status-go/vendor/github.com/elastic/gosigar/sys/windows/ntquery.go

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// +build windows
package windows
import (
"bytes"
"encoding/binary"
"io"
"runtime"
"syscall"
"time"
"unsafe"
"github.com/pkg/errors"
)
// On both 32-bit and 64-bit systems NtQuerySystemInformation expects the
// size of SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION to be 48.
const sizeofSystemProcessorPerformanceInformation = 48
// ProcessBasicInformation is an equivalent representation of
// PROCESS_BASIC_INFORMATION in the Windows API.
// https://msdn.microsoft.com/en-us/library/windows/desktop/ms684280(v=vs.85).aspx
type ProcessBasicInformation struct {
ExitStatus uint
PebBaseAddress uintptr
AffinityMask uint
BasePriority uint
UniqueProcessID uint
InheritedFromUniqueProcessID uint
}
// NtQueryProcessBasicInformation queries basic information about the process
// associated with the given handle (provided by OpenProcess). It uses the
// NtQueryInformationProcess function to collect the data.
// https://msdn.microsoft.com/en-us/library/windows/desktop/ms684280(v=vs.85).aspx
func NtQueryProcessBasicInformation(handle syscall.Handle) (ProcessBasicInformation, error) {
var processBasicInfo ProcessBasicInformation
processBasicInfoPtr := (*byte)(unsafe.Pointer(&processBasicInfo))
size := uint32(unsafe.Sizeof(processBasicInfo))
ntStatus, _ := _NtQueryInformationProcess(handle, 0, processBasicInfoPtr, size, nil)
if ntStatus != 0 {
return ProcessBasicInformation{}, errors.Errorf("NtQueryInformationProcess failed, NTSTATUS=0x%X", ntStatus)
}
return processBasicInfo, nil
}
// SystemProcessorPerformanceInformation contains CPU performance information
// for a single CPU.
type SystemProcessorPerformanceInformation struct {
IdleTime time.Duration // Amount of time spent idle.
KernelTime time.Duration // Kernel time does NOT include time spent in idle.
UserTime time.Duration // Amount of time spent executing in user mode.
}
// _SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION is an equivalent representation of
// SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION in the Windows API. This struct is
// used internally with NtQuerySystemInformation call and is not exported. The
// exported equivalent is SystemProcessorPerformanceInformation.
// https://msdn.microsoft.com/en-us/library/windows/desktop/ms724509(v=vs.85).aspx
type _SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION struct {
IdleTime int64
KernelTime int64
UserTime int64
Reserved1 [2]int64
Reserved2 uint32
}
// NtQuerySystemProcessorPerformanceInformation queries CPU performance
// information for each CPU. It uses the NtQuerySystemInformation function to
// collect the SystemProcessorPerformanceInformation.
// https://msdn.microsoft.com/en-us/library/windows/desktop/ms724509(v=vs.85).aspx
func NtQuerySystemProcessorPerformanceInformation() ([]SystemProcessorPerformanceInformation, error) {
// NTSTATUS code for success.
// https://msdn.microsoft.com/en-us/library/cc704588.aspx
const STATUS_SUCCESS = 0
// From the _SYSTEM_INFORMATION_CLASS enum.
// http://processhacker.sourceforge.net/doc/ntexapi_8h.html#ad5d815b48e8f4da1ef2eb7a2f18a54e0
const systemProcessorPerformanceInformation = 8
// Create a buffer large enough to hold an entry for each processor.
b := make([]byte, runtime.NumCPU()*sizeofSystemProcessorPerformanceInformation)
// Query the performance information. Note that this function uses 0 to
// indicate success. Most other Windows functions use non-zero for success.
var returnLength uint32
ntStatus, _ := _NtQuerySystemInformation(systemProcessorPerformanceInformation, &b[0], uint32(len(b)), &returnLength)
if ntStatus != STATUS_SUCCESS {
return nil, errors.Errorf("NtQuerySystemInformation failed, NTSTATUS=0x%X, bufLength=%v, returnLength=%v", ntStatus, len(b), returnLength)
}
return readSystemProcessorPerformanceInformationBuffer(b)
}
// readSystemProcessorPerformanceInformationBuffer reads from a buffer
// containing SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION data. The buffer should
// contain one entry for each CPU.
// https://msdn.microsoft.com/en-us/library/windows/desktop/ms724509(v=vs.85).aspx
func readSystemProcessorPerformanceInformationBuffer(b []byte) ([]SystemProcessorPerformanceInformation, error) {
n := len(b) / sizeofSystemProcessorPerformanceInformation
r := bytes.NewReader(b)
rtn := make([]SystemProcessorPerformanceInformation, 0, n)
for i := 0; i < n; i++ {
_, err := r.Seek(int64(i*sizeofSystemProcessorPerformanceInformation), io.SeekStart)
if err != nil {
return nil, errors.Wrapf(err, "failed to seek to cpuN=%v in buffer", i)
}
times := make([]uint64, 3)
for j := range times {
err := binary.Read(r, binary.LittleEndian, &times[j])
if err != nil {
return nil, errors.Wrapf(err, "failed reading cpu times for cpuN=%v", i)
}
}
idleTime := time.Duration(times[0] * 100)
kernelTime := time.Duration(times[1] * 100)
userTime := time.Duration(times[2] * 100)
rtn = append(rtn, SystemProcessorPerformanceInformation{
IdleTime: idleTime,
KernelTime: kernelTime - idleTime, // Subtract out idle time from kernel time.
UserTime: userTime,
})
}
return rtn, nil
}