FiFo Queue - Simple

[Bilgus]

Went looking for a FIFO queue there are a few examples here on the forum but I didn't like the complexit/lack of flexibility in what I found

The Queue Ive implemented uses a single dimension array  set up as a circular buffer

The position and Item Count are stored in an extra slot of the array inside a 'DllStruct'

Convenience Functions are included

FifoQueue_Create($iSlots) ;Initialize the Queue

Func FifoQueue_($eFQ, ByRef $aQ) ;For Status Functions - (So you don't have to supply $vOut)

Available operations:

$eFQ_Create = 0, $eFQ_Push, $eFQ_Peek, $eFQ_Pop, $eFQ_IsEmpty, $eFQ_IsFull, $eFQ_Count, $eFQ_Empty, $eFQ_IsInit

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Global Enum $eFQ_Create = 0, $eFQ_Push, $eFQ_Peek, $eFQ_Pop, $eFQ_IsEmpty, $eFQ_IsFull, $eFQ_Count, $eFQ_Empty, $eFQ_IsInit

Func FifoQueue($eFQ, ByRef $aQ, ByRef $vOut)
    ;Bilgus 2020
    Local Const $IDInit = 0xF1F0

    Local $iErr = 0
    Local $iPos, $iItems
    Local $tKey, $IDKey
    Local $iSlots = UBound($aQ, 1) - 1
    If $iSlots > 0xFFFE Then Return SetError(0xFFFE, -1, $vOut)

    If $eFQ <> $eFQ_Create Then
        If Not IsArray($aQ) Or $iSlots < 2 Then
            $iErr = 1 ;Queue not initialized
        ElseIf IsDllStruct($aQ[$iSlots]) Then
            $tKey = $aQ[$iSlots] ;MQ_Create adds an extra Slot -- pos data is stored there..
            $iPos = DllStructGetData($tKey, 1, 1)
            $iItems = DllStructGetData($tKey, 1, 2)
            If DllStructGetData($tKey, 1, 3) <> $IDInit Then $iErr += 2 ;Queue not initialized (BY MQ_Create)
        EndIf

        If $iErr And $eFQ <> $eFQ_IsInit Then
            ConsoleWrite("Queue Error: " & $iErr & @CRLF)
            Return SetError($iErr, 0, $vOut)
        EndIf
    Else
        If $iSlots < 2 Then $iSlots = 10
        Local $a[$iSlots + 1]
        $tKey = DllStructCreate("USHORT[4]")
        DllStructSetData($tKey, 1, 0xF1F0, 3)
        $a[$iSlots] = $tKey
        $vOut = $a
        ;ConsoleWrite("Created Queue[" & $iSlots & "]" & @CRLF)
        Return SetError($iErr, $iSlots, $vOut)
    EndIf
    ;Circular Queue Logic
    Switch ($eFQ)
        Case $eFQ_Push
            If $iItems >= $iSlots Then Return False
             ;Rollover after last element
            $aQ[Mod($iItems + $iPos, $iSlots)] = $vOut
            $iItems += 1
        Case $eFQ_Peek
            If $iItems = 0 Then Return False
            $vOut = $aQ[$iPos]
        Case $eFQ_Pop
            If $iItems = 0 Then Return False
            $vOut = $aQ[$iPos]
            $iPos += 1
            $iItems -= 1
        Case $eFQ_IsEmpty
            Return ($iItems = 0)
        Case $eFQ_IsFull
            Return ($iItems >= $iSlots)
        Case $eFQ_Count
            Return $iItems
        Case $eFQ_Empty
            $iItems = 0
        Case $eFQ_IsInit
            Return ($iErr = 0)
        Case Else
            Return False
    EndSwitch

    $iPos = Mod($iPos, $iSlots) ;Rollover after last element
    DllStructSetData($tKey, 1, $iPos, 1)
    DllStructSetData($tKey, 1, $iItems, 2)
    Return SetError($iErr, $iItems, True)
EndFunc   ;==>FifoQueue



;--Convenience Functions-------------------------------
Func FifoQueue_Create($iSlots = 10)
    Local $aE
    Return FifoQueue($eFQ_Create, $iSlots, $aE)
EndFunc   ;==>FifoQueue_Create

Func FifoQueue_($eFQ, ByRef $aQ)
    Local $aE
    If $eFQ < $eFQ_IsEmpty Then
        $aE = FifoQueue($eFQ, $aQ, $aE)
        Return SetError(@error, 0, $aE)
    Else
        Return FifoQueue($eFQ, $aQ, $aE)
    EndIf
EndFunc   ;==>FifoQueue_
;--Convenience Functions-------------------------------

 

Example (With Debug function)

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;Bilgus 2020
Global Enum $eFQ_Create = 0, $eFQ_Push, $eFQ_Peek, $eFQ_Pop, $eFQ_IsEmpty, $eFQ_IsFull, $eFQ_Count, $eFQ_Empty, $eFQ_IsInit
Global $aQueue
ConsoleWrite("!Queue" & (FifoQueue_($eFQ_IsInit, $aQueue) ? " IS " : " NOT ") & "initialized" & @CRLF)
$aQueue = FifoQueue_Create(4)
ConsoleWrite("!Queue" & (FifoQueue_($eFQ_IsInit, $aQueue) ? " IS " : " NOT ") & "initialized" & @CRLF)

FifoQueueTest()


Func FifoQueueTest()
    Local $aTest
    If FifoQueue_Dbg($eFQ_Pop, $aQueue, $aTest) Then ConsoleWrite(StringFormat("!%s, %s, %s, %s" & @CRLF, $aTest[0], $aTest[1], $aTest[2], $aTest[3]))
    ConsoleWrite("!Push 9" & @CRLF)
    For $i = 0 To 80 Step 10
        Local $aIn[4] = [$i, $i + 1, $i + 2, $i + 3]
        If FifoQueue_Dbg($eFQ_Push, $aQueue, $aIn) Then
            ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aIn[0], $aIn[1], $aIn[2], $aIn[3]))
        EndIf
    Next
    ConsoleWrite("!Pop All" & @CRLF)
    While FifoQueue_Dbg($eFQ_Pop, $aQueue, $aTest)
        ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aTest[0], $aTest[1], $aTest[2], $aTest[3]))
    WEnd
    ConsoleWrite("!Push 9" & @CRLF)
    For $i = 100 To 900 Step 100
        Local $aIn[4] = [$i, $i + 1, $i + 2, $i + 3]
        If FifoQueue_Dbg($eFQ_Push, $aQueue, $aIn) Then
            ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aIn[0], $aIn[1], $aIn[2], $aIn[3]))
        EndIf
    Next
    ConsoleWrite("!Queue" & (FifoQueue_($eFQ_IsFull, $aQueue) ? " IS " : " NOT ") & "full" & @CRLF)
    ConsoleWrite("!Queue Items: " & FifoQueue_($eFQ_Count, $aQueue) & @CRLF)
    ConsoleWrite("!Push 1" & @CRLF)
    Local $aIn[6] = [5555, 6666, 7777, 8888]
    FifoQueue_Dbg($eFQ_Push, $aQueue, $aIn)
    ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aIn[0], $aIn[1], $aIn[2], $aIn[3]))

    
    If FifoQueue_Dbg($eFQ_Peek, $aQueue, $aTest) Then ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aTest[0], $aTest[1], $aTest[2], $aTest[3]))
    ConsoleWrite("!Pop 2" & @CRLF)
    If FifoQueue_Dbg($eFQ_Pop, $aQueue, $aTest) Then ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aTest[0], $aTest[1], $aTest[2], $aTest[3]))
    If FifoQueue_Dbg($eFQ_Pop, $aQueue, $aTest) Then ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aTest[0], $aTest[1], $aTest[2], $aTest[3]))
    ConsoleWrite("!Queue" & (FifoQueue_($eFQ_IsFull, $aQueue) ? " IS " : " NOT ") & "full" & @CRLF)
    ConsoleWrite("!Queue Items: " & FifoQueue_($eFQ_Count, $aQueue) & @CRLF)
    ConsoleWrite("!Push 4" & @CRLF)
    For $i = 1000 To 5000 Step 1000
        Local $aIn[4] = [$i, $i + 1, $i + 2, $i + 3]
        If FifoQueue_Dbg($eFQ_Push, $aQueue, $aIn) Then
            ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aIn[0], $aIn[1], $aIn[2], $aIn[3]))
        EndIf
    Next
    ConsoleWrite("!Pop 2" & @CRLF)
    For $i = 1 To 2
        If FifoQueue_Dbg($eFQ_Pop, $aQueue, $aTest) Then ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aTest[0], $aTest[1], $aTest[2], $aTest[3]))
    Next
    ConsoleWrite("!Push 7" & @CRLF)
    For $i = 10000 To 70000 Step 10000
        Local $aIn[4] = [$i, $i + 1, $i + 2, $i + 3]
        If FifoQueue_Dbg($eFQ_Push, $aQueue, $aIn) Then
            ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aIn[0], $aIn[1], $aIn[2], $aIn[3]))
        EndIf
    Next
    ConsoleWrite("!Pop 2" & @CRLF)
    For $i = 1 To 2
        If FifoQueue_Dbg($eFQ_Pop, $aQueue, $aTest) Then ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aTest[0], $aTest[1], $aTest[2], $aTest[3]))
    Next
    ConsoleWrite("!PopAll" & @CRLF)
    While FifoQueue_Dbg($eFQ_Pop, $aQueue, $aTest)
        ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aTest[0], $aTest[1], $aTest[2], $aTest[3]))
    WEnd
    ConsoleWrite("!Queue" & (FifoQueue_($eFQ_IsEmpty, $aQueue) ? " IS " : " NOT ") & "empty" & @CRLF)
    ConsoleWrite("!Push 6" & @CRLF)
    For $i = 0 To 50 Step 10
        Local $aIn[4] = [$i, $i + 1, $i + 2, $i + 3]
        If FifoQueue_Dbg($eFQ_Push, $aQueue, $aIn) Then
            ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aIn[0], $aIn[1], $aIn[2], $aIn[3]))
        EndIf
    Next
    ConsoleWrite("!Pop 4 [2]" & @CRLF)
    Local $aTest[2]
    For $i = 1 To 4
        If FifoQueue_Dbg($eFQ_Pop, $aQueue, $aTest) Then ConsoleWrite(StringFormat("%s, %s" & @CRLF, $aTest[0], $aTest[1]))
    Next
    Local $aTest = 0
    ConsoleWrite("!Push 7" & @CRLF)
    For $i = 100 To 700 Step 100
        Local $aIn[4] = ["N" & $i, $i + 1, $i + 2, $i + 3]
        If FifoQueue_Dbg($eFQ_Push, $aQueue, $aIn) Then
            ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aIn[0], $aIn[1], $aIn[2], $aIn[3]))
        EndIf
    Next
    ConsoleWrite("!Empty All" & @CRLF)
    FifoQueue_($eFQ_Empty, $aQueue)
    ConsoleWrite("!Queue" & (FifoQueue_($eFQ_IsEmpty, $aQueue) ? " IS " : " NOT ") & "empty" & @CRLF)
    ConsoleWrite("!Push 10" & @CRLF)
    For $i = 0 To 9
        Local $aIn[4] = ["A" & $i, $i + 1, $i + 2, $i + 3]
        If FifoQueue_Dbg($eFQ_Push, $aQueue, $aIn) Then
            ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aIn[0], $aIn[1], $aIn[2], $aIn[3]))
        EndIf
    Next
    ConsoleWrite("!Pop 2" & @CRLF)
    If FifoQueue_Dbg($eFQ_Pop, $aQueue, $aTest) Then ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aTest[0], $aTest[1], $aTest[2], $aTest[3]))
    If FifoQueue_Dbg($eFQ_Pop, $aQueue, $aTest) Then ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aTest[0], $aTest[1], $aTest[2], $aTest[3]))
    ConsoleWrite("!Push 1" & @CRLF)
    Local $aIn[6] = [5555, 6666, 7777, 8888]
    FifoQueue_Dbg($eFQ_Push, $aQueue, $aIn)
    ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aIn[0], $aIn[1], $aIn[2], $aIn[3]))
    ConsoleWrite("!Pop 2" & @CRLF)
    If FifoQueue_Dbg($eFQ_Pop, $aQueue, $aTest) Then ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aTest[0], $aTest[1], $aTest[2], $aTest[3]))
    If FifoQueue_Dbg($eFQ_Pop, $aQueue, $aTest) Then ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aTest[0], $aTest[1], $aTest[2], $aTest[3]))
    ConsoleWrite("!Push 2" & @CRLF)
    Local $aIn[4] = ["P" & 0, 1, 2, 3]
    If FifoQueue_Dbg($eFQ_Push, $aQueue, $aIn) Then
        ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aIn[0], $aIn[1], $aIn[2], $aIn[3]))
    EndIf
    Local $aIn[4] = ["P" & 10, 20, 30, 40]
    If FifoQueue_Dbg($eFQ_Push, $aQueue, $aIn) Then
        ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aIn[0], $aIn[1], $aIn[2], $aIn[3]))
    EndIf
    ConsoleWrite("!Queue Items: " & FifoQueue_($eFQ_Count, $aQueue) & @CRLF)
    ConsoleWrite("!PopAll" & @CRLF)
    While FifoQueue_Dbg($eFQ_Pop, $aQueue, $aTest)
        ConsoleWrite(StringFormat("%s, %s, %s, %s" & @CRLF, $aTest[0], $aTest[1], $aTest[2], $aTest[3]))
    WEnd
EndFunc   ;==>FifoQueueTest

;--Convenience Functions-------------------------------
Func FifoQueue_Create($iSlots = 10)
    Local $aE
    Return FifoQueue($eFQ_Create, $iSlots, $aE)
EndFunc   ;==>FifoQueue_Create

Func FifoQueue_($eFQ, ByRef $aQ)
    Local $aE
    If $eFQ < $eFQ_IsEmpty Then
        $aE = FifoQueue($eFQ, $aQ, $aE)
        Return SetError(@error, 0, $aE)
    Else
        Return FifoQueue($eFQ, $aQ, $aE)
    EndIf
EndFunc   ;==>FifoQueue_
;--Convenience Functions-------------------------------

Func FifoQueue_Dbg($eFQ, ByRef $aQ, ByRef $vOut)
    Local Const $aDbg[9] = ["<>Create", ">Push [%d]", "<Peek [%d]", "<Pop [%d]", "=IsEmpty", "=IsFull", "=Count", "<>Empty", "=IsInit"]

    Local $iSlots = UBound($aQ, 1) - 1
    If $iSlots > 65534 Then MsgBox(0, "ERROR", "Too many Slots")

    If $iSlots > 0 Then
        If IsDllStruct($aQ[$iSlots]) Then
            $tKey = $aQ[$iSlots]
            Local $iElKey = DllStructGetData($tKey, 1, 3)
            Local $iItems = DllStructGetData($tKey, 1, 2)
            Local $iPos = DllStructGetData($tKey, 1, 1)
            If $eFQ > $eFQ_Pop Then
                ConsoleWrite($aDbg[$eFQ] & @CRLF)
            ElseIf $eFQ = $eFQ_Push Then
                ConsoleWrite(StringFormat($aDbg[$eFQ] & @CRLF, Mod($iItems + $iPos, $iSlots)))
            Else
                ConsoleWrite(StringFormat($aDbg[$eFQ] & @CRLF, $iPos))
            EndIf
        Else
            ConsoleWrite("Invalid Array $aQ" & @CRLF)
        EndIf
    Else
        ConsoleWrite($aDbg[$eFQ] & @CRLF)
    EndIf
    Local $aRes = FifoQueue($eFQ, $aQ, $vOut)

    Return $aRes
EndFunc   ;==>FifoQueue_Dbg

Func FifoQueue($eFQ, ByRef $aQ, ByRef $vOut)
                    ;Bilgus 2020
    Local Const $IDInit = 0xF1F0

    Local $iErr = 0
    Local $iPos, $iItems
    Local $tKey, $IDKey
    Local $iSlots = UBound($aQ, 1) - 1
    If $iSlots > 0xFFFE Then Return SetError(0xFFFE, -1, $vOut)

    If $eFQ <> $eFQ_Create Then
        If Not IsArray($aQ) Or $iSlots < 2 Then
            $iErr = 1 ;Queue not initialized
        ElseIf IsDllStruct($aQ[$iSlots]) Then
            $tKey = $aQ[$iSlots] ;MQ_Create adds an extra Slot -- pos data is stored there..
            $iPos = DllStructGetData($tKey, 1, 1)
            $iItems = DllStructGetData($tKey, 1, 2)
            If DllStructGetData($tKey, 1, 3) <> $IDInit Then $iErr += 2 ;Queue not initialized (BY MQ_Create)
        EndIf

        If $iErr And $eFQ <> $eFQ_IsInit Then
            ConsoleWrite("Queue Error: " & $iErr & @CRLF)
            Return SetError($iErr, 0, $vOut)
        EndIf
    Else
        If $iSlots < 2 Then $iSlots = 10
        Local $a[$iSlots + 1]
        $tKey = DllStructCreate("USHORT[4]")
        DllStructSetData($tKey, 1, 0xF1F0, 3)
        $a[$iSlots] = $tKey
        $vOut = $a
        ;ConsoleWrite("Created Queue[" & $iSlots & "]" & @CRLF)
        Return SetError($iErr, $iSlots, $vOut)
    EndIf
    ;Circular Queue Logic
    Switch ($eFQ)
        Case $eFQ_Push
            If $iItems >= $iSlots Then Return False
             ;Rollover after last element
            $aQ[Mod($iItems + $iPos, $iSlots)] = $vOut
            $iItems += 1
        Case $eFQ_Peek
            If $iItems = 0 Then Return False
            $vOut = $aQ[$iPos]
        Case $eFQ_Pop
            If $iItems = 0 Then Return False
            $vOut = $aQ[$iPos]
            $iPos += 1
            $iItems -= 1
        Case $eFQ_IsEmpty
            Return ($iItems = 0)
        Case $eFQ_IsFull
            Return ($iItems >= $iSlots)
        Case $eFQ_Count
            Return $iItems
        Case $eFQ_Empty
            $iItems = 0
        Case $eFQ_IsInit
            Return ($iErr = 0)
        Case Else
            Return False
    EndSwitch

    $iPos = Mod($iPos, $iSlots) ;Rollover after last element
    DllStructSetData($tKey, 1, $iPos, 1)
    DllStructSetData($tKey, 1, $iItems, 2)
    Return SetError($iErr, $iItems, True)
EndFunc   ;==>FifoQueue

 

 

[Bilgus]

Here is a second version with Redim supported

Note redim only works when items are in the array if you are making it larger

Queue needs to be empty to redim smaller.

It also BitXORs the number of slots with 0xF1F0 to be a bit more robust with checking if the Queue array is valid

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Global Enum $eFQ_Create = 0, $eFQ_Push, $eFQ_Peek, $eFQ_Pop, $eFQ_Redim, $eFQ_Empty, $eFQ_IsEmpty, $eFQ_IsFull, $eFQ_Count, $eFQ_IsInit, $eFQ_ENUMCOUNT

Func FifoQueue($eFQ, ByRef $aQ, ByRef $vOut)
    Local Const $IDInit = 0xF1F0, $_FQ_Error = -1
    Local Enum $eiPos = 1, $eiItems, $eID, $eiSlots
    Local $tKey, $iPos, $iItems, $iErr = 0
    Local $iSlots = UBound($aQ, 1) - 1
    If $iSlots > 0xFFFE Then Return SetError(0xFFFE, -1, $vOut)

    If $eFQ <> $eFQ_Create Then
        If Not IsArray($aQ) Or $iSlots < 2 Then
            $iErr = 1 ;Queue not initialized
        ElseIf IsDllStruct($aQ[$iSlots]) Then
            $tKey = $aQ[$iSlots] ;MQ_Create adds an extra Slot -- pos data is stored there..
            If DllStructGetData($tKey, 1, $eID) <> $IDInit Then $iErr += 2 ;Queue not initialized (BY MQ_Create)
            If BitXOR($iSlots, $IDInit) <> DllStructGetData($tKey, 1, $eiSlots) Then $iErr += 4 ;number of slots doesn't match
            $iPos = DllStructGetData($tKey, 1, $eiPos)
            $iItems = DllStructGetData($tKey, 1, $eiItems)
        EndIf
        If $iErr And $eFQ <> $eFQ_IsInit Then $eFQ = $_FQ_Error
    Else
        $iSlots = $aQ ;
        If $iSlots < 2 Then $iSlots = 10
        Local $a[$iSlots + 1]
        $tKey = DllStructCreate("USHORT keys[4]")

        DllStructSetData($tKey, 1, $IDInit, $eID)
        DllStructSetData($tKey, 1, BitXOR($iSlots, $IDInit), $eiSlots)
        $a[$iSlots] = $tKey
        $vOut = $a
        ;ConsoleWrite("Created Queue[" & $iSlots & "]" & @CRLF)
        Return SetError($iErr, $iSlots, $vOut)
    EndIf
    ;Circular Queue Logic
    Switch ($eFQ)
        Case $_FQ_Error
            ConsoleWrite("Queue Error: " & $iErr & @CRLF)
            Return SetError($iErr, 0, $vOut)
        Case $eFQ_Push
            If $iItems >= $iSlots Then Return False
            ;Rollover after last element
            $aQ[Mod($iItems + $iPos, $iSlots)] = $vOut
            $iItems += 1
        Case $eFQ_Peek
            If $iItems = 0 Then Return False
            $vOut = $aQ[$iPos]
            Return True ; Speed up peek
        Case $eFQ_Pop
            If $iItems = 0 Then Return False
            $vOut = $aQ[$iPos]
            $iPos += 1
            $iItems -= 1
        Case $eFQ_Redim
            If $vOut <= $iSlots or $iItems <> 0 Then Return False
            If $iItems = 0 Then $iPos = 0 ;Reset to empty
            $vOut += 10
            $aQ[$iSlots] = Default
            ReDim $aQ[$vOut + 1]
            $aQ[$vOut] = $tKey 
            DllStructSetData($tKey, 1, BitXOR($vOut, $IDInit), $eiSlots)
        Case $eFQ_Empty
            $iItems = 0
        Case $eFQ_IsEmpty
            Return ($iItems = 0)
        Case $eFQ_IsFull
            Return ($iItems >= $iSlots)
        Case $eFQ_Count
            Return SetExtended($iSlots, $iItems)
        Case $eFQ_IsInit
            Return ($iErr = 0)
        Case Else
            Return False
    EndSwitch

    $iPos = Mod($iPos, $iSlots) ;Rollover after last element
    DllStructSetData($tKey, 1, $iPos, $eiPos)
    DllStructSetData($tKey, 1, $iItems, $eiItems)
    Return SetError($iErr, $iItems, True)
EndFunc   ;==>FifoQueue

;--Convenience Functions-------------------------------
Func FifoQueue_Create($iSlots = 10)
    Local $aE
    Return FifoQueue($eFQ_Create, $iSlots, $aE)
EndFunc   ;==>FifoQueue_Create

Func FifoQueue_($eFQ, ByRef $aQ)
    Local $aE
    $aE = FifoQueue($eFQ, $aQ, $aE)
    Return SetError(@error, @extended, $aE)
EndFunc   ;==>FifoQueue_
;--Convenience Functions-------------------------------