add context switch test code

Author: rcitach

examples/utest/testcases/perf/context_switch.c

@@ -0,0 +1,177 @@
+/*
+ * Copyright (c) 2006-2025, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2025-07-03     rcitach      test case for context_switch
+ */
+
+#include <rtthread.h>
+#include <rthw.h>
+#include <rtdevice.h>
+#include <utest.h>
+#include <utest_assert.h>
+
+static rt_sem_t sem1, sem2;
+static rt_thread_t thread1, thread2;
+#define THREAD_STACK_SIZE       1024
+#define THREAD_PRIORITY         10
+#define THREAD_TIMESLICE        5
+
+#define SWITCH_COUNT 1000  /* Number of context switches */
+
+#ifdef USING_HWTIME_AS_TIME_REF
+static rt_device_t hw_dev = RT_NULL;
+
+static rt_size_t get_timer_us(rt_hwtimerval_t *timeout_s)
+{
+    if (hw_dev)
+        return rt_device_read(hw_dev, 0, timeout_s, sizeof(rt_hwtimerval_t));
+    return 0;
+}
+#endif
+
+static void thread1_entry(void *parameter)
+{
+    while (1)
+    {
+        rt_sem_take(sem1, RT_WAITING_FOREVER);
+        rt_sem_release(sem2);
+    }
+}
+
+static void thread2_entry(void *parameter)
+{
+    rt_uint32_t total_time = 0;
+    rt_uint32_t sem_op_time = 0;
+    rt_uint32_t i;
+#ifdef USING_HWTIME_AS_TIME_REF
+    rt_hwtimerval_t start_time, end_time;
+    rt_uint16_t ret;
+    /* Getting Signal Time */
+    ret = get_timer_us(&start_time);
+    for (i = 0; i < SWITCH_COUNT; i++)
+    {
+        rt_sem_take(sem2, RT_WAITING_FOREVER);
+        rt_sem_release(sem2);
+    }
+    ret +=get_timer_us(&end_time);
+    sem_op_time = (end_time.sec - start_time.sec) * 1000000u + (end_time.usec - start_time.usec);
+
+    ret += get_timer_us(&start_time);
+    for (i = 0; i < SWITCH_COUNT; i++)
+    {
+        rt_sem_take(sem2, RT_WAITING_FOREVER);
+        rt_sem_release(sem1);
+    }
+    ret +=get_timer_us(&end_time);
+    total_time = (end_time.sec - start_time.sec) * 1000000u + (end_time.usec - start_time.usec);
+#else
+    rt_uint32_t start_time, end_time;
+    /* Getting Signal Time */
+    start_time = rt_tick_get();
+    for (i = 0; i < SWITCH_COUNT; i++)
+    {
+        rt_sem_take(sem2, RT_WAITING_FOREVER);
+        rt_sem_release(sem2);
+    }
+    end_time = rt_tick_get();
+    sem_op_time = (end_time - start_time) / RT_TICK_PER_SECOND;
+    sem_op_time += ((end_time - start_time) % RT_TICK_PER_SECOND) * (1000000u / RT_TICK_PER_SECOND);
+
+    start_time = rt_tick_get();
+    for (i = 0; i < SWITCH_COUNT; i++)
+    {
+       rt_sem_take(sem2, RT_WAITING_FOREVER);
+       rt_sem_release(sem1);
+    }
+    end_time = rt_tick_get();
+    total_time = (end_time - start_time) / RT_TICK_PER_SECOND;
+    total_time += ((end_time - start_time) % RT_TICK_PER_SECOND) * (1000000u / RT_TICK_PER_SECOND);
+#endif
+
+    rt_uint32_t single_switch_time = total_time / SWITCH_COUNT; /* Total single switching time */
+    rt_uint32_t single_sem_op_time = sem_op_time / SWITCH_COUNT; /* Single semaphore operation time */
+    rt_uint32_t context_switch_time = single_switch_time - single_sem_op_time; /* Context switching time */
+
+    LOG_I("Total time for %d switches: %d us", SWITCH_COUNT, total_time);
+    LOG_I("Single switch time (including semaphore): %d us", single_switch_time);
+    LOG_I("Semaphore operation time: %d us", single_sem_op_time);
+    LOG_I("Pure context switch time: %d us", context_switch_time);
+}
+
+void context_switch_test(void)
+{
+    thread1 = rt_thread_create("thread1", thread1_entry, RT_NULL, THREAD_STACK_SIZE, THREAD_PRIORITY, THREAD_TIMESLICE);
+    if (thread1 != RT_NULL)
+    {
+        rt_thread_startup(thread1);
+    }
+
+    thread2 = rt_thread_create("thread2", thread2_entry, RT_NULL, THREAD_STACK_SIZE, THREAD_PRIORITY, THREAD_TIMESLICE);
+    if (thread2 != RT_NULL)
+    {
+        rt_thread_startup(thread2);
+    }
+}
+
+static rt_err_t utest_tc_init(void)
+{
+    int ret = RT_EOK;
+#ifdef USING_HWTIME_AS_TIME_REF
+    rt_hwtimerval_t timeout_s;
+
+    hw_dev = rt_device_find(UTEST_HWTIMER_DEV_NAME);
+    if (hw_dev == RT_NULL)
+    {
+        ret = RT_ERROR;
+        LOG_E("hwtimer sample run failed! can't find %s device!", UTEST_HWTIMER_DEV_NAME);
+        return ret;
+    }
+
+    ret = rt_device_open(hw_dev, RT_DEVICE_OFLAG_RDWR);
+    if (ret != RT_EOK)
+    {
+        LOG_E("open %s device failed!", UTEST_HWTIMER_DEV_NAME);
+        return ret;
+    }
+
+    timeout_s.sec  = 5;      /* s  */
+    timeout_s.usec = 0;     /* us */
+    if (rt_device_write(hw_dev, 0, &timeout_s, sizeof(rt_hwtimerval_t)) != sizeof(rt_hwtimerval_t))
+    {
+        ret = RT_ERROR;
+        LOG_E("set timeout value failed");
+        return ret;
+    }
+#endif
+    sem1 = rt_sem_create("sem1", 1, RT_IPC_FLAG_FIFO);
+    sem2 = rt_sem_create("sem2", 0, RT_IPC_FLAG_FIFO);
+    if (sem1 == RT_NULL || sem2 == RT_NULL)
+    {
+        ret = RT_ERROR;
+        LOG_E("Semaphore create failed!");
+        return ret;
+    }
+    return ret;
+}
+
+static rt_err_t utest_tc_cleanup(void)
+{
+    if (thread1) rt_thread_delete(thread1);
+    if(sem1) rt_sem_delete(sem1);
+    if(sem2) rt_sem_delete(sem2);
+#ifdef USING_HWTIME_AS_TIME_REF
+    if(hw_dev) rt_device_close(hw_dev);
+#endif
+    return RT_EOK;
+}
+
+static void testcase(void)
+{
+    UTEST_UNIT_RUN(context_switch_test);
+}
+
+UTEST_TC_EXPORT(testcase, "testcase.pref.context", utest_tc_init, utest_tc_cleanup, 10);