Retire Threads wake_up() and sleep()

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index dc82d34d312b4d3966984f685fa447ef68ede848..a97c73485523eaf13002ddf3c6895b3f7c52d663 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -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())
@@ -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;
               }
           }
@@ -1696,7 +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