Careful SMP locking - Fix very occasional hangs

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 57a5517614e67c5f9f37febb857b9d2a0b3840d5..54a9ec878c44f5b617a30fbc85280de160f49628 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -341,7 +341,7 @@ namespace {
     Move easyMove = EasyMove.get(pos.key());
     EasyMove.clear();
 
-    std::memset(ss-2, 0, 5 * sizeof(Stack));
+    std::memset(stack, 0, 5 * sizeof(Stack));
 
     depth = DEPTH_ZERO;
     BestMoveChanges = 0;
@@ -531,7 +531,7 @@ namespace {
     Depth extension, newDepth, predictedDepth;
     Value bestValue, value, ttValue, eval, nullValue, futilityValue;
     bool ttHit, inCheck, givesCheck, singularExtensionNode, improving;
-    bool captureOrPromotion, dangerous, doFullDepthSearch;
+    bool captureOrPromotion, doFullDepthSearch;
     int moveCount, quietCount;
 
     // Step 1. Initialize node
@@ -847,10 +847,6 @@ moves_loop: // When in check and at SpNode search starts from here
                   ? ci.checkSquares[type_of(pos.piece_on(from_sq(move)))] & to_sq(move)
                   : pos.gives_check(move, ci);
 
-      dangerous =   givesCheck
-                 || type_of(move) != NORMAL
-                 || pos.advanced_pawn_push(move);
-
       // Step 12. Extend checks
       if (givesCheck && pos.see_sign(move) >= VALUE_ZERO)
           extension = ONE_PLY;
@@ -883,7 +879,8 @@ moves_loop: // When in check and at SpNode search starts from here
       if (   !RootNode
           && !captureOrPromotion
           && !inCheck
-          && !dangerous
+          && !givesCheck
+          && !pos.advanced_pawn_push(move)
           &&  bestValue > VALUE_MATED_IN_MAX_PLY)
       {
           // Move count based pruning
@@ -1625,6 +1622,7 @@ void Thread::idle_loop() {
           else
               assert(false);
 
+          spinlock.acquire();
           assert(searching);
 
           searching = false;
@@ -1636,6 +1634,7 @@ void Thread::idle_loop() {
           // After releasing the lock we can't access any SplitPoint related data
           // in a safe way because it could have been released under our feet by
           // the sp master.
+          spinlock.release();
           sp->spinlock.release();
 
           // Try to late join to another split point if none of its slaves has