UniRx 에셋 추가

Gameton-06/Assets/Plugins/UniRx/Scripts/Disposables/SingleAssignmentDisposable.cs

@@ -0,0 +1,68 @@
+using System;
+using System.Collections;
+
+namespace UniRx
+{
+    // should be use Interlocked.CompareExchange for Threadsafe?
+    // but CompareExchange cause ExecutionEngineException on iOS.
+    // AOT...
+    // use lock instead
+
+    public sealed class SingleAssignmentDisposable : IDisposable, ICancelable
+    {
+        readonly object gate = new object();
+        IDisposable current;
+        bool disposed;
+
+        public bool IsDisposed { get { lock (gate) { return disposed; } } }
+
+        public IDisposable Disposable
+        {
+            get
+            {
+                return current;
+            }
+            set
+            {
+                var old = default(IDisposable);
+                bool alreadyDisposed;
+                lock (gate)
+                {
+                    alreadyDisposed = disposed;
+                    old = current;
+                    if (!alreadyDisposed)
+                    {
+                        if (value == null) return;
+                        current = value;
+                    }
+                }
+
+                if (alreadyDisposed && value != null)
+                {
+                    value.Dispose();
+                    return;
+                }
+
+                if (old != null) throw new InvalidOperationException("Disposable is already set");
+            }
+        }
+
+
+        public void Dispose()
+        {
+            IDisposable old = null;
+
+            lock (gate)
+            {
+                if (!disposed)
+                {
+                    disposed = true;
+                    old = current;
+                    current = null;
+                }
+            }
+
+            if (old != null) old.Dispose();
+        }
+    }
+}