1 files changed, 58 insertions, 1 deletions
diff --git a/Ryujinx.Graphics.OpenGL/Queries/CounterQueueEvent.cs b/Ryujinx.Graphics.OpenGL/Queries/CounterQueueEvent.cs
index 0e1025af..8b0ae30e 100644
--- a/Ryujinx.Graphics.OpenGL/Queries/CounterQueueEvent.cs
+++ b/Ryujinx.Graphics.OpenGL/Queries/CounterQueueEvent.cs
@@ -1,4 +1,5 @@
 using OpenTK.Graphics.OpenGL;
+using Ryujinx.Common.Logging;
 using Ryujinx.Graphics.GAL;
 using System;
 using System.Threading;
@@ -21,7 +22,11 @@ namespace Ryujinx.Graphics.OpenGL.Queries
         private CounterQueue _queue;
         private BufferedQuery _counter;
 
+        private bool _hostAccessReserved = false;
+        private int _refCount = 1; // Starts with a reference from the counter queue.
+
         private object _lock = new object();
+        private ulong _result = ulong.MaxValue;
 
         public CounterQueueEvent(CounterQueue queue, QueryTarget type, ulong drawIndex)
         {
@@ -76,6 +81,8 @@ namespace Ryujinx.Graphics.OpenGL.Queries
 
                 result += (ulong)queryResult;
 
+                _result = result;
+
                 OnResult?.Invoke(this, result);
 
                 Dispose(); // Return the our resources to the pool.
@@ -95,10 +102,60 @@ namespace Ryujinx.Graphics.OpenGL.Queries
             _queue.FlushTo(this);
         }
 
+        public void DecrementRefCount()
+        {
+            if (Interlocked.Decrement(ref _refCount) == 0)
+            {
+                DisposeInternal();
+            }
+        }
+
+        public bool ReserveForHostAccess()
+        {
+            if (_hostAccessReserved)
+            {
+                return true;
+            }
+
+            if (IsValueAvailable())
+            {
+                return false;
+            }
+
+            if (Interlocked.Increment(ref _refCount) == 1)
+            {
+                Interlocked.Decrement(ref _refCount);
+
+                return false;
+            }
+
+            _hostAccessReserved = true;
+
+            return true;
+        }
+
+        public void ReleaseHostAccess()
+        {
+            _hostAccessReserved = false;
+
+            DecrementRefCount();
+        }
+
+        private void DisposeInternal()
+        {
+            _queue.ReturnQueryObject(_counter);
+        }
+
+        private bool IsValueAvailable()
+        {
+            return _result != ulong.MaxValue || _counter.TryGetResult(out _);
+        }
+
         public void Dispose()
         {
             Disposed = true;
-            _queue.ReturnQueryObject(_counter);
+
+            DecrementRefCount();
         }
     }
 }