Critical sections and interrupt disabling in FreeRTOS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to enter a critical section using FreeRTOS API.

FreeRTOS

taskENTER_CRITICAL();
// Critical code here
[1]();

Drag options to blanks, or click blank then click option'

AtaskEXIT_CRITICAL

BtaskENTER_CRITICAL

CtaskENTER_CRITICAL()

DtaskEXIT_CRITICAL()

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting the parentheses when calling the function.

Using the enter function instead of the exit function.

You must call taskEXIT_CRITICAL() with parentheses to exit the critical section properly.

2fill in blank

medium

Complete the code to disable interrupts in FreeRTOS.

FreeRTOS

[1]();
// Critical code here
portENABLE_INTERRUPTS();

Drag options to blanks, or click blank then click option'

AportDISABLE_INTERRUPTS

BportENABLE_INTERRUPTS()

CportDISABLE_INTERRUPTS()

DportENABLE_INTERRUPTS

Attempts:

3 left

💡 Hint

Common Mistakes

Calling the enable interrupts function instead of disable.

Omitting parentheses when calling the function.

Use portDISABLE_INTERRUPTS() with parentheses to disable interrupts before critical code.

3fill in blank

hard

Fix the error in the code to properly exit a critical section.

FreeRTOS

taskENTER_CRITICAL();
// Critical code
[1];

Drag options to blanks, or click blank then click option'

AtaskEXIT_CRITICAL

BtaskEXIT_CRITICAL()

CtaskENTER_CRITICAL()

DtaskENTER_CRITICAL

Attempts:

3 left

💡 Hint

Common Mistakes

Missing parentheses causing the function not to execute.

Using the enter function instead of exit.

The function taskEXIT_CRITICAL() must be called with parentheses to properly exit the critical section.

4fill in blank

hard

Fill both blanks to create a critical section that disables interrupts and then enables them.

FreeRTOS

void critical_function() {
    [1]();
    // Critical code here
    [2]();
}

Drag options to blanks, or click blank then click option'

AportDISABLE_INTERRUPTS

BportENABLE_INTERRUPTS

CtaskENTER_CRITICAL

DtaskEXIT_CRITICAL

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing enter/exit critical section functions with interrupt macros.

Forgetting parentheses on function calls.

Use portDISABLE_INTERRUPTS() to disable interrupts and portENABLE_INTERRUPTS() to enable them after the critical code.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that maps task names to their priority if priority is above 3.

FreeRTOS

task_priorities = { [1]: [2] for [1] in tasks if [2] > 3 }

Drag options to blanks, or click blank then click option'

Atask.name

Btask.priority

Ctask

Dpriority

Attempts:

3 left

💡 Hint

Common Mistakes

Using undefined variables like 'priority' instead of 'task.priority'.

Mixing keys and values incorrectly in the comprehension.

The comprehension iterates over task in tasks, maps task.name to task.priority, and filters where task.priority is greater than 3.