mirror of https://github.com/kubernetes/kops.git
55 lines
1.2 KiB
Go
55 lines
1.2 KiB
Go
package util
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import (
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"fmt"
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"sync"
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"github.com/golang/glog"
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)
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// Stoppable implements the standard stop / shutdown logic
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type Stoppable struct {
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// mutex is used to enforce only a single call to Stop is active.
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// Needed because we allow stopping through an http endpoint and
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// allowing concurrent stoppers leads to stack traces.
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// We also use it for lazy-init
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mutex sync.Mutex
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shutdown bool
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stopChannel chan struct{}
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}
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// StopChannel gets the stopChannel, initializing it if needed
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func (s *Stoppable) StopChannel() <-chan struct{} {
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s.mutex.Lock()
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defer s.mutex.Unlock()
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if s.stopChannel == nil {
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s.stopChannel = make(chan struct{})
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}
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return s.stopChannel
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}
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// Stop stops the controller.
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func (s *Stoppable) Stop() error {
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s.mutex.Lock()
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defer s.mutex.Unlock()
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if s.shutdown {
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return fmt.Errorf("shutdown already in progress")
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}
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// We initialize the channel to avoid a race if we Stop before anyone is watching
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if s.stopChannel == nil {
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s.stopChannel = make(chan struct{})
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}
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close(s.stopChannel)
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glog.Infof("shutting down controller")
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s.shutdown = true
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return nil
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}
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func (s *Stoppable) StopRequested() bool {
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return s.shutdown
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}
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