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31 lines
877 B
31 lines
877 B
package sync
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import "sync"
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// Closer implements a primitive to close a channel that signals process
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// termination while allowing a caller to call Close multiple times safely. It
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// should be used in cases where guarantees cannot be made about when and how
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// many times closure is executed.
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type Closer struct {
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closeOnce sync.Once
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doneCh chan struct{}
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}
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// NewCloser returns a reference to a new Closer.
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func NewCloser() *Closer {
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return &Closer{doneCh: make(chan struct{})}
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}
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// Done returns the internal done channel allowing the caller either block or wait
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// for the Closer to be terminated/closed.
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func (c *Closer) Done() <-chan struct{} {
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return c.doneCh
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}
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// Close gracefully closes the Closer. A caller should only call Close once, but
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// it is safe to call it successive times.
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func (c *Closer) Close() {
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c.closeOnce.Do(func() {
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close(c.doneCh)
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})
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}
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