Re: [Usbpicprog-technical] [usbpicprog-technical] Initialization of libusb

[Francesco <f18...@ya...>]

Hi Frans,

2010/3/4 Frans Schreuder <fra...@gm...>:
> I saw that in your modifications, you called libusb_init() from main.cpp (as
> well ass libusb_exit).
> I think it is better to move this to the hardware constructor and
> destructor.
hmmm, why?

> I already tested this in linux, but I don't know if it works out
> well on all systems?
on Windows it didn't work well with the earlier versions of the libusb
windows port. I didn't test recently but in any case I think that the
initialization is a bit slow because the windows port needs to
internally enumerate the USB hubs AFAIR.

> What was the reason for you to call these functions from main?
in general the initialization of all libraries is done in the main()
of a program and never repeated (as it shouldn't really be
necessary!). The initialization routines usually allocate memory and
perform many operations which maybe time-consuming. I don't think we
should repeat them multiple times unless absolutely necessary.

In fact, I think that also the current organization of the Hardware
class, which gets allocated and deleted multiple times should also be
avoided: upp_wx currently is very slow to start up and IIRC this is
because Hardware is created and deleted 2-3 times at the startup.
I'd really like much more to have a
  Hardware m_hw;
member in UsbPicProg class definition and then have just a
  bool Connect(HardwareType hwToTryToConnect);
member in the Hardware class which would be used by UppMainWindow
(only when necessary).

I think this would be:
1) a better design from a OOP point of view.
2) more efficient design => reduce startup time of upp_wx.

If you agree I can do such modifications in the weekend...

Francesco