Change semantics of maxvisits so it counts weightless visits

cpp/search/search.cpp

@@ -41,6 +41,7 @@ SearchThread::SearchThread(int tIdx, const Search& search)
    history(search.rootHistory),
    graphHash(search.rootGraphHash),
    graphPath(),
+   shouldCountPlayout(false),
    rand(makeSeed(search,tIdx)),
    nnResultBuf(),
    statsBuf(),
@@ -1102,7 +1103,11 @@ bool Search::runSinglePlayout(SearchThread& thread, double upperBoundVisitsLeft)
   //Store this value, used for futile-visit pruning this thread's root children selections.
   thread.upperBoundVisitsLeft = upperBoundVisitsLeft;
 
+  //Prep this value, playoutDescend will set it to true if we do have a playout
+  thread.shouldCountPlayout = false;
+
   bool finishedPlayout = playoutDescend(thread,*rootNode,true);
+  (void)finishedPlayout;
 
   //Restore thread state back to the root state
   thread.pla = rootPla;
@@ -1111,7 +1116,7 @@ bool Search::runSinglePlayout(SearchThread& thread, double upperBoundVisitsLeft)
   thread.graphHash = rootGraphHash;
   thread.graphPath.clear();
 
-  return finishedPlayout;
+  return thread.shouldCountPlayout;
 }
 
 bool Search::playoutDescend(
@@ -1136,6 +1141,7 @@ bool Search::playoutDescend(
       double lead = 0.0;
       double weight = (searchParams.useUncertainty && nnEvaluator->supportsShorttermError()) ? searchParams.uncertaintyMaxWeight : 1.0;
       addLeafValue(node, winLossValue, noResultValue, scoreMean, scoreMeanSq, lead, weight, true, false);
+      thread.shouldCountPlayout = true;
       return true;
     }
     else {
@@ -1146,6 +1152,7 @@ bool Search::playoutDescend(
       double lead = scoreMean;
       double weight = (searchParams.useUncertainty && nnEvaluator->supportsShorttermError()) ? searchParams.uncertaintyMaxWeight : 1.0;
       addLeafValue(node, winLossValue, noResultValue, scoreMean, scoreMeanSq, lead, weight, true, false);
+      thread.shouldCountPlayout = true;
       return true;
     }
   }
@@ -1171,6 +1178,7 @@ bool Search::playoutDescend(
       //Perform the nn evaluation and finish!
       node.initializeChildren();
       node.state.store(SearchNode::STATE_EXPANDED0, std::memory_order_seq_cst);
+      thread.shouldCountPlayout = true;
       return true;
     }
   }
@@ -1221,13 +1229,15 @@ bool Search::playoutDescend(
       //Return TRUE though, so that the parent path we traversed increments its edge visits.
       //We want the search to continue as best it can, so we increment visits so search will still make progress
       //even if this keeps happening in some really bad transposition or something.
+      thread.shouldCountPlayout = true;
       return true;
     }
 
     if(bestChildIdx <= -1) {
       //This might happen if all moves have been forbidden. The node will just get stuck counting visits without expanding
       //and we won't do any search.
       addCurrentNNOutputAsLeafValue(node,false);
+      thread.shouldCountPlayout = true;
       return true;
     }
 
@@ -1295,6 +1305,7 @@ bool Search::playoutDescend(
       if(countEdgeVisit && maybeCatchUpEdgeVisits(thread, node, child, nodeState, bestChildIdx)) {
         updateStatsAfterPlayout(node,thread,isRoot);
         child->virtualLosses.fetch_add(-1,std::memory_order_release);
+        thread.shouldCountPlayout = true;
         return true;
       }
     }
@@ -1312,6 +1323,7 @@ bool Search::playoutDescend(
       if(countEdgeVisit && maybeCatchUpEdgeVisits(thread, node, child, nodeState, bestChildIdx)) {
         updateStatsAfterPlayout(node,thread,isRoot);
         child->virtualLosses.fetch_add(-1,std::memory_order_release);
+        thread.shouldCountPlayout = true;
         return true;
       }
 
@@ -1339,6 +1351,7 @@ bool Search::playoutDescend(
         SearchNodeChildrenReference children = node.getChildren(nodeState);
         children[bestChildIdx].addEdgeVisits(1);
         updateStatsAfterPlayout(node,thread,isRoot);
+        thread.shouldCountPlayout = true;
       }
       child->virtualLosses.fetch_add(-1,std::memory_order_release);
       // If we didn't count an edge visit, none of the parents need to update either.

cpp/search/search.h

@@ -50,6 +50,10 @@ struct SearchThread {
   //The path we trace down the graph as we do a playout
   std::unordered_set<SearchNode*> graphPath;
 
+  //Tracks whether this thread did something that "should" be counted as a playout
+  //for the purpose of playout limits
+  bool shouldCountPlayout;
+
   Rand rand;
 
   NNResultBuf nnResultBuf;