In x/sys package, there are a few uses of rutime.KeepAlive(x any) function.
One of these is in windows/setupapi_windows.go SetupDiGetDeviceProperty():
func SetupDiGetDeviceProperty(deviceInfoSet DevInfo, deviceInfoData *DevInfoData, propertyKey *DEVPROPKEY) (value interface{}, err error) {
reqSize := uint32(256)
for {
var dataType DEVPROPTYPE
buf := make([]byte, reqSize)
err = setupDiGetDeviceProperty(deviceInfoSet, deviceInfoData, propertyKey, &dataType, &buf[0], uint32(len(buf)), &reqSize, 0)
if err == ERROR_INSUFFICIENT_BUFFER {
continue
}
if err != nil {
return
}
switch dataType {
case DEVPROP_TYPE_STRING:
ret := UTF16ToString(bufToUTF16(buf))
runtime.KeepAlive(buf)
return ret, nil
}
return nil, errors.New("unimplemented property type")
}
}
What is runtime.KeepAlive(buf) trying to achieve here, and can it not cause a memory leak?