mirror of
https://github.com/arangodb/kube-arangodb.git
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61 lines
1.4 KiB
Go
61 lines
1.4 KiB
Go
//
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// DISCLAIMER
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//
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// Copyright 2016-2022 ArangoDB GmbH, Cologne, Germany
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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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//
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// Copyright holder is ArangoDB GmbH, Cologne, Germany
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//
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package trigger
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import "sync"
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// Trigger is a synchronization utility used to wait (in a select statement)
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// until someone triggers it.
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type Trigger struct {
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mu sync.Mutex
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done chan struct{}
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pendingTriggers int
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}
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// Done returns the channel to use in a select case.
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// This channel is closed when someone calls Trigger.
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func (t *Trigger) Done() <-chan struct{} {
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t.mu.Lock()
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defer t.mu.Unlock()
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if t.done == nil {
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t.done = make(chan struct{})
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}
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if t.pendingTriggers > 0 {
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t.pendingTriggers = 0
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d := t.done
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close(t.done)
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t.done = nil
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return d
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}
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return t.done
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}
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// Trigger closes any Done channel.
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func (t *Trigger) Trigger() {
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t.mu.Lock()
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defer t.mu.Unlock()
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t.pendingTriggers++
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if t.done != nil {
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close(t.done)
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t.done = nil
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}
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}
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