CET Embedded Systems & Programming 4

Question 1

In a Real-Time Operating System (RTOS), what is the primary purpose of a semaphore?

Accepted Answer

To synchronize access to shared resources or signal events between tasks

Answer

A semaphore is a signaling mechanism that controls access to shared resources and coordinates task execution order in an RTOS.

Question 2

What is 'priority inversion' in the context of RTOS scheduling?

Accepted Answer

When a low-priority task holds a resource needed by a high-priority task, indirectly blocking it

Answer

Priority inversion occurs when a high-priority task is blocked waiting for a resource held by a low-priority task, allowing medium-priority tasks to preempt and delay the high-priority one.

Question 3

How does a mutex differ from a binary semaphore in most RTOS implementations?

Accepted Answer

A mutex enforces ownership—only the task that took it can release it—while a binary semaphore has no ownership

Answer

A mutex tracks which task owns it and prevents other tasks from releasing it, enabling priority inheritance; a binary semaphore has no owner concept.

Question 4

What scheduling algorithm assigns each ready task an equal, fixed time slice in a round-robin fashion?

Accepted Answer

Time-sliced round-robin preemptive scheduling

Answer

Round-robin preemptive scheduling cycles through ready tasks of equal priority, preempting each after its time slice expires to ensure fairness.

Question 5

What is a race condition in embedded firmware?

Accepted Answer

Undefined behavior that occurs when multiple execution contexts access shared data without proper synchronization

Answer

A race condition arises when the outcome of concurrent accesses to shared data depends on the unpredictable order of execution, leading to intermittent bugs.

(CET) Certified Euthanasia Technician Practice Test

(CET) Certified Euthanasia Technician Practice Test

CET Embedded Systems & Programming 4