OCaml-tracy

This repo contains bindings to Tracy, a profiler and trace visualizer. It's licensed, like Tracy, under BSD-3-Clause.

The bindings are pretty basic and go through the C API, not the C++ one (RAII is not compatible with having a function call to enter, and one to exit).

It depends on a C++ compiler to build, along with the dependencies of Tracy-client.

Feature table

In some cases the feature might not provide all options.

Example

The file examples/prof1.ml shows basic instrumentation on a program that computes the Fibonacci function (yes, not representative) in a loop on 3 threads. If Tracy is running and is waiting for a connection (press "connect"), running dune exec ./examples/prof1.exe should start tracing and display something like this:

Usage

• the tracy library is a virtual dune library which provides the type signatures for instrumenting your code. It's very small and is ok to add to a library.

  For example in prof1.ml, we start with:

  T.name_thread (Printf.sprintf "thread_%d" th_n);

  to name the n-th worker thread. Then later we have calls like:

  T.with_ ~file:__FILE__ ~line:__LINE__ ~name:"inner.fib" () @@ fun _sp ->
    T.set_color _sp 0xaa000f;
    (* rest of code in the span _sp *)
    …

  to create a span in Tracy, with a custom color, and the name inner.fib. One can also add text and values to the span. Alternatively, Tracy.enter and Tracy.exit can be used to delimit the span manually.

  To start, one needs to call Tracy.enable().

• the tracy-client package contains the actual C bindings (using a vendored copy of tracy), and implements the virtual library by providing actual instrumentation.

• the tracy.none library (comes in tracy) replaces all instrumentation calls with no-op, which might be inlined by ocamlopt. This is the default implementation and it means that just adding tracy to a library will not incur much at compile time and runtime.