metric/system/numcpu/cpu_bsd.go

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//     http://www.apache.org/licenses/LICENSE-2.0
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//go:build openbsd || freebsd
// +build openbsd freebsd

package numcpu

/*
#include <sys/param.h>
#include <sys/types.h>
#include <sys/sysctl.h>
#include <stdlib.h>
#include <unistd.h>
*/
import "C"

import (
	"syscall"
	"unsafe"
)

// getCPU implements NumCPU on openbsd
// This is just using the HW_NCPU sysctl value.
func getCPU() (int, bool, error) {

	// Get count of available CPUs
	ncpuMIB := [2]int32{C.CTL_HW, C.HW_NCPU}
	callSize := uintptr(0)
	var ncpu int
	// Get size of return value.
	_, _, errno := syscall.Syscall6(syscall.SYS___SYSCTL, uintptr(unsafe.Pointer(&ncpuMIB[0])), 2, 0, uintptr(unsafe.Pointer(&callSize)), 0, 0)

	if errno != 0 || callSize == 0 {
		return -1, false, errno
	}

	// Get CPU count
	_, _, errno = syscall.Syscall6(syscall.SYS___SYSCTL, uintptr(unsafe.Pointer(&ncpuMIB[0])), 2, uintptr(unsafe.Pointer(&ncpu)), uintptr(unsafe.Pointer(&callSize)), 0, 0)

	return ncpu, true, nil
}