Goβs CompareAndSwap is not always Compare-and-swap
>Go's standard package sync/atomics provides programmers with functions to use the underlying CPU-level atomic operations such as compare-and-swap (CAS), through atomic.CompareAndSwapT (where T is an integer type).
> Problem: Not all CPU architectures offers a CAS instruction to rely on to implement atomic.CompareAndSwapT. However, Go must compile that function code to something semantically equivalentβlet's see what.
https://lu.sagebl.eu/notes/go-cas/
>Go's standard package sync/atomics provides programmers with functions to use the underlying CPU-level atomic operations such as compare-and-swap (CAS), through atomic.CompareAndSwapT (where T is an integer type).
> Problem: Not all CPU architectures offers a CAS instruction to rely on to implement atomic.CompareAndSwapT. However, Go must compile that function code to something semantically equivalentβlet's see what.
https://lu.sagebl.eu/notes/go-cas/
Forwarded from πΊπ¦ Go performance channel (Oleg)
Hiring Challenge: Smallest #golang Websocket Client
https://dyte.io/blog/hiring-challenge-smallest-golang-websocket-client/ by @dyte_io
https://dyte.io/blog/hiring-challenge-smallest-golang-websocket-client/ by @dyte_io
Dyte
Hiring Challenge: Smallest golang Websocket Client
Learn to create a compact Go program for a websocket server, optimizing the binary size. Insights from a Dyte hiring challenge.
Collections what's new in Go 1.22:
- slices.Concat https://blog.carlana.net/post/2024/golang-slices-concat/
- reflect.TypeFor https://blog.carlana.net/post/2024/golang-reflect-type-for/
- https://pkg.go.dev/cmp#Or
- https://pkg.go.dev/net/http@master#FileServerFS
- https://pkg.go.dev/database/sql#Null
- slices.Concat https://blog.carlana.net/post/2024/golang-slices-concat/
- reflect.TypeFor https://blog.carlana.net/post/2024/golang-reflect-type-for/
- https://pkg.go.dev/cmp#Or
- https://pkg.go.dev/net/http@master#FileServerFS
- https://pkg.go.dev/database/sql#Null
TIL: a % 128 = 0 is the same as a & 127 = 0
'Which is a faster operation since it just requires doing the AND and not the whole division and remainder comparison' @jesusvazquezp
from https://github.com/prometheus/prometheus/pull/14118#pullrequestreview-2068077407
'Which is a faster operation since it just requires doing the AND and not the whole division and remainder comparison' @jesusvazquezp
from https://github.com/prometheus/prometheus/pull/14118#pullrequestreview-2068077407
GitHub
Check context every 128 labels instead of 100 by colega Β· Pull Request #14118 Β· prometheus/prometheus
Follow up on #14096
As promised, I bring a benchmark, which shows a very small improvement if context is checked every 128 iterations of label instead of every 100.
It's much easier for a compu...
As promised, I bring a benchmark, which shows a very small improvement if context is checked every 128 iterations of label instead of every 100.
It's much easier for a compu...
How do you track code coverage for OSS projects?
codecov seems very flaky, (will provide some details in thread)
wdyt about https://github.com/vladopajic/go-test-coverage?tab=readme-ov-file
codecov seems very flaky, (will provide some details in thread)
wdyt about https://github.com/vladopajic/go-test-coverage?tab=readme-ov-file
GitHub
GitHub - vladopajic/go-test-coverage: go-test-coverage is a tool designed to report issues when test coverage falls below a specifiedβ¦
go-test-coverage is a tool designed to report issues when test coverage falls below a specified threshold - vladopajic/go-test-coverage
For all GO haters :) https://juli1.substack.com/p/why-i-fell-in-love-with-go
Nice quote and summary:
>Technologies like JavaScript or Go are like a good burger: itβs an option that the majority understand and choose regularly. It may not be the most elegant option, but it does the job and allows us to focus on problems that matter.
Nice quote and summary:
>Technologies like JavaScript or Go are like a good burger: itβs an option that the majority understand and choose regularly. It may not be the most elegant option, but it does the job and allows us to focus on problems that matter.
Substack
Why I fell in love with Go
When I was still young in my career, I was obsessed with niche-languages mentioned in big stories on Hackernews.
What do you think if I start posting not only about Golang, but some related topics like k8s/containers?
Anonymous Poll
50%
Yes
20%
No
16%
Strong Yes
14%
i don't care
Old but still worth to read about why one shouldn;t defer Close() on writable files:
https://www.joeshaw.org/dont-defer-close-on-writable-files/
https://www.joeshaw.org/dont-defer-close-on-writable-files/
www.joeshaw.org
Don't defer Close() on writable files
It'll bite you some day
Some pitfalls about generating Kubernetes Custom Resources with `controller-gen` over the years, and how to do more rigid validation and defaulting with it:
https://ahmet.im/blog/crd-generation-pitfalls/
https://ahmet.im/blog/crd-generation-pitfalls/
Ahmet Alp Balkan
Kubernetes CRD generation pitfalls
A quick code search query reveals at least 7,000 Kubernetes Custom Resource Definitions in the open source corpus,1 most of which are likely generated with controller-gen βa tool that turns Go structs with comments-based markers into Kubernetes CRD...
Providing context to cancellations in Go 1.20 with the new context WithCause API
https://josephwoodward.co.uk/2023/01/context-cancellation-cause-with-cancel-cause
and proposal https://github.com/golang/go/issues/51365
https://josephwoodward.co.uk/2023/01/context-cancellation-cause-with-cancel-cause
and proposal https://github.com/golang/go/issues/51365
Joseph Woodward's Blog
Providing context to cancellations in Go 1.20 with the new context WithCause API
TIL: strings.Split returns [""] if s does not contain sep and sep is not empty π
Split returns a slice of length 1 whose only element is s:
package main
import (
"fmt"
"strings"
)
func main() {
fmt.Printf("%q\n", strings.Split("", ","))
}
Split returns a slice of length 1 whose only element is s:
[""]
After releasing go1.24, we can manage tools as dependencies!
Here is very good step by step article about how to do it https://www.alexedwards.net/blog/how-to-manage-tool-dependencies-in-go-1.24-plus
Also it includes example how to add tools to seperate
Here is very good step by step article about how to do it https://www.alexedwards.net/blog/how-to-manage-tool-dependencies-in-go-1.24-plus
Also it includes example how to add tools to seperate
go.mod file (TIL!)www.alexedwards.net
How to manage tool dependencies in Go 1.24+ - Alex Edwards
FYI: https://semgrep.dev/blog/2025/popular-github-action-tj-actionschanged-files-is-compromised/
https://www.stepsecurity.io/blog/harden-runner-detection-tj-actions-changed-files-action-is-compromised
https://www.stepsecurity.io/blog/harden-runner-detection-tj-actions-changed-files-action-is-compromised
Semgrep
Semgrep | π¨ Popular GitHub Action tj-actions/changed-files is compromised
Popular GitHub Action tj-actions/changed-files has been compromised with a payload that appears to attempt to dump secrets, impacting thousands of CI pipelines.