[3.0.8.0] PoA mining fix

src/Stratis.Bitcoin.Features.PoA.Tests/PoATestsBase.cs

@@ -34,6 +34,7 @@ public class PoATestsBase
         protected readonly IFederationManager federationManager;
         protected readonly VotingManager votingManager;
         protected readonly Mock<IPollResultExecutor> resultExecutorMock;
+        protected readonly Mock<IConsensusManager> consensusManager;
         protected readonly ISignals signals;
         protected readonly DBreezeSerializer dBreezeSerializer;
         protected readonly ChainState chainState;
@@ -52,7 +53,10 @@ public PoATestsBase(TestPoANetwork network = null)
             this.consensusSettings = new ConsensusSettings(NodeSettings.Default(this.network));
 
             this.federationManager = CreateFederationManager(this, this.network, this.loggerFactory, this.signals);
-            this.slotsManager = new SlotsManager(this.network, this.federationManager, this.loggerFactory);
+
+            this.consensusManager = new Mock<IConsensusManager>();
+            this.consensusManager.Setup(x => x.Tip).Returns(new ChainedHeader(new BlockHeader(), 0, 0));
+            this.slotsManager = new SlotsManager(this.network, this.federationManager, this.consensusManager.Object, this.loggerFactory);
 
             this.poaHeaderValidator = new PoABlockHeaderValidator(this.loggerFactory);
             this.asyncProvider = new AsyncProvider(this.loggerFactory, this.signals, new Mock<INodeLifetime>().Object);

src/Stratis.Bitcoin.Features.PoA.Tests/SlotsManagerTests.cs

@@ -1,8 +1,10 @@
 using System.Collections.Generic;
 using Microsoft.Extensions.Logging;
+using Moq;
 using NBitcoin;
 using Stratis.Bitcoin.Configuration;
 using Stratis.Bitcoin.Configuration.Logging;
+using Stratis.Bitcoin.Consensus;
 using Stratis.Bitcoin.Tests.Common;
 using Xunit;
 
@@ -12,16 +14,18 @@ public class SlotsManagerTests
     {
         private ISlotsManager slotsManager;
         private TestPoANetwork network;
-        private PoAConsensusOptions consensusOptions;
-        private IFederationManager federationManager;
+        private readonly PoAConsensusOptions consensusOptions;
+        private readonly IFederationManager federationManager;
+        private Mock<IConsensusManager> consensusManagerMock;
 
         public SlotsManagerTests()
         {
             this.network = new TestPoANetwork();
             this.consensusOptions = this.network.ConsensusOptions;
 
             this.federationManager = PoATestsBase.CreateFederationManager(this);
-            this.slotsManager = new SlotsManager(this.network, this.federationManager, new LoggerFactory());
+            this.consensusManagerMock = new Mock<IConsensusManager>();
+            this.slotsManager = new SlotsManager(this.network, this.federationManager, this.consensusManagerMock.Object, new LoggerFactory());
         }
 
         [Fact]
@@ -61,9 +65,10 @@ public void GetMiningTimestamp()
             this.network = new TestPoANetwork(new List<PubKey>() { tool.GeneratePrivateKey().PubKey, key.PubKey, tool.GeneratePrivateKey().PubKey });
 
             IFederationManager fedManager = PoATestsBase.CreateFederationManager(this, this.network, new ExtendedLoggerFactory(), new Signals.Signals(new LoggerFactory(), null));
-            this.slotsManager = new SlotsManager(this.network, fedManager, new LoggerFactory());
+            this.consensusManagerMock.Setup(x => x.Tip).Returns(new ChainedHeader(new BlockHeader(), 0, 0));
+            this.slotsManager = new SlotsManager(this.network, fedManager, this.consensusManagerMock.Object, new LoggerFactory());
 
-            List<IFederationMember> federationMembers = this.federationManager.GetFederationMembers();
+            List<IFederationMember> federationMembers = fedManager.GetFederationMembers();
             uint roundStart = this.consensusOptions.TargetSpacingSeconds * (uint)federationMembers.Count * 5;
 
             fedManager.SetPrivatePropertyValue(typeof(FederationManagerBase), nameof(IFederationManager.CurrentFederationKey), key);
@@ -77,6 +82,25 @@ public void GetMiningTimestamp()
             Assert.Equal(roundStart + this.consensusOptions.TargetSpacingSeconds, this.slotsManager.GetMiningTimestamp(roundStart - this.consensusOptions.TargetSpacingSeconds + 1));
 
             Assert.True(this.slotsManager.IsValidTimestamp(this.slotsManager.GetMiningTimestamp(roundStart - 5)));
+
+            uint thisTurnTimestamp = roundStart + this.consensusOptions.TargetSpacingSeconds;
+            uint nextTurnTimestamp = thisTurnTimestamp + this.consensusOptions.TargetSpacingSeconds * (uint)federationMembers.Count;
+
+            // If we are past our last timestamp's turn, always give us the NEXT timestamp.
+            uint justPastOurTurnTime = thisTurnTimestamp + (this.consensusOptions.TargetSpacingSeconds / 2) + 1;
+            Assert.Equal(nextTurnTimestamp, this.slotsManager.GetMiningTimestamp(justPastOurTurnTime));
+
+            // If we are only just past our last timestamp, but still in the "range" and we haven't mined a block yet, get THIS turn's timestamp.
+            Assert.Equal(thisTurnTimestamp, this.slotsManager.GetMiningTimestamp(thisTurnTimestamp + 1));
+
+            // If we are only just past our last timestamp, but we've already mined a block there, then get the NEXT turn's timestamp.
+            this.consensusManagerMock.Setup(x => x.Tip).Returns(new ChainedHeader(new BlockHeader
+            {
+                Time = thisTurnTimestamp
+            }, 0, 0));
+            this.slotsManager = new SlotsManager(this.network, fedManager, this.consensusManagerMock.Object, new LoggerFactory());
+            Assert.Equal(nextTurnTimestamp, this.slotsManager.GetMiningTimestamp(thisTurnTimestamp + 1));
+
         }
     }
 }

src/Stratis.Bitcoin.Features.PoA/SlotsManager.cs

@@ -34,13 +34,15 @@ public class SlotsManager : ISlotsManager
 
         private readonly IFederationManager federationManager;
 
+        private readonly IConsensusManager consensusManager;
+
         private readonly ILogger logger;
 
-        public SlotsManager(Network network, IFederationManager federationManager, ILoggerFactory loggerFactory)
+        public SlotsManager(Network network, IFederationManager federationManager, IConsensusManager consensusManager, ILoggerFactory loggerFactory)
         {
             Guard.NotNull(network, nameof(network));
             this.federationManager = Guard.NotNull(federationManager, nameof(federationManager));
-
+            this.consensusManager = consensusManager;
             this.consensusOptions = (network as PoANetwork).ConsensusOptions;
             this.logger = loggerFactory.CreateLogger(this.GetType().FullName);
         }
@@ -83,9 +85,11 @@ public uint GetMiningTimestamp(uint currentTime)
             uint roundStartTimestamp = (currentTime / roundTime) * roundTime;
             uint nextTimestampForMining = roundStartTimestamp + slotIndex * this.consensusOptions.TargetSpacingSeconds;
 
-            // We already passed our slot in this round.
-            // Get timestamp of our slot from next round.
-            if (nextTimestampForMining < currentTime)
+            // Check if we have missed our turn for this round.
+            // We still consider ourselves "in a turn" if we are in the first half of the turn and we haven't mined there yet.
+            // This might happen when starting the node for the first time or if there was a problem when mining.
+            if (currentTime > nextTimestampForMining + (this.consensusOptions.TargetSpacingSeconds / 2) // We are closer to the next turn than our own
+                  || this.consensusManager.Tip.Header.Time == nextTimestampForMining) // We have already mined in that slot
             {
                 // Get timestamp for next round.
                 nextTimestampForMining = roundStartTimestamp + roundTime + slotIndex * this.consensusOptions.TargetSpacingSeconds;