Ensure that the appliedIndex is changed before the trigger

Author: sakno

src/cluster/DotNext.Net.Cluster/Net/Cluster/Consensus/Raft/StateMachine/WriteAheadLog.Applier.cs

@@ -31,7 +31,7 @@ private async Task ApplyAsync(CancellationToken token)
             await lockManager.AcquireReadLockAsync(token).ConfigureAwait(false);
             try
             {
-                await ApplyAsync(appliedIndex + 1L, newIndex, token).ConfigureAwait(false);
+                await ApplyAsync(LastAppliedIndex + 1L, newIndex, token).ConfigureAwait(false);
             }
             catch (Exception e) when (e is not OperationCanceledException canceledEx || canceledEx.CancellationToken != token)
             {
@@ -54,9 +54,11 @@ private async Task ApplyAsync(CancellationToken token)
     public long LastAppliedIndex
     {
         get => Volatile.Read(in appliedIndex);
+        [MethodImpl(MethodImplOptions.NoInlining)]
         private set
         {
-            Volatile.Write(ref appliedIndex, value);
+            appliedIndex = value;
+            Interlocked.MemoryBarrier();
             appliedEvent.Signal(resumeAll: true);
         }
     }

src/cluster/DotNext.Net.Cluster/Net/Cluster/Consensus/Raft/StateMachine/WriteAheadLog.Flusher.cs

@@ -169,7 +169,7 @@ private long Commit(long index)
         return index - oldCommitIndex;
     }
 
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    [MethodImpl(MethodImplOptions.NoInlining)]
     private void OnCommitted(long count)
     {
         if (flushOnCommit)

src/cluster/DotNext.Net.Cluster/Net/Cluster/Consensus/Raft/StateMachine/WriteAheadLog.cs

@@ -255,7 +255,7 @@ public async ValueTask AppendAsync<TEntry>(TEntry entry, long startIndex, Cancel
                 if (startIndex <= LastCommittedEntryIndex)
                     throw new InvalidOperationException(ExceptionMessages.InvalidAppendIndex);
 
-                appliedIndex = await stateMachine.ApplyAsync(new LogEntry(entry, startIndex), token).ConfigureAwait(false);
+                LastAppliedIndex = await stateMachine.ApplyAsync(new LogEntry(entry, startIndex), token).ConfigureAwait(false);
                 var snapshotIndex = stateMachine.Snapshot?.Index ?? startIndex;
                 LastEntryIndex = long.Max(tailIndex, LastCommittedEntryIndex = snapshotIndex);
             }