生产者/消费者中的信号量与互斥量 [英] Semaphore vs Mutex in Producer/Consumer

问题描述

在生产者－消费者问题中，为什么我们经常建议使用信号量而不是使用锁/互斥锁?

In the Producer-Consumer problem, why are we often suggested use to semaphores instead of using a lock/mutex?

我看不到使用信号量的正当理由，因为我们只有 2个线程进行协调.在这种情况下，锁似乎更容易编写代码并进行推理，因为一个线程将锁定缓冲区然后释放它，以便另一个线程可以执行相同的操作.只有2个线程，所以我看不到信令的使用.

I don't see a valid reason to use a semaphore because we only have 2 threads coordinating. In this case a lock seems much easier to code and reason about because a thread will lock the buffer then free it so the other thread can do the same. There are only 2 threads so I don't see the use of signaling.

有人可以说为什么建议通常将信号量用于生产者-消费者吗?

Can anyone say why it is suggested to use semaphores usually for producer-consumer?

推荐答案

据我所知.

请阅读以下两种情况.

第一种情况

信号量就像摩托车的钥匙.假设您的摩托车最多有两个座位.让我们以摩托车为资源，座位为共享内存中的两个缓冲空间.

Semaphore is like a key for your motorbike. Lets say your motorbike has a maximum of two seats. Lets think that the motorbike is the resource and the seats are the two buffer space inside the shared memory.

第二种情况

让我们想到一个男孩腹泻.他赶到洗手间，但发现他的兄弟仍在使用洗手间.他需要等到他的兄弟完成之后:)让我们以为洗手间是一个很大的回忆.

Let's think of a boy having diarrhea. He rushed to the bathroom but found out that his brother is still using the bathroom. He need to wait until his brother is done :) Lets think that the bathroom is a one big memory.

对于生产者和消费者，

让我们说生产者的商店每天有最多x件商品.

Lets say the producer has a store with x maximum items for each day.

消费者根据商品的可用性购买x件商品.

The consumer buys x items depending on the availability of the item.

这意味着互斥量和信号量具有自己的目的或应用程序，具体取决于您的需求. 仅仅是生产者－消费者的想法，信号量就赢了.

This means that mutex and semaphore have their own purpose or application depending on what you need. It is just that for Producer-consumer idea, the semaphore has won.

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