fix(script): preserve scheduler counter increment

crates/fparkan-script/tests/handler2_native_oracle.cs

@@ -0,0 +1,87 @@
+using System;
+using System.IO;
+using System.Runtime.InteropServices;
+using System.Security.Cryptography;
+using System.Text;
+
+internal static class Handler2NativeOracle {
+    private const uint LoadWithAlteredSearchPath = 0x00000008;
+    private const int RefreshRecordRva = 0x5070;
+    private const string ExpectedSha256 = "c19cd6cd31cd2896f8c4ba0f0e700dd3408aec8182daaf4863d98a7d233a2abc";
+
+    [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
+    private static extern IntPtr LoadLibraryEx(string fileName, IntPtr file, uint flags);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    private static extern bool FreeLibrary(IntPtr module);
+
+    [UnmanagedFunctionPointer(CallingConvention.ThisCall)]
+    private delegate void RefreshRecord(IntPtr record);
+
+    private static int Main() {
+        if (IntPtr.Size != 4) {
+            Console.Error.WriteLine("Build this oracle with an x86 target; ai.dll is 32-bit.");
+            return 2;
+        }
+
+        string dllPath = Environment.GetEnvironmentVariable("FPARKAN_ORIGINAL_AI_DLL");
+        if (String.IsNullOrEmpty(dllPath) || !File.Exists(dllPath)) {
+            Console.Error.WriteLine("Set FPARKAN_ORIGINAL_AI_DLL to the original GOG ai.dll.");
+            return 3;
+        }
+
+        string actualSha256;
+        using (SHA256 sha256 = SHA256.Create())
+        using (FileStream input = File.OpenRead(dllPath)) {
+            byte[] digest = sha256.ComputeHash(input);
+            StringBuilder hex = new StringBuilder(digest.Length * 2);
+            foreach (byte value in digest) hex.Append(value.ToString("x2"));
+            actualSha256 = hex.ToString();
+        }
+        if (actualSha256 != ExpectedSha256) {
+            Console.Error.WriteLine("Unexpected ai.dll SHA-256: " + actualSha256);
+            return 4;
+        }
+
+        IntPtr module = LoadLibraryEx(dllPath, IntPtr.Zero, LoadWithAlteredSearchPath);
+        if (module == IntPtr.Zero) {
+            Console.Error.WriteLine("LoadLibraryEx failed: " + Marshal.GetLastWin32Error());
+            return 5;
+        }
+
+        try {
+            var refresh = (RefreshRecord)Marshal.GetDelegateForFunctionPointer(
+                IntPtr.Add(module, RefreshRecordRva), typeof(RefreshRecord));
+            IntPtr record = Marshal.AllocHGlobal(100);
+            try {
+                for (int offset = 0; offset < 100; offset += 4) Marshal.WriteInt32(record, offset, 0);
+                Marshal.WriteInt32(record, 0x24, 4);
+                Marshal.WriteInt32(record, 0x28, 4);
+                AssertRefresh(refresh, record, 8);
+                AssertRefresh(refresh, record, 12);
+
+                Marshal.WriteInt32(record, 0x24, unchecked((int)UInt32.MaxValue));
+                Marshal.WriteInt32(record, 0x28, unchecked((int)UInt32.MaxValue));
+                AssertRefresh(refresh, record, UInt32.MaxValue - 1);
+                AssertRefresh(refresh, record, UInt32.MaxValue - 2);
+            }
+            finally { Marshal.FreeHGlobal(record); }
+        }
+        finally { FreeLibrary(module); }
+        return 0;
+    }
+
+    private static void AssertRefresh(RefreshRecord refresh, IntPtr record, uint expectedCounter) {
+        uint savedIncrement = unchecked((uint)Marshal.ReadInt32(record, 0x28));
+        refresh(record);
+        uint actualCounter = unchecked((uint)Marshal.ReadInt32(record, 0x24));
+        uint actualIncrement = unchecked((uint)Marshal.ReadInt32(record, 0x28));
+        Console.WriteLine("record[+0x24]=0x{0:X8} record[+0x28]=0x{1:X8}",
+            actualCounter, actualIncrement);
+        if (actualCounter != expectedCounter || actualIncrement != savedIncrement) {
+            throw new InvalidOperationException(String.Format(
+                "Expected +0x24=0x{0:X8}, +0x28 unchanged at 0x{1:X8}.",
+                expectedCounter, savedIncrement));
+        }
+    }
+}