39 lines
741 B
Go
39 lines
741 B
Go
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package resync
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import (
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"sync"
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"sync/atomic"
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)
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// Once is an object that will perform exactly one action
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// until Reset is called.
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// See http://golang.org/pkg/sync/#Once
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type Once struct {
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m sync.Mutex
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done uint32
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}
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// Do simulates sync.Once.Do by executing the specified function
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// only once, until Reset is called.
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// See http://golang.org/pkg/sync/#Once
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func (o *Once) Do(f func()) {
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if atomic.LoadUint32(&o.done) == 1 {
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return
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}
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// Slow-path.
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o.m.Lock()
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defer o.m.Unlock()
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if o.done == 0 {
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defer atomic.StoreUint32(&o.done, 1)
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f()
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}
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}
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// Reset indicates that the next call to Do should actually be called
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// once again.
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func (o *Once) Reset() {
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o.m.Lock()
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defer o.m.Unlock()
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atomic.StoreUint32(&o.done, 0)
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}
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