X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fsearch.cpp;h=a97c73485523eaf13002ddf3c6895b3f7c52d663;hb=ea6c1f7a17572f1cd291ffd00e28cfbd3b2947d5;hp=3ba0dbc905b9f6a75c4da3be45dca9b23a2d17f2;hpb=3cf6471738dc704ddf553d5f8d2dc9875c2ccbe7;p=stockfish

diff --git a/src/search.cpp b/src/search.cpp
index 3ba0dbc9..a97c7348 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -194,7 +194,7 @@ void Search::think() {
       goto finalize;
   }
 
-  if (Options["OwnBook"] && !Limits.infinite)
+  if (Options["OwnBook"] && !Limits.infinite && !Limits.mate)
   {
       Move bookMove = book.probe(RootPos, Options["Book File"], Options["Best Book Move"]);
 
@@ -227,7 +227,15 @@ void Search::think() {
           << std::endl;
   }
 
-  Threads.wake_up();
+  // Reset and wake up the threads
+  for (size_t i = 0; i < Threads.size(); i++)
+  {
+      Threads[i].maxPly = 0;
+      Threads[i].do_sleep = false;
+
+      if (!Threads.use_sleeping_threads())
+          Threads[i].notify_one();
+  }
 
   // Set best timer interval to avoid lagging under time pressure. Timer is
   // used to check for remaining available thinking time.
@@ -242,7 +250,11 @@ void Search::think() {
   id_loop(RootPos); // Let's start searching !
 
   Threads.set_timer(0); // Stop timer
-  Threads.sleep();
+
+  // Main thread will go to sleep by itself to avoid a race with start_searching()
+  for (size_t i = 0; i < Threads.size(); i++)
+      if (&Threads[i] != Threads.main_thread())
+          Threads[i].do_sleep = true;
 
   if (Options["Use Search Log"])
   {
@@ -262,10 +274,15 @@ void Search::think() {
 finalize:
 
   // When we reach max depth we arrive here even without Signals.stop is raised,
-  // but if we are pondering or in infinite search, we shouldn't print the best
-  // move before we are told to do so.
+  // but if we are pondering or in infinite search, according to UCI protocol,
+  // we shouldn't print the best move before the GUI sends a "stop" or "ponderhit"
+  // command. We simply wait here until GUI sends one of those commands (that
+  // raise Signals.stop).
   if (!Signals.stop && (Limits.ponder || Limits.infinite))
-      RootPos.this_thread()->wait_for_stop_or_ponderhit();
+  {
+      Signals.stopOnPonderhit = true;
+      RootPos.this_thread()->wait_for(Signals.stop);
+  }
 
   // Best move could be MOVE_NONE when searching on a stalemate position
   sync_cout << "bestmove " << move_to_uci(RootMoves[0].pv[0], RootPos.is_chess960())
@@ -410,6 +427,12 @@ namespace {
         if (depth > 2 && BestMoveChanges)
             bestMoveNeverChanged = false;
 
+        // Do we have found a "mate in x"?
+        if (   Limits.mate
+            && bestValue >= VALUE_MATE_IN_MAX_PLY
+            && VALUE_MATE - bestValue <= 2 * Limits.mate)
+            Signals.stop = true;
+
         // Do we have time for the next iteration? Can we stop searching now?
         if (Limits.use_time_management() && !Signals.stopOnPonderhit)
         {
@@ -578,15 +601,9 @@ namespace {
 
     else if (tte)
     {
-        // Following asserts are valid only in single thread condition because
-        // TT access is always racy and its contents cannot be trusted.
-        assert(tte->static_value() != VALUE_NONE || Threads.size() > 1);
-        assert(ttValue != VALUE_NONE || tte->type() == BOUND_NONE || Threads.size() > 1);
-
-        ss->staticEval = eval = tte->static_value();
-        ss->evalMargin = tte->static_value_margin();
-
-        if (eval == VALUE_NONE || ss->evalMargin == VALUE_NONE) // Due to a race
+        // Never assume anything on values stored in TT
+        if (  (ss->staticEval = eval = tte->static_value()) == VALUE_NONE
+            ||(ss->evalMargin = tte->static_value_margin()) == VALUE_NONE)
             eval = ss->staticEval = evaluate(pos, ss->evalMargin);
 
         // Can ttValue be used as a better position evaluation?
@@ -902,7 +919,7 @@ split_point_start: // At split points actual search starts from here
           continue;
       }
 
-      pvMove = PvNode ? moveCount == 1 : false;
+      pvMove = PvNode && moveCount == 1;
       ss->currentMove = move;
       if (!SpNode && !captureOrPromotion && playedMoveCount < 64)
           movesSearched[playedMoveCount++] = move;
@@ -994,24 +1011,21 @@ split_point_start: // At split points actual search starts from here
 
       if (value > bestValue)
       {
-          bestValue = value;
-          if (SpNode) sp->bestValue = value;
+          bestValue = SpNode ? sp->bestValue = value : value;
 
           if (value > alpha)
           {
-              bestMove = move;
-              if (SpNode) sp->bestMove = move;
+              bestMove = SpNode ? sp->bestMove = move : move;
 
-              if (PvNode && value < beta)
-              {
-                  alpha = value; // Update alpha here! Always alpha < beta
-                  if (SpNode) sp->alpha = value;
-              }
+              if (PvNode && value < beta) // Update alpha! Always alpha < beta
+                  alpha = SpNode ? sp->alpha = value : value;
               else
               {
                   assert(value >= beta); // Fail high
 
-                  if (SpNode) sp->cutoff = true;
+                  if (SpNode)
+                      sp->cutoff = true;
+
                   break;
               }
           }
@@ -1109,7 +1123,7 @@ split_point_start: // At split points actual search starts from here
     Key posKey;
     Move ttMove, move, bestMove;
     Value bestValue, value, ttValue, futilityValue, futilityBase, oldAlpha;
-    bool givesCheck, enoughMaterial, evasionPrunable, fromNull;
+    bool givesCheck, enoughMaterial, evasionPrunable;
     Depth ttDepth;
 
     // To flag BOUND_EXACT a node with eval above alpha and no available moves
@@ -1118,7 +1132,6 @@ split_point_start: // At split points actual search starts from here
 
     ss->currentMove = bestMove = MOVE_NONE;
     ss->ply = (ss-1)->ply + 1;
-    fromNull = (ss-1)->currentMove == MOVE_NULL;
 
     // Check for an instant draw or maximum ply reached
     if (pos.is_draw<false, false>() || ss->ply > MAX_PLY)
@@ -1156,20 +1169,11 @@ split_point_start: // At split points actual search starts from here
     }
     else
     {
-        if (fromNull)
+        if (tte)
         {
-            // Approximated score. Real one is slightly higher due to tempo
-            ss->staticEval = bestValue = -(ss-1)->staticEval;
-            ss->evalMargin = VALUE_ZERO;
-        }
-        else if (tte)
-        {
-            assert(tte->static_value() != VALUE_NONE || Threads.size() > 1);
-
-            ss->staticEval = bestValue = tte->static_value();
-            ss->evalMargin = tte->static_value_margin();
-
-            if (ss->staticEval == VALUE_NONE || ss->evalMargin == VALUE_NONE) // Due to a race
+            // Never assume anything on values stored in TT
+            if (  (ss->staticEval = bestValue = tte->static_value()) == VALUE_NONE
+                ||(ss->evalMargin = tte->static_value_margin()) == VALUE_NONE)
                 ss->staticEval = bestValue = evaluate(pos, ss->evalMargin);
         }
         else
@@ -1209,7 +1213,6 @@ split_point_start: // At split points actual search starts from here
       // Futility pruning
       if (   !PvNode
           && !InCheck
-          && !fromNull
           && !givesCheck
           &&  move != ttMove
           &&  enoughMaterial
@@ -1707,7 +1710,7 @@ void Thread::idle_loop() {
               && !sp->slavesMask)
           {
               assert(!sp->master->is_searching);
-              sp->master->wake_up();
+              sp->master->notify_one();
           }
 
           // After releasing the lock we cannot access anymore any SplitPoint