'Classes/ActiveBasic/Windows/CriticalSection.ab

#require <Classes/System/index.ab>

Namespace ActiveBasic
Namespace Windows

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 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 p = InterlockedExchangePointer(ByVal VarPtr(pcs), 0)
		If p <> 0 Then
			LeaveCriticalSection(ByVal p)
		End If
	End Sub
Private
	pcs As *CRITICAL_SECTION
End Class

End Namespace 'Windows
End Namespace 'ActiveBasic