copy the ShardokEngine instead of using a shared_ptr across multiple threads

src/main/cpp/net/eagle0/shardok/ai/AIScoreCalculator.cpp

@@ -95,7 +95,7 @@ struct ImmediateAndLookaheadScore {
         bool isDefender,
         int remainingLookahead,
         int maxRepeatCount,
-        const shared_ptr<ShardokEngine> &innerEngine,
+        const ShardokEngine innerEngine,
         ScoreValue currentUtility,
         const AIStrategy &attackerStrategy,
         const SettingsGetter &settingsGetter,
@@ -964,7 +964,7 @@ auto BasicLookaheadCalculator(
         const bool isDefender,
         const int remainingLookahead,
         const int maxRepeatCount,
-        const shared_ptr<ShardokEngine> &innerEngine,
+        const ShardokEngine innerEngine,
         const ScoreValue currentUtility,
         const AIStrategy &attackerStrategy,
         const SettingsGetter &settingsGetter,
@@ -975,7 +975,7 @@ auto BasicLookaheadCalculator(
         -> std::future<eagle0::common::TaskResult<ScoreValue>> {
     const auto nextUtility = currentUtility;
 
-    if (const CommandListSPtr nextCommands = innerEngine->GetAvailableCommandsForAIPlayer(pid);
+    if (const CommandListSPtr nextCommands = innerEngine.GetAvailableCommandsForAIPlayer(pid);
         nextCommands && !nextCommands->empty()) {
         // Get the future from BestCommandIndex without calling .get()
         auto bestCommandFuture = BestCommandIndex(
@@ -983,7 +983,7 @@ auto BasicLookaheadCalculator(
                 isDefender,
                 remainingLookahead - 1,
                 maxRepeatCount,
-                *innerEngine,
+                innerEngine,
                 attackerStrategy,
                 nextUtility,
                 settingsGetter,
@@ -1003,7 +1003,7 @@ auto BasicLookaheadCalculator(
                             bestCommandFuture.get();
 
                     if (auto &nextCommand =
-                                innerEngine->GetAvailableCommandsForAIPlayer(pid)->at(index);
+                                innerEngine.GetAvailableCommandsForAIPlayer(pid)->at(index);
                         nextCommand->GetCommandType() !=
                         net::eagle0::shardok::common::END_TURN_COMMAND) {
                         return eagle0::common::TaskResult<ScoreValue>::Success(immediateScore);
@@ -1045,12 +1045,12 @@ auto CalcOne(
         return returnValue;
     }
 
-    auto innerEngine = std::make_shared<ShardokEngine>(guessedEngine, false);
-    innerEngine->PostCommand(pid, commandIndex, randomGenerator);
+    auto innerEngine = ShardokEngine(guessedEngine, false);
+    innerEngine.PostCommand(pid, commandIndex, randomGenerator);
 
     auto innerUtility = AIScoreCalculator::GuessedStateScore(
             isDefender,
-            innerEngine->GetCurrentGameState(),
+            innerEngine.GetCurrentGameState(),
             attackerStrategy,
             allCastleCoords,
             settingsGetter,