Implemented pondering

matthewlai · matthewlai · commit a4230fc1b3b3 · 2015-12-09T15:19:04.000-08:00
diff --git a/backend.cpp b/backend.cpp
@@ -26,7 +26,11 @@
 #include "gtb.h"
 
 Backend::Backend()
-	: m_mode(Backend::EngineMode_force), m_searchInProgress(false), m_maxDepth(0), m_showThinking(false),
+	: m_mode(Backend::EngineMode_force),
+	  m_searchInProgress(false),
+	  m_maxDepth(0),
+	  m_showThinking(false),
+	  m_pondering(false),
 	  m_whiteClock(ChessClock::CONVENTIONAL_INCREMENTAL_MODE, 0, 300, 0),
 	  m_blackClock(ChessClock::CONVENTIONAL_INCREMENTAL_MODE, 0, 300, 0),
 	  m_tTable(DEFAULT_TTABLE_SIZE / sizeof(TTEntry)),
@@ -394,6 +398,20 @@ void Backend::StartSearch_(Search::SearchType searchType)
 			m_whiteClock.Stop();
 			m_blackClock.Start();
 		}
+
+		if (m_pondering)
+		{
+			// we have to do this in a new thread so that the search thread itself can die
+			auto startPonderThreadFunc = [this]()
+			{
+				std::lock_guard<std::mutex> lock(m_mutex);
+				StopSearch_(lock);
+				StartSearch_(Search::SearchType_infinite);
+			};
+
+			std::thread t(startPonderThreadFunc);
+			t.detach();
+		}
 	};
 
 	m_search.reset(new Search::AsyncSearch(*m_searchContext));
diff --git a/backend.h b/backend.h
@@ -63,6 +63,8 @@ class Backend
 
 	void SetAnalyzing(bool enabled);
 
+	void SetPondering(bool enabled) { std::lock_guard<std::mutex> lock(m_mutex); m_pondering = enabled; }
+
 	void Undo(int32_t moves);
 
 	void SetTimeControl(const ChessClock &cc)
@@ -122,6 +124,8 @@ class Backend
 
 	bool m_showThinking;
 
+	bool m_pondering;
+
 	ChessClock m_whiteClock;
 	ChessClock m_blackClock;
 
