This specifically deals with two threads closing the same device at the same
time, and a thread trying to reopen the device as it's still in process of
being closed. This can happen in normal usage if a device is disconnected:
the OS might send a disconnect event, while the device thread also attempts
to manage a disconnect as system calls start to report failure.
This effort is necessary because we have to release the device lock during
close to allow the device thread to unblock and cleanly shutdown. But the
good news is that all the places that call ClosePhysicalAudioDevice can now
safely hold the device lock on entry, and that one function will manage the
lock tapdancing.
Otherwise, a disconnect/default change on another thread may cause the
device pointer to become invalid by the time the management thread runs the
task.
This can be used to work around issues where the Apple GCController driver doesn't work for some controllers but there's no way to know which GCController maps to which IOKit device.
This mouse actually enumerates as a gamepad with 2 axes, 8 buttons and a hat.
We'll ignore it like the other ROG mice, unless someone specifically wants to use it as a gamepad.
The hash table can be recursively locked from the same thread, which can cause issues with RWLocks, as locking them recursively can result in undefined behavior or deadlocks. Use a mutex instead, as it can be safely recursively locked.
This patch adds an API for querying pressure-
sensitive pens, cf. SDL_pen.h:
- Enumerate all pens
- Get pen capabilities, names, GUIDs
- Distinguishes pens and erasers
- Distinguish attached and detached pens
- Pressure and tilt support
- Rotation, distance, throttle wheel support
(throttle wheel untested)
- Pen type and meta-information reporting
(partially tested)
Pen event reporting:
- Three new event structures: PenTip, PenMotion, and
PenButton
- Report location with sub-pixel precision
- Include axis and button status, is-eraser flag
Internal pen tracker, intended to be independent
of platform APIs, cf. SDL_pen_c.h:
- Track known pens
- Handle pen hotplugging
Automatic test:
- testautomation_pen.c
Other features:
- XInput2 implementation, incl. hotplugging
- Wayland implementation, incl. hotplugging
- Backward compatibility: pen events default to
emulating pens with mouse ID SDL_PEN_MOUSEID
- Can be toggled via SDL_HINT_PEN_NOT_MOUSE
- Test/demo program (testpen)
- Wacom pen feature identification by pen ID
Acknowledgements:
- Ping Cheng (Wacom) provided extensive feedback
on Wacom pen features and detection so that
hopefully untested Wacom devices have a
realistic chance of working out of the box.
This gives applications and binding systems a clearer view of what the hardware is so they can make intelligent decisions about how to present things to the user.
Gamepad mappings continue to use abxy for the face buttons for simplicity and compatibility with earlier versions of SDL, however the "SDL_GAMECONTROLLER_USE_BUTTON_LABELS" hint no longer has any effect.
Fixes https://github.com/libsdl-org/SDL/issues/6117
It just proxies all its necessary releases and frees to these without
blocking, and sets the appropriate fields to NULL so they can be used again
immediately, regardless of when the old stuff actually gets released.