8bd8098cab
Within `connlib` - on UNIX platforms - we have dedicated threads that read from and write to the TUN device. These threads are connected with `connlib`'s main thread via bounded channels: one in each direction. When these channels are full, `connlib`'s main thread will suspend and not read any network packets from the sockets in order to maintain back-pressure. Reading more packets from the socket would mean most likely sending more packets out the TUN device. When debugging #7763, it became apparent that _something_ must be wrong with these threads and that somehow, we either consider them as full or aren't emptying them and as a result, we don't read _any_ network packets from our sockets. To maintain back-pressure here, we currently use our own `AtomicWaker` construct that is shared with the TUN thread(s). This is unnecessary. We can also directly convert the `flume::Sender` into a `flume::async::SendSink` and therefore directly access a `poll` interface.
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.