private bool TryCreateSetup(TKey key, out ConstructionState state)
{
if (Storage.ContainsKey(key))
{
state = null;
return(false);
}
state = new ConstructionState();
if (States.TryAdd(key, state))
{
if (Storage.ContainsKey(key))
{
TryCreateTeardown(key, state);
return(false);
}
return(true);
}
else
{
state.Dispose();
return(false);
}
}
private void TryCreateTeardown(TKey key, ConstructionState state)
{
if (States.TryRemove(key, out state))
{
state.Set();
state.Dispose();
}
}
public bool TryCreate(TKey key, Func <TValue> creator)
{
ConstructionState state;
if (Storage.ContainsKey(key))
{
return(false);
}
state = new ConstructionState();
if (States.TryAdd(key, state))
{
try {
if (Storage.ContainsKey(key))
{
return(false);
}
var result = creator();
if (!Storage.TryAdd(key, result))
{
throw new InvalidOperationException("Cache entry was created by someone else while construction lock was held");
}
return(true);
} finally {
States.TryRemove(key, out state);
state.Set();
state.Dispose();
}
}
else
{
state.Dispose();
}
return(false);
}