Recording Traces with the Rust SDK

In this guide, you'll learn how to:

Use the Perfetto Rust SDK to add trace points to a Rust application.
Record a trace containing your custom events.
Use the #[tracefn] attribute macro for automatic function tracing.
Use the tracing crate with Perfetto as a backend.
Extend TracePacket with GPU event protos.

NOTE: The Rust SDK is a community-maintained project. It may not have the same level of support, stability, or feature coverage as the official C++ SDK.

The Perfetto Rust SDK provides safe and ergonomic bindings for the Perfetto tracing framework. It wraps the Perfetto C API with Rust abstractions for tracing sessions, data sources, and track events.

Crates

The SDK is split into several crates:

Crate	Description
`perfetto-sdk`	Core SDK with tracing sessions, data sources, and track events
`perfetto-sdk-sys`	Low-level FFI bindings to the Perfetto C API
`perfetto-sdk-derive`	`#[tracefn]` proc macro for automatic function instrumentation
`perfetto-sdk-protos-gpu`	GPU event protobuf bindings extending `TracePacket`
`perfetto-sdk-protos-trace-processor`	Trace processor protobuf bindings
`tracing-perfetto-sdk`	`tracing-subscriber` Layer for Perfetto

Setup

Add the SDK to your Cargo.toml:

toml

[dependencies]
perfetto-sdk = "1"

By default, this compiles and statically links the bundled Perfetto C library. No external dependencies are required.

Track events

Initialize Perfetto and define your tracing categories:

rust

use perfetto_sdk::producer::*;
use perfetto_sdk::track_event::*;
use perfetto_sdk::{scoped_track_event, track_event_begin, track_event_end, track_event_instant};

// Define tracing categories. Each category can be independently
// enabled or disabled in the trace configuration.
perfetto_sdk::track_event_categories! {
    pub mod my_categories {
        ("rendering", "Events from the graphics subsystem", []),
        ("network", "Network upload and download statistics", []),
    }
}
use my_categories as perfetto_te_ns;

fn main() {
    Producer::init(
        ProducerInitArgsBuilder::new()
            .backends(Backends::IN_PROCESS)
            .build(),
    );
    TrackEvent::init();
    my_categories::register().unwrap();

    // Scoped event — ends when the scope exits.
    scoped_track_event!("rendering", "DrawPlayer",
        |ctx: &mut EventContext| {
            ctx.add_debug_arg("player_number",
                TrackEventDebugArg::Uint64(1));
        },
        |_| {}
    );

    // Manual begin/end events.
    track_event_begin!("rendering", "DrawGame");
    track_event_end!("rendering");

    // Instant event.
    track_event_instant!("rendering", "VSync");
}

Collecting traces

In-process tracing

For self-contained trace collection without a tracing service, create a TracingSession with the in-process backend. See contrib/rust-sdk/perfetto/examples/tracing_session.rs for a complete working example.

System tracing

To connect to a running Perfetto tracing service (traced), use the system backend instead:

rust

use perfetto_sdk::producer::*;

Producer::init(
    ProducerInitArgsBuilder::new()
        .backends(Backends::SYSTEM)
        .build(),
);

Your application acts as a producer, and the system tracing service controls when tracing starts and stops. Record a trace using the system tracing tools.

Automatic function tracing with `#[tracefn]`

The perfetto-sdk-derive crate provides a proc macro that automatically instruments a function with a track event. It captures all input parameters as debug annotations.

toml

[dependencies]
perfetto-sdk = "1"
perfetto-sdk-derive = "1"

Then annotate functions with #[tracefn]:

rust

// Assuming categories are defined as in the example above.
use perfetto_sdk::producer::*;
use perfetto_sdk::track_event::*;
perfetto_sdk::track_event_categories! {
    pub mod my_categories {
        ("rendering", "Events from the graphics subsystem", []),
    }
}
use my_categories as perfetto_te_ns;
use perfetto_sdk_derive::tracefn;

#[tracefn("rendering")]
fn draw_player(player_number: u32, x: f64, y: f64) {
    // A "draw_player" track event is emitted automatically.
    // player_number, x, and y are captured as debug annotations.
}

The macro wraps the function body in a scoped_track_event! so the event spans the full function execution. The category name is passed as the macro argument.

Using the `tracing` crate

If your application uses the Rust tracing crate, you can use tracing-perfetto-sdk to send events to Perfetto without changing your existing instrumentation:

toml

[dependencies]
tracing = "0.1"
tracing-subscriber = "0.3"
tracing-perfetto-sdk = "1"

Initialize and install the layer:

rust

use tracing_subscriber::prelude::*;

tracing_perfetto_sdk::init();
tracing_subscriber::registry()
    .with(tracing_perfetto_sdk::PerfettoLayer::new())
    .init();

// Standard tracing macros emit Perfetto events.
let _span = tracing::info_span!("DrawGame").entered();
tracing::info!(player = 1, "drawing player");

Spans become duration slices and events become instant events, with fields captured as debug annotations and source locations attached automatically.

GPU event protos

The perfetto-sdk-protos-gpu crate extends TracePacket with GPU-specific fields for emitting GPU counter events, render stage events, Vulkan events, and more.

toml

[dependencies]
perfetto-sdk = "1"
perfetto-sdk-protos-gpu = "1"

Import the TracePacketExt trait to access the GPU fields:

rust

use perfetto_sdk_protos_gpu::protos::trace::trace_packet::prelude::*;
use perfetto_sdk_protos_gpu::protos::trace::gpu::gpu_counter_event::*;

fn emit_gpu_counter(packet: &mut perfetto_sdk::protos::trace::trace_packet::TracePacket) {
    packet.set_gpu_counter_event(|event: &mut GpuCounterEvent| {
        event.set_counters(|counter: &mut GpuCounterEventGpuCounter| {
            counter.set_counter_id(1);
            counter.set_double_value(42.0);
        });
    });
}

This is typically used inside a custom data source's trace callback. See contrib/rust-sdk/perfetto-protos-gpu/examples/gpu_counters.rs for a complete example.

Track event extensions

Track events can be extended with custom protobuf fields using the extension mechanism. The perfetto-sdk-protos-gpu crate defines GPU extensions such as gpu_api that tag track events with the GPU API type.

Use set_proto_fields on EventContext to add extension fields:

rust

// Assuming categories are defined as in the example above.
use perfetto_sdk::producer::*;
use perfetto_sdk::track_event::*;
use perfetto_sdk::track_event_instant;
perfetto_sdk::track_event_categories! {
    pub mod my_categories {
        ("rendering", "Events from the graphics subsystem", []),
    }
}
use my_categories as perfetto_te_ns;
use perfetto_sdk_protos_gpu::protos::trace::gpu::gpu_track_event::{
    GpuApi, TrackEventExtFieldNumber,
};

track_event_instant!("rendering", "cuLaunchKernel", |ctx: &mut EventContext| {
    ctx.set_proto_fields(&TrackEventProtoFields {
        fields: &[TrackEventProtoField::VarInt(
            TrackEventExtFieldNumber::GpuApi as u32,
            GpuApi::GpuApiCuda as u64,
        )],
    });
});

The extension field appears in the trace as gpu_api: GPU_API_CUDA on the track event, which the trace processor decodes into the gpu_api column of the slice table args.

Next steps

Track Events: Learn more about the different types of track events.
Rust SDK examples: Working examples of data sources, track events, and tracing sessions.
GPU counter example: Example of a GPU counter data source.

Recording Traces with the Rust SDK

Recording Traces with the Rust SDK

Crates

Setup

Track events

Collecting traces

In-process tracing

System tracing

Automatic function tracing with #[tracefn]

Using the tracing crate

GPU event protos

Track event extensions

Next steps

Automatic function tracing with `#[tracefn]`

Using the `tracing` crate