source-engine/tier0/cpu_usage.cpp
2021-04-28 18:24:16 +03:00

137 lines
3.4 KiB
C++

//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose: return the cpu usage as a float value
//
// On win32 this is 0.0 to 1.0 indicating the amount of CPU time used
// On posix its the load avg from the last minute
//
// On win32 you need to call this once in a while. Every few seconds.
// First call returns zero
//=============================================================================//
#include "pch_tier0.h"
#include "tier0/platform.h"
#ifdef WIN32
#include <windows.h>
#define SystemBasicInformation 0
#define SystemPerformanceInformation 2
#define SystemTimeInformation 3
#define Li2Double(x) ((double)((x).HighPart) * 4.294967296E9 + (double)((x).LowPart))
typedef struct
{
DWORD dwUnknown1;
ULONG uKeMaximumIncrement;
ULONG uPageSize;
ULONG uMmNumberOfPhysicalPages;
ULONG uMmLowestPhysicalPage;
ULONG uMmHighestPhysicalPage;
ULONG uAllocationGranularity;
PVOID pLowestUserAddress;
PVOID pMmHighestUserAddress;
ULONG uKeActiveProcessors;
BYTE bKeNumberProcessors;
BYTE bUnknown2;
WORD wUnknown3;
} SYSTEM_BASIC_INFORMATION;
typedef struct
{
LARGE_INTEGER liIdleTime;
DWORD dwSpare[80];
} SYSTEM_PERFORMANCE_INFORMATION;
typedef struct
{
LARGE_INTEGER liKeBootTime;
LARGE_INTEGER liKeSystemTime;
LARGE_INTEGER liExpTimeZoneBias;
ULONG uCurrentTimeZoneId;
DWORD dwReserved;
} SYSTEM_TIME_INFORMATION;
typedef LONG (WINAPI *PROCNTQSI)(UINT,PVOID,ULONG,PULONG);
static PROCNTQSI NtQuerySystemInformation;
float GetCPUUsage()
{
SYSTEM_PERFORMANCE_INFORMATION SysPerfInfo;
SYSTEM_TIME_INFORMATION SysTimeInfo;
SYSTEM_BASIC_INFORMATION SysBaseInfo;
double dbIdleTime;
double dbSystemTime;
LONG status;
static LARGE_INTEGER liOldIdleTime = {0,0};
static LARGE_INTEGER liOldSystemTime = {0,0};
if ( !NtQuerySystemInformation)
{
NtQuerySystemInformation = (PROCNTQSI)GetProcAddress( GetModuleHandle("ntdll"), "NtQuerySystemInformation" );
if ( !NtQuerySystemInformation )
return(0);
}
// get number of processors in the system
status = NtQuerySystemInformation( SystemBasicInformation,&SysBaseInfo,sizeof(SysBaseInfo),NULL );
if ( status != NO_ERROR )
return(0);
// get new system time
status = NtQuerySystemInformation( SystemTimeInformation,&SysTimeInfo,sizeof(SysTimeInfo),0 );
if ( status!=NO_ERROR )
return(0);
// get new CPU's idle time
status = NtQuerySystemInformation( SystemPerformanceInformation,&SysPerfInfo,sizeof(SysPerfInfo),NULL );
if ( status != NO_ERROR )
return(0);
// if it's a first call - skip it
if ( liOldIdleTime.QuadPart != 0 )
{
// CurrentValue = NewValue - OldValue
dbIdleTime = Li2Double(SysPerfInfo.liIdleTime) - Li2Double(liOldIdleTime);
dbSystemTime = Li2Double(SysTimeInfo.liKeSystemTime) - Li2Double(liOldSystemTime);
// CurrentCpuIdle = IdleTime / SystemTime
dbIdleTime = dbIdleTime / dbSystemTime / (double)SysBaseInfo.bKeNumberProcessors;
// CurrentCpuUsage% = 100 - (CurrentCpuIdle * 100) / NumberOfProcessors
// dbIdleTime = 100.0 - dbIdleTime * 100.0 / (double)SysBaseInfo.bKeNumberProcessors + 0.5;
}
else
{
dbIdleTime = 1.0f;
}
// store new CPU's idle and system time
liOldIdleTime = SysPerfInfo.liIdleTime;
liOldSystemTime = SysTimeInfo.liKeSystemTime;
return (float)(1.0f - dbIdleTime);
}
#endif // WIN32
#ifdef POSIX
#include <stdlib.h>
float GetCPUUsage()
{
#ifdef ANDROID
return 0;
#else
double loadavg[3];
getloadavg( loadavg, 3 );
return loadavg[0];
#endif
}
#endif //POSIX