Add Mac platform

Source/Engine/Platform/Mac/MacThread.h

@@ -0,0 +1,31 @@
+// Copyright (c) 2012-2021 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+#if PLATFORM_MAC
+
+#include "../Base/ThreadBase.h"
+
+/// <summary>
+/// Thread object for Mac platform.
+/// </summary>
+class MacThread : public ThreadBase
+{
+public:
+
+    MacThread(IRunnable* runnable, const String& name, ThreadPriority priority);
+    ~MacThread();
+    static MacThread* Create(IRunnable* runnable, const String& name, ThreadPriority priority = ThreadPriority::Normal, uint32 stackSize = 0);
+
+    // [ThreadBase]
+    void Join() override;
+
+protected:
+
+    // [ThreadBase]
+    void ClearHandleInternal();
+    void SetPriorityInternal(ThreadPriority priority);
+    void KillInternal(bool waitForJoin);
+};
+
+#endif