Refactor search context to use unsafe pointers

Switch VMMDLL_MEM_SEARCH_CONTEXT to an unsafe struct and replace IntPtr with void* for the search field. Refactor VmmSearch to use fixed blocks instead of GCHandle for pinning, assigning the pointer directly to the context. Move related logic inside the fixed block and remove unnecessary GCHandle usage. This improves interop safety and performance.

Author: lone7254

src/VmmSharpEx/Internal/Vmmi.cs

@@ -886,15 +886,15 @@ public struct VMMDLL_MEM_SEARCH_CONTEXT_SEARCHENTRY
     public delegate bool SearchResultCallback(VMMDLL_MEM_SEARCH_CONTEXT ctx, ulong va, uint iSearch);
 
     [StructLayout(LayoutKind.Sequential, Pack = 8)]
-    public struct VMMDLL_MEM_SEARCH_CONTEXT
+    public unsafe struct VMMDLL_MEM_SEARCH_CONTEXT
     {
         public uint dwVersion;
         private readonly uint _Filler01;
         private readonly uint _Filler02;
         public int fAbortRequested;
         public uint cMaxResult;
         public uint cSearch;
-        public IntPtr search;
+        public void* search;
         public ulong vaMin;
         public ulong vaMax;
         public readonly ulong vaCurrent;

src/VmmSharpEx/VmmSearch.cs

@@ -91,55 +91,56 @@ public static unsafe SearchResult MemSearch(this Vmm vmm,
         {
             return result; // No search items, return empty result.
         }
-        var hSearches = GCHandle.Alloc(searches, GCHandleType.Pinned);
         var context = (Vmmi.VMMDLL_MEM_SEARCH_CONTEXT*)NativeMemory.Alloc((nuint)sizeof(Vmmi.VMMDLL_MEM_SEARCH_CONTEXT));
         try
         {
-            Vmmi.SearchResultCallback del = SearchResultCallback; // Prevent delegate from being GC'ed during the call.
-            *context = new Vmmi.VMMDLL_MEM_SEARCH_CONTEXT
+            fixed (void* pSearches = searches)
             {
-                dwVersion = VMMDLL_MEM_SEARCH_VERSION,
-                vaMin = addr_min,
-                vaMax = addr_max,
-                cMaxResult = cMaxResult,
-                ReadFlags = (uint)readFlags,
-                pfnResultOptCB = Marshal.GetFunctionPointerForDelegate(del)
-            };
-            context->cSearch = (uint)searches.Length;
-            context->search = hSearches.AddrOfPinnedObject();
-            var ctReg = ct.Register(() =>
-            {
-                context->fAbortRequested = 1;
-            });
-            try
-            {
-                result.IsSuccess = Vmmi.VMMDLL_MemSearch(vmm, pid, context, IntPtr.Zero, IntPtr.Zero);
-            }
-            finally
-            {
-                // IMPORTANT: Ensure we unregister the cancellation token callback before the context is freed.
-                // This will block (WaitForCallbackIfNecessary) until the callback is completed (if it is already in progress).
-                ctReg.Dispose();
-            }
+                Vmmi.SearchResultCallback del = SearchResultCallback; // Prevent delegate from being GC'ed during the call.
+                *context = new Vmmi.VMMDLL_MEM_SEARCH_CONTEXT
+                {
+                    dwVersion = VMMDLL_MEM_SEARCH_VERSION,
+                    vaMin = addr_min,
+                    vaMax = addr_max,
+                    cMaxResult = cMaxResult,
+                    ReadFlags = (uint)readFlags,
+                    pfnResultOptCB = Marshal.GetFunctionPointerForDelegate(del),
+                    cSearch = (uint)searches.Length,
+                    search = pSearches
+                };
+                var ctReg = ct.Register(() =>
+                {
+                    context->fAbortRequested = 1;
+                });
+                try
+                {
+                    result.IsSuccess = Vmmi.VMMDLL_MemSearch(vmm, pid, context, IntPtr.Zero, IntPtr.Zero);
+                }
+                finally
+                {
+                    // IMPORTANT: Ensure we unregister the cancellation token callback before the context is freed.
+                    // This will block (WaitForCallbackIfNecessary) until the callback is completed (if it is already in progress).
+                    ctReg.Dispose();
+                }
 
-            ct.ThrowIfCancellationRequested();
-            return result;
+                ct.ThrowIfCancellationRequested();
+                return result;
 
-            bool SearchResultCallback(Vmmi.VMMDLL_MEM_SEARCH_CONTEXT ctx, ulong va, uint iSearch)
-            {
-                var e = new SearchResult.Entry
+                bool SearchResultCallback(Vmmi.VMMDLL_MEM_SEARCH_CONTEXT ctx, ulong va, uint iSearch)
                 {
-                    Address = va,
-                    SearchTermId = iSearch
-                };
-                result._results.Add(e);
-                return result._results.Count < ctx.cMaxResult;
+                    var e = new SearchResult.Entry
+                    {
+                        Address = va,
+                        SearchTermId = iSearch
+                    };
+                    result._results.Add(e);
+                    return result._results.Count < ctx.cMaxResult;
+                }
             }
         }
         finally
         {
             NativeMemory.Free(context);
-            hSearches.Free();
         }
     }