/*

   Version: MPL 1.1/GPL 2.0/LGPL 2.1

   The contents of this file are subject to the Mozilla Public License Version

   1.1 (the "License"); you may not use this file except in compliance with

   the License. You may obtain a copy of the License at

   http://www.mozilla.org/MPL/

   Software distributed under the License is distributed on an "AS IS" basis,

   WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License

   for the specific language governing rights and limitations under the License.

   The Original Code is the Open Hardware Monitor code.

   The Initial Developer of the Original Code is 

   Michael Möller <m.moeller@gmx.ch>.

   Portions created by the Initial Developer are Copyright (C) 2010

   the Initial Developer. All Rights Reserved.

   Contributor(s):

   Alternatively, the contents of this file may be used under the terms of

   either the GNU General Public License Version 2 or later (the "GPL"), or

   the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),

   in which case the provisions of the GPL or the LGPL are applicable instead

   of those above. If you wish to allow use of your version of this file only

   under the terms of either the GPL or the LGPL, and not to allow others to

   use your version of this file under the terms of the MPL, indicate your

   decision by deleting the provisions above and replace them with the notice

   and other provisions required by the GPL or the LGPL. If you do not delete

   the provisions above, a recipient may use your version of this file under

   the terms of any one of the MPL, the GPL or the LGPL.

 */

 using System;

 using System.Collections.Generic;

 using System.Diagnostics;

 using System.Globalization;

 using System.Runtime.InteropServices;

 using System.Text;

 using System.Threading;

 namespace OpenHardwareMonitor.Hardware.CPU {

   internal class GenericCPU : Hardware {

     protected readonly CPUID[][] cpuid;

     protected readonly uint family;

     protected readonly uint model;

     protected readonly uint stepping;

     protected readonly int processorIndex;

     protected readonly int coreCount;

     protected readonly string name;

     private readonly bool hasModelSpecificRegisters;

     private readonly bool hasTimeStampCounter;

     private readonly bool isInvariantTimeStampCounter;

     private readonly double estimatedTimeStampCounterFrequency;

     private ulong lastTimeStampCount;

     private long lastTime;

     private double timeStampCounterFrequency;    

     private readonly Vendor vendor;

     private readonly CPULoad cpuLoad;

     private readonly Sensor totalLoad;

     private readonly Sensor[] coreLoads;

     protected string CoreString(int i) {

       if (coreCount == 1)

         return "CPU Core";

       else

         return "CPU Core #" + (i + 1);

     }

     public GenericCPU(int processorIndex, CPUID[][] cpuid, ISettings settings) {

       this.cpuid = cpuid;

       this.vendor = cpuid[0][0].Vendor;

       this.family = cpuid[0][0].Family;

       this.model = cpuid[0][0].Model;

       this.stepping = cpuid[0][0].Stepping;

       this.processorIndex = processorIndex;

       this.coreCount = cpuid.Length;

       this.name = cpuid[0][0].Name;    

       // check if processor has MSRs

       if (cpuid[0][0].Data.GetLength(0) > 1

         && (cpuid[0][0].Data[1, 3] & 0x20) != 0)

         hasModelSpecificRegisters = true;

       else

         hasModelSpecificRegisters = false;

       // check if processor has a TSC

       if (cpuid[0][0].Data.GetLength(0) > 1

         && (cpuid[0][0].Data[1, 3] & 0x10) != 0)

         hasTimeStampCounter = true;

       else

         hasTimeStampCounter = false;

       // check if processor supports an invariant TSC 

       if (cpuid[0][0].ExtData.GetLength(0) > 7

         && (cpuid[0][0].ExtData[7, 3] & 0x100) != 0)

         isInvariantTimeStampCounter = true;

       else

         isInvariantTimeStampCounter = false;

       if (coreCount > 1)

         totalLoad = new Sensor("CPU Total", 0, SensorType.Load, this, settings);

       else

         totalLoad = null;

       coreLoads = new Sensor[coreCount];

       for (int i = 0; i < coreLoads.Length; i++)

         coreLoads[i] = new Sensor(CoreString(i), i + 1,

           SensorType.Load, this, settings);

       cpuLoad = new CPULoad(cpuid);

       if (cpuLoad.IsAvailable) {

         foreach (Sensor sensor in coreLoads)

           ActivateSensor(sensor);

         if (totalLoad != null)

           ActivateSensor(totalLoad);

       }

       if (hasTimeStampCounter) {

         estimatedTimeStampCounterFrequency = 

           EstimateTimeStampCounterFrequency();        

       } else {

         estimatedTimeStampCounterFrequency = 0;

       }

       timeStampCounterFrequency = estimatedTimeStampCounterFrequency;                  

     }

     private static double EstimateTimeStampCounterFrequency() {

       // preload the function

       EstimateTimeStampCounterFrequency(0);

       EstimateTimeStampCounterFrequency(0);

       // estimate the frequency in MHz      

       List<double> estimatedFrequency = new List<double>(3);

       for (int i = 0; i < 3; i++)

         estimatedFrequency.Add(1e-6 * EstimateTimeStampCounterFrequency(0.025));

       estimatedFrequency.Sort();

       return estimatedFrequency[1];

     }

     private static double EstimateTimeStampCounterFrequency(double timeWindow) {

       long ticks = (long)(timeWindow * Stopwatch.Frequency);

       ulong countBegin, countEnd;

       Thread.BeginThreadAffinity();

       long timeBegin = Stopwatch.GetTimestamp() +

         (long)Math.Ceiling(0.001 * ticks);

       long timeEnd = timeBegin + ticks;

       while (Stopwatch.GetTimestamp() < timeBegin) { }

       countBegin = Opcode.Rdtsc();

       while (Stopwatch.GetTimestamp() < timeEnd) { }

       countEnd = Opcode.Rdtsc();

       Thread.EndThreadAffinity();

       return (((double)(countEnd - countBegin)) * Stopwatch.Frequency) /

         (timeEnd - timeBegin);

     }

     private static void AppendMSRData(StringBuilder r, uint msr, int thread) {

       uint eax, edx;

       if (Ring0.RdmsrTx(msr, out eax, out edx, (UIntPtr)(1L << thread))) {

         r.Append(" ");

         r.Append((msr).ToString("X8", CultureInfo.InvariantCulture));

         r.Append("  ");

         r.Append((edx).ToString("X8", CultureInfo.InvariantCulture));

         r.Append("  ");

         r.Append((eax).ToString("X8", CultureInfo.InvariantCulture));

         r.AppendLine();

       }

     }

     protected virtual uint[] GetMSRs() {

       return null;

     }

     public override string GetReport() {

       StringBuilder r = new StringBuilder();

       switch (vendor) {

         case Vendor.AMD: r.AppendLine("AMD CPU"); break;

         case Vendor.Intel: r.AppendLine("Intel CPU"); break;

         default: r.AppendLine("Generic CPU"); break;

       }

       r.AppendLine();

       r.AppendFormat("Name: {0}{1}", name, Environment.NewLine);

       r.AppendFormat("Number of Cores: {0}{1}", coreCount,

         Environment.NewLine);

       r.AppendFormat("Threads per Core: {0}{1}", cpuid[0].Length,

         Environment.NewLine);

       r.AppendLine(string.Format(CultureInfo.InvariantCulture,

         "Timer Frequency: {0} MHz", Stopwatch.Frequency * 1e-6));

       r.AppendLine("Time Stamp Counter: " + (hasTimeStampCounter ? (

         isInvariantTimeStampCounter ? "Invariant" : "Not Invariant") : "None"));

       r.AppendLine(string.Format(CultureInfo.InvariantCulture,

         "Time Stamp Counter Frequency: {0} MHz",

         Math.Round(timeStampCounterFrequency * 100) * 0.01));   

       r.AppendLine();

       uint[] msrArray = GetMSRs();

       if (msrArray != null && msrArray.Length > 0) {

         for (int i = 0; i < cpuid.Length; i++) {

           r.AppendLine("MSR Core #" + (i + 1));

           r.AppendLine();

           r.AppendLine(" MSR       EDX       EAX");

           foreach (uint msr in msrArray)

             AppendMSRData(r, msr, cpuid[i][0].Thread);

           r.AppendLine();

         }

       }

       return r.ToString();

     }

     public override Identifier Identifier {

       get {

         string s;

         switch (vendor) {

           case Vendor.AMD: s = "amdcpu"; break;

           case Vendor.Intel: s = "intelcpu"; break;

           default: s = "genericcpu"; break;

         }

         return new Identifier(s, 

           processorIndex.ToString(CultureInfo.InvariantCulture));

       }

     }

     public override string Name {

       get { return name; }

     }

     public override HardwareType HardwareType {

       get { return HardwareType.CPU; }

     }

     public bool HasModelSpecificRegisters {

       get { return hasModelSpecificRegisters; }

     }

     public bool HasTimeStampCounter {

       get { return hasTimeStampCounter; }

     }

     public double TimeStampCounterFrequency {

       get { return timeStampCounterFrequency; }

     }

     public override void Update() {

       if (hasTimeStampCounter && isInvariantTimeStampCounter) {

         // make sure always the same thread is used

         IntPtr thread = NativeMethods.GetCurrentThread();

         UIntPtr mask = NativeMethods.SetThreadAffinityMask(thread,

           (UIntPtr)(1L << cpuid[0][0].Thread));

         // read time before and after getting the TSC to estimate the error

         long firstTime = Stopwatch.GetTimestamp();

         ulong timeStampCount = Opcode.Rdtsc();

         long time = Stopwatch.GetTimestamp();

         // restore the thread affinity mask

         NativeMethods.SetThreadAffinityMask(thread, mask);

         double delta = ((double)(time - lastTime)) / Stopwatch.Frequency;

         double error = ((double)(time - firstTime)) / Stopwatch.Frequency;

         // only use data if they are measured accuarte enough (max 0.1ms delay)

         if (error < 0.0001) {

           // ignore the first reading because there are no initial values 

           // ignore readings with too large or too small time window

           if (lastTime != 0 && delta > 0.5 && delta < 2) {

             // update the TSC frequency with the new value

             timeStampCounterFrequency =

               (timeStampCount - lastTimeStampCount) / (1e6 * delta);

           }

           lastTimeStampCount = timeStampCount;

           lastTime = time;

         }        

       }

       if (cpuLoad.IsAvailable) {

         cpuLoad.Update();

         for (int i = 0; i < coreLoads.Length; i++)

           coreLoads[i].Value = cpuLoad.GetCoreLoad(i);

         if (totalLoad != null)

           totalLoad.Value = cpuLoad.GetTotalLoad();

       }

     }

     private static class NativeMethods {

       private const string KERNEL = "kernel32.dll";

       [DllImport(KERNEL, CallingConvention = CallingConvention.Winapi)]

       public static extern UIntPtr

         SetThreadAffinityMask(IntPtr handle, UIntPtr mask);

       [DllImport(KERNEL, CallingConvention = CallingConvention.Winapi)]

       public static extern IntPtr GetCurrentThread();

     }

   }

 }