cleanup code

CpuMonitor.cs

@@ -8,62 +8,78 @@ using System.Threading;
 
 namespace VRCX
 {
-    public static class CpuMonitor
+    public class CpuMonitor
     {
-        public static float CpuUsage { get; private set; }
-        private static Thread m_Thread;
+        public static CpuMonitor Instance { get; private set; }
+        public float CpuUsage { get; private set; }
+        private readonly PerformanceCounter m_Counter;
+        private Thread m_Thread;
 
-        public static void Init()
+        static CpuMonitor()
         {
-            m_Thread = new Thread(() =>
+            Instance = new CpuMonitor();
+        }
+
+        public CpuMonitor()
+        {
+            try
+            {
+                m_Counter = new PerformanceCounter("Processor Information", "% Processor Utility", "_Total", true);
+            }
+            catch
+            {
+            }
+
+            // fallback
+            if (m_Counter == null)
             {
-                PerformanceCounter counter = null;
                 try
                 {
-                    counter = new PerformanceCounter("Processor Information", "% Processor Utility", "_Total", true);
+                    m_Counter = new PerformanceCounter("Processor", "% Processor Time", "_Total", true);
                 }
                 catch
                 {
                 }
-                try
-                {
-                    if (counter == null)
-                    {
-                        counter = new PerformanceCounter("Processor", "% Processor Time", "_Total", true);
-                    }
-                }
-                catch
-                {
-                }
-                if (counter != null)
-                {
-                    while (m_Thread != null)
-                    {
-                        try
-                        {
-                            Thread.Sleep(1000);
-                        }
-                        catch
-                        {
-                            // ThreadInterruptedException
-                        }
-                        CpuUsage = counter.NextValue();
-                    }
-                    counter.Dispose();
-                }
-            })
+            }
+
+            m_Thread = new Thread(ThreadLoop)
             {
                 IsBackground = true
             };
+        }
+
+        internal void Init()
+        {
             m_Thread.Start();
         }
 
-        public static void Exit()
+        internal void Exit()
         {
-            var T = m_Thread;
+            var thread = m_Thread;
             m_Thread = null;
-            T.Interrupt();
-            T.Join();
+            thread.Interrupt();
+            thread.Join();
+            m_Counter?.Dispose();
+        }
+
+        private void ThreadLoop()
+        {
+            while (m_Thread != null)
+            {
+                if (m_Counter != null)
+                {
+                    CpuUsage = m_Counter.NextValue();
+                }
+
+                try
+                {
+                    Thread.Sleep(1000);
+                }
+                catch
+                {
+                    // ThreadInterruptedException
+                }
+            }
         }
     }
 }