UM1722 On semaphores example

[Williamzhangtw]

I am using cubemx v4.21.0. and the freertos version is 8.2.3. & the cmsis-rtos version is 1.02.
I am using the examples of STM32F413ZH-Nucleo in stm32cube F4 v1.16.0, when I download the program. It works wrong!
I found the issure here

static void SemaphoreThread2(void const *argument)
{
....
for (;;)
{
if (semaphore != NULL)
{
/* Try to obtain the semaphore */
if (osSemaphoreWait(semaphore , 0) == osOK)

If I use if (osSemaphoreWait(semaphore , osWaitForever) == osOK) instead,It works fine!
Could anyone tell me why if (osSemaphoreWait(semaphore , 0) == osOK) works wrong?

[Williamzhangtw]

The trace tool processing need enough Idle time to finish its job. If cpu load is too high,It will slower the real speed and seem like an error. so, when using the tracealyzer, we have to make sure that there are enough idle time for its processing.