Module queue 

Disruptor-inspired queue. The queue implemented in this module is based on a ring buffer, with producers and consumers accessing it in an orderly fashion.

Structs

ConcurrentProducer

A producer for a queue that can be concurrent with other (concurrent) producers

Consumer

A consumer of items from the queue

ConsumerAccess

An access to items from the queue through a consumer

MultiBarrier

A barrier to be used to await for the output of multiple other queue users, producer or consumers

OwnedOutput

The output of a single queue user The construction of producers and consumers guarantee a single writer

RingBuffer

A circular queue to be accessed by producer(s) and consumers

Sequence

The position of an item in the queue. This also uniquely identifies the item within the queue and is used by queue users to keep track of what items are still expected or consumed. Sequence has two usages:

SharedOutput

The common output for multiple queue users, usually concurrent producers

SingleBarrier

A barrier to be used to await for the output of a single other queue user, producer or consumer

SingleProducer

A single producer that will be the only producer for a queue

Enums

ConsumerMode

The blocking mode for a consumer Blocking consumers prevent producers from writing new items in the queue that would replace items not already seen by the consumer. On the contrary, non-blocking consumers do not block producers, enabling producers to still write onto the queue. Non-blocking consumers then run the risk of lagging behind. In that case trying to receive messages will produce TryRecvError::Lagging.

Traits

Output

The output of a user of a queue, be it a producer or a consumer. For producers, this is the last sequence available to consumers. For consumers, this is the last item they finished handling that could then be seen by other downchain consumers.

QueueUser

The user of a queue, be it a producer or a consumer This trait abstracts over producers and consumers so that the associated UserOutput can be retrieved. The UserOutput can be used in turn to await items published by the queue user. This enables the construction of consumers that await the items directly from producer, but also from one or more other producers using an appropriate Barrier.