生产者 消费者问题
生产者-消费者问题是一个经典的进程同步问题，该问题最早由Dijkstra提出，用以演示他提出的信号量机制。在同一个进程地址空间内执行的两个线程生产者线程生产物品，然后将物品放置在一个空缓冲区中供消费者线程消费。消费者线程从缓冲区中获得物品，然后释放缓冲区。当生产者线程生产物品时，如果没有空缓冲区可用，那么生产者线程必须等待消费者线程释放出一个空缓冲区。当消费者线程消费物品时，如果没有满的缓冲区，那么消费者线程将被阻塞，直到新的物品被生产出来。(prodecer consumer
The producer consumer problem is a classic process synchronization problem that was first proposed by Dijkstra to demonstrate the proposed semaphore mechanism. Two threads executed in the same process address space, the producer thread produces the article, and then puts the item in an empty buffer for consumer thread consumption. The consumer thread gets the items from the buffer and then releases the buffer. When the producer thread produces the goods, if there is no empty buffer available, then the producer thread must wait for the consumer thread to release an empty buffer. When consumer threads consume objects, if there is no full buffer, then the consumer thread will be blocked until new items are produced.)