[dBFT CONSENSUS]: dBFT 3.0 with double speakers model

src/DBFTPlugin/Consensus/ConsensusContext.MakePayload.cs

@@ -106,7 +106,6 @@ internal void EnsureMaxBlockLimitation(IEnumerable<Transaction> txs, uint pID)
 
         public ExtensiblePayload MakePrepareRequest(uint pID)
         {
-            Log($"MakePrepareRequest I", LogLevel.Debug);
             EnsureMaxBlockLimitation(neoSystem.MemPool.GetSortedVerifiedTransactions(), pID);
             Block[pID].Header.Timestamp = Math.Max(TimeProvider.Current.UtcNow.ToTimestampMS(), PrevHeader.Timestamp + 1);
             Block[pID].Header.Nonce = GetNonce();
@@ -132,7 +131,7 @@ public ExtensiblePayload MakeRecoveryRequest()
         public ExtensiblePayload MakeRecoveryMessage()
         {
             PrepareRequest prepareRequestMessage = null;
-            if (TransactionHashes != null)
+            if (TransactionHashes[0] != null)
             {
                 prepareRequestMessage = new PrepareRequest
                 {
@@ -171,7 +170,7 @@ public ExtensiblePayload MakePreCommit(uint i)
         {
             return PreCommitPayloads[i][MyIndex] = MakeSignedPayload(new PreCommit
             {
-                PreparationHash = PreCommitPayloads[i][Block[i].PrimaryIndex].Hash,
+                PreparationHash = PreparationPayloads[i][Block[i].PrimaryIndex].Hash,
                 Id = i
             });
         }

src/DBFTPlugin/Consensus/ConsensusContext.cs

@@ -67,16 +67,16 @@ public partial class ConsensusContext : IDisposable, ISerializable
         public bool IsPriorityPrimary => MyIndex == GetPriorityPrimaryIndex(ViewNumber);
         public bool IsFallbackPrimary => MyIndex == GetFallbackPrimaryIndex(ViewNumber);
 
-        public bool IsAPrimary => IsPriorityPrimary || IsFallbackPrimary;
+        public bool IsAPrimary => IsPriorityPrimary || (ViewNumber == 0 && IsFallbackPrimary);
 
         //Modify to be 1 or 4/3
         public float PrimaryTimerPriorityMultiplier => 1;
-        public float PrimaryTimerFallBackMultiplier => 4 / 3;
+        public float PrimaryTimerFallBackMultiplier => (float)4 / 3;
         public float PrimaryTimerMultiplier => IsPriorityPrimary ? PrimaryTimerPriorityMultiplier : PrimaryTimerFallBackMultiplier;
-        public bool IsBackup => MyIndex >= 0 && !IsPriorityPrimary && IsFallbackPrimary;
+        public bool IsBackup => MyIndex >= 0 && !IsPriorityPrimary && !IsFallbackPrimary;
         public bool WatchOnly => MyIndex < 0;
         public Header PrevHeader => NativeContract.Ledger.GetHeader(Snapshot, Block[0].PrevHash);
-        public int CountCommitted => CommitPayloads.Count(p => p != null);
+        public int CountCommitted => CommitPayloads[0].Count(p => p != null);
         public int CountFailed
         {
             get
@@ -98,10 +98,11 @@ public bool ValidatorsChanged
         }
 
         #region Consensus States
-        public bool RequestSentOrReceived => (PreparationPayloads[0][GetPriorityPrimaryIndex(ViewNumber)] != null || PreparationPayloads[1][GetFallbackPrimaryIndex(ViewNumber)] != null);
-        public bool ResponseSent => !WatchOnly && (PreparationPayloads[0][MyIndex] != null || PreparationPayloads[1][MyIndex] != null);
-        public bool CommitSent => !WatchOnly && (CommitPayloads[0][MyIndex] != null || CommitPayloads[1][MyIndex] != null);
-        public bool BlockSent => (Block[0].Transactions != null || Block[1].Transactions != null);
+        public bool RequestSentOrReceived => PreparationPayloads[0][GetPriorityPrimaryIndex(ViewNumber)] != null || (ViewNumber == 0 && PreparationPayloads[1][GetFallbackPrimaryIndex(ViewNumber)] != null);
+        public bool ResponseSent => !WatchOnly && (PreparationPayloads[0][MyIndex] != null || (ViewNumber == 0 && PreparationPayloads[1][MyIndex] != null));
+        public bool PreCommitSent => !WatchOnly && (PreCommitPayloads[0][MyIndex] != null || (ViewNumber == 0 && PreCommitPayloads[1][MyIndex] != null));
+        public bool CommitSent => !WatchOnly && (CommitPayloads[0][MyIndex] != null || (ViewNumber == 0 && CommitPayloads[1][MyIndex] != null));
+        public bool BlockSent => Block[0].Transactions != null || (ViewNumber == 0 && Block[1]?.Transactions != null);
         public bool ViewChanging => !WatchOnly && GetMessage<ChangeView>(ChangeViewPayloads[MyIndex])?.NewViewNumber > ViewNumber;
         public bool NotAcceptingPayloadsDueToViewChanging => ViewChanging && !MoreThanFNodesCommittedOrLost;
         // A possible attack can happen if the last node to commit is malicious and either sends change view after his
@@ -228,7 +229,10 @@ public void Reset(byte viewNumber)
                 }
                 MyIndex = -1;
                 for (uint i = 0; i <= 1; i++)
+                {
+                    PreCommitPayloads[i] = new ExtensiblePayload[Validators.Length];
                     CommitPayloads[i] = new ExtensiblePayload[Validators.Length];
+                }
                 ChangeViewPayloads = new ExtensiblePayload[Validators.Length];
                 LastChangeViewPayloads = new ExtensiblePayload[Validators.Length];
                 if (ValidatorsChanged || LastSeenMessage is null)
@@ -266,7 +270,6 @@ public void Reset(byte viewNumber)
             ViewNumber = viewNumber;
             for (uint pID = 0; pID <= 1; pID++)
             {
-                Block[pID].Header.PrimaryIndex = GetPriorityPrimaryIndex(viewNumber);
                 Block[pID].Header.MerkleRoot = null;
                 Block[pID].Header.Timestamp = 0;
                 Block[pID].Header.Nonce = 0;
@@ -275,7 +278,8 @@ public void Reset(byte viewNumber)
                 PreparationPayloads[pID] = new ExtensiblePayload[Validators.Length];
                 if (MyIndex >= 0) LastSeenMessage[Validators[MyIndex]] = Block[pID].Index;
             }
-
+            Block[0].Header.PrimaryIndex = GetPriorityPrimaryIndex(viewNumber);
+            Block[1].Header.PrimaryIndex = GetFallbackPrimaryIndex(viewNumber);
             //=========================================
             // Disable Fallback if viewnumber > 1
             if (viewNumber > 0)
@@ -299,8 +303,10 @@ public void Save()
         public void Deserialize(ref MemoryReader reader)
         {
             Reset(0);
+            ViewNumber = reader.ReadByte();
             for (uint pID = 0; pID <= 1; pID++)
             {
+                if (ViewNumber > 0 && pID > 0) break;
                 if (reader.ReadUInt32() != Block[pID].Version) throw new FormatException();
                 if (reader.ReadUInt32() != Block[pID].Index) throw new InvalidOperationException();
                 Block[pID].Header.Timestamp = reader.ReadUInt64();
@@ -326,17 +332,17 @@ public void Deserialize(ref MemoryReader reader)
                         VerificationContext[pID].AddTransaction(tx);
                 }
             }
-
-            ViewNumber = reader.ReadByte();
             ChangeViewPayloads = reader.ReadNullableArray<ExtensiblePayload>(neoSystem.Settings.ValidatorsCount);
             LastChangeViewPayloads = reader.ReadNullableArray<ExtensiblePayload>(neoSystem.Settings.ValidatorsCount);
 
         }
 
         public void Serialize(BinaryWriter writer)
         {
+            writer.Write(ViewNumber);
             for (uint i = 0; i <= 1; i++)
             {
+                if (ViewNumber > 0 && i > 0) break;
                 writer.Write(Block[i].Version);
                 writer.Write(Block[i].Index);
                 writer.Write(Block[i].Timestamp);
@@ -349,7 +355,6 @@ public void Serialize(BinaryWriter writer)
                 writer.WriteNullableArray(PreCommitPayloads[i]);
                 writer.WriteNullableArray(CommitPayloads[i]);
             }
-            writer.Write(ViewNumber);
             writer.WriteNullableArray(ChangeViewPayloads);
             writer.WriteNullableArray(LastChangeViewPayloads);
         }

src/DBFTPlugin/Consensus/ConsensusService.Check.cs

@@ -25,7 +25,7 @@ private bool CheckPrepareResponse(uint i)
             {
                 // if we are the primary for this view, but acting as a backup because we recovered our own
                 // previously sent prepare request, then we don't want to send a prepare response.
-                if (context.IsAPrimary || context.WatchOnly) return true;
+                if ((i == 0 && context.IsPriorityPrimary) || (i == 1 && context.IsFallbackPrimary) || context.WatchOnly) return true;
 
                 // Check maximum block size via Native Contract policy
                 if (context.GetExpectedBlockSize(i) > dbftSettings.MaxBlockSize)
@@ -101,25 +101,30 @@ private void CheckExpectedView(byte viewNumber)
 
         private void CheckPreparations(uint pID)
         {
-            int thresholdForPrep = pID == 0 ? context.F + 1 : context.M;
-
-            if (context.PreparationPayloads[pID].Count(p => p != null) >= thresholdForPrep && context.TransactionHashes[pID].All(p => context.Transactions[pID].ContainsKey(p)))
+            if (context.TransactionHashes[pID].All(p => context.Transactions[pID].ContainsKey(p)))
             {
-                ExtensiblePayload payload = context.MakePreCommit(pID);
-                Log($"Sending {nameof(PreCommit)} pOrF={pID}");
-                context.Save();
-                localNode.Tell(new LocalNode.SendDirectly { Inventory = payload });
-                // Set timer, so we will resend the commit in case of a networking issue
-                ChangeTimer(TimeSpan.FromMilliseconds(neoSystem.Settings.MillisecondsPerBlock));
-                CheckPreCommits(pID);
-
-                // ==============================================
-                // Speed-up path to also send commit
-                if (pID == 0 && context.PreparationPayloads[0].Count(p => p != null) >= context.M)
+                var preparationsCount = context.PreparationPayloads[pID].Count(p => p != null);
+                if (context.ViewNumber > 0)
+                {
+                    if (preparationsCount >= context.M)
+                        CheckPreCommits(0, true);
+                    return;
+                }
+                if (!context.PreCommitSent
+                    && ((pID == 0 && preparationsCount >= context.F + 1)
+                        || (pID == 1 && preparationsCount >= context.M)))
+                {
+                    ExtensiblePayload payload = context.MakePreCommit(pID);
+                    Log($"Sending {nameof(PreCommit)} pOrF={pID}");
+                    context.Save();
+                    localNode.Tell(new LocalNode.SendDirectly { Inventory = payload });
+                    // Set timer, so we will resend the commit in case of a networking issue
+                    ChangeTimer(TimeSpan.FromMilliseconds(neoSystem.Settings.MillisecondsPerBlock));
+                }
+                if (context.ViewNumber == 0 && pID == 0 && preparationsCount >= context.M)
+                {
                     CheckPreCommits(0, true);
-                // ==============================================                    
-
-                return;
+                }
             }
         }
     }

src/DBFTPlugin/Consensus/ConsensusService.OnMessage.cs

@@ -80,7 +80,7 @@ private void OnConsensusPayload(ExtensiblePayload payload)
         private void OnPrepareRequestReceived(ExtensiblePayload payload, PrepareRequest message)
         {
             if (context.RequestSentOrReceived || context.NotAcceptingPayloadsDueToViewChanging) return;
-            uint pOrF = Convert.ToUInt32(message.ValidatorIndex == context.GetPriorityPrimaryIndex(context.ViewNumber));
+            uint pOrF = message.ValidatorIndex == context.GetPriorityPrimaryIndex(context.ViewNumber) || context.ViewNumber > 0 ? 0u : 1u;
             // Add verification for Fallback
             if (message.ValidatorIndex != context.Block[pOrF].PrimaryIndex || message.ViewNumber != context.ViewNumber) return;
             if (message.Version != context.Block[pOrF].Version || message.PrevHash != context.Block[pOrF].PrevHash) return;
@@ -160,8 +160,14 @@ private void OnPrepareResponseReceived(ExtensiblePayload payload, PrepareRespons
         {
             if (message.ViewNumber != context.ViewNumber) return;
             if (context.PreparationPayloads[message.Id][message.ValidatorIndex] != null || context.NotAcceptingPayloadsDueToViewChanging) return;
-            if (context.PreparationPayloads[message.Id][context.Block[message.Id].PrimaryIndex] != null && !message.PreparationHash.Equals(context.PreparationPayloads[message.Id][context.Block[message.Id].PrimaryIndex].Hash))
-                return;
+            if (context.RequestSentOrReceived)
+            {
+                // Check if we have joined another consensus process
+                if (context.PreparationPayloads[message.Id][context.Block[message.Id].PrimaryIndex] == null) return;
+                if (!message.PreparationHash.Equals(context.PreparationPayloads[message.Id][context.Block[message.Id].PrimaryIndex].Hash))
+                    return;
+            }
+
 
             // Timeout extension: prepare response has been received with success
             // around 2*15/M=30.0/5 ~ 40% block time (for M=5)
@@ -177,8 +183,8 @@ private void OnPrepareResponseReceived(ExtensiblePayload payload, PrepareRespons
         private void OnPreCommitReceived(ExtensiblePayload payload, PreCommit message)
         {
             if (message.ViewNumber != context.ViewNumber) return;
-            if (context.PreparationPayloads[message.Id][message.ValidatorIndex] != null || context.NotAcceptingPayloadsDueToViewChanging) return;
-            if (context.PreparationPayloads[message.Id][context.Block[message.Id].PrimaryIndex] != null && !message.PreparationHash.Equals(context.PreparationPayloads[message.Id][context.Block[message.Id].PrimaryIndex].Hash))
+            if (context.PreCommitPayloads[message.Id][message.ValidatorIndex] != null || context.NotAcceptingPayloadsDueToViewChanging) return;
+            if (context.PreCommitPayloads[message.Id][context.Block[message.Id].PrimaryIndex] != null && !message.PreparationHash.Equals(context.PreparationPayloads[message.Id][context.Block[message.Id].PrimaryIndex].Hash))
                 return;
 
             Log($"{nameof(OnPreCommitReceived)}: height={message.BlockIndex} view={message.ViewNumber} index={message.ValidatorIndex} Id={message.Id}");

src/DBFTPlugin/Consensus/ConsensusService.cs

@@ -81,7 +81,7 @@ private void InitializeConsensus(byte viewNumber)
             if (viewNumber > 0)
                 Log($"View changed: view={viewNumber} primary={context.Validators[context.GetPriorityPrimaryIndex((byte)(viewNumber - 1u))]}", LogLevel.Warning);
             uint blockCurrentIndex = context.Block[0].Index;
-            Log($"Initialize: height={blockCurrentIndex} view={viewNumber} index={context.MyIndex} role={(context.IsPriorityPrimary ? "PrimaryP1" : context.IsFallbackPrimary ? "PrimaryP2" : context.WatchOnly ? "WatchOnly" : "Backup")}");
+            Log($"Initialize: height={blockCurrentIndex} view={viewNumber} index={context.MyIndex} role={(context.IsPriorityPrimary ? (viewNumber > 0 ? "Primary" : "PrimaryP1") : (context.IsFallbackPrimary && viewNumber == 0 ? "PrimaryP2" : (context.WatchOnly ? "WatchOnly" : "Backup")))}");
             if (context.WatchOnly) return;
             if (context.IsAPrimary)
             {
@@ -168,7 +168,7 @@ private void OnStart()
 
         private void OnTimer(Timer timer)
         {
-            uint pID = Convert.ToUInt32(!context.IsPriorityPrimary);
+            uint pID = Convert.ToUInt32(!(context.IsPriorityPrimary || context.ViewNumber > 0));
             if (context.WatchOnly || context.BlockSent) return;
             if (timer.Height != context.Block[pID].Index || timer.ViewNumber != context.ViewNumber) return;
             if (context.IsAPrimary && !context.RequestSentOrReceived)
@@ -206,14 +206,11 @@ private void SendPrepareRequest(uint pID)
             if (context.Validators.Length == 1)
                 CheckPreparations(pID);
 
-            Log($"SendPrepareRequest I", LogLevel.Debug);
-
             if (context.TransactionHashes[pID].Length > 0)
             {
                 foreach (InvPayload payload in InvPayload.CreateGroup(InventoryType.TX, context.TransactionHashes[pID]))
                     localNode.Tell(Message.Create(MessageCommand.Inv, payload));
             }
-            Log($"SendPrepareRequest II", LogLevel.Debug);
             ChangeTimer(TimeSpan.FromMilliseconds(context.PrimaryTimerMultiplier * ((neoSystem.Settings.MillisecondsPerBlock << (context.ViewNumber + 1)) - (context.ViewNumber == 0 ? neoSystem.Settings.MillisecondsPerBlock : 0))));
         }