FAQs On Difference between Spinlock and Semaphore
Q1. How does a spinlock work?
Answer:
When a thread wants to enter a critical section, it checks if the spinlock is available. If it is, the thread “acquires” the lock and enters the critical section. If the lock is already held by another thread, the requesting thread enters a busy-wait loop, repeatedly checking the lock’s status until it becomes available.
Q2. When should I use a spinlock?
Answer:
Spinlocks are suitable in scenarios where the expected time a thread will spend waiting for the lock to be released is very short. They are efficient when contention is low and the wait times are minimal. However, if the wait times are longer, spinlocks can waste CPU cycles and lead to performance degradation.
Q3. What are the advantages of spinlocks?
Answers:
Spinlocks have low overhead compared to other synchronization primitives like mutexes or semaphores. They avoid the overhead of putting a thread to sleep and waking it up, which can be costly. They are also easy to implement in environments without support for more complex synchronization mechanisms.
Difference between Spinlock and Semaphore
Semaphore is just a shared, non-negative variable that is used by multiple threads. A semaphore is a signalling device, and another thread may signal a thread that is awaiting a semaphore. It uses two atomic actions for process synchronisation:
1) wait, and 2) signal.
In accordance with how it is configured, a semaphore either permits or prohibits access to the resource.