refactor WiiCompiled.Setup into WiiCompiled.Setup.Windows and add WiiCompiled.Setup.Common

the idea behind this is C# code that is OS agnostic can go in WiiCompiled.Setup.Common to be shared by any OS specific code (eg: WiiCompiled.Setup.Windows and WiiCompiled.Setup.Linux).
2026-09-11 01:23:15 -04:00 · 2026-08-26 20:10:20 -04:00
parent f09590aa5d
commit c0ed2bfbeb
48 changed files with 444 additions and 340 deletions
@@ -0,0 +1,75 @@
+namespace WiiCompiled.Setup.Windows;
+
+/// <summary>
+/// Bridges a frontend-owned, named Windows event into the cancellation token used by setup.
+/// </summary>
+internal sealed class CancellationSignal : IDisposable
+{
+    public const string EnvironmentVariable = "MKWCOMPILED_CANCEL_EVENT";
+
+    private readonly EventWaitHandle? _event;
+    private readonly CancellationTokenSource? _source;
+    private readonly RegisteredWaitHandle? _registration;
+
+    private CancellationSignal(EventWaitHandle? @event, CancellationTokenSource? source,
+        RegisteredWaitHandle? registration)
+    {
+        _event = @event;
+        _source = source;
+        _registration = registration;
+    }
+
+    public CancellationToken Token => _source?.Token ?? CancellationToken.None;
+
+    public static CancellationSignal ObserveEnvironment()
+    {
+        var eventName = Environment.GetEnvironmentVariable(EnvironmentVariable);
+        if (eventName is null)
+            return new CancellationSignal(null, null, null);
+        if (string.IsNullOrWhiteSpace(eventName))
+            throw new InvalidOperationException(
+                $"The cancellation event named by {EnvironmentVariable} is empty.");
+
+        EventWaitHandle signal;
+        try
+        {
+            signal = EventWaitHandle.OpenExisting(eventName.Trim());
+        }
+        catch (Exception ex) when (ex is WaitHandleCannotBeOpenedException or UnauthorizedAccessException
+                                   or IOException or ArgumentException)
+        {
+            throw new InvalidOperationException(
+                $"The cancellation event named by {EnvironmentVariable} could not be opened.", ex);
+        }
+
+        var source = new CancellationTokenSource();
+        RegisteredWaitHandle registration;
+        try
+        {
+            registration = ThreadPool.RegisterWaitForSingleObject(signal, static (state, _) =>
+            {
+                try { ((CancellationTokenSource)state!).Cancel(); }
+                catch (ObjectDisposedException) { }
+            }, source, Timeout.Infinite, executeOnlyOnce: true);
+
+            // Registering and checking explicitly closes the race where the event was already set
+            // before RegisterWaitForSingleObject installed its wait.
+            if (signal.WaitOne(0)) source.Cancel();
+        }
+        catch
+        {
+            source.Dispose();
+            signal.Dispose();
+            throw;
+        }
+
+        return new CancellationSignal(signal, source, registration);
+    }
+
+    public void Dispose()
+    {
+        _registration?.Unregister(null);
+        _event?.Dispose();
+        _source?.Dispose();
+    }
+}