checkpoint for real

SafeListHandle.cs

@@ -1,46 +1,49 @@
 using System;
 using System.Runtime.CompilerServices;
 using System.Runtime.ConstrainedExecution;
+using System.Runtime.InteropServices;
 
 namespace Foodsoft.Alpm
 {
-    internal struct ListRef : CriticalFinalIDisposable
+    internal sealed class SafeListHandle : SafeHandle
     {
         public SafeAlpmHandle SafeAlpmHandle
         {
             [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
             [PrePrepareMethod]
             get;
-        }
+        } = null!;
         
-        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail), PrePrepareMethod]
-        public ListRef(SafeAlpmHandle handle)
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
+        [PrePrepareMethod]
+        internal SafeListHandle(SafeAlpmHandle safeAlpmHandle)
+            : base(IntPtr.Zero, true)
         {
-            SafeAlpmHandle = null!;
+            var success = false;
             RuntimeHelpers.PrepareConstrainedRegions();
             try { }
             finally
             {
-                SafeAlpmHandle = handle;
-                var success = false;
-                handle.DangerousAddRef(ref success);
+                safeAlpmHandle.DangerousAddRef(ref success);
                 if (success)
-                    SafeAlpmHandle = handle;
-                else
-                {
-                    SafeAlpmHandle = null!;
-                    throw new ObjectDisposedException(GetType().FullName);
-                }
+                    SafeAlpmHandle = safeAlpmHandle;
             }
+
+            if (!success)
+                throw new ObjectDisposedException(GetType().FullName);
         }
 
-        ~ListRef()
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success), PrePrepareMethod]
+        protected override bool ReleaseHandle()
         {
-            
+            SafeAlpmHandle.DangerousRelease();
+            return true;
         }
-        
-        public void Dispose()
+
+        public override bool IsInvalid
         {
+            [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success), PrePrepareMethod]
+            get => SafeAlpmHandle.IsInvalid;
         }
     }
 }