Detect Cross Runtime Wakes

A quick experimental utility that detects and reports when async tasks are executed in a different runtime context than where they were created.

Purpose

This experimental tool helps debug scenarios where tasks might inadvertently cross runtime boundaries by:

• Detecting when a task is woken up in a different runtime than where it was created
• Generating and dumping a backtrace when such cross-runtime task execution occurs

Usage

This is a development/debugging tool designed to help identify potential issues in async code where tasks may unintentionally cross runtime boundaries.

To use this tool, wrap your futures with the instrument function, passing the runtime handle:

use tokio::runtime::Handle;
use runtime_task_context_validator::instrument;

let handle = Handle::current();
let my_future = async {
    // Your async code here
};

// Wrap the future to detect cross-runtime wake ups
let instrumented = instrument(&handle, my_future);
tokio::spawn(instrumented);

When a task is woken up in a different runtime context than its creation context, a backtrace will be generated showing where the cross-runtime execution occurred.

Output

When a cross-runtime task execution is detected, a backtrace will be printed to stderr in the following format:

WARNING: Task woken in different runtime than created in!
Backtrace:
   0: runtime_task_context_validator::WakeWarner::wake_by_ref
   1: <your code's stack trace here>
   ...

Notes

• This is a quick experimental project intended for development debugging purposes only
• Performance impact: This adds a small overhead to task wake-ups to perform the runtime context check
• Thread-safe: The validator is safe to use in multi-threaded environments