2012/11/12 Stefano Di Martino <stefan...@gmx.net>:
> Hi,
> I tested it under Linux, but there was no problem. But I tested it on an
> another Computer with Python 2.7 instead of 2.5.
> The other thing is, I can't reproduce this problem, with C.
>
> I made a simple stress test with python:
>
> This works:
>
> for i in range(100):
> usb.core.find(find_all=True)
>
> This don't work!
>
> for i in range(100):
> device_list = usb.core.find(find_all=True)
>
> Two lines of code (besides the import), nothing more...
> The error message:
>
> "usb.core.USBError: [Errno 19] No such device (it may have been disconnected)"
>
> Where it happens:
>
> class _DevIterator(object):
> def __init__(self):
> self.dev_list = POINTER(c_void_p)()
> self.num_devs = _check(_lib.libusb_get_device_list(
> None,
> byref(self.dev_list))
> ).value # Here!
>
>
> def _check(retval):
> if isinstance(retval, int):
> retval = c_int(retval)
> if isinstance(retval, c_int):
> if retval.value < 0:
> from usb.core import USBError
> ret = retval.value
> raise USBError(_str_error[ret], ret, _libusb_errno[ret]) # Here
> the Exception rises.
> return retval
>
>
> My simple C code:
>
> for(i = 0; i < 100; i++) {
> cnt = libusb_get_device_list(NULL, &devs);
> if (cnt < 0)
> return (int) cnt;
> if (i < 99)
> libusb_free_device_list(devs, 1);
> }
>
What happens if you don't call libusb_free_device_list?
--
Best Regards,
Wander Lairson Costa
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