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| Code Block | ||
|---|---|---|
| ||
// Uses atomic utilities
class Foo {
private final AtomicReference<Helper> helperRef =
new AtomicReference<Helper>();
public Helper getHelper() {
Helper helper = helperRef.get();
if (helper != null) {
return helper;
}
Helper newHelper = new Helper();
return helperRef.compareAndSet(null, newHelper) ?
newHelper :
helperRef.get();
}
}
|
Note that while this code ensures that only one Helper}] object is preserved, it may potentially allow multiple {{Helper objects to be created; with all but one being garbage-collected. But if constructing multiple Helper objects is infeasible or expensive, then this solution might not be appropriate.
Compliant Solution (immutable)
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