// Static function that obtains the propagation cookie to be given to the SQL Server to which
// the connection is made to, so that the server will enlist the connection in the
// distributed transaction. Function returns bool indicating whether the cookie was obtained.
public static bool GetTransactionCookie(byte[] dtcAddr, ITransaction transaction,
ref UnsafeNativeMethods.ITransactionExport transactionExport,
ref byte[] cookie, ref int length)
{
bool fSuccess = true;
Debug.Assert(dtcAddr != null, "GetTransactionCookie: dtcAddr null!");
Debug.Assert(transaction != null, "GetTransactionCookie: transaction null!");
// local UInt32 variables, since the interfaces expect the UInt32 type
UInt32 cookieLength = 0;
UInt32 dtcLength = (UInt32)dtcAddr.Length;
// if the user's transactionExport is null, create one for them!
if (null == transactionExport)
{
// if creation fails, return false so connection will re-obtain DTC and retry
if (!CreateTransactionExport(dtcAddr, dtcLength, transaction,
ref transactionExport))
{
fSuccess = false;
}
}
if (fSuccess)
{
// obtain the cookie length
transactionExport.Export(transaction, ref cookieLength);
// If export call failed, kill the instance of transactionExport and return false!
// Checked with ShaiwalS, and this is the correct behavior.
if (0 == cookieLength)
{
transactionExport = null;
fSuccess = false;
}
else
{
// allocate the cookie to be the appropriate length
cookie = new byte[(int)cookieLength];
// obtain the cookie
transactionExport.GetTransactionCookie(transaction, cookieLength, cookie, ref cookieLength);
// set the passed in length - before we were using local UInt32
length = (int)cookieLength;
//if (AdapterSwitches.SqlPooling.TraceVerbose) {
// Debug.WriteLine("Transaction.GetTransactionCookie(): cookieLength: " + cookieLength.ToString());
// Debug.WriteLine("Transaction.GetTransactionCookie(): cookie: ");
// for (int i=0; i<cookieLength; i++)
// Debug.Write((cookie[i]).ToString("x2") + " ");
// Debug.WriteLine("");
//}
}
}
return(fSuccess);
}
private void EnlistNonNullDistributedTransaction(ITransaction transaction)
{
//if (AdapterSwitches.SqlPooling.TraceVerbose)
// Debug.WriteLine("SqlInternalConnection.EnlistDistributedTransaction(): Enlisting connection in distributed transaction...");
if (null == _dtcAddress)
{
_dtcAddress = _parser.GetDTCAddress(_connectionOptions.ConnectTimeout);
}
Debug.Assert(_dtcAddress != null, "SqlInternalConnection.EnlistDistributedTransaction(): dtcAddress null, error #1");
byte[] cookie = null;
int length = 0;
UnsafeNativeMethods.ITransactionExport transactionExport = null;
if (null != _transactionExport)
{
transactionExport = _transactionExport.GetITransactionExport();
}
// if the call for the cookie fails, re-obtain the DTCAddress and recall the function
if (!Transaction.GetTransactionCookie(_dtcAddress, transaction,
ref transactionExport, ref cookie,
ref length))
{
_dtcAddress = _parser.GetDTCAddress(_connectionOptions.ConnectTimeout);
Debug.Assert(_dtcAddress != null, "SqlInternalConnection.Activate(): dtcAddress null, error #2");
if (!Transaction.GetTransactionCookie(_dtcAddress, transaction,
ref transactionExport, ref cookie,
ref length))
{
throw SQL.TransactionEnlistmentError();
}
}
if (null != transactionExport)
{
_transactionExport = new TransactionExportWrapper(transactionExport);
}
else
{
_transactionExport = null;
}
// send cookie to server to finish enlistment
_parser.PropagateDistributedTransaction(cookie, length, _connectionOptions.ConnectTimeout);
}
// Private method that creates a TransactionExport for the passed in DTCAddr.
private static bool CreateTransactionExport(byte[] dtcAddr, UInt32 dtcLength,
ITransaction transaction,
ref UnsafeNativeMethods.ITransactionExport transactionExport)
{
object transactionExportFactory = null;
// UNDONE - when not using pooling - the below cast to IGetDispenser call seems to fail
// on the 3rd pooling object. Investigate when time permits.
// cast to IGetDispenser, then call GetDispenser to obtain an
// ITtransactionExportFactory interface
((UnsafeNativeMethods.IGetDispenser)transaction).GetDispenser(s_transactionExportFactoryGuid,
ref transactionExportFactory);
// cast to ITransactionExportFactory, then make call to create a ITransactionExport
((UnsafeNativeMethods.ITransactionExportFactory)transactionExportFactory).Create(dtcLength, dtcAddr,
ref transactionExport);
// if the create call failed, then transactionExport is null and return false!
return(null != transactionExport);
}
internal UnsafeNativeMethods.ITransactionExport GetITransactionExport()
{
UnsafeNativeMethods.ITransactionExport value = (UnsafeNativeMethods.ITransactionExport)System.Runtime.Remoting.Services.EnterpriseServicesHelper.WrapIUnknownWithComObject(this.iunknown);
GC.KeepAlive(this);
return(value);
}
internal TransactionExportWrapper(UnsafeNativeMethods.ITransactionExport transactionExport)
{
this.iunknown = Marshal.GetIUnknownForObject(transactionExport);
}
