1ebee00699
On a high level, `connlib` is a state machine that gets driven by a custom event-loop. For time-related actions, the state machine computes, when it would like to be woken next. The event-loop sets a timer for that value and emits this value when the timer fires. There is an edge-case where this may result in the time going backwards within the state machine. Specifically, if - for whatever reason - the state machine emits a time value that is in the past, the timer in the `Io` component will fire right away **but the `deadline` will point to the time in the past**. The only thing we are actually interested in is that the timer fires at all. Instead of passing back the deadline of the timer, we fetch the _current_ time and pass that back to the state machine as the current input. This ensures that we never jump back in time because Rust guarantees for calls to `Instant::now` to be monotonic. (https://doc.rust-lang.org/std/time/struct.Instant.html#:~:text=a%20measurement%20of%20a%20monotonically%20nondecreasing%20clock.)
Rust development guide
Firezone uses Rust for all data plane components. This directory contains the Linux and Windows clients, and low-level networking implementations related to STUN/TURN.
We target the last stable release of Rust using rust-toolchain.toml.
If you are using rustup, that is automatically handled for you.
Otherwise, ensure you have the latest stable version of Rust installed.
Reading Client logs
The Client logs are written as JSONL for machine-readability.
To make them more human-friendly, pipe them through jq like this:
cd path/to/logs # e.g. `$HOME/.cache/dev.firezone.client/data/logs` on Linux
cat *.log | jq -r '"\(.time) \(.severity) \(.message)"'
Resulting in, e.g.
2024-04-01T18:25:47.237661392Z INFO started log
2024-04-01T18:25:47.238193266Z INFO GIT_VERSION = 1.0.0-pre.11-35-gcc0d43531
2024-04-01T18:25:48.295243016Z INFO No token / actor_name on disk, starting in signed-out state
2024-04-01T18:25:48.295360641Z INFO null
Benchmarking on Linux
The recommended way for benchmarking any of the Rust components is Linux' perf utility.
For example, to attach to a running application, do:
- Ensure the binary you are profiling is compiled with the
releaseprofile. sudo perf record -g --freq 10000 --pid $(pgrep <your-binary>).- Run the speed test or whatever load-inducing task you want to measure.
sudo perf script > profile.perf- Open profiler.firefox.com and load
profile.perf
Instead of attaching to a process with --pid, you can also specify the path to executable directly.
That is useful if you want to capture perf data for a test or a micro-benchmark.