Add kernel ticker test

TESTS/mbedmicro-rtos-mbed/kernel_tick_count/main.cpp

@@ -0,0 +1,119 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2018-2018 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 "greentea-client/test_env.h"
+#include "utest/utest.h"
+#include "unity/unity.h"
+
+#include "rtos/Kernel.h"
+#include "mbed.h"
+
+
+using utest::v1::Case;
+
+#define TEST_REPEAT_COUNT   1000
+#define NUM_WAIT_TICKS      1000
+
+// all in [us]
+#define ONE_SECOND          1000000
+#define SMALL_DELTA         1500        // 0.15%
+#define BIG_DELTA           15000       // 1.5%
+
+/** Test if kernel ticker frequency is 1kHz
+
+    Given a RTOS kernel ticker
+    When check it frequency
+    Then the the frequency is 1kHz
+ */
+void test_frequency()
+{
+    uint32_t freq = osKernelGetTickFreq();
+    TEST_ASSERT_EQUAL_UINT32_MESSAGE(1000, freq, "Expected SysTick frequency is 1kHz");
+}
+
+/** Test if kernel ticker increments by one
+
+    Given a RTOS kernel ticker
+    When perform subsequent calls of @a rtos::Kernel::get_ms_count
+    Then subsequent reads should not differ by more than one
+ */
+void test_increment(void)
+{
+    for (uint32_t i = 0; i < TEST_REPEAT_COUNT; i++) {
+        const uint64_t start = rtos::Kernel::get_ms_count();
+        while (true) {
+            uint64_t diff = rtos::Kernel::get_ms_count() - start;
+            if (diff != 0) {
+                TEST_ASSERT_EQUAL_UINT64(1, diff);
+                break;
+            }
+        }
+    }
+}
+
+/** Test if kernel ticker interval is 1ms
+
+    Given a RTOS kernel ticker
+    When perform subsequent calls of @a rtos::Kernel::get_ms_count
+    Then the ticker interval should be 1ms
+ */
+void test_interval()
+{
+    uint64_t start, stop;
+    Timer timer;
+
+    start = rtos::Kernel::get_ms_count();
+    // wait for tick
+    do {
+        stop = rtos::Kernel::get_ms_count();
+    } while ((stop - start) == 0);
+    timer.start();
+    start = stop;
+
+    // wait for NUM_WAIT_TICKS ticks
+    do {
+        stop = rtos::Kernel::get_ms_count();
+    } while ((stop - start) != NUM_WAIT_TICKS);
+    timer.stop();
+    TEST_ASSERT_EQUAL_UINT64(NUM_WAIT_TICKS, (stop - start));
+
+#if defined(NO_SYSTICK) || defined(MBED_TICKLESS)
+    // On targets with NO_SYSTICK/MBED_TICKLESS enabled, systick is emulated by lp_ticker what makes it less accurate
+    // for more details https://os.mbed.com/docs/latest/reference/tickless.html
+    TEST_ASSERT_UINT64_WITHIN(BIG_DELTA, ONE_SECOND, timer.read_high_resolution_us());
+#else
+    TEST_ASSERT_UINT64_WITHIN(SMALL_DELTA, ONE_SECOND, timer.read_high_resolution_us());
+#endif
+}
+
+// Test cases
+Case cases[] = {
+    Case("Test kernel ticker frequency", test_frequency),
+    Case("Test if kernel ticker increments by one", test_increment),
+    Case("Test if kernel ticker interval is 1ms", test_interval)
+};
+
+utest::v1::status_t greentea_test_setup(const size_t number_of_cases)
+{
+    GREENTEA_SETUP(10, "timing_drift_auto");
+    return utest::v1::greentea_test_setup_handler(number_of_cases);
+}
+
+utest::v1::Specification specification(greentea_test_setup, cases);
+
+int main()
+{
+    return !utest::v1::Harness::run(specification);
+}