6919b9879b
Use a single exported implementation, so that we can maintain the GoDoc string in one place, and use non-exported functions for the actual implementation (which were already in place). Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
36 lines
978 B
Go
36 lines
978 B
Go
package sysinfo // import "github.com/docker/docker/pkg/sysinfo"
|
|
|
|
import (
|
|
"unsafe"
|
|
|
|
"golang.org/x/sys/windows"
|
|
)
|
|
|
|
var (
|
|
kernel32 = windows.NewLazySystemDLL("kernel32.dll")
|
|
getCurrentProcess = kernel32.NewProc("GetCurrentProcess")
|
|
getProcessAffinityMask = kernel32.NewProc("GetProcessAffinityMask")
|
|
)
|
|
|
|
// Returns bit count of 1, used by NumCPU
|
|
func popcnt(x uint64) (n byte) {
|
|
x -= (x >> 1) & 0x5555555555555555
|
|
x = (x>>2)&0x3333333333333333 + x&0x3333333333333333
|
|
x += x >> 4
|
|
x &= 0x0f0f0f0f0f0f0f0f
|
|
x *= 0x0101010101010101
|
|
return byte(x >> 56)
|
|
}
|
|
|
|
func numCPU() int {
|
|
// Gets the affinity mask for a process
|
|
var mask, sysmask uintptr
|
|
currentProcess, _, _ := getCurrentProcess.Call()
|
|
ret, _, _ := getProcessAffinityMask.Call(currentProcess, uintptr(unsafe.Pointer(&mask)), uintptr(unsafe.Pointer(&sysmask)))
|
|
if ret == 0 {
|
|
return 0
|
|
}
|
|
// For every available thread a bit is set in the mask.
|
|
ncpu := int(popcnt(uint64(mask)))
|
|
return ncpu
|
|
}
|