#Concurrency

Go quirks: function closures capturing mutable references

A Go closure holds a live reference to whatever it captures, not a snapshot. Real examples of where this trips people up, and how to keep it boring.

Redowan Delowar·Apr 25·6 min read

Go Concurrency

Mutate your locked state inside a closure

Why your mutex wrapper should accept a closure for mutation instead of a plain value, with examples from the standard library and Tailscale.

Redowan Delowar·Mar 5·6 min read

Go Concurrency API

What canceled my Go context?

How Go 1.20's WithCancelCause and Go 1.21's WithTimeoutCause let you attach a reason to context cancellation, plus a gotcha with manual cancel and the stdlib pattern that covers every path.

Redowan Delowar·Feb 24·12 min read

Go Error Handling Concurrency

Structured concurrency & Go

How Python and Kotlin provide structured concurrency out of the box while Go achieves the same patterns explicitly using errgroup, WaitGroup, and context.

Redowan Delowar·Feb 21·14 min read

Go Python Kotlin Concurrency

Early return and goroutine leak

Prevent goroutine leaks caused by early returns with unbuffered channels. Learn buffering, draining, errgroup patterns, and goleak testing.

Redowan Delowar·Sep 7·4 min read

Go Concurrency Testing

Preventing accidental struct copies in Go

Prevent dangerous struct copies with noCopy sentinel and go vet's copylock checker. Protect mutexes and sync primitives from value copies.

Redowan Delowar·Apr 21·4 min read

Go TIL Concurrency

Limit goroutines with buffered channels

Control goroutine concurrency with buffered channels as semaphores. Prevent resource exhaustion with backpressure patterns in Go workers.

Redowan Delowar·Aug 23·4 min read

Go TIL Concurrency

Signal handling in a multithreaded socket server

Gracefully shutdown Python's ThreadingTCPServer with signal handlers for SIGINT, SIGTERM handling and client notification on server shutdown.

Redowan Delowar·Feb 26·8 min read

Python Networking Concurrency

Pausing and resuming a socket server in Python

Build a pausable socket server with Python's socketserver module using threading for intermittent request handling and background tasks.

Redowan Delowar·Feb 5·5 min read

Python Networking Concurrency

Using tqdm with concurrent.fututes in Python

Display progress bars for concurrent Python tasks using tqdm with ThreadPoolExecutor and as_completed for real-time execution monitoring.

Redowan Delowar·Jan 6·2 min read

Python Concurrency

Stream process a CSV file in Python

Process large CSV files without OOM errors by streaming content line-by-line with HTTPX and concurrent.futures for parallel processing.

Redowan Delowar·Jul 1·4 min read

Python Networking Concurrency

Bulk operations in Django with process pool

Speed up Django bulk operations with ProcessPoolExecutor while preserving signals and hooks that bulk_create/bulk_update bypass.

Redowan Delowar·Jun 27·3 min read

Python Django Concurrency Database

Limit concurrency with semaphore in Python asyncio

Control concurrent async requests with Python asyncio.Semaphore to respect rate limits and prevent overwhelming APIs or services.

Redowan Delowar·Feb 10·3 min read

Python Async Concurrency

Effortless concurrency with Python's concurrent.futures

Master Python's concurrent.futures module for easy threading and multiprocessing. Learn ThreadPoolExecutor and ProcessPoolExecutor with examples.

Redowan Delowar·Apr 21·13 min read

Python Concurrency