# run [](https://godoc.org/github.com/oklog/run) [](https://travis-ci.org/oklog/run) [](https://goreportcard.com/report/github.com/oklog/run) [](https://raw.githubusercontent.com/oklog/run/master/LICENSE) run.Group is a universal mechanism to manage goroutine lifecycles. Create a zero-value run.Group, and then add actors to it. Actors are defined as a pair of functions: an **execute** function, which should run synchronously; and an **interrupt** function, which, when invoked, should cause the execute function to return. Finally, invoke Run, which blocks until the first actor returns. This general-purpose API allows callers to model pretty much any runnable task, and achieve well-defined lifecycle semantics for the group. run.Group was written to manage component lifecycles in func main for [OK Log](https://github.com/oklog/oklog). But it's useful in any circumstance where you need to orchestrate multiple goroutines as a unit whole. [Click here](https://www.youtube.com/watch?v=LHe1Cb_Ud_M&t=15m45s) to see a video of a talk where run.Group is described. ## Examples ### context.Context ```go ctx, cancel := context.WithCancel(context.Background()) g.Add(func() error { return myProcess(ctx, ...) }, func(error) { cancel() }) ``` ### net.Listener ```go ln, _ := net.Listen("tcp", ":8080") g.Add(func() error { return http.Serve(ln, nil) }, func(error) { ln.Close() }) ``` ### io.ReadCloser ```go var conn io.ReadCloser = ... g.Add(func() error { s := bufio.NewScanner(conn) for s.Scan() { println(s.Text()) } return s.Err() }, func(error) { conn.Close() }) ``` ## Comparisons Package run is somewhat similar to package [errgroup](https://godoc.org/golang.org/x/sync/errgroup), except it doesn't require actor goroutines to understand context semantics. It's somewhat similar to package [tomb.v1](https://godoc.org/gopkg.in/tomb.v1) or [tomb.v2](https://godoc.org/gopkg.in/tomb.v2), except it has a much smaller API surface, delegating e.g. staged shutdown of goroutines to the caller.