Fix endless reaparenting loop

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index b38b7bab92ef84df92eb625b3316b496280a8dcf..21d5d786b6ba8be9e558bca2ffb18dfd78c951f1 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1337,7 +1337,7 @@ split_point_start: // At split points actual search starts from here
     // Rule 1. Checks which give opponent's king at most one escape square are dangerous
     b = kingAtt & ~pos.pieces(them) & ~newAtt & ~(1ULL << to);
 
-    if (single_bit(b)) // Catches also !b
+    if (!more_than_one(b))
         return true;
 
     // Rule 2. Queen contact check is very dangerous
@@ -1386,7 +1386,7 @@ split_point_start: // At split points actual search starts from here
 
     // Case 3: Moving through the vacated square
     p2 = pos.piece_on(f2);
-    if (piece_is_slider(p2) && (squares_between(f2, t2) & f1))
+    if (piece_is_slider(p2) && (between_bb(f2, t2) & f1))
       return true;
 
     // Case 4: The destination square for m2 is defended by the moving piece in m1
@@ -1397,7 +1397,7 @@ split_point_start: // At split points actual search starts from here
     // Case 5: Discovered check, checking piece is the piece moved in m1
     ksq = pos.king_square(pos.side_to_move());
     if (    piece_is_slider(p1)
-        && (squares_between(t1, ksq) & f2)
+        && (between_bb(t1, ksq) & f2)
         && (pos.attacks_from(p1, t1, pos.pieces() ^ f2) & ksq))
         return true;
 
@@ -1469,7 +1469,7 @@ split_point_start: // At split points actual search starts from here
     // Case 3: If the moving piece in the threatened move is a slider, don't
     // prune safe moves which block its ray.
     if (    piece_is_slider(pos.piece_on(tfrom))
-        && (squares_between(tfrom, tto) & mto)
+        && (between_bb(tfrom, tto) & mto)
         &&  pos.see_sign(m) >= 0)
         return true;
 
@@ -1844,6 +1844,7 @@ void Thread::idle_loop(SplitPoint* sp_master) {
           assert(is_searching);
 
           is_searching = false;
+          sp->allSlavesRunning = false;
           sp->slavesMask &= ~(1ULL << idx);
           sp->nodes += pos.nodes_searched();
 
@@ -1860,20 +1861,19 @@ void Thread::idle_loop(SplitPoint* sp_master) {
           // unsafe because if we are exiting there is a chance are already freed.
           lock_release(sp->lock);
 
-          // Try to reparent to another split point
+          // Try to reparent to the first split point, with still all slaves
+          // running, where we are available as a possible slave.
           for (int i = 0; i < Threads.size(); i++)
           {
               Thread* th = &Threads[i];
               int spCnt = th->splitPointsCnt;
               SplitPoint* latest = &th->splitPoints[spCnt ? spCnt - 1 : 0];
 
-              // Find the first split point with still all slaves running
-              // where we are available as a possible slave.
               if (    this->is_available_to(th)
                   &&  spCnt > 0
-                  && !latest->cutoff
-                  &&  latest->slavesMask == latest->allSlavesMask
-                  && !single_bit(latest->allSlavesMask))
+                  && !th->cutoff_occurred()
+                  &&  latest->allSlavesRunning
+                  &&  more_than_one(latest->slavesMask))
               {
                   lock_grab(latest->lock);
                   lock_grab(Threads.splitLock);
@@ -1882,11 +1882,11 @@ void Thread::idle_loop(SplitPoint* sp_master) {
                   // of a race storm here !
                   if (    this->is_available_to(th)
                       &&  spCnt == th->splitPointsCnt
-                      && !latest->cutoff
-                      &&  latest->slavesMask == latest->allSlavesMask
-                      && !single_bit(latest->allSlavesMask))
+                      && !th->cutoff_occurred()
+                      &&  latest->allSlavesRunning
+                      &&  more_than_one(latest->slavesMask))
                   {
-                      latest->slavesMask |= 1ULL << idx; // allSlavesMask is not updated
+                      latest->slavesMask |= 1ULL << idx;
                       curSplitPoint = latest;
                       is_searching = true;
                   }