Simulation.Aivika.Queue

Tested with: GHC 7.8.3

This module defines a queue that can use the specified strategies. So, having only the FCFS, LCFS, SIRO and StaticPriorities strategies, you can build 4 x 4 x 4 = 64 different types of the queue, each of them will have its own behaviour.

Queue Types

type FCFSQueue a = Queue FCFS FCFS FCFS a

A type synonym for the ordinary FIFO queue also known as the FCFS (First Come - First Serviced) queue.

type LCFSQueue a = Queue FCFS LCFS FCFS a

A type synonym for the ordinary LIFO queue also known as the LCFS (Last Come - First Serviced) queue.

type SIROQueue a = Queue FCFS SIRO FCFS a

A type synonym for the SIRO (Serviced in Random Order) queue.

type PriorityQueue a = Queue FCFS StaticPriorities FCFS a

A type synonym for the queue with static priorities applied when storing the elements in the queue.

data Queue si sm so a

Represents a queue using the specified strategies for enqueueing (input), si, internal storing (in memory), sm, and dequeueing (output), so, where a denotes the type of items stored in the queue.

Instances

(Show si, Show sm, Show so, ResultItemable (ResultValue si), ResultItemable (ResultValue sm), ResultItemable (ResultValue so)) => ResultProvider (Queue si sm so a)

Creating Queue

newFCFSQueue :: Int -> Event (FCFSQueue a)

Create a new FCFS queue with the specified capacity.

newLCFSQueue :: Int -> Event (LCFSQueue a)

Create a new LCFS queue with the specified capacity.

newSIROQueue :: Int -> Event (SIROQueue a)

Create a new SIRO queue with the specified capacity.

newPriorityQueue :: Int -> Event (PriorityQueue a)

Create a new priority queue with the specified capacity.

newQueue

Arguments

:: (QueueStrategy si, QueueStrategy sm, QueueStrategy so)

=> si

the strategy applied to the enqueueing (input) processes when the queue is full

-> sm

the strategy applied when storing items in the queue

-> so

the strategy applied to the dequeueing (output) processes when the queue is empty

-> Int

the queue capacity

-> Event (Queue si sm so a)

Create a new queue with the specified strategies and capacity.

Queue Properties and Activities

enqueueStrategy :: Queue si sm so a -> si

The strategy applied to the enqueueing (input) processes when the queue is full.

enqueueStoringStrategy :: Queue si sm so a -> sm

The strategy applied when storing (in memory) items in the queue.

dequeueStrategy :: Queue si sm so a -> so

The strategy applied to the dequeueing (output) processes when the queue is empty.

queueNull :: Queue si sm so a -> Event Bool

Test whether the queue is empty.

See also queueNullChanged and queueNullChanged_.

queueFull :: Queue si sm so a -> Event Bool

Test whether the queue is full.

See also queueFullChanged and queueFullChanged_.

queueMaxCount :: Queue si sm so a -> Int

The queue capacity.

queueCount :: Queue si sm so a -> Event Int

Return the current queue size.

See also queueCountStats, queueCountChanged and queueCountChanged_.

queueCountStats :: Queue si sm so a -> Event (TimingStats Int)

Return the queue size statistics.

enqueueCount :: Queue si sm so a -> Event Int

Return the total number of input items that were enqueued.

See also enqueueCountChanged and enqueueCountChanged_.

enqueueLostCount :: Queue si sm so a -> Event Int

Return the number of lost items.

See also enqueueLostCountChanged and enqueueLostCountChanged_.

enqueueStoreCount :: Queue si sm so a -> Event Int

Return the total number of input items that were stored.

See also enqueueStoreCountChanged and enqueueStoreCountChanged_.

dequeueCount :: Queue si sm so a -> Event Int

Return the total number of requests for dequeueing the items, not taking into account the failed attempts to dequeue immediately without suspension.

See also dequeueCountChanged and dequeueCountChanged_.

dequeueExtractCount :: Queue si sm so a -> Event Int

Return the total number of output items that were actually dequeued.

See also dequeueExtractCountChanged and dequeueExtractCountChanged_.

queueLoadFactor :: Queue si sm so a -> Event Double

Return the load factor: the queue size divided by its maximum size.

See also queueLoadFactorChanged and queueLoadFactorChanged_.

enqueueRate :: Queue si sm so a -> Event Double

Return the rate of the input items that were enqueued: how many items per time.

enqueueStoreRate :: Queue si sm so a -> Event Double

Return the rate of the items that were stored: how many items per time.

dequeueRate :: Queue si sm so a -> Event Double

Return the rate of the requests for dequeueing the items: how many requests per time. It does not include the failed attempts to dequeue immediately without suspension.

dequeueExtractRate :: Queue si sm so a -> Event Double

Return the rate of the output items that were actually dequeued: how many items per time.

queueWaitTime :: Queue si sm so a -> Event (SamplingStats Double)

Return the wait time from the time at which the item was stored in the queue to the time at which it was dequeued.

See also queueWaitTimeChanged and queueWaitTimeChanged_.

queueTotalWaitTime :: Queue si sm so a -> Event (SamplingStats Double)

Return the total wait time from the time at which the enqueueing operation was initiated to the time at which the item was dequeued.

In some sense, queueTotalWaitTime == queueInputWaitTime + queueWaitTime.

See also queueTotalWaitTimeChanged and queueTotalWaitTimeChanged_.

enqueueWaitTime :: Queue si sm so a -> Event (SamplingStats Double)

Return the enqueue wait time from the time at which the enqueueing operation was initiated to the time at which the item was stored in the queue.

See also enqueueWaitTimeChanged and enqueueWaitTimeChanged_.

dequeueWaitTime :: Queue si sm so a -> Event (SamplingStats Double)

Return the dequeue wait time from the time at which the item was requested for dequeueing to the time at which it was actually dequeued.

See also dequeueWaitTimeChanged and dequeueWaitTimeChanged_.

queueRate :: Queue si sm so a -> Event Double

Return a long-term average queue rate calculated as the average queue size divided by the average wait time.

This value may be less than the actual arrival rate as the queue is finite and new arrivals may be locked while the queue remains full.

See also queueRateChanged and queueRateChanged_.

Dequeuing and Enqueuing

dequeue

Arguments

:: (DequeueStrategy si, DequeueStrategy sm, EnqueueStrategy so)

=> Queue si sm so a

the queue

-> Process a

the dequeued value

Dequeue suspending the process if the queue is empty.

dequeueWithOutputPriority

Arguments

:: (DequeueStrategy si, DequeueStrategy sm, PriorityQueueStrategy so po)

=> Queue si sm so a

the queue

-> po

the priority for output

-> Process a

the dequeued value

Dequeue with the output priority suspending the process if the queue is empty.

tryDequeue

Arguments

:: (DequeueStrategy si, DequeueStrategy sm)

=> Queue si sm so a

the queue

-> Event (Maybe a)

the dequeued value of Nothing

Try to dequeue immediately.

enqueue

Arguments

:: (EnqueueStrategy si, EnqueueStrategy sm, DequeueStrategy so)

=> Queue si sm so a

the queue

-> a

the item to enqueue

-> Process ()

Enqueue the item suspending the process if the queue is full.

enqueueWithInputPriority

Arguments

:: (PriorityQueueStrategy si pi, EnqueueStrategy sm, DequeueStrategy so)

=> Queue si sm so a

the queue

-> pi

the priority for input

-> a

the item to enqueue

-> Process ()

Enqueue with the input priority the item suspending the process if the queue is full.

enqueueWithStoringPriority

Arguments

:: (EnqueueStrategy si, PriorityQueueStrategy sm pm, DequeueStrategy so)

=> Queue si sm so a

the queue

-> pm

the priority for storing

-> a

the item to enqueue

-> Process ()

Enqueue with the storing priority the item suspending the process if the queue is full.

enqueueWithInputStoringPriorities

Arguments

:: (PriorityQueueStrategy si pi, PriorityQueueStrategy sm pm, DequeueStrategy so)

=> Queue si sm so a

the queue

-> pi

the priority for input

-> pm

the priority for storing

-> a

the item to enqueue

-> Process ()

Enqueue with the input and storing priorities the item suspending the process if the queue is full.

tryEnqueue

Arguments

:: (EnqueueStrategy sm, DequeueStrategy so)

=> Queue si sm so a

the queue

-> a

the item which we try to enqueue

-> Event Bool

Try to enqueue the item. Return False in the monad if the queue is full.

tryEnqueueWithStoringPriority

Arguments

:: (PriorityQueueStrategy sm pm, DequeueStrategy so)

=> Queue si sm so a

the queue

-> pm

the priority for storing

-> a

the item which we try to enqueue

-> Event Bool

Try to enqueue with the storing priority the item. Return False in the monad if the queue is full.

enqueueOrLost

Arguments

:: (EnqueueStrategy sm, DequeueStrategy so)

=> Queue si sm so a

the queue

-> a

the item which we try to enqueue

-> Event Bool

Try to enqueue the item. If the queue is full then the item will be lost and False will be returned.

enqueueOrLost_

Arguments

:: (EnqueueStrategy sm, DequeueStrategy so)

=> Queue si sm so a

the queue

-> a

the item which we try to enqueue

-> Event ()

Try to enqueue the item. If the queue is full then the item will be lost.

enqueueWithStoringPriorityOrLost

Arguments

:: (PriorityQueueStrategy sm pm, DequeueStrategy so)

=> Queue si sm so a

the queue

-> pm

the priority for storing

-> a

the item which we try to enqueue

-> Event Bool

Try to enqueue with the storing priority the item. If the queue is full then the item will be lost and False will be returned.

enqueueWithStoringPriorityOrLost_

Arguments

:: (PriorityQueueStrategy sm pm, DequeueStrategy so)

=> Queue si sm so a

the queue

-> pm

the priority for storing

-> a

the item which we try to enqueue

-> Event ()

Try to enqueue with the storing priority the item. If the queue is full then the item will be lost.

Awaiting

waitWhileFullQueue :: Queue si sm so a -> Process ()

Wait while the queue is full.

Summary

queueSummary :: (Show si, Show sm, Show so) => Queue si sm so a -> Int -> Event ShowS

Return the summary for the queue with desciption of its properties and activities using the specified indent.

Derived Signals for Properties

queueNullChanged :: Queue si sm so a -> Signal Bool

Signal when the queueNull property value has changed.

queueNullChanged_ :: Queue si sm so a -> Signal ()

Signal when the queueNull property value has changed.

queueFullChanged :: Queue si sm so a -> Signal Bool

Signal when the queueFull property value has changed.

queueFullChanged_ :: Queue si sm so a -> Signal ()

Signal when the queueFull property value has changed.

queueCountChanged :: Queue si sm so a -> Signal Int

Signal when the queueCount property value has changed.

queueCountChanged_ :: Queue si sm so a -> Signal ()

Signal when the queueCount property value has changed.

enqueueCountChanged :: Queue si sm so a -> Signal Int

Signal when the enqueueCount property value has changed.

enqueueCountChanged_ :: Queue si sm so a -> Signal ()

Signal when the enqueueCount property value has changed.

enqueueLostCountChanged :: Queue si sm so a -> Signal Int

Signal when the enqueueLostCount property value has changed.

enqueueLostCountChanged_ :: Queue si sm so a -> Signal ()

Signal when the enqueueLostCount property value has changed.

enqueueStoreCountChanged :: Queue si sm so a -> Signal Int

Signal when the enqueueStoreCount property value has changed.

enqueueStoreCountChanged_ :: Queue si sm so a -> Signal ()

Signal when the enqueueStoreCount property value has changed.

dequeueCountChanged :: Queue si sm so a -> Signal Int

Signal when the dequeueCount property value has changed.

dequeueCountChanged_ :: Queue si sm so a -> Signal ()

Signal when the dequeueCount property value has changed.

dequeueExtractCountChanged :: Queue si sm so a -> Signal Int

Signal when the dequeueExtractCount property value has changed.

dequeueExtractCountChanged_ :: Queue si sm so a -> Signal ()

Signal when the dequeueExtractCount property value has changed.

queueLoadFactorChanged :: Queue si sm so a -> Signal Double

Signal when the queueLoadFactor property value has changed.

queueLoadFactorChanged_ :: Queue si sm so a -> Signal ()

Signal when the queueLoadFactor property value has changed.

queueWaitTimeChanged :: Queue si sm so a -> Signal (SamplingStats Double)

Signal when the queueWaitTime property value has changed.

queueWaitTimeChanged_ :: Queue si sm so a -> Signal ()

Signal when the queueWaitTime property value has changed.

queueTotalWaitTimeChanged :: Queue si sm so a -> Signal (SamplingStats Double)

Signal when the queueTotalWaitTime property value has changed.

queueTotalWaitTimeChanged_ :: Queue si sm so a -> Signal ()

Signal when the queueTotalWaitTime property value has changed.

enqueueWaitTimeChanged :: Queue si sm so a -> Signal (SamplingStats Double)

Signal when the enqueueWaitTime property value has changed.

enqueueWaitTimeChanged_ :: Queue si sm so a -> Signal ()

Signal when the enqueueWaitTime property value has changed.

dequeueWaitTimeChanged :: Queue si sm so a -> Signal (SamplingStats Double)

Signal when the dequeueWaitTime property value has changed.

dequeueWaitTimeChanged_ :: Queue si sm so a -> Signal ()

Signal when the dequeueWaitTime property value has changed.

queueRateChanged :: Queue si sm so a -> Signal Double

Signal when the queueRate property value has changed.

queueRateChanged_ :: Queue si sm so a -> Signal ()

Signal when the queueRate property value has changed.

Basic Signals

enqueueInitiated :: Queue si sm so a -> Signal a

Return a signal that notifies when the enqueuing operation is initiated.

enqueueStored :: Queue si sm so a -> Signal a

Return a signal that notifies when the enqueuing operation is completed and the item is stored in the internal memory of the queue.

enqueueLost :: Queue si sm so a -> Signal a

Return a signal which notifies that the item was lost when attempting to add it to the full queue with help of enqueueOrLost, enqueueOrLost_ or similar functions that imply that the element can be lost. All their names are ending with OrLost or OrLost_.

In other cases the enqueued items are not lost but the corresponded process can suspend until the internal queue storage is freed. Although there is one exception from this rule. If the process trying to enqueue a new element was suspended but then canceled through cancelProcess from the outside then the item will not be added.

dequeueRequested :: Queue si sm so a -> Signal ()

Return a signal that notifies when the dequeuing operation was requested.

dequeueExtracted :: Queue si sm so a -> Signal a

Return a signal that notifies when the item was extracted from the internal storage of the queue and prepared for immediate receiving by the dequeuing process.

Overall Signal

queueChanged_ :: Queue si sm so a -> Signal ()

Signal whenever any property of the queue changes.

The property must have the corresponded signal. There are also characteristics similar to the properties but that have no signals. As a rule, such characteristics already depend on the simulation time and therefore they may change at any time point.