public static bool TryGet(LinkII <TKey, TValue> link, TKey key, out TValue value)
{
while (link != null)
{
if ((object)key == (object)link.Key)
{
value = link.Value;
return(true);
}
link = link.Tail;
}
value = default(TValue);
return(false);
}
public static bool TryAdd(ref LinkII <TKey, TValue> head, TKey key, ref TValue value)
{
bool tryAgain;
do
{
var snapshot = Interlocked.CompareExchange(ref head, null, null);
TValue found;
if (TryGet(snapshot, key, out found))
{ // existing match; report the existing value instead
value = found;
return(false);
}
var newNode = new LinkII <TKey, TValue>(key, value, snapshot);
// did somebody move our cheese?
tryAgain = Interlocked.CompareExchange(ref head, newNode, snapshot) != snapshot;
} while (tryAgain);
return(true);
}
private LinkII(TKey key, TValue value, LinkII <TKey, TValue> tail)
{
Key = key;
Value = value;
Tail = tail;
}
