Thorsten Ballandmaan2003
43d1a8040d
This change ensures that the event loop prioritizes enqueueing another render or handling user input over executing runnables. It's a subtle change as a result of a week of digging into performance on X11. It's also not perfect: ideally we'd get rid of the intermediate channel here and had more control over when and how we run runnables vs. X11 events, but I think short of rewriting how we use an event loop, this is good cost/benefit change. To illustrate: Before this change, it was possible to block the app from rendering for a long time by just creating a ton of futures that were executed on the "main" thread (we don't have a "main" thread on Linux, but we have a single thread in which we run the event loop). That was relatively easy to reproduce by opening the `zed` repository and starting `rust-analyzer`: at some point `rust-analyzer` sends us so many notifications, that are all handled in futures, that the event loop is busy just working off the runnables, never getting to the events that X11 sends us or our own timer to re-enqueue another render. When you put print statements into the code to show when which event was handled, you'd see something like this **before this change**: ``` [ ... hundreds of runnable.run() ... ] runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() new render tick timer. lag: 56.942049ms X11 event new render tick timer. lag: 9.668µs X11 event new render tick timer. lag: 9.955µs X11 event runnable.run() runnable.run() runnable.run() runnable.run() new render tick timer. lag: 12.462µs X11 event new render tick timer. lag: 14.868µs X11 event new render tick timer. lag: 11.234µs X11 event new render tick timer. lag: 11.681µs X11 event new render tick timer. lag: 13.926µs X11 event ``` Note the `lag: 56ms`: that's the difference between when we wanted to execute the callback that enqueues another render and when it ran. Longer lags are possible, this is just the first one I grabbed from the logs. Now, compare this with the logs **after this change**: ``` runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() new render tick timer. lag: 36.051µs runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() X11 event runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() runnable.run() ``` In-between many `runnable.run()` we'll always handle events. So, in essence, what this change does is to introduce 2 priorities into the X11 event queue: - high: X11 events (user events, render events, ...), render tick, XIM events, ... - low: all async rust code I've tested this with a debug build and release build and I think the app now feels more responsive. It doesn't feel perfect still, especially in the slow debug builds, but I couldn't observe 10s lockups anymore. Since it's a pretty small change, I think we should go for it and see how it behaves. Thanks to @maan2003 this now also includes the same change to Wayland. Release Notes: - N/A --------- Co-authored-by: maan2003 <manmeetmann2003@gmail.com>
Zed
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:
- Linux (tracking issue)
- Windows (tracking issue)
- Web (tracking issue)
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
- Building Zed for macOS
- Building Zed for Linux
- Building Zed for Windows
- Running Collaboration Locally
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 specifiederror for a crate you've created? If so, addpublish = falseunder[package]in your crate's Cargo.toml. - Is the error
failed to satisfy license requirementsfor 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 theacceptedarray inscript/licenses/zed-licenses.toml. - Is
cargo-aboutunable to find the license for a dependency? If so, add a clarification field at the end ofscript/licenses/zed-licenses.toml, as specified in the cargo-about book.