4510b27a9b
This is partial fix because pipeware relies on udev-specific properties that aren't provided by libudev-zero. Fixes: #26
libudev-zero
Drop-in replacement for libudev that intended to work with any device manager
Why?
Because udev sucks, it is bloated and overengineered. udev is just
like systemd, it locks you into using non-portable crap that you can't
avoid because multiple programs depend on it. Look, even FreeBSD was forced
to rewrite[0] this crappy library because libinput hard-depends on udev.
Without libinput you can't use wayland and many other cool stuff.
Michael Forney (author of cproc, samurai, Oasis Linux, ...) decided to
fork[1] libinput and remove the hard dependency on udev. Is this a
solution? Yes. Is this a complete solution? No. This fork has a lot of
disadvantages like requiring patching applications to use libinput_netlink
instead of the libinput_udev API in order to use the automatic detection of
input devices and hotplugging. Static configuration is also required for
anything other than input devices (e.g drm devices). Moreover hotplugging is
vulnerable to race conditions when libinput handles the uevent faster than
the device manager which can lead to file permission issues. libudev-zero
prevents these race conditions by design.
Thankfully udev has stable API and hopefully no changes will be made to it
the future. On this basis I decided to create this clean-room implementation
of libudev which can be used with any or without a device manager.
[0] https://github.com/FreeBSDDesktop/libudev-devd
[1] https://github.com/oasislinux/libinput
What Works
- xorg-server
- dosfstools - need to implement udev_enumerate_add_match_parent()
- libinput
- usbutils
- wlroots
- weston
- libusb
- kwin
- ???
Dependencies
- C99 compiler (build time)
- POSIX make (build time)
- POSIX & XSI libc
- inotify & eventfd
- Linux >= 2.6.39
Installation
make
make PREFIX=/usr install
Hotplugging
Note that hotplugging support is fully optional. You can skip this step if you don't have a need for the hotplugging capability.
In order to use hotplugging, you need to configure device manager to send
uevent messages to UDEV_MONITOR_DIR. UDEV_MONITOR_DIR is arbitrary
shared directory used by libudev-zero to receive uevent messages. By
default, UDEV_MONITOR_DIR points to /tmp/.libudev-zero. You can change
that directory at compile time by passing -DUDEV_MONITOR_DIR=<dir> to
CFLAGS or at runtime by setting UDEV_MONITOR_DIR environment variable.
Keep in mind that already processed uevent messages wouldn't be automatically
purged. You can set UDEV_MONITOR_DIR to directory on tmpfs to purge them on
reboot/shutdown.
Refer to contrib for usage examples and configs.
Donate
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Thank you very much!