Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web/Management/AppDomainResourcePerfCounters.cs

@@ -0,0 +1,133 @@
+//------------------------------------------------------------------------------
+// <copyright file="AppDomainResourcePerfCounters.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+
+namespace System.Web.Management {
+    using System;
+    using System.Configuration;
+    using System.Web;
+    using System.Threading;
+
+    internal class AppDomainResourcePerfCounters {
+
+        private const  uint      NUM_SECONDS_TO_POLL = 5;
+
+        /////////////////////////////////////////////////////////////////////////////
+        /////////////////////////////////////////////////////////////////////////////
+        /////////////////////////////////////////////////////////////////////////////
+        internal static void Init() {
+            if (_fInit)
+                return;
+
+            lock (_InitLock) {
+                if (_fInit)
+                    return;
+
+                if (AppDomain.MonitoringIsEnabled) {
+                    PerfCounters.SetCounter(AppPerfCounter.APP_CPU_USED_BASE, 100);
+                    _Timer = new Timer((new AppDomainResourcePerfCounters()).TimerCallback, null,
+                                       NUM_SECONDS_TO_POLL * 1000, NUM_SECONDS_TO_POLL * 1000);
+                }
+                _fInit = true;
+            }
+        }
+
+        /////////////////////////////////////////////////////////////////////////////
+        /////////////////////////////////////////////////////////////////////////////
+        /////////////////////////////////////////////////////////////////////////////
+        internal static void Stop() {
+            if (_Timer == null)
+                return; // already stopped
+
+            _StopRequested = true;
+
+            lock (_InitLock) {
+                if (_Timer != null) {
+                    ((IDisposable)_Timer).Dispose();
+                    _Timer = null;
+                }
+            }
+
+            // Wait for the _inProgressLock lock
+            while (_inProgressLock != 0) {
+                Thread.Sleep(100);
+            }
+        }
+
+        /////////////////////////////////////////////////////////////////////////////
+        /////////////////////////////////////////////////////////////////////////////
+        /////////////////////////////////////////////////////////////////////////////
+        // Static data
+        private static bool      _fInit                = false;
+        private static object    _InitLock             = new object();
+        private static Timer     _Timer                = null;
+        private static int       _inProgressLock       = 0;
+        private static bool      _StopRequested        = false;
+
+        // Instance data
+        private int       _MemUsageLastReported = 0;
+        private int       _CPUUsageLastReported = 0;
+        private TimeSpan  _TotalCPUTime;
+        private DateTime  _LastCollectTime;
+
+
+        /////////////////////////////////////////////////////////////////////////////
+        /////////////////////////////////////////////////////////////////////////////
+        /////////////////////////////////////////////////////////////////////////////
+        private AppDomainResourcePerfCounters() {
+            _TotalCPUTime = AppDomain.CurrentDomain.MonitoringTotalProcessorTime;
+            _LastCollectTime = DateTime.UtcNow;
+        }
+
+        /////////////////////////////////////////////////////////////////////////////
+        /////////////////////////////////////////////////////////////////////////////
+        /////////////////////////////////////////////////////////////////////////////
+        private void TimerCallback(Object state) {
+
+            if ( _StopRequested ||  // Stop has been called -- exit immediately
+                 !AppDomain.MonitoringIsEnabled || // Monitoring APIs will throw NotSupportedException if not-enabled
+                 Interlocked.Exchange(ref _inProgressLock, 1) != 0) // Is some thread currently executing the callback
+            {
+                return;
+            }
+
+            try {
+                SetPerfCounters();
+            } catch { // don't bubble up exceptions, since we are on a timer thread
+            } finally {
+                Interlocked.Exchange(ref _inProgressLock, 0);
+            }
+        }
+
+        /////////////////////////////////////////////////////////////////////////////
+        /////////////////////////////////////////////////////////////////////////////
+        /////////////////////////////////////////////////////////////////////////////
+        private void SetPerfCounters() {
+
+            ////////////////////////////////////////////////////////////
+            // Calculate memory: Limited to 2TB (Int32.MaxValue * 1024 bytes)
+            long memInKB = (AppDomain.CurrentDomain.MonitoringSurvivedMemorySize / 1024); // Mem used in KB
+            _MemUsageLastReported = (int) Math.Min(Int32.MaxValue, Math.Max(0, memInKB)); // Make sure its within 0 and Int32.MaxValue
+            PerfCounters.SetCounter(AppPerfCounter.APP_MEMORY_USED, _MemUsageLastReported);
+
+            ////////////////////////////////////////////////////////////
+            // Calculate CPU
+            DateTime dtUtcNow = DateTime.UtcNow;
+            TimeSpan newTotalCPUTime = AppDomain.CurrentDomain.MonitoringTotalProcessorTime;
+
+            double  timeElapsed = (dtUtcNow - _LastCollectTime).TotalMilliseconds; // Total time since last collect
+            double  cpuTimeUsed = (newTotalCPUTime - _TotalCPUTime).TotalMilliseconds; // Total CPU time used since last collect
+            int     cpuPercent  = (int) ((cpuTimeUsed * 100) / timeElapsed); // Percent of CPU time used
+
+            _CPUUsageLastReported = Math.Min(100, Math.Max(0, cpuPercent)); // Make sure it's within 0 and 100
+            PerfCounters.SetCounter(AppPerfCounter.APP_CPU_USED, _CPUUsageLastReported);
+
+            // Update variables for next time
+            _TotalCPUTime = newTotalCPUTime;
+            _LastCollectTime = dtUtcNow;
+        }
+    }
+}
+