public void Prepare(PreparingEnlistment preparingEnlistment)
{
CheckDisposed();
Debug.Assert(_transaction != null, "No transaction");
Debug.Assert(_localTx != null, "No local transaction");
Debug.Assert(_connector != null, "No connector");
Log.Debug($"Two-phase transaction prepare (localid={_txId})", _connector.Id);
// The PostgreSQL prepared transaction name is the distributed GUID + our connection's process ID, for uniqueness
_preparedTxName = $"{_transaction.TransactionInformation.DistributedIdentifier}/{_connector.BackendProcessId}";
try
{
using (_connector.StartUserAction())
_connector.ExecuteInternalCommand($"PREPARE TRANSACTION '{_preparedTxName}'");
// The MSDTC, which manages escalated distributed transactions, performs the 2nd phase
// asynchronously - this means that TransactionScope.Dispose() will return before all
// resource managers have actually commit.
// If the same connection tries to enlist to a new TransactionScope immediately after
// disposing an old TransactionScope, its EnlistedTransaction must have been cleared
// (or we'll throw a double enlistment exception). This must be done here at the 1st phase
// (which is sync).
if (_connector.Connection != null)
{
_connector.Connection.EnlistedTransaction = null;
}
preparingEnlistment.Prepared();
}
catch (Exception e)
{
Dispose();
preparingEnlistment.ForceRollback(e);
}
}