terminator

terminator

import "github.com/bruceesmith/terminator"

Package terminator permits orderly stopping / shutdown of a group of goroutines via methods which mimic stop of a sync.WaitGroup.There is a default Terminator accessible through top level functions (Add, Done, Wait and so on) that call the corresponding Terminator methods

Index

• func Add(delta int)
• func Done()
• func Go(f func())
• func SetDefault(t *Terminator)
• func ShutDown() <-chan struct{}
• func ShuttingDown() bool
• func Stop()
• func Wait()
• type ShutdownManager
  • func NewShutdownManager(total time.Duration) *ShutdownManager
  • func (s *ShutdownManager) Register(name string, timeout time.Duration, fn func(ctx context.Context) error)
  • func (s *ShutdownManager) Shutdown() error
• type Terminator
  • func Default() *Terminator
  • func New() *Terminator
  • func (t *Terminator) Add(delta int)
  • func (t *Terminator) Done()
  • func (t *Terminator) Go(f func())
  • func (t *Terminator) ShutDown() <-chan struct{}
  • func (t *Terminator) ShuttingDown() bool
  • func (t *Terminator) Stop()
  • func (t *Terminator) Wait()

func Add

func Add(delta int)

Add adds delta to the count of goroutines in the group

func Done

func Done()

Done decrements the count of goroutines in the group by one

func Go

func Go(f func())

Go runs a function inside an Add(1) --- Done() sequence

func SetDefault

func SetDefault(t *Terminator)

SetDefault sets the default Terminator

func ShutDown

func ShutDown() <-chan struct{}

ShutDown allows code to wait for a shut down signal

// --- Job processor ---
process := func(job string) {
	fmt.Println(job)
}
// --- Background Worker ---
queue := make(chan string, 10)
worker := func(ctx context.Context) {
	for {
		select {
		case <-ctx.Done():
			fmt.Println("worker stopped")
			return
		case job := <-queue:
			process(job)
		}
	}
}
// --- Launch the background worker inside a context.WithCancel ---
workerCtx, workerCancel := context.WithCancel(context.Background())
workerDone := make(chan struct{})
go func() {
	defer close(workerDone)
	worker(workerCtx)
}()
// --- Shutdown Manager ---
sm := NewShutdownManager(5 * time.Second)
// --- Register a drain function for the background worker
sm.Register(
	"worker-drain",
	20*time.Second,
	func(ctx context.Context) error {
		fmt.Println("draining worker")
		workerCancel() // signal the worker to stop
		select {
		case <-workerDone:
			return nil
		case <-ctx.Done():
			return fmt.Errorf("worker did not drain in time: %w", ctx.Err())
		}
	})
// Submit jobs to the worker queue
for i := range 5 {
	queue <- fmt.Sprintf("%s %d", "job", i+1)
}
fmt.Println("jobs sent")
// Give jobs a chance then quit gracefully
time.Sleep(1 * time.Second)
if err := sm.Shutdown(); err != nil {
	fmt.Println("shutdown completed with errors", "error", err)
}

// Output:
// jobs sent
// job 1
// job 2
// job 3
// job 4
// job 5
// draining worker
// worker stopped

jobs sent
job 1
job 2
job 3
job 4
job 5
draining worker
worker stopped

func ShuttingDown

func ShuttingDown() bool

ShuttingDown returns true if shutdown is in progress

func Stop

func Stop()

Stop signals that all goroutines in the group should safely exit

func Wait

func Wait()

Wait blocks until every goroutines in the group has called Done()

type ShutdownManager

ShutdownManager orchestrates ordered, phased shutdown.

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

func NewShutdownManager

func NewShutdownManager(total time.Duration) *ShutdownManager

func (*ShutdownManager) Register

func (s *ShutdownManager) Register(name string, timeout time.Duration, fn func(ctx context.Context) error)

Register adds a shutdown function to a named phase. Phases execute in registration order.

func (*ShutdownManager) Shutdown

func (s *ShutdownManager) Shutdown() error

Shutdown runs all phases sequentially with independent timeouts.

type Terminator

Terminator manages groups of goroutines

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

func Default

func Default() *Terminator

Default returns the default Terminator.

func New

func New() *Terminator

New returns a Terminator

func (*Terminator) Add

func (t *Terminator) Add(delta int)

Add adds delta to the count of goroutines in the group

func (*Terminator) Done

func (t *Terminator) Done()

Done decrements the count of goroutines in the group by one

func (*Terminator) Go

func (t *Terminator) Go(f func())

Go runs a function inside an Add(1) --- Done() sequence

func (*Terminator) ShutDown

func (t *Terminator) ShutDown() <-chan struct{}

ShutDown allows code to wait for a shut down signal

func (*Terminator) ShuttingDown

func (t *Terminator) ShuttingDown() bool

ShuttingDown returns true if shutdown is in Default().progress

func (*Terminator) Stop

func (t *Terminator) Stop()

Stop signals that all goroutines in the group should safely exit

func (*Terminator) Wait

func (t *Terminator) Wait()

Wait blocks until every goroutines in the group has called Done()

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