BloombergLP::bdlcc::SingleConsumerQueueImpl

Synopsis

Declared in <bdlcc_singleconsumerqueueimpl.h>

template<
    class TYPE,
    class ATOMIC_OP,
    class MUTEX,
    class CONDITION>
class SingleConsumerQueueImpl;

Description

The types ATOMIC_OP, MUTEX, and CONDITION are exposed for testing. Typical usage is with bsls::AtomicOperations for ATOMIC_OP, bslmt::Mutex for MUTEX, and bslmt::Condition for CONDITION.

Type Aliases

Name	Description
`value_type`	The type for elements stored in this queue.

Enums

Name	Description
`Unnamed enum`	Status codes returned by queue operations.

Member Functions

Name	Description
`SingleConsumerQueueImpl` [constructor]	Constructors
`~SingleConsumerQueueImpl` [destructor]	Destroy this container. The behavior is undefined unless all access or modification of the container has completed prior to this call.
`allocator`	Return the allocator used by this object to supply memory.
`disablePopFront`	Disable dequeueing from this queue. All subsequent invocations of `popFront` or `tryPopFront` will fail immediately. All blocked invocations of `popFront` and `waitUntilEmpty` will fail immediately. If the queue is already dequeue disabled, this method has no effect.
`disablePushBack`	Disable enqueueing into this queue. All subsequent invocations of `pushBack` or `tryPushBack` will fail immediately. All blocked invocations of `pushBack` will fail immediately. If the queue is already enqueue disabled, this method has no effect.
`enablePopFront`	Enable dequeueing. If the queue is not dequeue disabled, this call has no effect.
`enablePushBack`	Enable queuing. If the queue is not enqueue disabled, this call has no effect.
`isEmpty`	Return `true` if this queue is empty (has no elements), or `false` otherwise.
`isFull`	Return `true` if this queue is full (has no available capacity), or `false` otherwise. Note that for unbounded queues, this method always returns `false`.
`isPopFrontDisabled`	Return `true` if this queue is dequeue disabled, and `false` otherwise. Note that the queue is created in the "dequeue enabled" state.
`isPushBackDisabled`	Return `true` if this queue is enqueue disabled, and `false` otherwise. Note that the queue is created in the "enqueue enabled" state.
`numElements`	Returns the number of elements currently in this queue.
`popFront`	Remove the element from the front of this queue and load that element into the specified `value`. If the queue is empty, block until it is not empty. Return 0 on success, and a non-zero value otherwise. Specifically, return `e_DISABLED` if `isPopFrontDisabled()`. On failure, `value` is not changed. Threads blocked due to the queue being empty will return `e_DISABLED` if `disablePopFront` is invoked. The behavior is undefined unless the invoker of this method is the single consumer.
`pushBack`	`pushBack` overloads
`removeAll`	Remove all items currently in this queue. Note that this operation is not atomic; if other threads are concurrently pushing items into the queue the result of `numElements()` after this function returns is not guaranteed to be 0. The behavior is undefined unless the invoker of this method is the single consumer.
`tryPopFront`	Attempt to remove the element from the front of this queue without blocking, and, if successful, load the specified `value` with the removed element. Return 0 on success, and a non-zero value otherwise. Specifically, return `e_DISABLED` if `isPopFrontDisabled()`, and `e_EMPTY` if `!isPopFrontDisabled()` and the queue was empty. On failure, `value` is not changed. The behavior is undefined unless the invoker of this method is the single consumer.
`tryPushBack`	`tryPushBack` overloads
`waitUntilEmpty`	Block until all the elements in this queue are removed. Return 0 on success, and a non-zero value otherwise. Specifically, return `e_DISABLED` if `!isEmpty() && isPopFrontDisabled()`. A blocked thread waiting for the queue to empty will return `e_DISABLED` if `disablePopFront` is invoked.
`operator BloombergLP::bslmf::NestedTraitDeclaration<SingleConsumerQueueImpl, UsesBslmaAllocator>`	Declare that this type uses a `bslma` allocator.

Friends

Name	Description
`BloombergLP::bdlcc::SingleConsumerQueueImpl_AllocateLockGuard`	This class implements a guard that automatically invokes `releaseAllocateLock` on the managed queue upon destruction.
`BloombergLP::bdlcc::SingleConsumerQueueImpl_PopCompleteGuard`	This class implements a guard that automatically invokes `popComplete` on the managed queue upon destruction.
`BloombergLP::bdlcc::SingleConsumerQueueImpl_MarkReclaimProctor`	This class implements a proctor that, unless its `release` method has previously been invoked, automatically invokes `markReclaim` on a `NODE` upon destruction.