DependentTransaction Class

Definition

Namespace:

System.Transactions

Assembly:

System.Transactions.Local.dll

Source:

DependentTransaction.cs

Describes a clone of a transaction providing guarantee that the transaction cannot be committed until the application comes to rest regarding work on the transaction. This class cannot be inherited.

public ref class DependentTransaction sealed : System::Transactions::Transaction

public sealed class DependentTransaction : System.Transactions.Transaction

type DependentTransaction = class
    inherit Transaction

Public NotInheritable Class DependentTransaction
Inherits Transaction

Inheritance

Object

Transaction

DependentTransaction

Examples

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

static void Main(string[] args)
{
    try
    {
        using (TransactionScope scope = new TransactionScope())
        {
            // Perform transactional work here.

            //Queue work item
            ThreadPool.QueueUserWorkItem(new WaitCallback(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
            ConsoleKeyInfo c;
            while (true)
            {
                            Console.Write("Complete the transaction scope? [Y|N] ");
                c = Console.ReadKey();
                Console.WriteLine();

                if ((c.KeyChar == 'Y') || (c.KeyChar == 'y'))
                {
                    //Call complete on the scope
                    scope.Complete();
                    break;
                }
                else if ((c.KeyChar == 'N') || (c.KeyChar == 'n'))
                {
                    break;
                }
            }
        }
    }
    catch (System.Transactions.TransactionException ex)
    {
        Console.WriteLine(ex);
    }
    catch
    {
        Console.WriteLine("Cannot complete transaction");
        throw;
    }
}

private static void WorkerThread(object transaction)
{
    //Create a DependentTransaction from the object passed to the WorkerThread
    DependentTransaction dTx = (DependentTransaction)transaction;

    //Sleep for 1 second to force the worker thread to delay
    Thread.Sleep(1000);

    //Pass the DependentTransaction to the scope, so that work done in the scope becomes part of the transaction passed to the worker thread
    using (TransactionScope ts = new TransactionScope(dTx))
    {
        //Perform transactional work here.

        //Call complete on the transaction scope
        ts.Complete();
    }

    //Call complete on the dependent transaction
    dTx.Complete();
}

Public Shared Sub Main()
    Try
        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()
                Console.WriteLine()
                If (c.KeyChar = "Y") Or (c.KeyChar = "y") Then
                    scope.Complete()
                    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(ex)
    Catch
        Console.WriteLine("Cannot complete transaction")
        Throw
    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
    Thread.Sleep(1000)

    '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
        ts.Complete()
    End Using

    'Call complete on the dependent transaction
    dTx.Complete()
End Sub

Remarks

The DependentTransaction is a clone of a Transaction object created using the DependentClone method. Its sole purpose is to allow the application to come to rest and guarantee that the transaction cannot commit while work is still being performed on the transaction (for example, on a worker thread).

When the work done within the cloned transaction is finally complete and ready to be committed, it can inform the creator of the transaction using the Complete method. Thus you can preserve the consistency and correctness of data.

The DependentCloneOption enumeration is used to determine the behavior on commit. This behavior control allows an application to come to rest, as well as provides concurrency support. For more information on how this enumeration is used, see Managing Concurrency with DependentTransaction.

Properties

IsolationLevel	Gets the isolation level of the transaction. (Inherited from Transaction)
PromoterType	Uniquely identifies the format of the byte[] returned by the Promote method when the transaction is promoted. (Inherited from Transaction)
TransactionInformation	Retrieves additional information about a transaction. (Inherited from Transaction)

Methods

Clone()	Creates a clone of the transaction. (Inherited from Transaction)
Complete()	Attempts to complete the dependent transaction.
DependentClone(DependentCloneOption)	Creates a dependent clone of the transaction. (Inherited from Transaction)
Dispose()	Releases the resources that are held by the object. (Inherited from Transaction)
EnlistDurable(Guid, IEnlistmentNotification, EnlistmentOptions)	Enlists a durable resource manager that supports two phase commit to participate in a transaction. (Inherited from Transaction)
EnlistDurable(Guid, ISinglePhaseNotification, EnlistmentOptions)	Enlists a durable resource manager that supports single phase commit optimization to participate in a transaction. (Inherited from Transaction)
EnlistPromotableSinglePhase(IPromotableSinglePhaseNotification, Guid)	Enlists a resource manager that has an internal transaction using a promotable single phase enlistment (PSPE). (Inherited from Transaction)
EnlistPromotableSinglePhase(IPromotableSinglePhaseNotification)	Enlists a resource manager that has an internal transaction using a promotable single phase enlistment (PSPE). (Inherited from Transaction)
EnlistVolatile(IEnlistmentNotification, EnlistmentOptions)	Enlists a volatile resource manager that supports two phase commit to participate in a transaction. (Inherited from Transaction)
EnlistVolatile(ISinglePhaseNotification, EnlistmentOptions)	Enlists a volatile resource manager that supports single phase commit optimization to participate in a transaction. (Inherited from Transaction)
Equals(Object)	Determines whether this transaction and the specified object are equal. (Inherited from Transaction)
GetHashCode()	Returns the hash code for this instance. (Inherited from Transaction)
GetPromotedToken()	Gets the byte[] returned by the Promote method when the transaction is promoted. (Inherited from Transaction)
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
PromoteAndEnlistDurable(Guid, IPromotableSinglePhaseNotification, ISinglePhaseNotification, EnlistmentOptions)	Promotes and enlists a durable resource manager that supports two phase commit to participate in a transaction. (Inherited from Transaction)
Rollback()	Rolls back (aborts) the transaction. (Inherited from Transaction)
Rollback(Exception)	Rolls back (aborts) the transaction. (Inherited from Transaction)
SetDistributedTransactionIdentifier(IPromotableSinglePhaseNotification, Guid)	Sets the distributed transaction identifier generated by the non-MSDTC promoter. (Inherited from Transaction)
ToString()	Returns a string that represents the current object. (Inherited from Object)

Events

TransactionCompleted

Indicates that the transaction is completed. (Inherited from Transaction)

Explicit Interface Implementations

ISerializable.GetObjectData(SerializationInfo, StreamingContext)

Gets a SerializationInfo with the data required to serialize this transaction. (Inherited from Transaction)

Thread Safety

This type is thread safe.

See also

• Managing Concurrency with DependentTransaction