* Split `shutdown` into two separate methods for better control:
- `shutdown` - signals threads to stop accepting new work
- `wait_for_termination` - waits for threads to finish (with optional timeout)
* Add tracking of busy threads via `@busy_threads` Set
* Make idle_time parameter optional with 30-second default
* Improve thread spawning logic:
- Spawn initial thread immediately when work is posted
- Spawn additional threads when all threads are busy and work is queued
* Fix race condition in work distribution
* Add busy thread count to stats output
* Add test coverage for zero min_threads configuration
This commit makes the ThreadPool more reliable, easier to use, and adds
better visibility into its internal state.
---------
Co-authored-by: Alan Guo Xiang Tan <gxtan1990@gmail.com>
This commit introduces a new ThreadPool class that provides efficient worker
thread management for background tasks. Key features include:
- Dynamic scaling from min to max threads based on workload
- Proper database connection management in multisite setup
- Graceful shutdown with task completion
- Robust error handling and logging
- FIFO task processing with a managed queue
- Configurable idle timeout for worker threads
The implementation is thoroughly tested, including stress tests, error
scenarios, and multisite compatibility.
