同步生产者，使用者和生产者队列

本文介绍了同步生产者，使用者和生产者队列的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我有一个生产者和一个消费者。生产者用对象填充其内部队列，消费者逐一地取得这些对象。我想要使​​cosumer与生产者同步，这样当没有对象准备就绪时，消费者阻塞，并且我想使生产者与自身同步，以便在队列满时停止产生（并且当有空间时再次启动） 。我怎么做？我可以使用 NSConditionalLock 解决一个更简单的情况，但是队列中的问题看起来更复杂。

objectsReady 和 bufferFreeSlots ： / p>

@implementation生产者 - （id）getNextObject { [objectsReady wait]; id anObject = [[buffer objectAtIndex：0] retain]; [buffer removeObjectAtIndex：0]; [bufferFreeSlots signal]; return [anObject autorelease]; } - （void）decodeLoop { while（1）{ [bufferFreeSlots wait]; [buffer push：[self produceAnObject]]; [objectsReady signal]; } } @end

bufferFreeSlots 初始化为最大队列大小。到目前为止，它似乎工作，但上帝知道这是一种信仰的行为，而不是一个坚定的信心。

I have a producer and a consumer. Producer fills its internal queue with objects, consumer takes these objects one by one. I want to synchronize the cosumer with the producer, so that the consumer blocks when there are no objects ready, and I want to synchronize the producer with itself, so that it stops producing when the queue is full (and starts again when there’s space). How do I do that? I was able to solve a simpler case without the queue using NSConditionalLock, but with the queue the problem looks more complex.

解决方案

I ended up using two semaphores, objectsReady and bufferFreeSlots:

@implementation Producer - (id) getNextObject { [objectsReady wait]; id anObject = [[buffer objectAtIndex:0] retain]; [buffer removeObjectAtIndex:0]; [bufferFreeSlots signal]; return [anObject autorelease]; } - (void) decodeLoop { while (1) { [bufferFreeSlots wait]; [buffer push:[self produceAnObject]]; [objectsReady signal]; } } @end

The bufferFreeSlots is initialized to the maximum queue size. So far it seems to work, but God knows this is an act of faith, not a solid confidence.