The previous mac/hid.c implementation was kind of problematic. It worked
fine on 10.5, but on 10.7 I have gotten reports of really weird stuff
happening, such as the report callback being called with invalid context
data.
The problem was, the callback's don't get removed from the callback list
when you call IOHIDDeviceClose() in 10.7 like they used to. This means that
the report callback must be unregistered at hid_close() time. Further the
unregister will not work unless you pass _exactly_ the same parameters into
IOHIDDeviceRegisterInputReportCallback() that were passed in the first time
(with the exception of the function being NULL). Thanks Apple for your
stellar documentation and commitment to backwards compatibility.
Further, with the previous implementation, the OS only seemed to buffer
up 4 reports in between calls to CFRunLoopRun*(), causing the potential
for reports to get lost. The new method, being on a separate thread,
will now buffer up to a configurable 30 reports.
The interface number is added to the hid_device_info struct. Since the
Linux/libusb implementation can't put the Usage and Usage Page in the
hid_device_info struct because it requires detaching the kernel driver, the
interface number is added instead so that users with composite HID devices
can differentiate between the interfaces on the device.
Functions with no arguments should use void
hid.c:51: warning: function declaration isn’t a prototype
hid.c:210: warning: function declaration isn’t a prototype
Signed-off-by: Alan Ott <alan@signal11.us>
Alan Ott