23 lines
		
	
	
		
			607 B
		
	
	
	
		
			Go
		
	
	
	
			
		
		
	
	
			23 lines
		
	
	
		
			607 B
		
	
	
	
		
			Go
		
	
	
	
package util
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import "context"
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// ContextForChannel derives a child context from a parent channel.
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//
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// The derived context's Done channel is closed when the returned cancel function
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// is called or when the parent channel is closed, whichever happens first.
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//
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// Note the caller must *always* call the CancelFunc, otherwise resources may be leaked.
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func ContextForChannel(parentCh <-chan struct{}) (context.Context, context.CancelFunc) {
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	ctx, cancel := context.WithCancel(context.Background())
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	go func() {
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		select {
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		case <-parentCh:
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			cancel()
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		case <-ctx.Done():
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		}
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	}()
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	return ctx, cancel
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}
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