Transaction.DependentClone Method (DependentCloneOption)


Creates a dependent clone of the transaction.

Namespace:   System.Transactions
Assembly:  System.Transactions (in System.Transactions.dll)

Public Function DependentClone (
	cloneOption As DependentCloneOption
) As DependentTransaction


Type: System.Transactions.DependentCloneOption

A DependentCloneOption that controls what kind of dependent transaction to create.

Return Value

Type: System.Transactions.DependentTransaction

A DependentTransaction that represents the dependent clone.

A dependent transaction is a transaction whose outcome depends on the outcome of the transaction from which it was cloned.

The cloneoption parameter controls what kind of dependent transaction to create. If a dependent transaction is created with BlockCommitUntilComplete, it blocks the commit process of the transaction until the transaction times out, or Complete is called on the DependentTransaction. If it is created with RollbackIfNotComplete, it automatically aborts the transaction if Commit is called before Complete is called on the DependentTransaction.

The following example shows you how to create a dependent transaction.

Public Shared Sub Main()
		Using scope As TransactionScope = New TransactionScope()

			'Perform transactional work here.

			'Queue work item
			ThreadPool.QueueUserWorkItem(AddressOf WorkerThread, Transaction.Current.DependentClone(DependentCloneOption.BlockCommitUntilComplete))

			'Display transaction information
			Console.WriteLine("Transaction information:")
			Console.WriteLine("ID:             {0}", Transaction.Current.TransactionInformation.LocalIdentifier)
			Console.WriteLine("status:         {0}", Transaction.Current.TransactionInformation.Status)
			Console.WriteLine("isolationlevel: {0}", Transaction.Current.IsolationLevel)

			'Call Complete on the TransactionScope based on console input
			Dim c As ConsoleKeyInfo
			While (True)

				Console.Write("Complete the transaction scope? [Y|N] ")
				c = Console.ReadKey()
				If (c.KeyChar = "Y") Or (c.KeyChar = "y") Then
					Exit While
				ElseIf ((c.KeyChar = "N") Or (c.KeyChar = "n")) Then
					Exit While
				End If
			End While
		End Using

	Catch ex As TransactionException
		Console.WriteLine("Cannot complete transaction")
	End Try
End Sub

Public Shared Sub WorkerThread(ByVal myTransaction As Object)

	'Create a DependentTransaction from the object passed to the WorkerThread
	Dim dTx As DependentTransaction
	dTx = CType(myTransaction, DependentTransaction)

	'Sleep for 1 second to force the worker thread to delay

	'Pass the DependentTransaction to the scope, so that work done in the scope becomes part of the transaction passed to the worker thread
	Using ts As TransactionScope = New TransactionScope(dTx)
		'Perform transactional work here.

		'Call complete on the transaction scope
	End Using

	'Call complete on the dependent transaction
End Sub

.NET Framework
Available since 2.0

Transaction Class
System.Transactions Namespace
Manage Concurrency with DependentTransaction

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