rust_hawktracer

Rust bindings for the Hawktracer profiler.
This crate offers simple, minimal bindings to help you profile your rust programs.
If profiling is not enabled by specifying features=["profiling_enabled"], having tracepoints in your code has absolutely no overhead (everything gets removed at compile time).
A presentation I did on this is here: https://archive.fosdem.org/2019/schedule/event/rust_hawktracer/

Tools needed

You need an external tool in order to transform captured profiling data from a binary format to something that can be interpreted by chrome:://tracing (or other clients).

Profiling code

In Cargo.toml:

[dependencies.rust_hawktracer]
version = "0.6"
features=["profiling_enabled"]

If the bindings that come with it don't match what your platform expects change it to:

features=["profiling_enabled", "generate_bindings"]

In your main.rs:

#[macro_use]
extern crate rust_hawktracer;
use rust_hawktracer::*;
use std::{thread, time};

#[hawktracer(trace_this)]
fn method_to_trace() {
    thread::sleep(time::Duration::from_millis(1));
}

fn main() {
    let instance = HawktracerInstance::new();
    let _listener = instance.create_listener(HawktracerListenerType::ToFile {
        file_path: "trace.bin".into(),
        buffer_size: 4096,
    });

    // For a networked listner
    // let _listener = instance.create_listener(HawktracerListenerType::TCP {
    //     port: 12345,
    //     buffer_size: 4096,
    // });

    println!("Hello, world!");
    {
        scoped_tracepoint!(_test);
        thread::sleep(time::Duration::from_millis(10));

        {
            for _ in 0..10 {
                scoped_tracepoint!(_second_tracepoint);
                thread::sleep(time::Duration::from_millis(10));
            }
        }
    }
}

Visualization

I recommend getting hawktracer_converter using cargo install hawktracer-converter as described here.

If you use HawktracerListenerType::ToFile:

.\hawktracer-converter.exe --source trace.bin --output trace.json

If you use HawktracerListenerType::TCP you can listen and capture traces by specifying the IP:port as the --source parameter:

.\hawktracer-converter.exe --source 127.0.0.1:12345 --output trace.json

Open a chrome browser and go to this address: chrome://tracing/

By opening the trace.json for the program above you should see something like:

Things to watch out for

In rust macros I can't create new identifier names. This means that if you want to avoid warnings, the tracepoint names have to start with a leading _, as in scoped_tracepoint!(_my_tracepoint_name).
This doesn't apply to the function annotations.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE or http://opensource.org/licenses/MIT)

at your option.