Go-Concurrency on cassiobotaro

Go Concurrency - Tee

Thu, 15 Oct 2026 00:00:00 +0000

In the fan-out each value went to only one worker.

But what if both need to see everything? One writes to the log and the other updates a metric, for example. Neither of them can miss a value.

What a tee is Link to heading

A tee copies each value of an input channel to all the output channels. The name comes from the Unix tee command, which duplicates whatever it receives.

Go Concurrency - Fan-out

Tue, 13 Oct 2026 00:00:00 +0000

In the worker the fmt.Printf played the role of the processing. Now let’s pretend it takes a while.

A time.Sleep of 100 milliseconds per value. There are ten values, in other words, one second staring at the screen.

What if I put three workers reading from the same channel?

Go Concurrency - Pipeline

Thu, 08 Oct 2026 00:00:00 +0000

In the generator a goroutine wrote to the channel. In the worker it read from it.

What if it does both? It reads from a channel, transforms the value and writes to another.

What a pipeline is Link to heading

A pipeline is a chain of stages connected by channels. Each stage is a function that receives a channel, starts a goroutine to read from it and returns the channel where it writes the result.

Go Concurrency - Worker

Tue, 06 Oct 2026 00:00:00 +0000

In the generator a goroutine wrote to the channel and main read from it.

Now the roles flip. The one reading is the goroutine.

What a worker is Link to heading

A worker is a goroutine that receives values from a channel and processes them until the channel is closed.

Go Concurrency - Generators

Thu, 01 Oct 2026 00:00:00 +0000

In the hello world the channel carried a single message, from the goroutine to main.

But it’s almost never a single message. It’s the lines of a file, the pages of an API, the events of a queue. And this is where the first pattern of the series comes in.

Go Concurrency - Hello world

Thu, 24 Sep 2026 00:00:00 +0000

A few years ago I watched a talk by @andrebq about concurrency in Go and my mind was blown.

Much later I decided to transcribe the examples from that talk into a repository, and kept adding others I found in books, in articles and in Rob Pike’s talk Go Concurrency Patterns. It became concorrencia-go.