fix movegen and multi-threading bug

Passed non-regressive tests:
Book: f15-500M-12k
TC: 60+0.6
Total/Win/Draw/Lose: 26146 / 4611 / 17013 / 4522
PTNML: 223 / 2205 / 8130 / 2290 / 225
WinRate: 50.17%
ELO: 0.80[-1.85, 3.37]
LOS: 72.63
LLR: 2.20[-2.20, 2.20]

Book: s15-500M-16k
TC: 60+0.6
Total/Win/Draw/Lose: 17288 / 2701 / 11935 / 2652
PTNML: 113 / 1390 / 5620 / 1377 / 144
WinRate: 50.14%
ELO: 0.31[-3.25, 3.62]
LOS: 57.12
LLR: 1.28[-1.10, 1.10]

Book: r15-500M-16k
TC: 60+0.6
Total/Win/Draw/Lose: 20572 / 5827 / 8940 / 5805
PTNML: 502 / 2068 / 5140 / 2058 / 518
WinRate: 50.05%
ELO: -0.59[-5.24, 3.62]
LOS: 39.25
LLR: 1.17[-1.10, 1.10]

bench 454a4d48
bench (msvc clang) 37ddaa3a

Author: dhbloo

Rapfi/core/iohelper.cpp

@@ -81,6 +81,18 @@ int outputCoordYConvert(Pos pos, int boardsize)
         return pos.y();
 }
 
+Pos parseCoord(std::string coordStr)
+{
+    if (coordStr == "Pass" || coordStr == "pass")
+        return Pos::PASS;
+    if (coordStr == "None" || coordStr == "none")
+        return Pos::NONE;
+
+    int x = std::toupper(coordStr[0]) - 'A';
+    int y = std::atoi(coordStr.data() + 1) - '1';
+    return Pos(x, y);
+}
+
 // -------------------------------------------------
 
 std::ostream &operator<<(std::ostream &out, Pos pos)

Rapfi/core/iohelper.h

@@ -47,6 +47,8 @@ Pos inputCoordConvert(int x, int y, int boardsize);
 int outputCoordXConvert(Pos pos, int boardsize);
 int outputCoordYConvert(Pos pos, int boardsize);
 
+Pos parseCoord(std::string coordStr);
+
 // -------------------------------------------------
 // Formatters
 

Rapfi/game/movegen.cpp

@@ -550,10 +550,8 @@ ScoredMove *findB4F3Defence(const Board &board, ScoredMove *const moveList)
 
             *last++ = b4Pos;
 
-            for (int d = 0; d < 4; d++) {
-                if (d != dir)
-                    last = findAllB3CounterDefence(b4Pos, d, last);
-            }
+            for (int d = 0; d < 4; d++)
+                last = findAllB3CounterDefence(b4Pos, d, last);
         }
     }
 

Rapfi/search/searchthread.cpp

@@ -314,10 +314,6 @@ void ThreadPool::startThinking(const Board &board, const SearchOptions &options,
     assert(size() > 0);
     assert(searcher());
 
-    // Clear and init all threads state
-    for (size_t i = 1; i < size(); i++)
-        (*this)[i]->runTask([this](SearchThread &th) { th.clear(); });
-
     main()->clear();
     main()->inPonder      = inPonder;
     main()->searchOptions = options;
@@ -386,14 +382,14 @@ void ThreadPool::startThinking(const Board &board, const SearchOptions &options,
         }
     }
 
-    // Copy board and root moves from main thread to other threads
+    // Clear threads state and copy board and root moves to other threads sequentially
     for (size_t i = 1; i < size(); i++) {
-        (*this)[i]->runTask([this](SearchThread &th) {
-            th.setBoardAndEvaluator(*main()->board);
-            th.rootMoves = main()->rootMoves;
-            if (main()->searchOptions.balanceMode == Search::SearchOptions::BALANCE_TWO)
-                th.balance2Moves = main()->balance2Moves;
-        });
+        SearchThread &th = *(*this)[i];
+        th.clear();
+        th.setBoardAndEvaluator(*main()->board);
+        th.rootMoves = main()->rootMoves;
+        if (main()->searchOptions.balanceMode == Search::SearchOptions::BALANCE_TWO)
+            th.balance2Moves = main()->balance2Moves;
     }
 
     main()->runTask([searcher = searcher()](SearchThread &th) {