/// <summary>
/// 11/28/2011
/// Initializes a new instance of the <see cref = "TransactionManager" /> class.
/// </summary>
/// <remarks>
/// Side effects:
/// 1. currentTimeStamp is set to 0
/// 2. All the data structures are initialized
/// 3. All sites are initialized
/// </remarks>
public TransactionManager()
{
currentTimeStamp = 0;
committedTransactions = new List<Transaction>();
activeTransactions = new Dictionary<int, Transaction>();
waitingTransactions = new Dictionary<int, Transaction>();
abortedTransactions = new Dictionary<int, string>();
waitingOps = new List<Operation>();
sites = new Dictionary<int, Site>(NumberOfSites);
results = new List<Result>();
for (int i = 1; i <= NumberOfSites; i++)
{
sites[i] = new Site(i);
}
}
public void FailedTest()
{
Site target = new Site();
bool expected = false;
bool actual;
actual = target.Failed();
Assert.AreEqual(expected, actual);
target.Fail(1);
actual = target.Failed();
expected = true;
Assert.AreEqual(expected, actual);
actual = target.Failed();
expected = true;
Assert.AreEqual(expected, actual);
}
public void GetFirstFailureTest()
{
Site target = new Site(1);
int beginning = 0;
int expected = 1;
int? actual;
actual = target.GetFirstFailureSinceAccess(beginning);
Assert.IsNull(actual);
target.Fail(1);
target.Fail(4);
target.Fail(2);
target.Fail(10);
target.Fail(7);
actual = target.GetFirstFailureSinceAccess(beginning);
Assert.AreEqual(expected, actual);
expected = 4;
beginning = 3;
actual = target.GetFirstFailureSinceAccess(beginning);
Assert.AreEqual(expected, actual);
expected = 10;
beginning = 11;
actual = target.GetFirstFailureSinceAccess(beginning);
Assert.IsNull(actual);
}
public void TickTest()
{
Site target = new Site(1);
// setup the site
target.AddMessage(new Operation(Enumerations.OperationMode.Begin, 1));
target.AddMessage(new Operation(Enumerations.OperationMode.Read, 1, 2));
target.AddMessage(new Operation(Enumerations.OperationMode.Write, 1, 2, 40));
target.AddMessage(new Operation(Enumerations.OperationMode.Read, 2, 2));
target.AddMessage(new Operation(Enumerations.OperationMode.Write, 2, 4, 30));
target.AddMessage(new Operation(Enumerations.OperationMode.Read, 2, 4));
List<Result> actual = target.Tick();
List<Result> expected = new List<Result>();
expected.Add(new Result(1, Enumerations.OperationMode.Begin, 1, Enumerations.ResultStatus.Success,
new List<int>() {1}));
expected.Add(new Result(1, Enumerations.OperationMode.Read, 1, Enumerations.ResultStatus.Success,
new List<int>() {1}, 20, 2));
expected.Add(new Result(1, Enumerations.OperationMode.Write, 1, Enumerations.ResultStatus.Success,
new List<int>() {1}, dataItem: 2));
expected.Add(new Result(2, Enumerations.OperationMode.Read, 1, Enumerations.ResultStatus.Failure,
new List<int>() {1}, 0, 2));
expected.Add(new Result(2, Enumerations.OperationMode.Write, 1, Enumerations.ResultStatus.Success,
new List<int>() {2}, 0, 4));
expected.Add(new Result(2, Enumerations.OperationMode.Read, 1, Enumerations.ResultStatus.Success,
new List<int>() {2}, 30, 4));
for (int i = 0; i < Math.Max(actual.Count, expected.Count); i++)
{
Assert.AreEqual(expected[i].DataItem, actual[i].DataItem);
Assert.AreEqual(expected[i].Status, actual[i].Status);
Assert.AreEqual(expected[i].TransId[0], actual[i].TransId[0]);
Assert.AreEqual(expected[i].Val, actual[i].Val);
Assert.AreEqual(1, actual[i].SiteNumber);
Assert.AreEqual(expected[i].OpMode, actual[i].OpMode);
}
// Nothing should be returned because:
// a. no new operations were enqueued and
// b. no data items became free because of operations
actual = target.Tick();
Assert.AreEqual(0, actual.Count);
// make (1) release all locks and commit all values
// thus (2) can read data item 1 and should read the value committed by (1)
target.AddMessage(new Operation(Enumerations.OperationMode.Commit, 1));
target.AddMessage(new Operation(Enumerations.OperationMode.Read, 2, 2));
actual = target.Tick();
expected = new List<Result>();
expected.Add(new Result(1, Enumerations.OperationMode.Commit, 1, Enumerations.ResultStatus.Success,
new List<int>() {1}, dataItem:-1));
expected.Add(new Result(1, Enumerations.OperationMode.Read, 1, Enumerations.ResultStatus.Success,
new List<int>() {2}, 40, 2));
for (int i = 0; i < Math.Max(actual.Count, expected.Count); i++)
{
Assert.AreEqual(expected[i].DataItem, actual[i].DataItem);
Assert.AreEqual(expected[i].Status, actual[i].Status);
Assert.AreEqual(expected[i].TransId[0], actual[i].TransId[0]);
Assert.AreEqual(expected[i].Val, actual[i].Val);
Assert.AreEqual(1, actual[i].SiteNumber);
Assert.AreEqual(expected[i].OpMode, actual[i].OpMode);
}
}
public void TestMVCC()
{
Site target = new Site(1);
// Setup the site
target.AddMessage(new Operation(Enumerations.OperationMode.Write, 1, 2, 5));
target.AddMessage(new Operation(Enumerations.OperationMode.Commit, 1, 2, ts:1));
target.AddMessage(new Operation(Enumerations.OperationMode.Read, 2, 2, ro: true, ts: 0));
List<Result> actual = target.Tick();
Result ROResult = actual.Find(matching => matching.IssuingTransaction == 2);
// RO should have read the original value of data item 2
Assert.AreEqual(20, ROResult.Val);
target.AddMessage(new Operation(Enumerations.OperationMode.Write, 3, 2, 50));
target.AddMessage(new Operation(Enumerations.OperationMode.Commit, 3, 2, ts: 2));
target.AddMessage(new Operation(Enumerations.OperationMode.Read, 4, 2, ro: true, ts: 2));
target.AddMessage(new Operation(Enumerations.OperationMode.Read, 5, 2, ro: true, ts: 0));
target.AddMessage(new Operation(Enumerations.OperationMode.Read, 6, 2, ro: true, ts: 3));
actual = target.Tick();
// transaction ID 4 has issued a read command with ts = 2, so it should read 5 (value committed at time 0, before ts=1)
ROResult = actual.Find(matching => matching.IssuingTransaction == 4);
Assert.AreEqual(5, ROResult.Val);
// transaction ID 5 has issued a read command with ts = 0, so it should read 20 (original value)
ROResult = actual.Find(matching => matching.IssuingTransaction == 5);
Assert.AreEqual(20, ROResult.Val);
// Transaction ID 6 has issued a read command with ts = 3, so it should read 50
ROResult = actual.Find(matching => matching.IssuingTransaction == 6);
Assert.AreEqual(50, ROResult.Val);
// a transction should read values written BEFORE its timestamp
target.AddMessage(new Operation(Enumerations.OperationMode.Write, 7, 4, 4));
target.AddMessage(new Operation(Enumerations.OperationMode.Commit, 7, ts: 1));
target.AddMessage(new Operation(Enumerations.OperationMode.Read, 8, 4, ro: true, ts: 1));
actual = target.Tick();
ROResult = actual.Find(matching => matching.IssuingTransaction == 8);
Assert.AreEqual(40, ROResult.Val);
}
public void RecoverTest()
{
Site target = new Site(4);
target.Fail(0);
target.Recover();
Assert.AreEqual(Enumerations.SiteStatus.Active, target.Status);
for (int i = 2; i <= 20; i += 2)
{
LockManagerTableEntry entry = target.GetCopyOfEntry(i);
Assert.AreEqual(1, entry.ActiveLocks.Count);
Assert.AreEqual(int.MinValue, entry.ActiveLocks[0].TransactionId);
}
}
public void ProcessOperationTest()
{
Site target = new Site(2);
// begin op should always succeed
Operation currentOp = new Operation(Enumerations.OperationMode.Begin, 1, 1);
Result actual = target.ProcessOperation(currentOp);
Assert.AreEqual(Enumerations.ResultStatus.Success, actual.Status);
Assert.AreEqual(currentOp.OpMode, actual.OpMode);
// A write op here would succeed
currentOp = new Operation(Enumerations.OperationMode.Write, 1, 2, 5);
actual = target.ProcessOperation(currentOp);
Assert.AreEqual(Enumerations.ResultStatus.Success, actual.Status);
Assert.AreEqual(currentOp.OpMode, actual.OpMode);
Assert.AreEqual(2, actual.SiteNumber);
// A read by the same transaction should succeed
currentOp = new Operation(Enumerations.OperationMode.Read, 1, 2);
actual = target.ProcessOperation(currentOp); // find out what value is read here
Assert.AreEqual(Enumerations.ResultStatus.Success, actual.Status);
Assert.AreEqual(5, actual.Val);
Assert.AreEqual(2, actual.SiteNumber);
Assert.AreEqual(currentOp.OpMode, actual.OpMode);
// A read by a different transaction should fail
currentOp = new Operation(Enumerations.OperationMode.Read, 2, 2);
actual = target.ProcessOperation(currentOp);
Assert.AreEqual(Enumerations.ResultStatus.Failure, actual.Status);
Assert.AreEqual(2, actual.SiteNumber);
Assert.AreEqual(currentOp.OpMode, actual.OpMode);
// A commit should succeed
currentOp = new Operation(Enumerations.OperationMode.Commit, 1, ts: 1);
actual = target.ProcessOperation(currentOp);
Assert.AreEqual(Enumerations.ResultStatus.Success, actual.Status);
Assert.AreEqual(2, actual.SiteNumber);
Assert.AreEqual(currentOp.OpMode, actual.OpMode);
// A read now should succeed and return the committed value of transaction 1
currentOp = new Operation(Enumerations.OperationMode.Read, 2, 2);
actual = target.ProcessOperation(currentOp);
Assert.AreEqual(Enumerations.ResultStatus.Success, actual.Status);
Assert.AreEqual(5, actual.Val);
Assert.AreEqual(2, actual.SiteNumber);
Assert.AreEqual(currentOp.OpMode, actual.OpMode);
// A read by another transaction should succeed (since no write locks) and return committed value of transaction 1
currentOp = new Operation(Enumerations.OperationMode.Read, 3, 2);
actual = target.ProcessOperation(currentOp);
Assert.AreEqual(Enumerations.ResultStatus.Success, actual.Status);
Assert.AreEqual(5, actual.Val);
Assert.AreEqual(2, actual.SiteNumber);
Assert.AreEqual(currentOp.OpMode, actual.OpMode);
// A write by another transaction should fail
currentOp = new Operation(Enumerations.OperationMode.Write, 4, 2, 5);
actual = target.ProcessOperation(currentOp);
Assert.AreEqual(Enumerations.ResultStatus.Failure, actual.Status);
Assert.AreEqual(2, actual.SiteNumber);
Assert.AreEqual(currentOp.OpMode, actual.OpMode);
// a commit should succeed
currentOp = new Operation(Enumerations.OperationMode.Commit, 2);
actual = target.ProcessOperation(currentOp);
Assert.AreEqual(Enumerations.ResultStatus.Success, actual.Status);
Assert.AreEqual(2, actual.SiteNumber);
// a commit should succeed
currentOp = new Operation(Enumerations.OperationMode.Commit, 3);
actual = target.ProcessOperation(currentOp);
Assert.AreEqual(Enumerations.ResultStatus.Success, actual.Status);
Assert.AreEqual(2, actual.SiteNumber);
Assert.AreEqual(currentOp.OpMode, actual.OpMode);
// A write should succeed now
currentOp = new Operation(Enumerations.OperationMode.Write, 4, 2, 2);
actual = target.ProcessOperation(currentOp);
Assert.AreEqual(Enumerations.ResultStatus.Success, actual.Status);
Assert.AreEqual(2, actual.SiteNumber);
// Dont know what to do with abort yet
currentOp = new Operation(Enumerations.OperationMode.Abort, 4);
actual = target.ProcessOperation(currentOp);
Assert.AreEqual(Enumerations.ResultStatus.Success, actual.Status);
Assert.AreEqual(2, actual.SiteNumber);
Assert.AreEqual(currentOp.OpMode, actual.OpMode);
// Handle some read only transactions and make sure they are correct
// This should return the latest value since it has the largest timestamp
currentOp = new Operation(Enumerations.OperationMode.Read, 4, 2, ro: true, ts: 5);
actual = target.ProcessOperation(currentOp);
Assert.AreEqual(Enumerations.ResultStatus.Success, actual.Status);
Assert.AreEqual(5, actual.Val);
Assert.AreEqual(currentOp.OpMode, actual.OpMode);
// This should return the original value since it has the smallest timestamp
currentOp = new Operation(Enumerations.OperationMode.Read, 4, 2, ro: true, ts: 0);
actual = target.ProcessOperation(currentOp);
Assert.AreEqual(Enumerations.ResultStatus.Success, actual.Status);
Assert.AreEqual(20, actual.Val);
Assert.AreEqual(2, actual.SiteNumber);
Assert.AreEqual(currentOp.OpMode, actual.OpMode);
}
/// <summary>
/// Date: 12/3/2011
/// A wrapper for site.AddMessage
/// </summary>
/// <param name = "site">The site.</param>
/// <param name = "op">The op.</param>
private void SendOpToSite(Site site, Operation op)
{
site.AddMessage(op);
}