library
advancedBlockingQueue Implementations
Choose the right BlockingQueue for producer-consumer patterns: ArrayBlockingQueue, LinkedBlockingQueue, or SynchronousQueue.
BlockingQueue is the foundation of producer-consumer patterns in Java. It extends Queue with blocking operations: put() blocks if full, take() blocks if empty.
BlockingQueue = a sushi conveyor belt. Chefs (producers) put plates on when there's space. Customers (consumers) take plates when available. If the belt is full, chefs wait. If empty, customers wait.
Key Concepts
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Implementations:
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ArrayBlockingQueue: bounded, backed by a fixed-size array. Fair ordering option (FIFO among waiting threads). Uses a single ReentrantLock — producers and consumers share the lock.
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LinkedBlockingQueue: optionally bounded (unbounded by default), backed by linked nodes. Uses separate locks for put and take — higher throughput than ArrayBlockingQueue under contention.
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PriorityBlockingQueue: unbounded, elements ordered by priority (Comparable or Comparator). take() returns the highest-priority element.
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SynchronousQueue: zero-capacity queue — every put() must wait for a corresponding take() and vice versa. Used for direct hand-off between threads. Executors.newCachedThreadPool() uses this.
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DelayQueue: elements are delayed — take() blocks until the element's delay has expired. Used for scheduling (retry after 5 seconds).
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Methods: offer() returns false if full (non-blocking), offer(timeout) waits up to timeout, put() blocks indefinitely. poll() returns null if empty, take() blocks indefinitely.