Running concurrently a list of commands

commands.go

package main

type Command interface {
	Run() error
}

func RunAll(cmds []Command) error {
	for _, cmd := range cmds {
		err := cmd.Run()
		if err != nil {
			return err
		}
	}
	return nil
}

func RunAllConc(cmds []Command) error {
	// We use a buffered channel to avoid goroutine leaking.
	errc := make(chan error, len(cmds))
	for _, cmd := range cmds {
		// We pass the command as a parameter to avoid a data race.
		go func(c Command) {
			errc <- c.Run()
		}(cmd)
	}

	// We iterate len(cmds) times.
	for _ = range cmds {
		err := <-errc
		if err != nil {
			return err
		}
	}
	return nil
}