This commit shrinks the size of the internal hotplug callback structure
by removing unused fields, using the correctly sized types for matching
fields, and adding a new flags field whose bits control how the callback
structure should behave.
The hotplug callback handle ID counter has also been moved to the
context structure instead of being a global variable shared amongst all
contexts. This lets each context independently manage handle IDs and use
the maximum range of possible IDs.
Finally, the hotplug callback deregistration mechanism has been improved
to signal to the event handler that an explicit deregistration needs to
be handled. This removes the need to send a dummy hotplug message, which
was using an invalid libusb_hotplug_event value anyway that was causing
some compilers to complain.
Closes#373
Signed-off-by: Chris Dickens <christopher.a.dickens@gmail.com>
To further consolidate libusb internal events, this change removes
the hotplug pipe. Hotplug messages are now kept in a list within the
context, and the event pipe is signalled when a new hotplug message
is added. When handling events, the hotplug messages will be processed
from the list instead of from a separate pipe.
This change is greatly beneficial for the Windows/WinCE backends which
do not allow pipes to be used in the WaitFor* functions.
Signed-off-by: Chris Dickens <christopher.a.dickens@gmail.com>
So that the device parameter can be NULL, in combination with a 0
events parameter, to be used to force lazy deregistration.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
The internal API is changing as follows:
- Adding two new functions. usbi_connect_device, and usbi_disconnect_device.
Backends must call these functions to add them to the context's device list
at one of two places: initial enumeration (done at init), and on device
attach and removal. These functions need to be called once per context.
- Backends that support hotplug should not provide a get_device_list funtion.
This function is now deprecated and will likely be removed once all backends
support hotplug.
The external API is changing as follows:
- Two new functions have been added to register and deregister callbacks for
hotplug notification: libusb_hotplug_register_callback(),
libusb_hotplug_deregister_callback(). Hotplug callbacks are called by
libusb_handle_events(). Details of the new API can be found in libusb.h.
- A new capability check has been added to check for hotplug support. See
LIBUSB_CAP_HAS_HOTPLUG.
Aa suggested by Xiaofan add new example has been added to show how to use
the new external hotplug API. See examples/hotplugtest.c.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
