What concurrency patterns do you know in Go?

In Go, there are several common concurrency patterns that help efficiently work with goroutines and channels:

• Worker Pool — a pool of workers that receive tasks from a channel and process them in parallel. It allows limiting the number of goroutines working simultaneously.

• Fan-out, Fan-in — a pattern where multiple goroutines (fan-out) process data in parallel, and results are collected into a single channel (fan-in).

• Pipeline — a sequence of data processing stages, each implemented in a separate goroutine connected by channels.

• Select for multiplexing — allows a goroutine to wait on multiple channels and react to the first one that becomes available.

• Mutex and RWMutex — for protecting shared resources during concurrent access.

• Context — for managing the lifetime of goroutines and canceling operations.

Example of Worker Pool:

func worker(id int, jobs <-chan int, results chan<- int) {
    for j := range jobs {
        fmt.Printf("worker %d processing job %d\n", id, j)
        results <- j * 2
    }
}

func main() {
    jobs := make(chan int, 5)
    results := make(chan int, 5)

    for w := 1; w <= 3; w++ {
        go worker(w, jobs, results)
    }

    for j := 1; j <= 5; j++ {
        jobs <- j
    }
    close(jobs)

    for a := 1; a <= 5; a++ {
        fmt.Println(<-results)
    }
}