How do I get all task handles without calling uxTaskGetSystemState?

[arnold_w]

I understand that I can use uxTaskGetSystemState to retrieve all task handles. However, isn’t there a more low-level way of getting pointers to all tasks? I mean, the RTOS itself must already have an array or a linked list with pointers to all tasks handles? What is the variable name of that array or beginning node of that linked list?

[aggarg (Gaurav Aggarwal)]

FreeRTOS maintains multiple lists according to the task state. You will need to traverse all those lists which is what uxTaskGetSystemState essentially does.

Here are all the task lists - FreeRTOS-Kernel/tasks.c at main · FreeRTOS/FreeRTOS-Kernel · GitHub

[arnold_w]

I see. But the struct tskTaskControlBlock objects are always at fixed addresses (as long as the corresponding task isn’t deleted), correct? So if I don’t create or delete tasks during runtime, it’s enough that I call uxTaskGetSystemState once, after all tasks have been created in the beginning of the code?

[aggarg (Gaurav Aggarwal)]

@arnold_w

But the struct tskTaskControlBlock objects are always at fixed addresses (as long as the corresponding task isn’t deleted), correct?

Correct.

@arnold_w

So if I don’t create or delete tasks during runtime, it’s enough that I call uxTaskGetSystemState once, after all tasks have been created in the beginning of the code?

That is true in your case as you only need the xHandle member of TaskStatus_t. Other members such as task state, stack information etc. keeps changing throughout the lifetime of the task.