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linux/x11: Custom run loop with mio instead of calloop (#13646)
This changes the implementation of the X11 client to use `mio`, as a
polling mechanism, and a custom run loop instead of `calloop` and its
callback-based approach.

We're doing this for one big reason: more control over how we handle
events.

With `calloop` we don't have any control over which events are processed
when and how long they're processes for. For example: we could be
blasted with 150 input events from X11 and miss a frame while processing
them, but instead of then drawing a new frame, calloop could decide to
work off the runnables that were generated from application-level code,
which would then again cause us to be behind.

We kinda worked around some of that in
https://github.com/zed-industries/zed/pull/12839 but the problem still
persists.

So what we're doing here is to use `mio` as a polling-mechanism. `mio`
notifies us if there are X11 on the XCB connection socket to be
processed. We also use its timeout mechanism to make sure that we don't
wait for events when we should render frames.

On top of `mio` we now have a custom run loop that allows us to decide
how much time to spend on what — input events, rendering windows, XDG
events, runnables — and in what order we work things off.

This custom run loop is consciously "dumb": we render all windows at the
highest frame rate right now, because we want to keep things predictable
for now while we test this approach more. We can then always switch to
more granular timings. But considering that our loop runs and checks for
windows to be redrawn whenever there's an event, this is more an
optimization than a requirement.

One reason for why we're doing this for X11 but not for Wayland is due
to how peculiar X11's event handling is: it's asynchronous and by
default X11 generates synthetic events when a key is held down. That can
lead to us being flooded with input events if someone keeps a key
pressed.

So another optimization that's in here is inspired by [GLFW's X11 input
handling](b35641f4a3/src/x11_window.c (L1321-L1349)):
based on a heuristic we detect whether a `KeyRelease` event was
auto-generated and if so, we drop it. That essentially halves the amount
of events we have to process when someone keeps a key pressed.

Release Notes:

- N/A

---------

Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>
Co-authored-by: Conrad <conrad@zed.dev>
2024-07-03 17:05:26 +02:00
.cargo Fix collab deploy (#13076) 2024-06-14 16:15:13 -06:00
.cloudflare Remove 2 removal (#11867) 2024-05-15 11:06:05 -06:00
.config tests: Test 'db' package sequentially (#2654) 2023-06-28 15:00:43 +02:00
.github Release notes upload fix (#13560) 2024-06-26 17:24:59 -04:00
.zed tasks: Add experimental support for user-defined task variables (#13699) 2024-07-01 15:59:19 +02:00
assets vim: Support for q and @ (#13761) 2024-07-03 09:03:39 -06:00
crates linux/x11: Custom run loop with mio instead of calloop (#13646) 2024-07-03 17:05:26 +02:00
docs vim: Support for q and @ (#13761) 2024-07-03 09:03:39 -06:00
extensions Allow extensions to define providers for indexing docs (#13755) 2024-07-02 19:49:20 -04:00
script Add jq as a dependency for Linux script for Arch Linux (#13569) 2024-06-27 09:58:53 -06:00
tooling/xtask xtask: Check for licenses that are duplicated instead of being symlinked (#11777) 2024-05-13 19:13:09 -04:00
.dockerignore Add serialized versions of themes (#6885) 2024-01-27 13:35:43 -05:00
.gitattributes Prevent GitHub from displaying comments within JSON files as errors (#7043) 2024-01-29 23:11:25 -05:00
.gitignore Add Flatpak build system and support (#12006) 2024-05-27 19:01:20 -06:00
.mailmap Update .mailmap (#13724) 2024-07-01 19:04:58 -04:00
Cargo.lock linux/x11: Custom run loop with mio instead of calloop (#13646) 2024-07-03 17:05:26 +02:00
Cargo.toml Organize dependencies in workspace Cargo.toml (#13746) 2024-07-02 13:30:55 -04:00
CODE_OF_CONDUCT.md Add CODE_OF_CONDUCT.md (#4239) 2024-01-23 22:31:39 -05:00
compose.yml Update Docker Compose configuration (#13530) 2024-06-26 08:05:23 -04:00
CONTRIBUTING.md docs: Fix some typos (#13509) 2024-06-25 10:58:11 -04:00
debug.plist WIP 2023-12-14 09:25:14 -07:00
docker-compose.sql Add config files for running Postgres inside Docker Compose (#3637) 2023-12-13 17:25:07 -05:00
Dockerfile chore: Bump Rust version to 1.79 (#12987) 2024-06-13 23:05:25 +02:00
LICENSE-AGPL chore: Add crate licenses. (#4158) 2024-01-23 16:56:22 +01:00
LICENSE-APACHE chore: Add crate licenses. (#4158) 2024-01-23 16:56:22 +01:00
LICENSE-GPL Licenses: change license fields in Cargo.toml to AGPL-3.0-or-later. (#5535) 2024-01-27 13:51:16 +01:00
livekit.yaml Add LiveKit server to Docker Compose (#7907) 2024-02-16 10:49:48 -05:00
Procfile Revert change to tracing (#10578) 2024-04-15 14:00:56 -06:00
README.md Fix typo in README (#13610) 2024-06-27 23:58:23 +02:00
rust-toolchain.toml chore: Bump Rust version to 1.79 (#12987) 2024-06-13 23:05:25 +02:00
typos.toml Restore vim docs (#11491) 2024-05-07 09:24:00 -06:00

Zed

CI

Welcome to Zed, a high-performance, multiplayer code editor from the creators of Atom and Tree-sitter.

Installation

You can download Zed today for macOS (v10.15+).

Support for additional platforms is on our roadmap:

For macOS users, you can also install Zed using Homebrew:

brew install --cask zed

Alternatively, to install the Preview release:

brew install --cask zed@preview

Developing Zed

Contributing

See CONTRIBUTING.md for ways you can contribute to Zed.

Also... we're hiring! Check out our jobs page for open roles.

Licensing

License information for third party dependencies must be correctly provided for CI to pass.

We use cargo-about to automatically comply with open source licenses. If CI is failing, check the following:

  • Is it showing a no license specified error for a crate you've created? If so, add publish = false under [package] in your crate's Cargo.toml.
  • Is the error failed to satisfy license requirements for a dependency? If so, first determine what license the project has and whether this system is sufficient to comply with this license's requirements. If you're unsure, ask a lawyer. Once you've verified that this system is acceptable add the license's SPDX identifier to the accepted array in script/licenses/zed-licenses.toml.
  • Is cargo-about unable to find the license for a dependency? If so, add a clarification field at the end of script/licenses/zed-licenses.toml, as specified in the cargo-about book.