Exemplo n.º 1
0
func finalizeMsg(datap *[]byte) error {
	hdrp := (*reflect.SliceHeader)(unsafe.Pointer(datap))
	if rc, err := C.nn_freemsg(unsafe.Pointer(hdrp.Data)); rc != 0 {
		return nnError(err)
	}
	return nil
}
Exemplo n.º 2
0
// Recv receives a message from the socket. The flags argument can be zero or
// DontWait.
func (s *Socket) Recv(flags int) ([]byte, error) {
	var err error
	var buf unsafe.Pointer
	var length C.int

	if length, err = C.nn_recv(s.socket, unsafe.Pointer(&buf), nn_msg, C.int(flags)); length < 0 {
		return nil, nnError(err)
	}

	// TODO why is the latter variant faster than the zero copy variant?
	zeroCopy := true
	if zeroCopy {
		capacity := int(length)
		header := &reflect.SliceHeader{
			Data: uintptr(buf),
			Len:  capacity,
			Cap:  capacity,
		}
		data := *((*[]byte)(unsafe.Pointer(header)))
		runtime.SetFinalizer(&data, finalizeMsg)
		return data, nil
	} else {
		data := C.GoBytes(buf, length)
		if rc, err := C.nn_freemsg(buf); rc != 0 {
			return data, nnError(err)
		}
		return data, nil
	}
}