[Solved] Given this ISR code snippet, what will be the va... Given this ISR code snippet, what will be the value of higherPriorityTaskWoken after calling xQueueSendFromISR if a higher priority task was woken? | FreeRTOS

FreeRTOS - Interrupt Management

Given this ISR code snippet, what will be the value of higherPriorityTaskWoken after calling xQueueSendFromISR if a higher priority task was woken?

BaseType_t higherPriorityTaskWoken = pdFALSE;
xQueueSendFromISR(queue, &data, &higherPriorityTaskWoken);

AUndefined

BpdTRUE

CNULL

DpdFALSE

Step-by-Step Solution

Solution:

Step 1: Understand the role of higherPriorityTaskWoken
This flag is set to pdTRUE by xQueueSendFromISR if sending the item caused a higher priority task to unblock.
Step 2: Analyze the scenario
If a higher priority task was woken, the flag changes from pdFALSE to pdTRUE.
Final Answer:
pdTRUE -> Option B
Quick Check:
Higher priority task woken flag = pdTRUE [OK]

Quick Trick: Check higherPriorityTaskWoken after FromISR calls to trigger context switch [OK]

Common Mistakes:

Assuming flag stays pdFALSE always
Confusing NULL with pdFALSE
Ignoring the flag update by FromISR functions

Master "Interrupt Management" in FreeRTOS

9 interactive learning modes - each teaches the same concept differently

Learn Why Deep Visual Try Challenge Project Recall Time

More FreeRTOS Quizzes

Given this ISR code snippet, what will be the value of higherPriorityTaskWoken after calling xQueueSendFromISR if a higher priority task was woken?

Step 1: Understand the role of higherPriorityTaskWoken

Step 2: Analyze the scenario

Final Answer:

Quick Check:

Want More Practice?