alive

README

What

alive waits for subtasks, coordinate graceful or fast shutdown. sync.WaitGroup on steroids.

Usage

Key takeaways:

• Zero value of alive.Alive{} is not ready, you must use NewAlive() constructor.

    srv := MyServer{ alive: alive.NewAlive() }

• Call .Add(n) and .Done() just as with WaitGroup, monitor .IsRunning().

    for srv.alive.IsRunning() {
        task := <-queue
        srv.alive.Add(1)
        go func() {
            // be useful
            srv.alive.Done()
        }()
    }

• Call .Stop() to switch IsRunning and stop creating new tasks if programmed so.

    sigShutdownChan := make(chan os.Signal, 1)
    signal.Notify(sigShutdownChan, syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT)
    go func(ch <-chan os.Signal) {
        <-ch
        log.Printf("graceful stop")
        sdnotify("READY=0\nSTATUS=stopping\n")
        srv.alive.Stop()
    }(sigShutdownChan)

• Call .Wait() to synchronize on all subtasks .Done(), just as with WaitGroup.

func main() {
    // ...
    srv.alive.Wait()
}

• .StopChan() lets your observe .Stop() call from another place. A better option to IsRunning() poll.

    stopch := srv.alive.StopChan()
    for {
        select {
        case job := <-queue:
            // be useful
        case <-stopch:
            // break for loop
        }
    }

• .WaitChan() is select-friendly version of .Wait().

Install

go get -u github.com/temoto/alive

Flair

Documentation

Overview

alive helps servers to coordinate graceful or fast stopping

Index

• type Alive
  • func NewAlive() *Alive
  • func (self *Alive) Add(delta int)
  • func (self *Alive) Done()
  • func (self *Alive) IsFinished() bool
  • func (self *Alive) IsRunning() bool
  • func (self *Alive) IsStopping() bool
  • func (self *Alive) Stop()
  • func (self *Alive) StopChan() <-chan struct{}
  • func (self *Alive) String() string
  • func (self *Alive) Wait()
  • func (self *Alive) WaitChan() <-chan struct{}
  • func (self *Alive) WaitTasks()

Types

type Alive

type Alive struct {
	// contains filtered or unexported fields
}

func NewAlive

func NewAlive() *Alive

func (*Alive) Add

func (self *Alive) Add(delta int)

func (*Alive) Done

func (self *Alive) Done()

func (*Alive) IsFinished

func (self *Alive) IsFinished() bool

func (*Alive) IsRunning

func (self *Alive) IsRunning() bool

func (*Alive) IsStopping

func (self *Alive) IsStopping() bool

func (*Alive) Stop

func (self *Alive) Stop()

func (*Alive) StopChan

func (self *Alive) StopChan() <-chan struct{}

func (*Alive) String

func (self *Alive) String() string

func (*Alive) Wait

func (self *Alive) Wait()

func (*Alive) WaitChan

func (self *Alive) WaitChan() <-chan struct{}

func (*Alive) WaitTasks

func (self *Alive) WaitTasks()