Producer-Consumer Bounded Queue

Problem Implement a thread-safe bounded queue (blocking buffer) shared by producer and consumer threads. Producers call put(item); consumers call take(). When the queue is full, put must block until space is available; when empty, take must block until an item arrives. No busy-waiting.

Input / Output

• Input: a fixed capacity, and concurrent put/take calls from many threads.
• Output: each item produced is consumed exactly once, in FIFO order, with no lost or duplicated items.

Constraints

• Bounded capacity — put blocks on full, take blocks on empty.
• Must be free of data races and deadlocks under many concurrent producers and consumers.
• No busy-wait / spin polling.

Example

• capacity 2; producers put a, b, c while a consumer takes: the third put blocks until the take frees a slot. Items come out a, b, c in order.