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
@@ -45,6 +45,32 @@ namespace StgSharp.HighPerformance.Memory
    public interface IL4Predict
    {

+        /*
+         * Planned optimization contract types:
+         * 1. internal interface IL4PredictOptimizationContract
+         *    - Trusted extension point queried once during predictor registration.
+         *    - Produces normalized compatibility tokens for a given map policy.
+         * 2. readonly struct L4PredictCompatibilityToken
+         *    - Hot-path comparable descriptor cached by L4.
+         *    - Should at least carry ResidentFamily, FlushFamily and AccessMode.
+         * 3. enum L4PredictAccessMode
+         *    - Distinguishes read-only sources from write-back or write-through targets.
+         *
+         * L4 should only use these cached tokens in the prefetch path. Predictors without the
+         * internal contract stay on the conservative path: write back the old owner, then
+         * rematerialize the cache line for the new predictor.
+         */
+
+        /// <summary>
+        ///   Determines whether a cache line materialized by <paramref name="predict" /> under
+        ///   <paramref name="policy" /> can be adopted by the current predictor without an
+        ///   intermediate rematerialization.
+        /// </summary>
+        /// <remarks>
+        ///   This is intentionally stronger than comparing raw policy bits for equality. A true
+        ///   result means the resident bytes can continue to be interpreted safely after ownership
+        ///   is transferred to the current predictor.
+        /// </remarks>
        bool IsSamePolicy(
             uint policy,
             IL4Predict predict