Enhanced verify search (#1338)

[stockfish] / src / thread.cpp

diff --git a/src/thread.cpp b/src/thread.cpp
index 208cb0b1279d07f23f0b530c8b599b1444ab9bcb..58d693cf2a52547c4fc5f1140436293bd9fcda2d 100644 (file)
--- a/src/thread.cpp
+++ b/src/thread.cpp
@@ -35,6 +35,7 @@ ThreadPool Threads; // Global object
 Thread::Thread(size_t n) : idx(n), stdThread(&Thread::idle_loop, this) {
 
   wait_for_search_finished();
+  clear(); // Zero-init histories (based on std::array)
 }
 
 
@@ -51,6 +52,21 @@ Thread::~Thread() {
 }
 
 
+/// Thread::clear() reset histories, usually before a new game
+
+void Thread::clear() {
+
+  counterMoves.fill(MOVE_NONE);
+  mainHistory.fill(0);
+  captureHistory.fill(0);
+
+  for (auto& to : contHistory)
+      for (auto& h : to)
+          h.fill(0);
+
+  contHistory[NO_PIECE][0].fill(Search::CounterMovePruneThreshold - 1);
+}
+
 /// Thread::start_searching() wakes up the thread that will start the search
 
 void Thread::start_searching() {
@@ -96,7 +112,7 @@ void Thread::idle_loop() {
 
 
 /// ThreadPool::init() creates and launches the threads that will go
-/// immediately to sleep in idle_loop. We cannot use the c'tor because
+/// immediately to sleep in idle_loop. We cannot use the constructor because
 /// Threads is a static object and we need a fully initialized engine at
 /// this point due to allocation of Endgames in the Thread constructor.
 
@@ -171,6 +187,8 @@ void ThreadPool::start_thinking(Position& pos, StateListPtr& states,
       th->rootDepth = th->completedDepth = DEPTH_ZERO;
       th->rootMoves = rootMoves;
       th->rootPos.set(pos.fen(), pos.is_chess960(), &setupStates->back(), th);
+      th->nmp_ply = 0;
+      th->pair = -1;
   }
 
   setupStates->back() = tmp;