Re: [Libusb-devel] Darwin: Loosing connection to IOService at fork()

[Pete B. <pe...@so...>]

On Wed, Dec 18, 2002 at 12:17:41PM +0100, Beat Birkhofer wrote:
> I try to get sane/libusb working on OSX.
> 
> I get quite far but then the there's a fork() in the sane backend 
> (plustek) I use and then I loose the connection to the IOService.
> 
> Any ideas how to solve this problem? I'm quite clueless.

I suspect this may be rather tricky to solve...

On most Unixes, the device_handle t libusb uses to communicate
with the device is a file handle, which will get inherited
by the child of a fork() call.

On OS X, the IOKit functions that are used to implement libusb
seem to use mach ports for communicating with the kernel rather
than file handles... I don't know the semantics of ports well,
but I'm guessing they don't get shared across a fork() call
(or at least not without a lot of extra work)

Pete.