/// <summary>
/// Enlists this <see cref="T:System.Data.Entity.Core.EntityClient.EntityConnection" /> in the specified transaction.
/// </summary>
/// <param name="transaction">The transaction object to enlist into.</param>
/// <exception cref="T:System.InvalidOperationException">
/// The state of the <see cref="T:System.Data.Entity.Core.EntityClient.EntityConnection" /> is not
/// <see
/// cref="F:System.Data.ConnectionState.Open" />
/// .
/// </exception>
public override void EnlistTransaction(Transaction transaction)
{
if (_storeConnection == null)
{
throw Error.EntityClient_ConnectionStringNeededBeforeOperation();
}
if (State != ConnectionState.Open)
{
throw Error.EntityClient_ConnectionNotOpen();
}
try
{
var interceptionContext = new EnlistTransactionInterceptionContext(InterceptionContext);
interceptionContext = interceptionContext.WithTransaction(transaction);
DbInterception.Dispatch.Connection.EnlistTransaction(_storeConnection, interceptionContext);
// null means "Unenlist transaction". It is fine if no transaction is in progress (no op). Otherwise
// _storeConnection.EnlistTransaction should throw and we would not get here.
Debug.Assert(
transaction != null || !EnlistedInUserTransaction,
"DbConnection should not allow unenlist from a transaction that has not completed.");
// It is OK to enlist in null transaction or multiple times in the same transaction.
// In the latter case we don't need to be called multiple times when the transaction completes
// so subscribe only when enlisting for the first time. Note that _storeConnection.EnlistTransaction
// will throw in invalid cases (like enlisting the connection in a transaction when another
// transaction has not completed) so when we get here we are sure that either no transactions are
// active or the transaction the caller tries enlisting to
// is the active transaction.
if (transaction != null
&& !EnlistedInUserTransaction)
{
transaction.TransactionCompleted += EnlistedTransactionCompleted;
}
_enlistedTransaction = transaction;
}
catch (Exception e)
{
if (e.IsCatchableExceptionType())
{
throw new EntityException(Strings.EntityClient_ProviderSpecificError(@"EnlistTransaction"), e);
}
throw;
}
}
