source: trunk/Include/Classes/ActiveBasic/Windows/CriticalSection.ab@ 335

'Classes/ActiveBasic/Windows/CriticalSection.ab

#require <Classes/System/index.ab>

Namespace ActiveBasic
Namespace Windows

Namespace Detail
    Const InterlockedExchangeAnyPointer(p, x) = InterlockedExchangePointer(ByVal VarPtr(p) As *VoidPtr, x)
End Namespace

Class CriticalSection
'   Inherits System.IDisposable
Public
    Sub CriticalSection()
        disposed = 0
        InitializeCriticalSection(cs)
    End Sub

    Sub ~CriticalSection()
        Dispose()
    End Sub

    /*Override*/ Sub Dispose()
        If InterlockedIncrement(disposed) = 0 Then
            DeleteCriticalSection(cs)
        End If
    End Sub

    Function Enter() As ActiveBasic.Windows.CriticalSectionLock
        Return New CriticalSectionLock(cs)
    End Function
Private
    cs As CRITICAL_SECTION
    disposed As Long
End Class

Class CriticalSectionLock
'   Inherits System.IDisposable
Public
    Sub CriticalSectionLock(ByRef cs As CRITICAL_SECTION)
        pcs = VarPtr(cs)
        EnterCriticalSection(cs)
    End Sub

    Sub ~CriticalSectionLock()
        Dispose()
    End Sub

    Sub Leave()
        Dispose()
    End Sub

    /*Override*/ Sub Dispose()
'       Dim pcsOld = ActiveBasic.Windows.Detail.InterlockedExchangeAnyPointer(pcs, 0)
        Dim pcsOld = InterlockedExchangePointer(pcs As VoidPtr, 0) As *CRITICAL_SECTION
        If pcsOld <> 0 Then
            LeaveCriticalSection(ByVal pcsOld)
        End If
    End Sub
Private
    pcs As *CRITICAL_SECTION
End Class

End Namespace 'Windows
End Namespace 'ActiveBasic