This crate allows one to generate logs about how tasks are scheduled, in order to generate a profile of the CPU usage of the binary.

This crate leverages https://github.com/catapult-project/catapult/tree/11513e359cd60e369bbbd1f4f2ef648c1bccabd0/tracing

Usage

First, import the traits:

use futures_diagnose_exec::{FutureExt as _, Future01Ext as _};

Then whenever you create a Future, append .with_diagnostics("name"). For example:

async_std::spawn(future.with_diagnostics("my-task-name"))

Set the environment variable PROFILE_DIR to a directory of your choice (e.g. profile) and then, run your code. Files named profile.<pid>.<num>.json will be generated in the directory set beforehand.

Then, open Chrome and go to the URL chrome://tracing, and load the profile.json.

FAQ

• Chrome tells me chrome://tracing "can't be reached".

  Chromium shipped with recent Debian versions has the tracing feature disabled. See the Debian bug report for details.