Fix a bogus use of mutex

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 948f526cce836613e4e88fa80db9533ab9613c8e..b08b687af2408f55d3690645963ae899db907fdd 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1396,8 +1396,8 @@ moves_loop: // When in check and at SpNode search starts from here
     *pv = MOVE_NONE;
   }
 
-  // update_stats() updates killers, history, countermoves and followupmoves stats after a fail-high
-  // of a quiet move.
+  // update_stats() updates killers, history, countermoves and followupmoves
+  // stats after a fail-high of a quiet move.
 
   void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt) {
 
@@ -1407,36 +1407,32 @@ moves_loop: // When in check and at SpNode search starts from here
         ss->killers[0] = move;
     }
 
-    // Increase history value of the cut-off move and decrease all the other
-    // played quiet moves.
     Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY));
+
+    Square prevSq = to_sq((ss-1)->currentMove);
+    HistoryStats& cmh = CounterMovesHistory[pos.piece_on(prevSq)][prevSq];
+
     History.update(pos.moved_piece(move), to_sq(move), bonus);
 
-    for (int i = 0; i < quietsCnt; ++i)
+    if (is_ok((ss-1)->currentMove))
     {
-        Move m = quiets[i];
-        History.update(pos.moved_piece(m), to_sq(m), -bonus);
+        Countermoves.update(pos.piece_on(prevSq), prevSq, move);
+        cmh.update(pos.moved_piece(move), to_sq(move), bonus);
     }
 
-    if (is_ok((ss-1)->currentMove))
+    // Decrease all the other played quiet moves
+    for (int i = 0; i < quietsCnt; ++i)
     {
-        Square prevMoveSq = to_sq((ss-1)->currentMove);
-        Piece prevMovePiece = pos.piece_on(prevMoveSq);
-        Countermoves.update(prevMovePiece, prevMoveSq, move);
+        History.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
 
-        HistoryStats& cmh = CounterMovesHistory[prevMovePiece][prevMoveSq];
-        cmh.update(pos.moved_piece(move), to_sq(move), bonus);
-        for (int i = 0; i < quietsCnt; ++i)
-        {
-            Move m = quiets[i];
-            cmh.update(pos.moved_piece(m), to_sq(m), -bonus);
-        }
+        if (is_ok((ss-1)->currentMove))
+            cmh.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus);
     }
 
     if (is_ok((ss-2)->currentMove) && (ss-1)->currentMove == (ss-1)->ttMove)
     {
-        Square prevOwnMoveSq = to_sq((ss-2)->currentMove);
-        Followupmoves.update(pos.piece_on(prevOwnMoveSq), prevOwnMoveSq, move);
+        Square prevPrevSq = to_sq((ss-2)->currentMove);
+        Followupmoves.update(pos.piece_on(prevPrevSq), prevPrevSq, move);
     }
   }
 
@@ -1603,7 +1599,7 @@ void Thread::idle_loop() {
             && !(this_sp && this_sp->slavesMask.none())
             && !searching)
       {
-          if (   !this_sp 
+          if (   !this_sp
               && !Threads.main()->thinking)
           {
               std::unique_lock<Mutex> lk(mutex);
@@ -1617,12 +1613,12 @@ void Thread::idle_loop() {
       // If this thread has been assigned work, launch a search
       while (searching)
       {
-          mutex.lock();
+          spinlock.acquire();
 
           assert(activeSplitPoint);
           SplitPoint* sp = activeSplitPoint;
 
-          mutex.unlock();
+          spinlock.release();
 
           Stack stack[MAX_PLY+4], *ss = stack+2; // To allow referencing (ss-2) and (ss+2)
           Position pos(*sp->pos, this);