limiter

A dead simple goroutine limiter. Example:

names := []string{"John", "Ada", "Merlin", "Tanya"}
// parameter is a limit
// .Start() method blocks until number 
// of running goroutines is reduced.
limit := limiter.New(2)
for _, name := range names {
    go func(name string, done func()) {
        defer done()
        fmt.Printf("Hello, %s!\n", name)
    // .Start()) blocks f the number of workers 
    // approaches the specified limit, 
    // then waits until the number of active workers decreases.
    }(name, limit.Start())
}
// .Wait() blocks until all tasks are completed.
limit.Wait()

To use limiter import it in your project or just copy-paste source code