Hands-On RTOS with Microcontrollers

Avoiding mutex acquisition failure

While mutexes help to provide protection against some priority inversion, we can take an additional step to make sure the mutex doesn't become an unnecessary crutch. The section of code that's protected by the mutex is referred to as a critical section:

if(xSemaphoreTake(mutexPtr, 200/portTICK_PERIOD_MS) == pdPASS){    //critical section is here    //KEEP THIS AS SHORT AS POSSIBLE    xSemaphoreGive(mutexPtr);}

Taking steps to ensure this critical section is as short as possible will help in a few areas:

• Less time in the critical section makes the shared data more available. The less time a mutex is being held, the more likely it is that another task will gain access in time.
• Minimizing the amount of time low priority ...