mmadfox / run

A universal mechanism to manage goroutine lifecycles

run

run.Group or run.PGroup is a universal mechanism to manage goroutine lifecycles.

Create a zero-value run.Group or run.PGroup, 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 concurrently runs all of the actors, waits until the first actor exits, invokes the interrupt functions, and finally returns control to the caller only once all actors have returned. This general-purpose API allows callers to model pretty much any runnable task, and achieve well-defined lifecycle semantics for the group.

Examples

Interrupt order

var g run.PGroup 

g.Add(func () error {
   return myProcess(ctx, ...)
}, func (error) {
   cancel()
}, 2)

g.Add(func() error {
   return myProcess(ctx, ...)
}, func(error) {
   cancel()
}, 1)

context.Context

var g run.Group
ctx, cancel := context.WithCancel(context.Background())
g.Add(func() error {
	return myProcess(ctx, ...)
}, func(error) {
	cancel()
})

OR run.PGroup with interrupt ordering

var g run.PGroup
g.Add(func() error {
    return myProcess(ctx, ...)
}, func(error) {
    cancel()
}, 2)

g.Add(func() error {
   return myProcess(ctx, ...)
}, func(error) {
   cancel()
}, 1) 

net.Listener

ln, _ := net.Listen("tcp", ":8080")
g.Add(func() error {
	return http.Serve(ln, nil)
}, func(error) {
	ln.Close()
})

io.ReadCloser

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()
})