public void Merge(ReadMap other)
{
foreach (var kvpair in other)
{
PutIfAbsent(kvpair.Key,kvpair.Value);
}
}
private static void WaitOnReadset(JVTransaction transaction, ReadMap readMap)
{
#if DEBUG
Console.WriteLine("ENTERED WAIT ON RETRY: " + transaction.Number);
#endif
if (readMap.Count == 0)
{
throw new STMInvalidRetryException();
}
var expectedEra = transaction.RetryLatch.Era;
foreach (var kvpair in readMap)
{
kvpair.Key.RegisterRetryLatch(transaction.RetryLatch, kvpair.Value, expectedEra);
}
if (!transaction.ReadMap.Validate())
{
transaction.Abort();
return;
}
#if DEBUG
Console.WriteLine("WAIT ON RETRY: " + transaction.Number);
#endif
transaction.Await(expectedEra);
transaction.RetryLatch.Reset();
#if DEBUG
Console.WriteLine("AWOKEN: " + transaction.Number);
#endif
transaction.Abort();
}
private static T AtomicInternal <T>(IList <Func <JVTransaction, T> > stmActions)
{
Debug.Assert(stmActions.Count > 0);
var result = default(T);
var index = 0;
var nrAttempts = 0;
var overAllReadSet = new ReadMap();
while (true)
{
var stmAction = stmActions[index];
var localTransaction = JVTransaction.LocalTransaction;
var transaction = localTransaction.Status == TransactionStatus.Active
? JVTransaction.StartNested(localTransaction)
: JVTransaction.Start();
JVTransaction.LocalTransaction = transaction;
try
{
//Execute transaction body
result = stmAction(transaction);
if (transaction.Commit())
{
return(result);
}
transaction.Abort();
}
catch (STMRetryException)
{
index = HandleRetry(stmActions, transaction, index, overAllReadSet);
}/*
* catch (Exception ex) //Catch non stm related exceptions which occurs in transactions
* {
* //Throw exception of transaction can commit
* //Else abort and rerun transaction
* if (transaction.Commit())
* {
* throw;
* }
* }*/
nrAttempts++;
//transaction.Abort();
if (transaction.IsNested)
{
JVTransaction.LocalTransaction = transaction.Parent;
}
if (nrAttempts == MAX_ATTEMPTS)
{
throw new STMMaxAttemptException("Fatal error: max attempts reached");
}
}
}
private JVTransaction(TransactionStatus status, int id, JVTransaction parent, ReadMap readMap, WriteMap writeMap)
{
Number = id;
Parent = parent;
ReadMap = readMap;
WriteMap = writeMap;
Status = status;
//Commutes = new List<BaseCommute>();
}
private JVTransaction(TransactionStatus status, ActiveTxnRecord txnRecord, JVTransaction parent, ReadMap readMap, WriteMap writeMap)
{
Number = txnRecord.TxNumber;
Parent = parent;
ReadMap = readMap;
WriteMap = writeMap;
Status = status;
_txnRecord = txnRecord;
//Commutes = new List<BaseCommute>();
}
public bool Validate(ReadMap readMap)
{
foreach (var writePair in this)
{
if (readMap.ContainsKey(writePair.Key))
{
return(false);
}
}
return(true);
}
private static int HandleRetry <T>(IList <Func <JVTransaction, T> > stmActions, JVTransaction transaction, int index, ReadMap overAllReadSet)
{
if (stmActions.Count == 1) //Optimized for when there are no orelse blocks
{
WaitOnReadset(transaction, transaction.ReadMap);
}
else if (stmActions.Count == index + 1) //Final orelse block
{
overAllReadSet.Merge(transaction.ReadMap);
WaitOnReadset(transaction, overAllReadSet);
index = 0;
}
else //Non final atomic or orelse blocks
{
#if DEBUG
Console.WriteLine("Transaction: " + transaction.Number + " ORELSE jump");
#endif
overAllReadSet.Merge(transaction.ReadMap);
index++;
}
return(index);
}
public bool Commit()
{
return(CommitLockFree());
if (WriteMap.Count == 0)
{
Status = TransactionStatus.Committed;
//_txnRecord.FinishTransaction();
return(true);
}
bool result;
ActiveTxnRecord commitRecord = null;
lock (CommitLock)
{
var newNumber = ActiveTxnRecord.LastCommitted.TxNumber + 1;
var valid = ReadMap.Validate();
if (!valid)
{
result = false;
}
else
{
if (IsNested)
{
Parent.ReadMap.Merge(ReadMap);
Parent.WriteMap.Merge(WriteMap);
}
else
{
//var bodies = new BaseVBoxBody[WriteMap.Count];
var i = 0;
foreach (var kvpair in WriteMap)
{
//bodies[i] = kvpair.Key.Install(kvpair.Value, newNumber);
kvpair.Key.Install(kvpair.Value, newNumber);
i++;
}
//commitRecord = new ActiveTxnRecord(newNumber, bodies);
commitRecord = new ActiveTxnRecord(newNumber);
ActiveTxnRecord.InsertNewRecord(commitRecord);
}
Status = TransactionStatus.Committed;
result = true;
}
}
/*
* if (result && !IsNested)
* {
* _txnRecord.FinishTransaction();
*
* if (commitRecord != null)
* {
* Interlocked.Decrement(ref commitRecord.Running);
* }
* }*/
return(result);;
}