Zed Improved. Aiming to improve upon Zed and make a truly delightful code editor.
https://zed.dev
a2e98e9f0e
Fix a segfault in CVDisplayLink
We see 1-2 crashes a day on macOS on the `CVDisplayLink` thread.
```
Segmentation fault: 11 on thread 9325960 (CVDisplayLink)
CoreVideo CVHWTime::reset()
CoreVideo CVXTime::reset()
CoreVideo CVDisplayLink::runIOThread()
libsystem_pthread.dylib _pthread_start
libsystem_pthread.dylib thread_start
```
With the help of the Zed AI, I dove into the crash report, which looks
like this:
```
Crashed Thread: 49 CVDisplayLink
Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x00000000000001f6
Exception Codes: 0x0000000000000001, 0x00000000000001f6
Thread 49 Crashed:: CVDisplayLink
0 CoreVideo 0x18c1ed994 CVHWTime::reset() + 64
1 CoreVideo 0x18c1ee474 CVXTime::reset() + 52
2 CoreVideo 0x18c1ee198 CVDisplayLink::runIOThread() + 176
3 libsystem_pthread.dylib 0x18285ac0c _pthread_start + 136
4 libsystem_pthread.dylib 0x182855b80 thread_start + 8
Thread 49 crashed with ARM Thread State (64-bit):
x0: 0x0000000000000000 x1: 0x000000018c206e08 x2: 0x0000002c00001513 x3: 0x0001d4630002a433
x4: 0x00000e2100000000 x5: 0x0001d46300000000 x6: 0x000000000000002c x7: 0x0000000000000000
x8: 0x000000000000002e x9: 0x000000004d555458 x10: 0x0000000000000000 x11: 0x0000000000000000
x12: 0x0000000000000000 x13: 0x0000000000000000 x14: 0x0000000000000000 x15: 0x0000000000000000
x16: 0x0000000182856a9c x17: 0x00000001f19bc540 x18: 0x0000000000000000 x19: 0x0000600003c56ed8
x20: 0x000000000002a433 x21: 0x0000000000000000 x22: 0x0000000000000000 x23: 0x0000000000000000
x24: 0x0000000000000000 x25: 0x0000000000000000 x26: 0x0000000000000000 x27: 0x0000000000000000
x28: 0x0000000000000000 fp: 0x000000016b02ade0 lr: 0x000000018c1ed984
sp: 0x000000016b02adc0 pc: 0x000000018c1ed994 cpsr: 0x80001000
far: 0x00000000000001f6 esr: 0x92000006 (Data Abort) byte read Translation fault
Binary Images:
0x1828c9000 - 0x182e07fff com.apple.CoreFoundation (6.9) <df489a59-b4f6-32b8-9bb4-9b832960aa52> /System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation
```
Using lldb to disassemble `CVHWTime::reset()` (and the AI to interpret
it), the crash is caused by dereferencing the pointer at the start of
the CVHWTime struct + 0x1c8. In this case the pointer has (the clearly
nonsense) value 0x2e (and 0x2e + 0x1c8 = 0x1f6, the failing address).
As to how this could happen...
Looking at the implementation of `CVDisplayLinkRelease`, it calls
straight into `CFRelease` on the main thread; and so it is not safe to
call `CVDisplayLinkRelease` concurrently with other threads that access
the CVDisplayLink. While we already stopped the display link, it turns
out that `CVDisplayLinkStop` just sets a flag on the struct to instruct
the io-thread to exit "soon", and returns immediately. That means we
don't know when the other thread will actually exit, and so we can't
safely call `CVDisplayLinkRelease`.
So, for now, we just leak these objects. They should be created
relatively infrequently (when the app is foregrounded/backgrounded), so
I don't think this is a huge problem.
Release Notes:
- Fix a rare crash on macOS when putting the app in the background.
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| .cloudflare | ||
| .config | ||
| .github | ||
| .zed | ||
| assets | ||
| crates | ||
| docs | ||
| extensions | ||
| legal | ||
| nix | ||
| script | ||
| tooling | ||
| .clinerules | ||
| .cursorrules | ||
| .git-blame-ignore-revs | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .prettierrc | ||
| .rules | ||
| .windsurfrules | ||
| Cargo.lock | ||
| Cargo.toml | ||
| CLAUDE.md | ||
| clippy.toml | ||
| CODE_OF_CONDUCT.md | ||
| compose.yml | ||
| CONTRIBUTING.md | ||
| Cross.toml | ||
| debug.plist | ||
| default.nix | ||
| docker-compose.sql | ||
| Dockerfile-collab | ||
| Dockerfile-collab.dockerignore | ||
| Dockerfile-cross | ||
| Dockerfile-cross.dockerignore | ||
| Dockerfile-distros | ||
| Dockerfile-distros.dockerignore | ||
| flake.lock | ||
| flake.nix | ||
| LICENSE-AGPL | ||
| LICENSE-APACHE | ||
| LICENSE-GPL | ||
| livekit.yaml | ||
| Procfile | ||
| Procfile.postgrest | ||
| README.md | ||
| renovate.json | ||
| rust-toolchain.toml | ||
| shell.nix | ||
| typos.toml | ||
Zed
Welcome to Zed, a high-performance, multiplayer code editor from the creators of Atom and Tree-sitter.
Installation
On macOS and Linux you can download Zed directly or install Zed via your local package manager.
Other platforms are not yet available:
- Windows (tracking issue)
- Web (tracking issue)
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.