public void GetSharedInstance_ExistingWeakRefIsNull_AnotherThreadCreatesInstanceWhileOurFactoryRuns_ReturnsExistingInstanceAndDisposesNewInstance()
{
// Arrange
WeakReference <MyDisposable> wr = null;
MyDisposable instanceThatWillBeCreatedFirst = new MyDisposable();
MyDisposable instanceThatWillBeCreatedSecond = new MyDisposable();
// Act
var retVal = WeakReferenceHelpers.GetSharedInstance(ref wr, () =>
{
// mimic another thread creating the instance while our factory is being invoked
WeakReferenceHelpers.GetSharedInstance(ref wr, () => instanceThatWillBeCreatedFirst);
return(instanceThatWillBeCreatedSecond);
});
// Assert
MyDisposable target;
Assert.NotNull(wr);
Assert.True(wr.TryGetTarget(out target));
Assert.Same(instanceThatWillBeCreatedFirst, target);
Assert.Same(instanceThatWillBeCreatedFirst, retVal);
Assert.False(instanceThatWillBeCreatedFirst.HasBeenDisposed);
Assert.True(instanceThatWillBeCreatedSecond.HasBeenDisposed);
}
public void GetSharedInstance_ExistingWeakRefIsNull_CreatesNew()
{
// Arrange
WeakReference <MyDisposable> wr = null;
MyDisposable newInstance = new MyDisposable();
// Act
var retVal = WeakReferenceHelpers.GetSharedInstance(ref wr, () => newInstance);
// Assert
Assert.NotNull(wr);
Assert.True(wr.TryGetTarget(out var target));
Assert.Same(newInstance, target);
Assert.Same(newInstance, retVal);
Assert.False(newInstance.HasBeenDisposed);
}
