+#include <stdio.h>
+
+using namespace utest::v1;
+
+#define TEST_STACK_SIZE     1024
+static uint32_t instance_count = 0;
+
+class TestClass {
+public:
+    TestClass() {
+        printf("TestClass ctor start\r\n");
+        Thread::wait(500);
+        instance_count++;
+        printf("TestClass ctor end\r\n");
+    }
+
+    void do_something() {
+        printf("Do something called\r\n");
+    }
+
+    ~TestClass() {
+        instance_count--;
+    }
+};
+
+static TestClass* get_test_class()
+{
+    static TestClass tc;
+    return &tc;
+}
+
+static SingletonPtr<TestClass> test_class;
+
+static void main_func_race()
+{
+    get_test_class();
+}
+
+static void main_class_race()
+{
+    test_class->do_something();
+}
+
+void test_case_func_race()
+{
+    printf("Running function race test\r\n");
+    Callback<void()> cb(main_func_race);
+    Thread *t1 = new Thread(osPriorityNormal, TEST_STACK_SIZE);
+    Thread *t2 = new Thread(osPriorityNormal, TEST_STACK_SIZE);
+
+    // Start start first thread
+    t1->start(cb);
+    // Start second thread while the first is inside the constructor
+    Thread::wait(250);
+    t2->start(cb);
+
+    // Wait for the threads to finish
+    t1->join();
+    t2->join();
+
+    delete t1;
+    delete t2;
+
+    TEST_ASSERT_EQUAL_UINT32(1, instance_count);
+
+    // Reset instance count
+    instance_count = 0;
+}
+
+void test_case_class_race()
+{
+    printf("Running class race test\r\n");
+    Callback<void()> cb(main_class_race);
+    Thread *t1 = new Thread(osPriorityNormal, TEST_STACK_SIZE);
+    Thread *t2 = new Thread(osPriorityNormal, TEST_STACK_SIZE);
+
+    // Start start first thread
+    t1->start(cb);
+    // Start second thread while the first is inside the constructor
+    Thread::wait(250);
+    t2->start(cb);
+
+    // Wait for the threads to finish
+    t1->join();
+    t2->join();
+
+    delete t1;
+    delete t2;
+
+    TEST_ASSERT_EQUAL_UINT32(1, instance_count);
+
+    // Reset instance count
+    instance_count = 0;
+}
+
+Case cases[] = {
+    Case("function init race", test_case_func_race),
+    Case("class init race", test_case_class_race),
+};
+
+utest::v1::status_t greentea_test_setup(const size_t number_of_cases)
+{
+    GREENTEA_SETUP(20, "default_auto");
+    return greentea_test_setup_handler(number_of_cases);
+}
+
+Specification specification(greentea_test_setup, cases, greentea_test_teardown_handler);
+
+int main()
+{
+    Harness::run(specification);
+}