L4 brief ok

StgSharp.Common/HighPerformance/Memory/L4.Evict.cs

@@ -73,7 +73,7 @@ namespace StgSharp.HighPerformance.Memory
                     int bitPos = BitOperations.TrailingZeroCount(evictMask);
                     int index = bitPos + i;
                     CacheLineHead* head = &_head[index];
-                    if (Interlocked.CompareExchange(ref head->_refCount, -1, 0) == 0)
+                    if (Interlocked.CompareExchange(ref head->_refCount, int.MinValue, 0) == 0)
                     {
                         // EvictLine(i + index);
                         _ = _map.TryRemove(head->_origin, out _);

StgSharp.Common/HighPerformance/Memory/L4.Prefetch.cs

@@ -82,6 +82,7 @@ namespace StgSharp.HighPerformance.Memory
                 CacheLineHead* head = (CacheLineHead*)handle;
                 int index = head->_id;
                 (*_eviction)[index] = 0; // reset eviction counter
+                return true;
             }
             return false;
         }

StgSharp.Common/HighPerformance/Memory/L4.cs

@@ -118,12 +118,16 @@ namespace StgSharp.HighPerformance.Memory
                 {
                     if (Interlocked.CompareExchange(ref _prefetching, 1, 0) == 0)
                     {
-                        if (_aheadCount < PredictionLeastAhead)
+                        try
                         {
-                            // do prefetch in work load now, sync
-                            Prefetch();
-                            break;
-                        } else
+                            if (_aheadCount < PredictionLeastAhead)
+                            {
+                                // do prefetch in work load now, sync
+                                Prefetch();
+                                break;
+                            }
+                        }
+                        finally
                         {
                             _prefetching = 0;
                         }
@@ -136,9 +140,10 @@ namespace StgSharp.HighPerformance.Memory
                 {
                     // cache hit
                     CacheLineHead* entry = (CacheLineHead*)entryHandle;
-                    if (Interlocked.Increment(ref entry->_refCount) < 0)
+                    if (Interlocked.Increment(ref entry->_refCount) > 0)
                     {
                         (*_eviction)[entry->_id] = 0;
+                        _ = Interlocked.Increment(ref _activeCount);
                         return new CacheLine(entry->_address, ref _activeCount, ref entry->_refCount);
                     } else
                     {
@@ -171,8 +176,6 @@ namespace StgSharp.HighPerformance.Memory
                 _handle = handle;
                 _refCount = ref cacheRefCount;
                 _activeCount = ref activeCount;
-                _ = Interlocked.Increment(ref _activeCount);
-                _ = Interlocked.Increment(ref _refCount);
             }
 
             [Obsolete("You should not create a CacheLineHandle outside a L4", true)]