Understanding CyclicBarrier in Java: Streamline Thread Synchronization for Iterative Workflows
5 min readOct 30, 2024
What is CyclicBarrier?
CyclicBarrier
is a synchronization aid in Java that allows a set of threads to wait for each other to reach a common barrier point before any can proceed. The key feature of CyclicBarrier is that it’s cyclic—meaning it can be reused once all threads reach the barrier, making it perfect for recurring tasks that require threads to align at multiple points.
In essence:
- Fixed Number of Threads: A CyclicBarrier is created with a specified number of participating threads. All these threads must call
await()
to reach the barrier. - Synchronization Point: Once the required number of threads call
await()
, they are released together to move to the next phase. - Cyclic Nature: After the barrier is tripped, it automatically resets, allowing threads to use it again.
int numberOfThreads = 3;
CyclicBarrier barrier = new CyclicBarrier(numberOfThreads, () -> {
System.out.println("All threads have reached the barrier. Proceeding to the next phase.");
});