Resource manager task pattern in FreeRTOS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a FreeRTOS task that manages a resource.

FreeRTOS

xTaskCreate([1], "ResourceManager", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY + 1, NULL);

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AvTaskDelete

BvTaskStartScheduler

CxQueueCreate

DResourceManagerTask

Attempts:

3 left

💡 Hint

Common Mistakes

Using scheduler or queue functions instead of the task function name.

Passing NULL instead of the task function.

The function xTaskCreate needs the task function name as the first argument. Here, ResourceManagerTask is the task function that manages the resource.

2fill in blank

medium

Complete the code to wait for a resource request in the resource manager task.

FreeRTOS

if (xQueueReceive(resourceQueue, &request, [1]) == pdPASS) {
    // Process request
}

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A0

BpdFALSE

CportMAX_DELAY

D100

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 which causes no wait and immediate return.

Using a small number which causes timeout.

Using portMAX_DELAY makes the task wait indefinitely until a request arrives in the queue.

3fill in blank

hard

Fix the error in the resource manager task to properly notify the requester after processing.

FreeRTOS

xTaskNotifyGive([1]);

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ArequestingTaskHandle

BNULL

CresourceQueue

DResourceManagerTaskHandle

Attempts:

3 left

💡 Hint

Common Mistakes

Passing NULL or the queue handle instead of the task handle.

Not notifying the requester task.

The function xTaskNotifyGive must be called with the handle of the task that requested the resource, so it can be notified.

4fill in blank

hard

Fill both blanks to correctly send a resource request and wait for notification.

FreeRTOS

xQueueSend(resourceQueue, &request, [1]);
ulTaskNotifyTake([2], portMAX_DELAY);

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AportMAX_DELAY

BpdTRUE

CpdFALSE

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using portMAX_DELAY for queue send block time which can block indefinitely.

Using pdFALSE for ulTaskNotifyTake which does not clear the notification.

When sending to a queue, a zero block time means do not wait if the queue is full. For ulTaskNotifyTake, pdTRUE clears one bit from the notification value before checking or waiting.

5fill in blank

hard

Fill the blanks to implement a resource manager task loop that receives requests, processes them, and notifies the requester.

FreeRTOS

void ResourceManagerTask(void *pvParameters) {
    ResourceRequest request;
    for (;;) {
        if (xQueueReceive(resourceQueue, &request, [1]) == pdPASS) {
            // Process the request
            processResource(request.data);
            xTaskNotifyGive([2]);
        }
    }
}

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AportMAX_DELAY

Brequest.taskHandle

CNULL

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong block time values.

Not notifying the correct task handle.

The task waits indefinitely for requests using portMAX_DELAY. After processing, it notifies the requesting task using request.taskHandle.