route/vendor/github.com/oklog/run/example_test.go

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2018-01-20 17:57:11 +00:00
package run_test
import (
"context"
"errors"
"fmt"
"net"
"net/http"
"time"
"github.com/oklog/run"
)
func ExampleGroup_Add_basic() {
var g run.Group
{
cancel := make(chan struct{})
g.Add(func() error {
select {
case <-time.After(time.Second):
fmt.Printf("The first actor had its time elapsed\n")
return nil
case <-cancel:
fmt.Printf("The first actor was canceled\n")
return nil
}
}, func(err error) {
fmt.Printf("The first actor was interrupted with: %v\n", err)
close(cancel)
})
}
{
g.Add(func() error {
fmt.Printf("The second actor is returning immediately\n")
return errors.New("immediate teardown")
}, func(err error) {
// Note that this interrupt function is called, even though the
// corresponding execute function has already returned.
fmt.Printf("The second actor was interrupted with: %v\n", err)
})
}
fmt.Printf("The group was terminated with: %v\n", g.Run())
// Output:
// The second actor is returning immediately
// The first actor was interrupted with: immediate teardown
// The second actor was interrupted with: immediate teardown
// The first actor was canceled
// The group was terminated with: immediate teardown
}
func ExampleGroup_Add_context() {
ctx, cancel := context.WithCancel(context.Background())
var g run.Group
{
ctx, cancel := context.WithCancel(ctx) // note: shadowed
g.Add(func() error {
return runUntilCanceled(ctx)
}, func(error) {
cancel()
})
}
go cancel()
fmt.Printf("The group was terminated with: %v\n", g.Run())
// Output:
// The group was terminated with: context canceled
}
func ExampleGroup_Add_listener() {
var g run.Group
{
ln, _ := net.Listen("tcp", ":0")
g.Add(func() error {
defer fmt.Printf("http.Serve returned\n")
return http.Serve(ln, http.NewServeMux())
}, func(error) {
ln.Close()
})
}
{
g.Add(func() error {
return errors.New("immediate teardown")
}, func(error) {
//
})
}
fmt.Printf("The group was terminated with: %v\n", g.Run())
// Output:
// http.Serve returned
// The group was terminated with: immediate teardown
}
func runUntilCanceled(ctx context.Context) error {
<-ctx.Done()
return ctx.Err()
}