folly::PriorityUnboundedQueueSet

Synopsis

Declared in <folly/concurrency/PriorityUnboundedQueueSet.h>

template<
    typename T,
    bool SingleProducer,
    bool SingleConsumer,
    bool MayBlock,
    size_t LgSegmentSize = 8,
    size_t LgAlign = constexpr_log2(hardware_destructive_interference_size),
    template<typename> typename Atom = atomic>
class PriorityUnboundedQueueSet;

Description

A set of per-priority queues, and an interface for accessing them.

Functions: Consumer operations: bool try_dequeue(T&); Optional<T> try_dequeue(); Tries to extract an element from the front of the least-priority backing queue which has an element, if any. T const* try_peek(); Returns a pointer to the element at the front of the least-priority backing queue which has an element, if any. Only allowed when SingleConsumer is true. Note: Queues at lower priority are tried before queues at higher priority.

Secondary functions: queue& at_priority(size_t); queue const& at_priority(size_t) const; Returns a reference to the owned queue at the given priority. size_t size() const; Returns an estimate of the total size of the owned queues. bool empty() const; Returns true only if all of the owned queues were empty during the call. Note: size() and empty() are guaranteed to be accurate only if the owned queues are not changed concurrently.

Type Aliases

Name	Description
`queue`	The backing unbounded queue type used for each priority.

Member Functions

Name	Description
`PriorityUnboundedQueueSet` [constructor]	Constructors
`operator=`	Assignment operators
`at_priority`	Returns the owned queue at the given priority.
`empty`	Checks whether all owned queues were empty during the call.
`priorities`	Returns the number of priority queues in the set.
`size`	Returns an estimate of the total number of elements across all queues.
`try_dequeue`	`try_dequeue` overloads
`try_peek`	Returns a pointer to the front element of the least-priority non-empty queue.