Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Publicly expose last error received from X11 #2378

Closed
Tracked by #2322
kchibisov opened this issue Jul 18, 2022 · 3 comments · Fixed by #2385
Closed
Tracked by #2322

Publicly expose last error received from X11 #2378

kchibisov opened this issue Jul 18, 2022 · 3 comments · Fixed by #2385
Labels
Milestone

Comments

@kchibisov
Copy link
Member

Unfortunately in multi-threaded environment there's no way to handle errors safely other than setting error handling routine and store the error information in some thread safe structure like we do in winit with mutex.

However the problem with xlib here is that error handling callback is global for the entire process, so if glutin wants to make use of GLX, but doesn't want to depend on winit, it must get the error information out of winit somehow(glutin can call X related functions to perform all it wants, it just has no way to safely obtain errors from X11.

For more one could read https://www.remlab.net/op/xlib.shtml it has a pretty good explanation on that matter.

The thing with winit is that it already exposes the error via XConnection, however it's hidden from the end users and is being used internally by some crates that know about it.

So, I'd suggest to document that and expose last error from X11 in some more defined way. Either via proving it in some sort of Arc<Mutex<>> or via pointer to some function to call in hope to obtain the error information in a thread safe way.

Note, that XCB doesn't have mentioned issues in general, however GLX and some other APIs do require the use of Xlib unfortunately.

cc @maroider

@kchibisov kchibisov added DS - x11 P - high Vital to have labels Jul 18, 2022
@kchibisov kchibisov added this to the Version 0.27 milestone Jul 18, 2022
@maroider
Copy link
Member

My first instinct would be to reach for something like this:

fn register_my_err_handler() {
    static PREV_ERR_HANDLER: Mutex<Option<fn()>> = Mutex::new(None);
    extern "C" fn my_error_handler(display: *mut Display, error: *mut XErrorEvent) {
        if let Some(prev) = PREV_ERR_HANDLER.lock().unwrap() {
            unsafe { prev(display, error) }
        }
    }

    let prev = unsafe { XSetErrorHandler(Some(my_error_handler)) };
    PREV_ERR_HANDLER.lock().unwrap() = prev;
}

Is this sort of ad-hoc error handler chaining not advisable?

@kchibisov
Copy link
Member Author

Is this sort of ad-hoc error handler chaining not advisable?

I'm not sure that it should work or I don't quite understand what are you supposed to do like that. The problem is that even if you use locks, we must ensure that winit is blocked before doing any xlib calls, and applications would block on the same mutex winit is blocked when they try to touch xlib.

The issue is that changing error handler could lead to breakage in multithreaded environment (read the link it's kind of explained there, since it's not obvious that the error handling is a per process global). So the only solution I can come up with, is that winit will provide a way to access error from xlib, but not to set error handler and advice from not setting error handler. How it could be exposed is a question. Right now we have an XConnection field like last_error, but it's a bit cumbersome to find it. We can provide an optional hook when building event loop so the users can pass a function pointer(not lambda) when building it and that will be used to deliver errors to the end user or winit.

However for wider integration this function should return an Xerror.

One more thing I can think of is if we provide a way to add a hook for winit's Xlib error handling. So we'd have a global array of functions that the winit error handling will call once received error(In a loop, passing the information from the X11 directly). Those functions will return an indicator bool, whether the error was handled or not. The issue is that how it should be registered. And for that purpose we'd need a function that could be passed to other applications that they can call it with their error handling function to register inside winit.
I'd probably suggest to put it in a static method on the event loop, so I could pass this method to the glutin display builder. I can't think of a better way to do this.

Such function could look like

impl EventLoop {
  fn register_xlib_error_hook(hook: fn(*mut Display, *mut error) -> bool );
}

Then in x11's event loop we'd have something like.

static ERROR_HOOKS: Mutex<Vec<fn(*mut Display, *mut error>>;

extern "C" fn winit_error_handler(display *mut Display, error: *mut XErrorEvent) {
  let hooks = HOOKS.lock();
  let mut should_warn = false;
  for hook in hooks {
      should_warn |= hook(display, error);
  }
  if should_warn {
      error!("X11 error {}", getErrorDescription);
  }  
}

The last solution is kind of Ok-ish, not very friendly, but Xlib is just a pain to begin with when it comes to error handling.

@kchibisov kchibisov mentioned this issue Jul 19, 2022
4 tasks
@MarijnS95 MarijnS95 changed the title Publicaly expose last error received from X11 Publicly expose last error received from X11 Jul 19, 2022
@maroider
Copy link
Member

I suppose that would work. Can you PR that, then?

kchibisov added a commit to kchibisov/winit that referenced this issue Jul 20, 2022
This should help glutin to handle errors comming from GLX
and provide multithreading access in a safe way.

Fixes rust-windowing#2378.
kchibisov added a commit to kchibisov/winit that referenced this issue Jul 20, 2022
This should help glutin to handle errors comming from GLX
and provide multithreading access in a safe way.

Fixes rust-windowing#2378.
kchibisov added a commit to kchibisov/winit that referenced this issue Jul 20, 2022
This should help glutin to handle errors coming from GLX
and provide multithreading access in a safe way.

Fixes rust-windowing#2378.
kchibisov added a commit to kchibisov/winit that referenced this issue Jul 20, 2022
This should help glutin to handle errors coming from GLX
and provide multithreading access in a safe way.

Fixes rust-windowing#2378.
kchibisov added a commit to kchibisov/winit that referenced this issue Jul 20, 2022
This should help glutin to handle errors coming from GLX
and provide multithreading access in a safe way.

Fixes rust-windowing#2378.
kchibisov added a commit to kchibisov/winit that referenced this issue Jul 21, 2022
This should help glutin to handle errors coming from GLX
and provide multithreading access in a safe way.

Fixes rust-windowing#2378.
kchibisov added a commit to kchibisov/winit that referenced this issue Jul 21, 2022
This should help glutin to handle errors coming from GLX
and provide multithreading access in a safe way.

Fixes rust-windowing#2378.
kchibisov added a commit to kchibisov/winit that referenced this issue Jul 22, 2022
This should help glutin to handle errors coming from GLX
and provide multithreading access in a safe way.

Fixes rust-windowing#2378.
kchibisov added a commit that referenced this issue Jul 22, 2022
This should help glutin to handle errors coming from GLX
and offer multithreading support in a safe way.

Fixes #2378.
a-llie pushed a commit to a-llie/winit that referenced this issue Aug 24, 2022
Unify `with_app_id` and `with_class` methods

Both APIs are used to set application name. This commit unifies the API
between Wayland and X11, so downstream applications can remove platform
specific code when using `WindowBuilderExtUnix`.

Fixes rust-windowing#1739.

Unify behavior of `resizable` across platforms

This makes X11 and Wayland follow Windows and macOS, so the size of the
window could be set even though it has resizable attribute set to false.

Fixes rust-windowing#2242.

Fix assigning the wrong monitor when receiving Windows move events (rust-windowing#2266)

Fix embedded NULs in C wide strings returned from Windows API (rust-windowing#2264)

On Wayland, fix hiding cursors on GNOME

`wl_pointer::set_cursor` expects a serial number of the last
`wl_pointer::enter` event. However other calls expect latest
observed pointer serial, so this commit tracks both and
use them as required by specification.

Fixes rust-windowing#2273.

Bump windows-sys version to 0.36 (rust-windowing#2277)

Add new `Ime` event for desktop platforms

This commit brings new Ime event to account for preedit state of input
method, also adding `Window::set_ime_allowed` to toggle IME input on
the particular window.

This commit implements API as designed in rust-windowing#1497 for desktop platforms.

On Wayland, provide option for better CSD

While most compositors provide server side decorations, the GNOME
does not, and won't provide them. Also Wayland clients must render
client side decorations.

Winit was already drawing some decorations, however they were bad
looking and provided no text rendering, so the title was missing.
However this commit makes use of the SCTK external frame similar to
GTK's Adwaita theme supporting text rendering and looking similar to
other GTK applications.

Fixes rust-windowing#1967.

Fix warnings on nightly rust (rust-windowing#2295)

This was causing CI to fail: https://github.com/rust-windowing/winit/runs/6506026326

On macOS, emit resize event on `frame_did_change`

When the window switches mode from normal to tabbed one, it doesn't
get resized, however the frame gets resized. This commit makes
winit to track resizes when frame changes instead of window.

Fixes rust-windowing#2191.

Reorganize `EventLoopBuilder::build()` platform documentation

Since there's a "Platform-specific" header, it makes sense to put the
Linux-specific part under it. On the other hand, "Can only be called on
the main thread." is true for all platforms, not just iOS, so there is
no reason to call it out for iOS specifically.

[Windows] Avoid GetModuleHandle(NULL) (rust-windowing#2301)

Use get_instance_handle() over GetModuleHandle(NULL)

On Windows, fix reported cursor position. (rust-windowing#2311)

When clicking and moving the cursor out of the window negative coordinates were not handled correctly.

Revert "On Wayland, fix resize not propagating properly"

This reverts commit 78e5a39.

It was discovered that in some cases mesa will lock the back
buffer, e.g. when making context current, leading to resize
missing. Given that applications can restructure their rendering
to account for that, and that winit isn't limited to playing
nice with mesa reverting the original commit.

Set `WindowBuilder` to must_use

Add X11 opt-in function for device events

Previously on X11, by default all global events were broadcasted to
every winit application. This unnecessarily drains battery due to
excessive CPU usage when moving the mouse.

To resolve this, device events are now ignored by default and users must
manually opt into it using
`EventLoopWindowTarget::set_filter_device_events`.

Fixes (rust-windowing#1634) on Linux.

Prevent null dereference on X11 with bad locale

Remove old dialog fix that is superseded by rust-windowing#2027 (rust-windowing#2292)

This fixes the run_return loop never returning on macos when using multiple windows

Migrate from lazy_static to once_cell

macOS: Emit LoopDestroyed on CMD+Q (rust-windowing#2073)

override applicationWillTerminate:

On Android, use `HasRawWindowHandle` directly from the `ndk` crate (rust-windowing#2318)

The `ndk` crate now implements [`HasRawWindowHandle` directly on
`NativeWindow`], relieving the burden to reimplement it on `winit`.

[`HasRawWindowHandle` directly on `NativeWindow`]: rust-mobile/ndk#274

Run clippy on CI

Fixes rust-windowing#1402.

Make `set_device_event_filter` non-mut

Commit f10a984 added `EventLoopWindowTarget::set_device_event_filter`
with for a mutable reference, however most winit APIs work with
immutable references, so altering API to play nicely with existing APIs.

This also disables device event filtering on debug example.

Make `WindowAttributes` private (rust-windowing#2134)

* Make `WindowAttributes` private, and move its documentation

* Reorder WindowAttributes title and fullscreen to match method order

Build docs on `docs.rs` for iOS and Android as well (rust-windowing#2324)

Remove core-video-sys dependency (rust-windowing#2326)

Hasn't been updated in over 2 years - many open PRs, seems abandoned. Is the cause of several duplicate dependencies in our dependency tree!

Fix macOS 32bit (rust-windowing#2327)

Documentation cleanup (rust-windowing#2328)

* Remove redundant documentation links

* Add note to README about windows not showing up on Wayland

* Fix documentation links

* Small documentation fixes

* Add note about doing stuff after StartCause::Init on macOS

Add `WindowBuilder::transparent`

This is required to help hardware accelerated libraries like glutin
that accept WindowBuilder instead of RawWindowHandle, since the api
to access builder properties directly was removed.

Follow up to 44288f6.

Refine `Window::set_cursor_grab` API

This commit renames `Window::set_cursor_grab` to
`Window::set_cursor_grab_mode`. The new API now accepts enumeration
to control the way cursor grab is performed. The value could be: `lock`,
`confine`, or `none`.

This commit also implements `Window::set_cursor_position` for Wayland,
since it's tied to locked cursor.

Implements API from rust-windowing#1677.

examples/window_run_return: Enable on Android (rust-windowing#2321)

Android also supports `EventLoopExtRunReturn`.  The user will still have
to follow the README to turn this example into a `cdylib` and add the
`ndk_glue::main()` initialization attribute, though.

Fix doubled device events on X11

Fixes rust-windowing#2332

macOS: disallow_highdpi will set explicity the value to avoid the SO value by default (rust-windowing#2339)

ci: Disallow warnings in rustdoc and test private items (rust-windowing#2341)

Make sure `cargo doc` runs cleanly without any warnings in the CI - some
recently introduced but still allowing a PR to get merged.

In case someone wishes to add docs on private items, make sure those
adhere to the same standards.

Bump smithay-client-toolkit to v0.16.0

Disallow multiple EventLoop creation

Fix conflict in `WindowFlags` on Windows

Map XK_Caps_Lock to VirtualKeyCode::Capital (rust-windowing#1864)

This allows applications to handle events for the caps lock key under X11

Less redundancy and improve fullscreen in examples

Remove examples/minimize which is redundant

Implement From<u64> for WindowId and vise-versa

This should help downstream applications to expose WindowId to the end
users via e.g. IPC to control particular windows in multi window
systems.

examples/multiwindow.rs: ignore synthetic key press events

Fix infinite recursion in `WindowId` conversion methods

Add 'WindowEvent::Occluded(bool)'

This commits and an event to track window occlusion state,
which could help optimize rendering downstream.

Add `refresh_rate_millihertz` for `MonitorHandle`

This also alters `VideoMode::refresh_rate` to
`VideoMode::refresh_rate_millihertz` which now returns monitor refresh rate in
mHz.

On Wayland send Focused(false) for new window

On Wayland winit will always get an explicit focused event from the
system and will transfer it downstream. So send focused false to enforce
it.

On Wayland, drop wl_surface on window close

web: Manually emit focused event on mouse click (rust-windowing#2202)

* Manually emit focused event on mouse click

* Update CHANGELOG.md

Co-authored-by: Markus Røyset <maroider@protonmail.com>

web: Add `EventLoop::spawn` (rust-windowing#2208)

* web: Add `EventLoop::spawn`

This is the same as `EventLoop::run`, but doesn't throw an exception in order to return `!`.

I decided to name it `spawn` rather than `run_web` because I think that's more descriptive, but I'm happy to change it to `run_web`.

Resolves rust-windowing#1714

* Update src/platform/web.rs

* Fix outdated names

Co-authored-by: Markus Røyset <maroider@protonmail.com>

Fix changelog entry for `EventLoopExtWebSys` (rust-windowing#2372)

android: Hold `NativeWindow` lock until after notifying the user with `Event::Suspended` (rust-windowing#2307)

This applies rust-mobile/ndk#117
on the `winit` side: Android destroys its window/surface as soon as the
user returns from [`onNativeWindowDestroyed`], and we "fixed" this on
the `ndk-glue` side by sending the `WindowDestroyed` event before
locking the window and removing it: this lock has to wait for any user
of `ndk-glue` - ie. `winit` - to give up its readlock on the window,
which is what we utilize here to give users of `winit` "time" to destroy
any resource created on top of a `RawWindowHandle`.

since we can't pass the user a `RawWindowHandle` through the
`HasRawWindowHandle` trait we have to document this case explicitly and
keep the lock alive on the `winit` side instead.

[`onNativeWindowDestroyed`]: https://developer.android.com/ndk/reference/struct/a-native-activity-callbacks#onnativewindowdestroyed

web: add `with_prevent_default`, `with_focusable` (rust-windowing#2365)

* web: add `with_prevent_default`, `with_focusable`

`with_prevent_default` controls whether `event.preventDefault` is called

`with_focusable` controls whether `tabindex` is added

Fixes rust-windowing#1768

* Remove extra space from CHANGELOG

windows: Use correct value for mouse wheel delta (rust-windowing#2374)

Make winit focus take activity into account on Windows (rust-windowing#2159)

winit's notion of "focus" is very simple; you're either focused or not.
However, Windows has both notions of focused window and active window
and paying attention only to WM_SETFOCUS/WM_KILLFOCUS can cause a window
to believe the user is interacting with it when they're not. (this
manifests when a user switches to another application between when a
winit application starts and it creates its first window)

Fix typos (rust-windowing#2375)

Bump sctk-adwaita to 0.4.1

This should force the use of system libraries for Fontconfig
and freetype instead of building them with cmake if missing.

This also fixes compilation failures on nightly.

Fixes rust-windowing#2373.

Tidy up "platform-specifc" doc sections (rust-windowing#2356)

* Tidy up "platform-specific" doc sections

* Unrelated grammatical fix

* Subjective improvements

Android: avoid deadlocks while handling UserEvent (rust-windowing#2343)

Replace `Arc<Mutex<VecDeque<T>>` by `mpsc`

Update raw-window-handle to v0.5.0

This updates raw-window-handle to v0.5.0.

On macOS, fix confirmed character inserted

When confirming input in e.g. Korean IME or using characters like
`+` winit was sending those twice, once via `Ime::Commit` and the
other one via `ReceivedCharacter`, since those events weren't generating
any `Ime::Preedit` and were forwarded due to `do_command_by_selector`.

Add method to hook xlib error handler

This should help glutin to handle errors coming from GLX
and offer multithreading support in a safe way.

Fixes rust-windowing#2378.

Windows: apply skip taskbar state when taskbar is restarted (rust-windowing#2380)

Fix hiding a maximized window On Windows (rust-windowing#2336)

Bump `ndk` and `ndk-glue` dependencies to stable `0.7.0` release (rust-windowing#2392)

Fix type hint reference for xlib hook

Consistently deliver a Resumed event on all platforms

To be more consistent with mobile platforms this updates the Windows,
macOS, Wayland, X11 and Web backends to all emit a Resumed event
immediately after the initial `NewEvents(StartCause::Init)` event.

The documentation for Suspended and Resumed has also been updated
to provide general recommendations for how to handle Suspended and
Resumed events in portable applications as well as providing
Android and iOS specific details.

This consistency makes it possible to write applications that lazily
initialize their graphics state when the application resumes without
any platform-specific knowledge. Previously, applications that wanted
to run on Android and other systems would have to maintain two,
mutually-exclusive, initialization paths.

Note: This patch does nothing to guarantee that Suspended events will
be delivered. It's still reasonable to say that most OSs without a
formal lifecycle for applications will simply never "suspend" your
application. There are currently no known portability issues caused
by not delivering `Suspended` events consistently and technically
it's not possible to guarantee the delivery of `Suspended` events if
the OS doesn't define an application lifecycle. (app can always be
terminated without any kind of clean up notification on most
non-mobile OSs)

Fixes rust-windowing#2185.

ci: manually point ANDROID_NDK_ROOT to latest supplied version

It seems the symlink to `ndk-bundle` and this environment variable
pointing to it have been removed to prevent the sdkmanager from failing,
when finding the SDK setup to be in an "indeterminate" state.  It is now
up to the users themselves to install an NDK through that tool or point
the right variables to a preinstalled "latest" NDK.

actions/runner-images#2689
actions/runner-images#5926

Fix changelog entry wrt scrolling

The breaking change was put into the wrong release section.

Release 0.27.0 version

Explicitly specify minimum supported rust version

This should help with distributing apps using winit.

Fixes rust-windowing#1075.

On X11, fix crash when can't disable IME

Fixes rust-windowing#2402.

Release 0.27.1 version

Windows: respect min/max sizes when creating the window (rust-windowing#2393)

On X11, fix window hints not persisting

This commit fixes the issue with min, max, and resize increments
not persisting across the dpi changes.

Fix tracking of phase changes for mousewheel on trackpad (rust-windowing#2158)

On Windows, add opt-in function for device events (rust-windowing#2409)

Add CODEOWNERS file (rust-windowing#2420)

* Add CODEOWNERS file

This makes it very clear when you're stepping down from the post as a maintainer, and makes it clear for users who is expected to review their PR

* Fix grammar

* Make @kchibisov receive pings for the X11 platform

* Fix typo

Implement version 0.4 of the HasRawWindowHandle trait

This makes Winit 0.27 compatible with crates like Wgpu 0.13 that are
using the raw_window_handle v0.4 crate and aren't able to upgrade to 0.5
until they do a new release (since it requires a semver change).

The change is intended to be self-contained (instead of pushing
the details into all the platform_impl backends) since this is only
intended to be a temporary trait implementation for backwards
compatibility that will likely be removed before the next Winit release.

Fixes rust-windowing#2415.

Fix missleading breaking change on Windows

The applications should not rely on not-implemented behavior and
should use the right functions for that.

Remove redundant steps from CI

Tests are already building the entire crate, so no need for a
separate builds slowing down the CI.

On Wayland, fix `Window::request_redraw` being delayed

On Waylnad when asking for redraw before `MainEventsCleared`
would result for redraw being send on the next event loop tick,
which is not expectable given that it must be delivered on the same
event loop tick.

Release 0.27.2 version

On Windows, improve support for undecorated windows (rust-windowing#2419)

Add touchpad magnify and rotate gestures support for macOS (rust-windowing#2157)

* Add touchpad magnify support for macOS

* Add touchpad rotate support for macOS

* Add macOS rotate and magnify gesture cancelled phases

* Correct docs for TouchpadRotate event

* Fix tracing macros

Document `WindowEvent::Moved` as unsupported on Wayland

Update `sctk-adwaita` to use `ab_glyph`

The crossfont will still be available under the option.

Mark new events as breaking change

Adding a new enum variant is a breaking change in winit.

Co-Authored-By: kas <exactly-one-kas@users.noreply.github.com>
Co-Authored-By: Artur Kovacs <kovacs.artur.barnabas@gmail.com>
Co-Authored-By: Markus Siglreithmaier <m.siglreith@gmail.com>
Co-Authored-By: Murarth <murarth@gmail.com>
Co-Authored-By: Yusuke Kominami <yukke.konan@gmail.com>
Co-Authored-By: moko256 <koutaro.mo@gmail.com>
Co-Authored-By: Mads Marquart <mads@marquart.dk>
Co-Authored-By: Markus Røyset <maroider@protonmail.com>
Co-Authored-By: Marijn Suijten <marijns95@gmail.com>
Co-Authored-By: Kirill Chibisov <contact@kchibisov.com>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
Development

Successfully merging a pull request may close this issue.

2 participants