31 lines
856 B
Go
31 lines
856 B
Go
// +build !solution
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package once
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// Once describes an object that will perform exactly one action.
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type Once struct {
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}
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// New creates Once.
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func New() *Once {
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return nil
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}
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// Do calls the function f if and only if Do is being called for the
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// first time for this instance of Once. In other words, given
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// once := New()
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// if once.Do(f) is called multiple times, only the first call will invoke f,
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// even if f has a different value in each invocation. A new instance of
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// Once is required for each function to execute.
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//
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// Do is intended for initialization that must be run exactly once.
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//
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// Because no call to Do returns until the one call to f returns, if f causes
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// Do to be called, it will deadlock.
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//
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// If f panics, Do considers it to have returned; future calls of Do return
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// without calling f.
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//
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func (o *Once) Do(f func()) {
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}
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