Fixed lost promotion during RandomAccessCache resize

Author: sakno

src/DotNext.Tests/Runtime/Caching/RandomAccessCacheTests.cs

@@ -568,8 +568,8 @@ static async Task AddAsync(CacheWithWeight cache, string key)
     [Fact]
     public static async Task ConcurrentResize()
     {
-        await using var cache = new CacheWithWeight(2, long.MaxValue, 1);
-        await Parallel.ForAsync(0, 20_000, new ParallelOptions { CancellationToken = TestToken }, async (i, token) =>
+        await using var cache = new CacheWithWeight(2, long.MaxValue, 2);
+        await Parallel.ForAsync(0, 1000, new ParallelOptions { CancellationToken = TestToken }, async (i, token) =>
         {
             var session = await cache.ChangeAsync(i.ToString(), token);
             session.SetValue(1L);

src/DotNext.Threading/Runtime/Caching/RandomAccessCache.Dictionary.cs

@@ -579,9 +579,14 @@ private async ValueTask GrowAsync(BucketList oldVersion, Timeout timeout, Cancel
             ProcessQueue();
 
             // restart eviction process
-            RebuildEvictionState(buckets = new(oldVersion, newSize));
+            var newVersion = new BucketList(oldVersion, newSize);
+            RebuildEvictionState(newVersion);
             queueHead = queueTail = new FakeKeyValuePair();
             evictionTask = DoEvictionAsync(newSource);
+
+            // Publish the new version last. The buckets beyond the old length have new locks that are not held,
+            // so the writers can promote to the queue as soon as the new version is visible
+            buckets = newVersion;
         }
         finally
         {