/// <summary> /// If visual is on channel, its reference count is increased. /// Otherwise, a new resource is created on that channel. /// </summary> internal bool ReleaseOnChannel(DUCE.Channel channel) { int index = Find(channel); bool proxyRemoved = false; int count = Count; if (index == PROXY_STORED_INLINE) { if (channel.ReleaseOnChannel(_head.Handle)) { // // Need to move the last of the non-empty tail to head // or clear the head. Erase the head if that was the last // proxy. // if (count == 1) { _head = new Proxy(); } else { _head = _tail[count - 2]; } proxyRemoved = true; } } else if (index >= 0) { if (channel.ReleaseOnChannel(_tail[index].Handle)) { // // Need to move the last of the non-empty tail to the // removed index. Avoid in-place copying. // if (index != count - 2) { _tail[index] = _tail[count - 2]; } proxyRemoved = true; } } else { Debug.Assert(index != PROXY_NOT_FOUND); return(false); } if (proxyRemoved) { if (_tail != null) { // // Keep the tail short. We allow for one extra free element // in tail to avoid constant allocations / reallocations. // if (count == 2) { // ------------------ // Before removal: [head] [tail c-1] [empty] // Here and now: [head] [ deleted] [empty] // After removal: [head] // _tail = null; } else if (count == _tail.Length) { // --------------------------------------------------- // Before removal: [head] [tail 0] [tail 1] ... [tail c-3] [tail c-2] [empty] // Here and now: [head] [tail 0] [tail 1] ... [tail c-3] [ deleted] [empty] // After removal: [head] [tail 0] [tail 1] ... [tail c-3] // ResizeTail(-2); } else { // ------------------------------------------------------ // Before removal: [head] [tail 0] [tail 1] ... [tail c-4] [tail c-3] [tail c-2] // Here and now: [head] [tail 0] [tail 1] ... [tail c-4] [tail c-3] [ deleted] // After removal: [head] [tail 0] [tail 1] ... [tail c-4] [tail c-3] [ empty] // _tail[count - 2] = new Proxy(); } } } return(proxyRemoved); }