1024cores Producer-Consumer Queues

NOTE: 1、这是我见到的，总结得最最详细的

Producer-consumer queues are one of the most fundamental components in concurrent systems, they represent means to transfer data/messages/tasks/transactions between threads/stages/agents.

"one-size-fits-all"

NOTE:

1、这是非常重要的一个事实

2、后面作者从多个角度进行了区分，programmer应该根据实际情况进行tradeoff

If you hope that there is a single magical "one-size-fits-all" concurrent queue (MS PPL and Intel TTB fallacy), sorry, there is no. So what flavours of queues are there?

NOTE:

1、后面从各个角度、标准来进行区分

Number of producer and consumer threads

Depending on allowed number of producer and consumer threads:

- Multi-producer/multi-consumer queues (MPMC)

- Single-producer/multi-consumer queues (SPMC)

- Multi-producer/single-consumer queues (MPSC)

- Single-producer/single-consumer queues (SPSC)

I hope this aspect is clear - for example, if you have only 1 producer and 1 consumer thread, you can use SPSC queue instead of more general MPMC queue, and as you may guess it will be significantly faster.

Underlying data structure

Depending on underlying data structure:

- Array-based

- Linked-list-based

- Hybrid

Array-based queues are generally faster, however they are usually not strictly lockfree. The drawback is that they need to preallocate memory for the worst case. Linked-list queues grow dynamically, thus no need to preallocate any memory up-front. And hybrid queues (linked-list of small fixed-size arrays) try to combine advantages of both.