Transaction.EnlistVolatile Method

Definition

Namespace:

System.Transactions

Assembly:

System.Transactions.Local.dll

Enlists a volatile resource manager to participate in a transaction.

Overloads

EnlistVolatile(IEnlistmentNotification, EnlistmentOptions)	Enlists a volatile resource manager that supports two phase commit to participate in a transaction.
EnlistVolatile(ISinglePhaseNotification, EnlistmentOptions)	Enlists a volatile resource manager that supports single phase commit optimization to participate in a transaction.

Remarks

Volatile resource managers cannot recovery from failure to complete a transaction in which they were participating. For more information on volatile and durable resources, as well as how to enlist a resource, see Implementing A Resource Manager. For more information on how a resource manager responds to commit notification and prepare the commit, see Committing A Transaction In Single-Phase and Multi-Phase.

EnlistVolatile(IEnlistmentNotification, EnlistmentOptions)

Source:

Transaction.cs

Enlists a volatile resource manager that supports two phase commit to participate in a transaction.

public:
 System::Transactions::Enlistment ^ EnlistVolatile(System::Transactions::IEnlistmentNotification ^ enlistmentNotification, System::Transactions::EnlistmentOptions enlistmentOptions);

public System.Transactions.Enlistment EnlistVolatile (System.Transactions.IEnlistmentNotification enlistmentNotification, System.Transactions.EnlistmentOptions enlistmentOptions);

member this.EnlistVolatile : System.Transactions.IEnlistmentNotification * System.Transactions.EnlistmentOptions -> System.Transactions.Enlistment

Public Function EnlistVolatile (enlistmentNotification As IEnlistmentNotification, enlistmentOptions As EnlistmentOptions) As Enlistment

Parameters

enlistmentNotification

IEnlistmentNotification

An object that implements the IEnlistmentNotification interface to receive two-phase commit notifications.

enlistmentOptions

EnlistmentOptions

EnlistDuringPrepareRequired if the resource manager wants to perform additional work during the prepare phase.

Returns

Enlistment

An Enlistment object that describes the enlistment.

Examples

The following example shows an implementation of IEnlistmentNotification interface, as well as enlisting the object as a participant in a transaction using the EnlistVolatile method.

static void Main(string[] args)
{
    try
    {
        using (TransactionScope scope = new TransactionScope())
        {
        
            //Create an enlistment object
            myEnlistmentClass myElistment = new myEnlistmentClass();

            //Enlist on the current transaction with the enlistment object
            Transaction.Current.EnlistVolatile(myElistment, EnlistmentOptions.None);

            //Perform transactional work here.

            //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'))
                {
                    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;
    }
}

class myEnlistmentClass : IEnlistmentNotification
{
    public void Prepare(PreparingEnlistment preparingEnlistment)
    {
        Console.WriteLine("Prepare notification received");

        //Perform transactional work

        //If work finished correctly, reply prepared
        preparingEnlistment.Prepared();

        // otherwise, do a ForceRollback
        preparingEnlistment.ForceRollback();
    }

    public void Commit(Enlistment enlistment)
    {
        Console.WriteLine("Commit notification received");

        //Do any work necessary when commit notification is received

        //Declare done on the enlistment
        enlistment.Done();
    }

    public void Rollback(Enlistment enlistment)
    {
        Console.WriteLine("Rollback notification received");

        //Do any work necessary when rollback notification is received

        //Declare done on the enlistment
        enlistment.Done();
    }

    public void InDoubt(Enlistment enlistment)
    {
        Console.WriteLine("In doubt notification received");

        //Do any work necessary when indout notification is received
        
        //Declare done on the enlistment
        enlistment.Done();
    }
}

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

                'Create an enlistment object
                Dim myEnlistmentClass As New EnlistmentClass

                'Enlist on the current transaction with the enlistment object
                Transaction.Current.EnlistVolatile(myEnlistmentClass, EnlistmentOptions.None)

                'Perform transactional work here.

                '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
End Class

Public Class EnlistmentClass
    Implements IEnlistmentNotification

    Public Sub Prepare(ByVal myPreparingEnlistment As PreparingEnlistment) Implements System.Transactions.IEnlistmentNotification.Prepare
        Console.WriteLine("Prepare notification received")

        'Perform transactional work

        'If work finished correctly, reply with prepared
        myPreparingEnlistment.Prepared()
    End Sub

    Public Sub Commit(ByVal myEnlistment As Enlistment) Implements System.Transactions.IEnlistmentNotification.Commit
        Console.WriteLine("Commit notification received")

        'Do any work necessary when commit notification is received

        'Declare done on the enlistment
        myEnlistment.Done()
    End Sub

    Public Sub Rollback(ByVal myEnlistment As Enlistment) Implements System.Transactions.IEnlistmentNotification.Rollback
        Console.WriteLine("Rollback notification received")

        'Do any work necessary when rollback notification is received

        'Declare done on the enlistment
        myEnlistment.Done()
    End Sub

    Public Sub InDoubt(ByVal myEnlistment As Enlistment) Implements System.Transactions.IEnlistmentNotification.InDoubt
        Console.WriteLine("In doubt notification received")

        'Do any work necessary when indout notification is received

        'Declare done on the enlistment
        myEnlistment.Done()
    End Sub
End Class

Remarks

Volatile resource managers cannot recovery from failure to complete a transaction in which they were participating. To obtain a durable enlistment in a transaction, use the EnlistDurable method.

Resource managers enlisted for participation in a transaction through this method receive two phase commit notifications that correspond to the methods defined on the IEnlistmentNotification interface.

EnlistVolatile(ISinglePhaseNotification, EnlistmentOptions)

Source:

Transaction.cs

Enlists a volatile resource manager that supports single phase commit optimization to participate in a transaction.

public:
 System::Transactions::Enlistment ^ EnlistVolatile(System::Transactions::ISinglePhaseNotification ^ singlePhaseNotification, System::Transactions::EnlistmentOptions enlistmentOptions);

public System.Transactions.Enlistment EnlistVolatile (System.Transactions.ISinglePhaseNotification singlePhaseNotification, System.Transactions.EnlistmentOptions enlistmentOptions);

member this.EnlistVolatile : System.Transactions.ISinglePhaseNotification * System.Transactions.EnlistmentOptions -> System.Transactions.Enlistment

Public Function EnlistVolatile (singlePhaseNotification As ISinglePhaseNotification, enlistmentOptions As EnlistmentOptions) As Enlistment

Parameters

singlePhaseNotification

ISinglePhaseNotification

An object that implements the ISinglePhaseNotification interface that must be able to receive single phase commit and two phase commit notifications.

enlistmentOptions

EnlistmentOptions

EnlistDuringPrepareRequired if the resource manager wants to perform additional work during the prepare phase.

Returns

Enlistment

An Enlistment object that describes the enlistment.

Remarks

Volatile resource managers cannot recovery from failure to complete a transaction in which they were participating. To obtain a durable enlistment in a transaction, use the EnlistDurable method. For more information on volatile and durable resources, as well as how to enlist a resource, see Implementing A Resource Manager. For more information on how a resource manager responds to commit notification and prepare the commit, see Committing A Transaction In Single-Phase and Multi-Phase.

You should note that even when your resource manager implementation enlists with this method, it is not guaranteed that it receives a single phase commit. The transaction manager can still send two phase commit notifications instead. For more information on the single phase commit optimization, see Optimization Using Single Phase Commit and Promotable Single Phase Notification.