![]() Spent a bit in a deep dive into how to handle this and honestly the
situation is rather unfortunate. The core problem is that when we have a
panic anywhere we need to tear down the app, and we'd like to do that as
cleanly as possible, avoiding throwing any other panics along the way if
possible.
We've been seeing a number of panics being reported which are
nonsensical, seemingly pointing to being a fallout panic from a worker
thread panic-ing, at which point we would write multiple panics to the
panic file, and we could possibly upload either both or the wrong panic
causing a wild goose chase. Unfortunately I've been entirely unable to
reproduce the specific panic we've been seeing but I was able to read
through the code responsible and confirm that under specific situations
a panic on one worker can cause another worker or the main thread to
also panic.
An easy solution to this is just to ignore any panics after the first
one. I'm thinking that *hopefully* we can trust the first panic to reach
the panic hook first so that the flag doesn't accidentally filter out
the panic we actually care about.
That being said we were expecting that to have already been the case
about which panic gets written to the panic file first, the first one in
the file being the one we upload, which doesn't seem to have been the
case. I'm hoping it was IO silliness causing that and that the flag
shouldn't be race-y, however this is still a shot in the dark. 🤞
As for cleanly shutting down, there's not really much we can do. One
thread physically cannot cause another to unwind without somehow sending
a message which isn't super useful. The only way for a thread to shut
down all threads and the process is to go nuclear and abort/exit the
process. This will never unwind other threads, effectively having the
same effect on those threads as compiling with `panic = "abort"` would.
With some (mis)use of `std::panic::resume_unwind` we can at least say
that for whatever thread actually panic-ed we will unwind, and any other
threads that panic as a result will probably get at least partway
through unwinding. This is weird, almost a combination of panic
rewinding and aborting, and may actually be worse than just biting the
bullet and aborting immediately.
I'm really not a fan of where I've ended up but it does seem to at the
very least an improvement. The main question in my mind at this point is
whether it would be better to attempt to unwind what we can or go all in
on abort. I'd love some input on that.
Release Notes:
- Improved panic reporting when a background thread panics.
|
||
---|---|---|
.cargo | ||
.config | ||
.github | ||
.vscode | ||
assets | ||
crates | ||
docs | ||
plugins | ||
script | ||
styles | ||
.dockerignore | ||
.gitignore | ||
.gitmodules | ||
Cargo.lock | ||
Cargo.toml | ||
Dockerfile | ||
Procfile | ||
README.md | ||
rust-toolchain.toml |
Zed
Welcome to Zed, a lightning-fast, collaborative code editor that makes your dreams come true.
Development tips
Dependencies
-
Install Postgres.app and start it.
-
Install the
LiveKit
server and theforeman
process supervisor:brew install livekit brew install foreman
-
Ensure the Zed.dev website is checked out in a sibling directory and install it's dependencies:
cd .. git clone https://github.com/zed-industries/zed.dev cd zed.dev && npm install npm install -g vercel
-
Return to Zed project directory and Initialize submodules
cd zed git submodule update --init --recursive
-
Set up a local
zed
database and seed it with some initial users:Create a personal GitHub token to run
script/bootstrap
once successfully: the token needs to have an access to private repositories for the script to work (repo
OAuth scope). Then delete that token.GITHUB_TOKEN=<$token> script/bootstrap
Testing against locally-running servers
Start the web and collab servers:
foreman start
If you want to run Zed pointed at the local servers, you can run:
script/zed-with-local-servers
# or...
script/zed-with-local-servers --release
Dump element JSON
If you trigger cmd-alt-i
, Zed will copy a JSON representation of the current window contents to the clipboard. You can paste this in a tool like DJSON to navigate the state of on-screen elements in a structured way.
Licensing
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, addpublish = 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 theaccepted
array inscript/licenses/zed-licenses.toml
. - Is
cargo-about
unable 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.
Wasm Plugins
Zed has a Wasm-based plugin runtime which it currently uses to embed plugins. To compile Zed, you'll need to have the wasm32-wasi
toolchain installed on your system. To install this toolchain, run:
rustup target add wasm32-wasi
Plugins can be found in the plugins
folder in the root. For more information about how plugins work, check the Plugin Guide in crates/plugin_runtime/README.md
.