profiling 0.1.4

This crate provides a very thin abstraction over other profiler crates.
Documentation

profiling

Provides a very thin abstraction over instrumented profiling crates like puffin, optick, tracy, and superluminal-perf. Currently, there's just four macros:

  • profiling::scope!(name: &str, [tag: &str])
    • name: scopes will appear in the profiler under this name
    • tag: optional extra data
  • #[profiling::function]
    • procmacro placed on a function to quickly wrap it in a scope using the function name
  • profiling::register_thread!([name: &str])
    • name: optional, defaults to std::thread::current().name, or .id if it's unnamed
  • profiling::finish_frame!()
    • Many profilers have the concept of a "frame" as a unit of work. Use this to indicate where one frame ends and the next one begins.

Support for individual profilers can be turned on/off with feature flags. By default, they're all off, resulting in no dependencies or runtime code.

Who is this for?

  • Authors of binaries that want to have multiple options for profiling their code, but don't want to duplicate their instrumentation once per each profiler's individual API.
  • Authors of libraries that would like to instrument their crate for their end-users.

This crate is intended to be TINY. It won't support every possible usage, just the basics. I'm open to adding a few more things but I plan to be very selective to maintain a very slim size.

Why not use the tracing crate? The tracing crate is significantly larger than necessary for this narrow use-case, and it's expected that these scopes may end up on a very hot path where any overhead at all can add noise to the captured data.

Why not use puffin/optick/etc. directly?

  • For authors of binaries, you'll still need to use APIs on those crates to get started. But when instrumenting your code, profiling::scope!("Scope Name") inside a function or #[profiling::function] on a function will instrument it for all the supported profiler-specific crates. You can still use those crates directly if you want to take advantage of custom APIs they provide to surface additional data.
  • For authors of upstream libraries, this crate lets you implement simple instrumentation once. Hopefully this will allow the community to benefit from instrumented profiling, even if a significant amount of a codebase is made of upstream crates.

Using from a Binary

It's up to you to initialize the profiling crate of your choice. The examples demonstrate this, but it's worth looking at the docs for the profiler you're interested in using! Once initialized, you can mix/match the macros provided by your profiler of choice and the generic ones in this crate. For example:

// This may map to something like:
// - puffin::profile_scope!("Scope Name")
// - optick::event!("Scope Name")
// - tracing::span!(tracing::Level::INFO, "Scope Name")
// - superluminal_perf::begin_event("Scope Name")
profiling::scope!("Scope Name");

// This may map to something like:
// - puffin::profile_scope_data!("Scope Name", "extra data")
// - optick::event!("Scope Name"); optick::tag!("tag", "extra data");
// - tracing::span!(tracing::Level::INFO, "Scope Name", tag = "extra data")
// - superluminal_perf::begin_event_with_data("Scope Name", "extra data", 0)
profiling::scope!("Scope Name", "extra data");

There is also a proc macro to decorate functions:

#[profiling::function]
fn my_function() {

}

Take a look at the code for the helpful macros register_thread!() and finish_frame!().

If you want to enable profiling in upstream crates, you'll need to enable the appropriate features in them. This also lets you turn them on/off per crate:

[dependencies]
profiling = "0.1"
some_upstream_crate = "0.1"

[features]
profile-with-puffin = ["profiling/profile-with-puffin", "some_upstream_crate/profile-with-puffin"]
profile-with-optick = ["profiling/profile-with-optick", "some_upstream_crate/profile-with-optick"]
profile-with-superluminal = ["profiling/profile-with-superluminal", "some_upstream_crate/profile-with-superluminal"]
profile-with-tracing = ["profiling/profile-with-tracing", "some_upstream_crate/profile-with-tracing"]
  • You can use the default feature to quickly/temporarily turn something on: default = ["profile-with-optick"]
  • cargo run --features=profile-with-optick works too!

Using from a Library

Add the profiling crate to Cargo.toml Add the following features but don't enable them. Those features should only be enabled by the binary. If the end-user of your library doesn't use profiling, the macros in this crate will emit no code at all.

[dependencies]
profiling = "0.1"

[features]
profile-with-puffin = ["profiling/profile-with-puffin"]
profile-with-optick = ["profiling/profile-with-optick"]
profile-with-superluminal = ["profiling/profile-with-superluminal"]
profile-with-tracing = ["profiling/profile-with-tracing"]

Now you can instrument your library using the API exposed via the profiling crate and support each profiler.

The downstream binary can now turn these features on per crate by enabling the appropriate features within the crate as described above.

Feature Flags

  • profile-with-puffin: Enable the puffin crate
  • profile-with-optick: Enable the optick crate
  • profile-with-superluminal: Enable the superluminal-perf crate
  • profile-with-tracing: Enable the tracing crate. (The profiler crate tracy consumes data through this abstraction)

Examples

  • simple: Shows a bare minimum requirements to do some simple instrumented profiling. Once it's running, you can connect to the process using optick/tracy/superluminal. Some of these are windows only!
run --package profiling --example simple --features="profile-with-optick,profile-with-tracy,profile-with-puffin,profile-with-superluminal"
  • puffin: Launches a basic app with imgui integration showing the puffin UI. This one should run everywhere that supports imgui.
cargo run --package profiling --example puffin --features="profile-with-puffin"

License

Licensed under either of

at your option.

The examples directory contains mplus-1p-regular.ttf, available under its own license.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

See LICENSE-APACHE and LICENSE-MIT.