solution to unsafe operation in l4

2026-04-13 00:12:29 +08:00
parent 556008ad8c
commit 61a5b49c22
2 changed files with 31 additions and 0 deletions
@@ -88,11 +88,16 @@ namespace StgSharp.HighPerformance.Memory

                        int predictId = head->_predictor;
                        IL4Predict belong = predictorSpan[predictId];
+                        // This branch performs resident-line adoption rather than a simple policy
+                        // equality check. Returning true means the current predictor can keep using
+                        // the existing cache bytes without a write-back plus re-prefetch cycle.
                        if (predict.IsSamePolicy(head->_profile, belong))
                        {
                            head->_predictor =predictIndex;
                        } else
                        {
+                            // Compatibility failed, so the old owner must first flush its view of
+                            // the line before the new predictor rematerializes the cache bytes.
                            belong.WriteBack(head->_origin, head->_profile, new ReadOnlySpan<byte>((byte*)head->_address, Unsafe.SizeOf<CacheLineData>()));
                            head->_profile = pHandle.MapPolicy;
                            predict.Prefetch(head->_origin, head->_profile, new Span<byte>((byte*)head->_address, Unsafe.SizeOf<CacheLineData>()));