66 lines
1.6 KiB
Go
66 lines
1.6 KiB
Go
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// Copyright 2015 clair authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package utils
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import (
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"sync"
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"time"
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)
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// Stopper eases the graceful termination of a group of goroutines
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type Stopper struct {
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wg sync.WaitGroup
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stop chan struct{}
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}
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// NewStopper initializes a new Stopper instance
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func NewStopper() *Stopper {
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return &Stopper{stop: make(chan struct{}, 0)}
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}
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// Begin indicates that a new goroutine has started.
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func (s *Stopper) Begin() {
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s.wg.Add(1)
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}
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// End indicates that a goroutine has stopped.
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func (s *Stopper) End() {
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s.wg.Done()
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}
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// Chan returns the channel on which goroutines could listen to determine if
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// they should stop. The channel is closed when Stop() is called.
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func (s *Stopper) Chan() chan struct{} {
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return s.stop
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}
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// Sleep puts the current goroutine on sleep during a duration d
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// Sleep could be interrupted in the case the goroutine should stop itself,
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// in which case Sleep returns false.
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func (s *Stopper) Sleep(d time.Duration) bool {
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select {
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case <-time.After(d):
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return true
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case <-s.stop:
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return false
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}
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}
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// Stop asks every goroutine to end.
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func (s *Stopper) Stop() {
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close(s.stop)
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s.wg.Wait()
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}
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