From d901c079b7b6c163f808d4e5aaa994cf653a8e2b Mon Sep 17 00:00:00 2001
From: asrulhadi <asrulhadi@users.noreply.github.com>
Date: Thu, 16 Mar 2023 17:28:47 +0800
Subject: [PATCH] Linux cpu load (#981)

---
 .../Hardware/Cpu/CpuLoad.cs                   | 81 ++++++++++++++++---
 1 file changed, 69 insertions(+), 12 deletions(-)

diff --git a/LibreHardwareMonitorLib/Hardware/Cpu/CpuLoad.cs b/LibreHardwareMonitorLib/Hardware/Cpu/CpuLoad.cs
index ceff770..e693041 100644
--- a/LibreHardwareMonitorLib/Hardware/Cpu/CpuLoad.cs
+++ b/LibreHardwareMonitorLib/Hardware/Cpu/CpuLoad.cs
@@ -5,6 +5,8 @@
 // All Rights Reserved.
 
 using System;
+using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices;
 
@@ -12,8 +14,9 @@ namespace LibreHardwareMonitor.Hardware.CPU;
 
 internal class CpuLoad
 {
-    private long[] _idleTimes;
     private readonly float[] _threadLoads;
+
+    private long[] _idleTimes;
     private float _totalLoad;
     private long[] _totalTimes;
 
@@ -21,6 +24,7 @@ internal class CpuLoad
     {
         _threadLoads = new float[cpuid.Sum(x => x.Length)];
         _totalLoad = 0;
+
         try
         {
             GetTimes(out _idleTimes, out _totalTimes);
@@ -38,6 +42,11 @@ internal class CpuLoad
     public bool IsAvailable { get; }
 
     private static bool GetTimes(out long[] idle, out long[] total)
+    {
+        return !Software.OperatingSystem.IsUnix ? GetWindowsTimes(out idle, out total) : GetUnixTimes(out idle, out total);
+    }
+
+    private static bool GetWindowsTimes(out long[] idle, out long[] total)
     {
         idle = null;
         total = null;
@@ -46,30 +55,80 @@ internal class CpuLoad
         Interop.NtDll.SYSTEM_PROCESSOR_IDLE_INFORMATION[] idleInformation = new Interop.NtDll.SYSTEM_PROCESSOR_IDLE_INFORMATION[64];
         int idleSize = Marshal.SizeOf(typeof(Interop.NtDll.SYSTEM_PROCESSOR_IDLE_INFORMATION));
         if (Interop.NtDll.NtQuerySystemInformation(Interop.NtDll.SYSTEM_INFORMATION_CLASS.SystemProcessorIdleInformation, idleInformation, idleInformation.Length * idleSize, out int idleReturn) != 0)
-        {
             return false;
-        }
 
         //Query processor performance information
         Interop.NtDll.SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION[] perfInformation = new Interop.NtDll.SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION[64];
         int perfSize = Marshal.SizeOf(typeof(Interop.NtDll.SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION));
-        if (Interop.NtDll.NtQuerySystemInformation(Interop.NtDll.SYSTEM_INFORMATION_CLASS.SystemProcessorPerformanceInformation, perfInformation, perfInformation.Length * perfSize, out int perfReturn) != 0)
+        if (Interop.NtDll.NtQuerySystemInformation(Interop.NtDll.SYSTEM_INFORMATION_CLASS.SystemProcessorPerformanceInformation,
+                                                   perfInformation,
+                                                   perfInformation.Length * perfSize,
+                                                   out int perfReturn) != 0)
         {
             return false;
         }
 
         idle = new long[idleReturn / idleSize];
         for (int i = 0; i < idle.Length; i++)
-        {
             idle[i] = idleInformation[i].IdleTime;
-        }
 
         total = new long[perfReturn / perfSize];
         for (int i = 0; i < total.Length; i++)
-        {
             total[i] = perfInformation[i].KernelTime + perfInformation[i].UserTime;
+
+        return true;
+    }
+
+    private static bool GetUnixTimes(out long[] idle, out long[] total)
+    {
+        idle = null;
+        total = null;
+
+        List<long> idleList = new();
+        List<long> totalList = new();
+
+        if (!File.Exists("/proc/stat"))
+            return false;
+
+        string[] cpuInfos = File.ReadAllLines("/proc/stat");
+
+        // currently parse the OverAll CPU info
+        // cpu   1583083 737    452845   36226266 723316   63685 31896     0       0       0
+        // cpu0  397468  189    109728   9040007  191429   16939 14954     0       0       0
+        // 0=cpu 1=user  2=nice 3=system 4=idle   5=iowait 6=irq 7=softirq 8=steal 9=guest 10=guest_nice
+        foreach (string cpuInfo in cpuInfos.Where(s => s.StartsWith("cpu") && s.Length > 3 && s[3] != ' '))
+        {
+            string[] overall = cpuInfo.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
+
+            try
+            {
+                // Parse idle information.
+                idleList.Add(long.Parse(overall[4]));
+            }
+            catch
+            {
+                // Ignored.
+            }
+
+            // Parse total information = user + nice + system + idle + iowait + irq + softirq + steal + guest + guest_nice.
+            long currentTotal = 0;
+            foreach (string item in overall.Skip(1))
+            {
+                try
+                {
+                    currentTotal += long.Parse(item);
+                }
+                catch
+                {
+                    // Ignored.
+                }
+            }
+
+            totalList.Add(currentTotal);
         }
 
+        idle = idleList.ToArray();
+        total = totalList.ToArray();
         return true;
     }
 
@@ -85,15 +144,13 @@ internal class CpuLoad
 
     public void Update()
     {
-        if (_idleTimes == null)
-            return;
-
-        if (!GetTimes(out long[] newIdleTimes, out long[] newTotalTimes))
+        if (_idleTimes == null || !GetTimes(out long[] newIdleTimes, out long[] newTotalTimes))
             return;
 
+        int minDiff = Software.OperatingSystem.IsUnix ? 100 : 100000;
         for (int i = 0; i < Math.Min(newTotalTimes.Length, _totalTimes.Length); i++)
         {
-            if (newTotalTimes[i] - _totalTimes[i] < 100000)
+            if (newTotalTimes[i] - _totalTimes[i] < minDiff)
                 return;
         }