/*

   This Source Code Form is subject to the terms of the Mozilla Public

   License, v. 2.0. If a copy of the MPL was not distributed with this

   file, You can obtain one at http://mozilla.org/MPL/2.0/.

   Copyright (C) 2010-2011 Michael Möller <mmoeller@openhardwaremonitor.org>

 */

 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;

     private readonly bool hasModelSpecificRegisters;

     private readonly bool hasTimeStampCounter;

     private readonly bool isInvariantTimeStampCounter;

     private readonly double estimatedTimeStampCounterFrequency;

     private readonly double estimatedTimeStampCounterFrequencyError;

     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)

       : base(cpuid[0][0].Name, CreateIdentifier(cpuid[0][0].Vendor, 

       processorIndex), 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;  

       // 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) {

         ulong mask = ThreadAffinity.Set(1UL << cpuid[0][0].Thread);

         EstimateTimeStampCounterFrequency(

           out estimatedTimeStampCounterFrequency, 

           out estimatedTimeStampCounterFrequencyError);  

         ThreadAffinity.Set(mask);

       } else {

         estimatedTimeStampCounterFrequency = 0;

       }

       timeStampCounterFrequency = estimatedTimeStampCounterFrequency;                  

     }

     private static Identifier CreateIdentifier(Vendor vendor,

       int processorIndex) 

     {

       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));

     }

     private void EstimateTimeStampCounterFrequency(out double frequency, 

       out double error) 

   {     

       double f, e;

       // preload the function

       EstimateTimeStampCounterFrequency(0, out f, out e);

       EstimateTimeStampCounterFrequency(0, out f, out e);

       // estimate the frequency

       error = double.MaxValue;

       frequency = 0;

       for (int i = 0; i < 5; i++) {

         EstimateTimeStampCounterFrequency(0.025, out f, out e);

         if (e < error) {

           error = e;

           frequency = f;

         }

         if (error < 1e-4)

           break;

       }                

     }

     private void EstimateTimeStampCounterFrequency(double timeWindow, 

       out double frequency, out double error) 

     {

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

       ulong countBegin, countEnd;

       long timeBegin = Stopwatch.GetTimestamp() +

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

       long timeEnd = timeBegin + ticks;

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

       countBegin = Opcode.Rdtsc();

       long afterBegin = Stopwatch.GetTimestamp();

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

       countEnd = Opcode.Rdtsc();

       long afterEnd = Stopwatch.GetTimestamp();

       double delta = (timeEnd - timeBegin);

       frequency = 1e-6 * 

         (((double)(countEnd - countBegin)) * Stopwatch.Frequency) / delta;

       double beginError = (afterBegin - timeBegin) / delta;

       double endError = (afterEnd - timeEnd) / delta;

       error = beginError + endError;

     }

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

       uint eax, edx;

       if (Ring0.RdmsrTx(msr, out eax, out edx, 1UL << 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,

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

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

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

         "Estimated Time Stamp Counter Frequency Error: {0} Mhz",

         Math.Round(estimatedTimeStampCounterFrequency *

         estimatedTimeStampCounterFrequencyError * 1e5) * 1e-5));

       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 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

         ulong mask = ThreadAffinity.Set(1UL << 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

         ThreadAffinity.Set(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();

       }

     }

   }

 }