1 files changed, 153 insertions, 0 deletions
diff --git a/src/Ryujinx.HLE/HOS/Services/Sockets/Bsd/Impl/EventFileDescriptor.cs b/src/Ryujinx.HLE/HOS/Services/Sockets/Bsd/Impl/EventFileDescriptor.cs
new file mode 100644
index 00000000..6514d485
--- /dev/null
+++ b/src/Ryujinx.HLE/HOS/Services/Sockets/Bsd/Impl/EventFileDescriptor.cs
@@ -0,0 +1,153 @@
+using Ryujinx.HLE.HOS.Services.Sockets.Bsd.Types;
+using System;
+using System.Runtime.InteropServices;
+using System.Threading;
+
+namespace Ryujinx.HLE.HOS.Services.Sockets.Bsd.Impl
+{
+    class EventFileDescriptor : IFileDescriptor
+    {
+        private ulong _value;
+        private readonly EventFdFlags _flags;
+
+        private object _lock = new object();
+
+        public bool Blocking { get => !_flags.HasFlag(EventFdFlags.NonBlocking); set => throw new NotSupportedException(); }
+
+        public ManualResetEvent WriteEvent { get; }
+        public ManualResetEvent ReadEvent { get; }
+
+        public EventFileDescriptor(ulong value, EventFdFlags flags)
+        {
+            // FIXME: We should support blocking operations.
+            // Right now they can't be supported because it would cause the
+            // service to lock up as we only have one thread processing requests.
+            flags |= EventFdFlags.NonBlocking;
+
+            _value = value;
+            _flags = flags;
+
+            WriteEvent = new ManualResetEvent(false);
+            ReadEvent = new ManualResetEvent(false);
+            UpdateEventStates();
+        }
+
+        public int Refcount { get; set; }
+
+        public void Dispose()
+        {
+            WriteEvent.Dispose();
+            ReadEvent.Dispose();
+        }
+
+        private void ResetEventStates()
+        {
+            WriteEvent.Reset();
+            ReadEvent.Reset();
+        }
+
+        private void UpdateEventStates()
+        {
+            if (_value > 0)
+            {
+                ReadEvent.Set();
+            }
+
+            if (_value != uint.MaxValue - 1)
+            {
+                WriteEvent.Set();
+            }
+        }
+
+        public LinuxError Read(out int readSize, Span<byte> buffer)
+        {
+            if (buffer.Length < sizeof(ulong))
+            {
+                readSize = 0;
+
+                return LinuxError.EINVAL;
+            }
+
+            lock (_lock)
+            {
+                ResetEventStates();
+
+                ref ulong count = ref MemoryMarshal.Cast<byte, ulong>(buffer)[0];
+
+                if (_value == 0)
+                {
+                    if (Blocking)
+                    {
+                        while (_value == 0)
+                        {
+                            Monitor.Wait(_lock);
+                        }
+                    }
+                    else
+                    {
+                        readSize = 0;
+
+                        UpdateEventStates();
+                        return LinuxError.EAGAIN;
+                    }
+                }
+
+                readSize = sizeof(ulong);
+
+                if (_flags.HasFlag(EventFdFlags.Semaphore))
+                {
+                    --_value;
+
+                    count = 1;
+                }
+                else
+                {
+                    count = _value;
+
+                    _value = 0;
+                }
+
+                UpdateEventStates();
+                return LinuxError.SUCCESS;
+            }
+        }
+
+        public LinuxError Write(out int writeSize, ReadOnlySpan<byte> buffer)
+        {
+            if (!MemoryMarshal.TryRead(buffer, out ulong count) || count == ulong.MaxValue)
+            {
+                writeSize = 0;
+
+                return LinuxError.EINVAL;
+            }
+
+            lock (_lock)
+            {
+                ResetEventStates();
+
+                if (_value > _value + count)
+                {
+                    if (Blocking)
+                    {
+                        Monitor.Wait(_lock);
+                    }
+                    else
+                    {
+                        writeSize = 0;
+
+                        UpdateEventStates();
+                        return LinuxError.EAGAIN;
+                    }
+                }
+
+                writeSize = sizeof(ulong);
+
+                _value += count;
+                Monitor.Pulse(_lock);
+
+                UpdateEventStates();
+                return LinuxError.SUCCESS;
+            }
+        }
+    }
+}
+\ No newline at end of file