// --------------------------------------------------------------------------------------------
public void RecordVisitToTopLevelMove(MCTSNode leafNode, MCTSNodeStructIndex indexOfChildDescendentFromRoot, LeafEvaluationResult evalResult)
{
#if NOT
if (indexOfChildDescendentFromRoot == -1)
{
return; // if the root
}
int childIndex = -1;
Span <MCTSNodeStructChild> children = Root.Ref.Children;
for (int i = 0; i < Root.NumChildrenExpanded; i++)
{
if (children[i].ChildIndex.Index == indexOfChildDescendentFromRoot)
{
childIndex = i;
break;
}
}
if (childIndex == -1)
{
throw new Exception("Internal error");
}
if (rootChildrenMovingAverageValues == null)
{
rootChildrenMovingAverageN = new float[Root.NumPolicyMoves];
rootChildrenMovingAverageValues = new float[Root.NumPolicyMoves];
rootChildrenMovingAverageSquaredValues = new float[Root.NumPolicyMoves];
}
float v = evalResult.V * (leafNode.Depth % 2 == 0 ? -1 : 1);
float diff = v - (float)Root.Ref.Children[childIndex].ChildRef.Q;
const float C1 = 0.99f;
const float C2 = 1.0f - C1;
/// <summary>
/// Constructor to create a store of specified maximum size.
/// </summary>
/// <param name="maxNodes"></param>
/// <param name="priorMoves"></param>
public MCTSNodeStore(int maxNodes, PositionWithHistory priorMoves = null)
{
if (priorMoves == null)
{
priorMoves = PositionWithHistory.StartPosition;
}
MaxNodes = maxNodes;
int allocNodes = maxNodes;
Nodes = new MCTSNodeStructStorage(allocNodes, null,
MCTSParamsFixed.STORAGE_USE_INCREMENTAL_ALLOC,
MCTSParamsFixed.STORAGE_LARGE_PAGES,
MCTSParamsFixed.STORAGE_USE_EXISTING_SHARED_MEM);
long reserveChildren = maxNodes * (long)AVG_CHILDREN_PER_NODE;
Children = new MCTSNodeStructChildStorage(this, reserveChildren);
// Save a copy of the prior moves
Nodes.PriorMoves = new PositionWithHistory(priorMoves);
CeresEnvironment.LogInfo("NodeStore", "Init", $"MCTSNodeStore created with max {maxNodes} nodes, max {reserveChildren} children");
MCTSNodeStruct.ValidateMCTSNodeStruct();
RootIndex = new MCTSNodeStructIndex(1);
}
internal ChildEnumeratorImplState(MCTSNodeStore store, MCTSNodeStructIndex nodeIndex, int maxIndex)
{
Store = store;
childSpan = store.Children.SpanForNode(nodeIndex);
index = UInt32.MaxValue;
endIndex = (int)maxIndex;
nodes = (MCTSNodeStruct *)Store.Nodes.nodes.RawMemory;
}
/// <summary>
/// Constructor to begin iteration within specified at a specified node.
/// </summary>
/// <param name="store"></param>
/// <param name="root"></param>
public MCTSNodeSequentialVisitor(MCTSNodeStore store, MCTSNodeStructIndex root)
{
Store = store;
Root = root;
currentNode = root;
pendingBranches = new SortedSet <MCTSNodeStructIndex>();
}
/// <summary>
/// Returns the MCTSNode having the specified index and stored in the cache
/// or null if not currently cached.
/// </summary>
/// <param name="nodeIndex"></param>
/// <returns></returns>
public MCTSNode Lookup(MCTSNodeStructIndex nodeIndex)
{
bool alreadyInCache = false;
MCTSNode cachedItem = default;
alreadyInCache = nodeCache.TryGetValue(nodeIndex.Index, out cachedItem);
return(cachedItem);
}
/// <summary>
/// Prunes cache down to approximately specified target size.
/// </summary>
/// <param name="store"></param>
/// <param name="targetSize">target numer of nodes, or -1 to use default sizing</param>
/// <returns></returns>
internal int Prune(MCTSNodeStore store, int targetSize)
{
int startNumInUse = numInUse;
// Default target size is 70% of maximum.
if (targetSize == -1)
{
targetSize = (nodes.Length * 70) / 100;
}
if (numInUse <= targetSize)
{
return(0);
}
lock (lockObj)
{
int count = 0;
for (int i = 0; i < nodes.Length; i++)
{
// TODO: the long is cast to int, could we possibly overflow? make long?
if (nodes[i] != null)
{
pruneSequenceNums[count++] = (int)nodes[i].LastAccessedSequenceCounter;
}
}
Span <int> slice = new Span <int>(pruneSequenceNums).Slice(0, count);
// Compute the minimum sequence number an entry must have
// to be retained (to enforce LRU eviction)
//float cutoff = KthSmallestValue.CalcKthSmallestValue(keyPrioritiesForSorting, numToPrune);
int cutoff;
cutoff = KthSmallestValueInt.CalcKthSmallestValue(slice, numInUse - targetSize);
//Console.WriteLine(slice.Length + " " + (numInUse-targetSize) + " --> "
// + cutoff + " correct " + slice[numInUse-targetSize] + " avg " + slice[numInUse/2]);
int maxEntries = pruneCount == 0 ? (numInUse + 1) : nodes.Length;
for (int i = 1; i < maxEntries; i++)
{
MCTSNode node = nodes[i];
if (node != null && node.LastAccessedSequenceCounter < cutoff)
{
MCTSNodeStructIndex nodeIndex = new MCTSNodeStructIndex(node.Index);
nodes[i] = null;
ref MCTSNodeStruct refNode = ref store.Nodes.nodes[nodeIndex.Index];
refNode.CacheIndex = 0;
numInUse--;
}
}
pruneCount++;
}
/// <summary>
/// Constructor which creates an MCTSNode wrapper for the raw node at specified index.
/// </summary>
/// <param name="context"></param>
/// <param name="index"></param>
/// <param name="parent">optionally the parent node</param>
internal MCTSNode(MCTSIterator context, MCTSNodeStructIndex index, MCTSNode parent = null)
{
Debug.Assert(context.Tree.Store.Nodes != null);
Debug.Assert(index.Index <= context.Tree.Store.Nodes.MaxNodes);
Context = context;
Tree = context.Tree;
this.parent = parent;
Span <MCTSNodeStruct> parentArray = context.Tree.Store.Nodes.Span;
ptr = (MCTSNodeStruct *)Unsafe.AsPointer(ref parentArray[index.Index]);
this.index = index;
}
private static LeafEvaluationResult ExtractTranspositionNodesFromSubtree(MCTSNode node, ref MCTSNodeStruct transpositionRootNode,
ref int numAlreadyLinked, MCTSNodeTranspositionVisitor linkedVisitor)
{
LeafEvaluationResult result = default;
// Determine how many evaluations we should extract (based on number requested and number available)
int numAvailable = linkedVisitor.TranspositionRootNWhenVisitsStarted - numAlreadyLinked;
int numDesired = node.NInFlight + node.NInFlight2;
if (numDesired > numAvailable && WARN_COUNT < 10)
{
Console.WriteLine(numDesired + " Warning: multiple nodes were requested from the transposition subtree, available " + numAvailable);
WARN_COUNT++;
}
int numToFetch = Math.Min(numDesired, numAvailable);
Debug.Assert(numToFetch > 0);
// Extract each evaluation
for (int i = 0; i < numToFetch; i++)
{
MCTSNodeStructIndex transpositionSubnodeIndex = linkedVisitor.Visitor.GetNext();
Debug.Assert(!transpositionSubnodeIndex.IsNull);
NumExtractedAndNeverCloned++;
numAlreadyLinked++;
// Prepare the result to return
ref MCTSNodeStruct transpositionSubnode = ref node.Context.Tree.Store.Nodes.nodes[transpositionSubnodeIndex.Index];
LeafEvaluationResult thisResult = new LeafEvaluationResult(transpositionSubnode.Terminal, transpositionRootNode.WinP,
transpositionRootNode.LossP, transpositionRootNode.MPosition);
// Update our result node to include this node
result = AddResultToResults(result, numToFetch, i, thisResult);
if (VERBOSE)
{
Console.WriteLine($"ProcessAlreadyLinked {node.Index} yields {result.WinP} {result.LossP} via linked subnode root {transpositionRootNode.Index.Index} {transpositionRootNode} chose {transpositionSubnode.Index.Index}");
}
node.Ref.NumNodesTranspositionExtracted++;
}
/// <summary>
/// Attempts to return the MCTSNode associated with an annotation in the cache,
/// or null if not found
/// </summary>
/// <param name="nodeIndex"></param>
/// <returns></returns>
public MCTSNode GetNode(MCTSNodeStructIndex nodeIndex, MCTSNode parent = null, bool checkCache = true)
{
MCTSNode ret = checkCache ? cache.Lookup(nodeIndex) : null;
if (ret is null)
{
if (parent is null && !nodeIndex.IsRoot)
{
parent = GetNode(nodeIndex.Ref.ParentIndex, null);
}
ret = new MCTSNode(Context, nodeIndex, parent);
cache?.Add(ret);
NUM_MISSES++;
}
else
{
NUM_HITS++;
ret.LastAccessedSequenceCounter = SEQUENCE_COUNTER++;
}
Debug.Assert(ret.Index == nodeIndex.Index);
return(ret);
}
/// <summary> /// Returns the MCTSNode having the specified index and stored in the cache /// or null if not currently cached. /// </summary> /// <param name="nodeIndex"></param> /// <returns></returns> public MCTSNode Lookup(MCTSNodeStructIndex nodeIndex) => nodes[nodeIndex.Index];
public ChildEnumeratorImpl(MCTSNodeStore store, MCTSNodeStructIndex nodeIndex, int overrideMaxIndex = int.MaxValue)
{
Store = store;
NodeIndex = nodeIndex;
MaxIndex = Math.Min(overrideMaxIndex, Store.Nodes.nodes[nodeIndex.Index].NumChildrenExpanded - 1);
}
/// <summary> /// Methods at MCTSNodeStore related to enumeration of children. /// /// NOTE: this is not currently used but possibly could/should be used. /// </summary> /// <param name="nodeIndex"></param> /// <param name="overrideMaxIndex"></param> /// <returns></returns> public ChildEnumeratorImpl ChildrenExpandedEnumerator(MCTSNodeStructIndex nodeIndex, int overrideMaxIndex = int.MaxValue) => new ChildEnumeratorImpl(this, nodeIndex, overrideMaxIndex);
/// <summary> /// Returns the MCTSNode having the specified index and stored in the cache /// or null if not currently cached. /// </summary> /// <param name="nodeIndex"></param> /// <returns></returns> public MCTSNode Lookup(MCTSNodeStructIndex nodeIndex) => subCaches[nodeIndex.Index % MAX_SUBCACHES].Lookup(nodeIndex);
/// <summary>
/// Returns the next branch to be iterated.
/// </summary>
/// <param name="thisNodeIndex"></param>
/// <param name="boundSeqNum"></param>
/// <returns></returns>
MCTSNodeStructIndex GetNextBranch(MCTSNodeStructIndex thisNodeIndex, int boundSeqNum)
{
int bestIndex1 = -1;
int bestSeq = int.MaxValue;
ref MCTSNodeStruct thisNode = ref Store.Nodes.nodes[thisNodeIndex.Index];