7 files changed, 523 insertions, 80 deletions
diff --git a/Ryujinx.Graphics.OpenGL/Counters.cs b/Ryujinx.Graphics.OpenGL/Counters.cs
deleted file mode 100644
index e82a040f..00000000
--- a/Ryujinx.Graphics.OpenGL/Counters.cs
+++ /dev/null
@@ -1,77 +0,0 @@
-using OpenTK.Graphics.OpenGL;
-using Ryujinx.Graphics.GAL;
-using System;
-
-namespace Ryujinx.Graphics.OpenGL
-{
-    class Counters
-    {
-        private int[] _queryObjects;
-
-        private ulong[] _accumulatedCounters;
-
-        public Counters()
-        {
-            int count = Enum.GetNames(typeof(CounterType)).Length;
-
-            _queryObjects = new int[count];
-
-            _accumulatedCounters = new ulong[count];
-        }
-
-        public void Initialize()
-        {
-            for (int index = 0; index < _queryObjects.Length; index++)
-            {
-                int handle = GL.GenQuery();
-
-                _queryObjects[index] = handle;
-
-                CounterType type = (CounterType)index;
-
-                GL.BeginQuery(GetTarget(type), handle);
-            }
-        }
-
-        public ulong GetCounter(CounterType type)
-        {
-            UpdateAccumulatedCounter(type);
-
-            return _accumulatedCounters[(int)type];
-        }
-
-        public void ResetCounter(CounterType type)
-        {
-            UpdateAccumulatedCounter(type);
-
-            _accumulatedCounters[(int)type] = 0;
-        }
-
-        private void UpdateAccumulatedCounter(CounterType type)
-        {
-            int handle = _queryObjects[(int)type];
-
-            QueryTarget target = GetTarget(type);
-
-            GL.EndQuery(target);
-
-            GL.GetQueryObject(handle, GetQueryObjectParam.QueryResult, out long result);
-
-            _accumulatedCounters[(int)type] += (ulong)result;
-
-            GL.BeginQuery(target, handle);
-        }
-
-        private static QueryTarget GetTarget(CounterType type)
-        {
-            switch (type)
-            {
-                case CounterType.SamplesPassed:                      return QueryTarget.SamplesPassed;
-                case CounterType.PrimitivesGenerated:                return QueryTarget.PrimitivesGenerated;
-                case CounterType.TransformFeedbackPrimitivesWritten: return QueryTarget.TransformFeedbackPrimitivesWritten;
-            }
-
-            return QueryTarget.SamplesPassed;
-        }
-    }
-}
diff --git a/Ryujinx.Graphics.OpenGL/Pipeline.cs b/Ryujinx.Graphics.OpenGL/Pipeline.cs
index dc04805d..80b07108 100644
--- a/Ryujinx.Graphics.OpenGL/Pipeline.cs
+++ b/Ryujinx.Graphics.OpenGL/Pipeline.cs
@@ -1,6 +1,7 @@
 using OpenTK.Graphics.OpenGL;
 using Ryujinx.Common.Logging;
 using Ryujinx.Graphics.GAL;
+using Ryujinx.Graphics.OpenGL.Queries;
 using Ryujinx.Graphics.Shader;
 using System;
 
@@ -1023,6 +1024,46 @@ namespace Ryujinx.Graphics.OpenGL
             }
         }
 
+        public bool TryHostConditionalRendering(ICounterEvent value, ulong compare, bool isEqual)
+        {
+            if (value is CounterQueueEvent)
+            {
+                // Compare an event and a constant value.
+                CounterQueueEvent evt = (CounterQueueEvent)value;
+
+                // Easy host conditional rendering when the check matches what GL can do:
+                //  - Event is of type samples passed.
+                //  - Result is not a combination of multiple queries.
+                //  - Comparing against 0.
+                //  - Event has not already been flushed.
+
+                if (evt.Disposed)
+                {
+                    // If the event has been flushed, then just use the values on the CPU.
+                    // The query object may already be repurposed for another draw (eg. begin + end).
+                    return false; 
+                }
+
+                if (compare == 0 && evt.Type == QueryTarget.SamplesPassed && evt.ClearCounter)
+                {
+                    GL.BeginConditionalRender(evt.Query, isEqual ? ConditionalRenderType.QueryNoWaitInverted : ConditionalRenderType.QueryNoWait);
+                    return true;
+                }
+            }
+
+            return false; // The GPU will flush the queries to CPU and evaluate the condition there instead.
+        }
+
+        public bool TryHostConditionalRendering(ICounterEvent value, ICounterEvent compare, bool isEqual)
+        {
+            return false; // We don't currently have a way to compare two counters for conditional rendering.
+        }
+
+        public void EndHostConditionalRendering()
+        {
+            GL.EndConditionalRender();
+        }
+
         public void Dispose()
         {
             _framebuffer?.Dispose();
diff --git a/Ryujinx.Graphics.OpenGL/Queries/BufferedQuery.cs b/Ryujinx.Graphics.OpenGL/Queries/BufferedQuery.cs
new file mode 100644
index 00000000..9750ec92
--- /dev/null
+++ b/Ryujinx.Graphics.OpenGL/Queries/BufferedQuery.cs
@@ -0,0 +1,105 @@
+using OpenTK.Graphics.OpenGL;
+using Ryujinx.Common.Logging;
+using System;
+using System.Runtime.InteropServices;
+using System.Threading;
+
+namespace Ryujinx.Graphics.OpenGL.Queries
+{
+    class BufferedQuery : IDisposable
+    {
+        private const int MaxQueryRetries = 5000;
+        private const long DefaultValue = -1;
+
+        public int Query { get; }
+
+        private int _buffer;
+        private IntPtr _bufferMap;
+        private QueryTarget _type;
+
+        public BufferedQuery(QueryTarget type)
+        {
+            _buffer = GL.GenBuffer();
+            Query = GL.GenQuery();
+            _type = type;
+
+            GL.BindBuffer(BufferTarget.QueryBuffer, _buffer);
+
+            unsafe
+            {
+                long defaultValue = DefaultValue;
+                GL.BufferStorage(BufferTarget.QueryBuffer, sizeof(long), (IntPtr)(&defaultValue), BufferStorageFlags.MapReadBit | BufferStorageFlags.MapWriteBit | BufferStorageFlags.MapPersistentBit);
+            }
+            _bufferMap = GL.MapBufferRange(BufferTarget.QueryBuffer, IntPtr.Zero, sizeof(long), BufferAccessMask.MapReadBit | BufferAccessMask.MapWriteBit | BufferAccessMask.MapPersistentBit);
+        }
+
+        public void Reset()
+        {
+            GL.EndQuery(_type);
+            GL.BeginQuery(_type, Query);
+        }
+
+        public void Begin()
+        {
+            GL.BeginQuery(_type, Query);
+        }
+
+        public unsafe void End()
+        {
+            GL.Flush();
+            GL.EndQuery(_type);
+
+            GL.BindBuffer(BufferTarget.QueryBuffer, _buffer);
+
+            Marshal.WriteInt64(_bufferMap, -1L);
+            GL.GetQueryObject(Query, GetQueryObjectParam.QueryResult, (long*)0);
+        }
+
+        public bool TryGetResult(out long result)
+        {
+            result = Marshal.ReadInt64(_bufferMap);
+
+            return result != DefaultValue;
+        }
+
+        public long AwaitResult(AutoResetEvent wakeSignal = null)
+        {
+            long data = DefaultValue;
+
+            if (wakeSignal == null)
+            {
+                while (data == DefaultValue)
+                {
+                    data = Marshal.ReadInt64(_bufferMap);
+                }
+            }
+            else
+            {
+                int iterations = 0;
+                while (data == DefaultValue && iterations++ < MaxQueryRetries)
+                {
+                    data = Marshal.ReadInt64(_bufferMap);
+                    if (data == DefaultValue)
+                    {
+                        wakeSignal.WaitOne(1);
+                    }
+                }
+
+                if (iterations >= MaxQueryRetries)
+                {
+                    Logger.PrintError(LogClass.Gpu, $"Error: Query result timed out. Took more than {MaxQueryRetries} tries.");
+                }
+            }
+
+            return data;
+        }
+
+        public void Dispose()
+        {
+            GL.BindBuffer(BufferTarget.QueryBuffer, _buffer);
+            GL.UnmapBuffer(BufferTarget.QueryBuffer);
+            GL.DeleteBuffer(_buffer);
+            GL.DeleteQuery(Query);
+        }
+    }
+}
diff --git a/Ryujinx.Graphics.OpenGL/Queries/CounterQueue.cs b/Ryujinx.Graphics.OpenGL/Queries/CounterQueue.cs
new file mode 100644
index 00000000..f34bc86d
--- /dev/null
+++ b/Ryujinx.Graphics.OpenGL/Queries/CounterQueue.cs
@@ -0,0 +1,209 @@
+using OpenTK.Graphics.OpenGL;
+using Ryujinx.Graphics.GAL;
+using System;
+using System.Collections.Generic;
+using System.Threading;
+
+namespace Ryujinx.Graphics.OpenGL.Queries
+{
+    class CounterQueue : IDisposable
+    {
+        private const int QueryPoolInitialSize = 100;
+
+        public CounterType Type { get; }
+        public bool Disposed { get; private set; }
+
+        private Queue<CounterQueueEvent> _events = new Queue<CounterQueueEvent>();
+        private CounterQueueEvent _current;
+
+        private ulong _accumulatedCounter;
+
+        private object _lock = new object();
+
+        private Queue<BufferedQuery> _queryPool;
+        private AutoResetEvent _queuedEvent = new AutoResetEvent(false);
+        private AutoResetEvent _wakeSignal = new AutoResetEvent(false);
+
+        private Thread _consumerThread;
+
+        internal CounterQueue(CounterType type)
+        {
+            Type = type;
+
+            QueryTarget glType = GetTarget(Type);
+
+            _queryPool = new Queue<BufferedQuery>(QueryPoolInitialSize);
+            for (int i = 0; i < QueryPoolInitialSize; i++)
+            {
+                _queryPool.Enqueue(new BufferedQuery(glType));
+            }
+
+            _current = new CounterQueueEvent(this, glType);
+
+            _consumerThread = new Thread(EventConsumer);
+            _consumerThread.Start();
+        }
+
+        private void EventConsumer()
+        {
+            while (!Disposed)
+            {
+                CounterQueueEvent evt = null;
+                lock (_lock)
+                {
+                    if (_events.Count > 0)
+                    {
+                        evt = _events.Dequeue();
+                    }
+                }
+
+                if (evt == null)
+                {
+                    _queuedEvent.WaitOne(); // No more events to go through, wait for more.
+                }
+                else
+                {
+                    evt.TryConsume(ref _accumulatedCounter, true, _wakeSignal);
+                }
+            }
+        }
+
+        internal BufferedQuery GetQueryObject()
+        {
+            // Creating/disposing query objects on a context we're sharing with will cause issues.
+            // So instead, make a lot of query objects on the main thread and reuse them.
+
+            lock (_lock)
+            {
+                if (_queryPool.Count > 0)
+                {
+                    BufferedQuery result = _queryPool.Dequeue();
+                    return result;
+                }
+                else
+                {
+                    return new BufferedQuery(GetTarget(Type));
+                }
+            }
+        }
+
+        internal void ReturnQueryObject(BufferedQuery query)
+        {
+            lock (_lock)
+            {
+                _queryPool.Enqueue(query);
+            }
+        }
+
+        public CounterQueueEvent QueueReport(EventHandler<ulong> resultHandler)
+        {
+            CounterQueueEvent result;
+
+            lock (_lock)
+            {
+                _current.Complete();
+                _events.Enqueue(_current);
+
+                result = _current;
+                result.OnResult += resultHandler;
+
+                _current = new CounterQueueEvent(this, GetTarget(Type));
+            }
+
+            _queuedEvent.Set();
+
+            return result;
+        }
+
+        public void QueueReset()
+        {
+            lock (_lock)
+            {
+                _current.Clear();
+            }
+        }
+
+        private static QueryTarget GetTarget(CounterType type)
+        {
+            switch (type)
+            {
+                case CounterType.SamplesPassed: return QueryTarget.SamplesPassed;
+                case CounterType.PrimitivesGenerated: return QueryTarget.PrimitivesGenerated;
+                case CounterType.TransformFeedbackPrimitivesWritten: return QueryTarget.TransformFeedbackPrimitivesWritten;
+            }
+
+            return QueryTarget.SamplesPassed;
+        }
+
+        public void Flush(bool blocking)
+        {
+            if (!blocking)
+            {
+                // Just wake the consumer thread - it will update the queries.
+                _wakeSignal.Set();
+                return;
+            }
+
+            lock (_lock)
+            {
+                // Tell the queue to process all events.
+                while (_events.Count > 0)
+                {
+                    CounterQueueEvent flush = _events.Peek();
+                    if (!flush.TryConsume(ref _accumulatedCounter, true))
+                    {
+                        return; // If not blocking, then return when we encounter an event that is not ready yet.
+                    }
+                    _events.Dequeue();
+                }
+            }
+        }
+
+        public void FlushTo(CounterQueueEvent evt)
+        {
+            lock (_lock)
+            {
+                if (evt.Disposed)
+                {
+                    return;
+                }
+
+                // Tell the queue to process all events up to this one.
+                while (_events.Count > 0)
+                {
+                    CounterQueueEvent flush = _events.Dequeue();
+                    flush.TryConsume(ref _accumulatedCounter, true);
+
+                    if (flush == evt)
+                    {
+                        return;
+                    }
+                }
+            }
+        }
+
+        public void Dispose()
+        {
+            lock (_lock)
+            {
+                while (_events.Count > 0)
+                {
+                    CounterQueueEvent evt = _events.Dequeue();
+
+                    evt.Dispose();
+                }
+
+                Disposed = true;
+            }
+
+            _queuedEvent.Set();
+
+            _consumerThread.Join();
+
+            foreach (BufferedQuery query in _queryPool)
+            {
+                query.Dispose();
+            }
+        }
+    }
+}
diff --git a/Ryujinx.Graphics.OpenGL/Queries/CounterQueueEvent.cs b/Ryujinx.Graphics.OpenGL/Queries/CounterQueueEvent.cs
new file mode 100644
index 00000000..0fba24a1
--- /dev/null
+++ b/Ryujinx.Graphics.OpenGL/Queries/CounterQueueEvent.cs
@@ -0,0 +1,100 @@
+using OpenTK.Graphics.OpenGL;
+using Ryujinx.Graphics.GAL;
+using System;
+using System.Threading;
+
+namespace Ryujinx.Graphics.OpenGL.Queries
+{
+    class CounterQueueEvent : ICounterEvent
+    {
+        public event EventHandler<ulong> OnResult;
+
+        public QueryTarget Type { get; }
+        public bool ClearCounter { get; private set; }
+        public int Query => _counter.Query;
+
+        public bool Disposed { get; private set; }
+        public bool Invalid { get; set; }
+
+        private CounterQueue _queue;
+        private BufferedQuery _counter;
+
+        private object _lock = new object();
+
+        public CounterQueueEvent(CounterQueue queue, QueryTarget type)
+        {
+            _queue = queue;
+
+            _counter = queue.GetQueryObject();
+            Type = type;
+
+            _counter.Begin();
+        }
+
+        internal void Clear()
+        {
+            _counter.Reset();
+            ClearCounter = true;
+        }
+
+        internal void Complete()
+        {
+            _counter.End();
+        }
+
+        internal bool TryConsume(ref ulong result, bool block, AutoResetEvent wakeSignal = null)
+        {
+            lock (_lock)
+            {
+                if (Disposed)
+                {
+                    return true;
+                }
+
+                if (ClearCounter || Type == QueryTarget.Timestamp)
+                {
+                    result = 0;
+                }
+
+                long queryResult;
+
+                if (block)
+                {
+                    queryResult = _counter.AwaitResult(wakeSignal);
+                }
+                else
+                {
+                    if (!_counter.TryGetResult(out queryResult))
+                    {
+                        return false;
+                    }
+                }
+
+                result += (ulong)queryResult;
+
+                OnResult?.Invoke(this, result);
+
+                Dispose(); // Return the our resources to the pool.
+
+                return true;
+            }
+        }
+
+        public void Flush()
+        {
+            if (Disposed)
+            {
+                return;
+            }
+
+            // Tell the queue to process all events up to this one.
+            _queue.FlushTo(this);
+        }
+
+        public void Dispose()
+        {
+            Disposed = true;
+            _queue.ReturnQueryObject(_counter);
+        }
+    }
+}
diff --git a/Ryujinx.Graphics.OpenGL/Queries/Counters.cs b/Ryujinx.Graphics.OpenGL/Queries/Counters.cs
new file mode 100644
index 00000000..7560fb17
--- /dev/null
+++ b/Ryujinx.Graphics.OpenGL/Queries/Counters.cs
@@ -0,0 +1,57 @@
+using Ryujinx.Graphics.GAL;
+using System;
+
+namespace Ryujinx.Graphics.OpenGL.Queries
+{
+    class Counters : IDisposable
+    {
+        private CounterQueue[] _counterQueues;
+
+        public Counters()
+        {
+            int count = Enum.GetNames(typeof(CounterType)).Length;
+
+            _counterQueues = new CounterQueue[count];
+        }
+
+        public void Initialize()
+        {
+            for (int index = 0; index < _counterQueues.Length; index++)
+            {
+                CounterType type = (CounterType)index;
+                _counterQueues[index] = new CounterQueue(type);
+            }
+        }
+
+        public CounterQueueEvent QueueReport(CounterType type, EventHandler<ulong> resultHandler)
+        {
+            return _counterQueues[(int)type].QueueReport(resultHandler);
+        }
+
+        public void QueueReset(CounterType type)
+        {
+            _counterQueues[(int)type].QueueReset();
+        }
+
+        public void Update()
+        {
+            foreach (var queue in _counterQueues)
+            {
+                queue.Flush(false);
+            }
+        }
+
+        public void Flush(CounterType type)
+        {
+            _counterQueues[(int)type].Flush(true);
+        }
+
+        public void Dispose()
+        {
+            foreach (var queue in _counterQueues)
+            {
+                queue.Dispose();
+            }
+        }
+    }
+}
diff --git a/Ryujinx.Graphics.OpenGL/Renderer.cs b/Ryujinx.Graphics.OpenGL/Renderer.cs
index 3f718345..b3ae8c33 100644
--- a/Ryujinx.Graphics.OpenGL/Renderer.cs
+++ b/Ryujinx.Graphics.OpenGL/Renderer.cs
@@ -1,7 +1,9 @@
 using OpenTK.Graphics.OpenGL;
 using Ryujinx.Common.Logging;
 using Ryujinx.Graphics.GAL;
+using Ryujinx.Graphics.OpenGL.Queries;
 using Ryujinx.Graphics.Shader;
+using System;
 
 namespace Ryujinx.Graphics.OpenGL
 {
@@ -66,9 +68,14 @@ namespace Ryujinx.Graphics.OpenGL
                 HwCapabilities.MaxSupportedAnisotropy);
         }
 
-        public ulong GetCounter(CounterType type)
+        public void UpdateCounters()
         {
-            return _counters.GetCounter(type);
+            _counters.Update();
+        }
+
+        public ICounterEvent ReportCounter(CounterType type, EventHandler<ulong> resultHandler)
+        {
+            return _counters.QueueReport(type, resultHandler);
         }
 
         public void Initialize()
@@ -89,7 +96,7 @@ namespace Ryujinx.Graphics.OpenGL
 
         public void ResetCounter(CounterType type)
         {
-            _counters.ResetCounter(type);
+            _counters.QueueReset(type);
         }
 
         public void Dispose()
@@ -97,6 +104,7 @@ namespace Ryujinx.Graphics.OpenGL
             TextureCopy.Dispose();
             _pipeline.Dispose();
             _window.Dispose();
+            _counters.Dispose();
         }
     }
 }