Big renaming in thread stuff

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

src/benchmark.cpp

@@ -130,8 +130,8 @@ void benchmark(const Position& current, istream& is) {
       }
       else
       {
-          Threads.start_searching(pos, limits, vector<Move>(), st);
+          Threads.start_thinking(pos, limits, vector<Move>(), st);
-          Threads.wait_for_search_finished();
+          Threads.wait_for_think_finished();
           nodes += Search::RootPos.nodes_searched();
       }
   }

src/position.h

@@ -30,7 +30,7 @@
 /// The checkInfo struct is initialized at c'tor time and keeps info used
 /// to detect if a move gives check.
 class Position;
-class Thread;
+struct Thread;
 
 struct CheckInfo {
 

src/search.cpp

@@ -1007,7 +1007,7 @@ split_point_start: // At split points actual search starts from here
 
       // Step 19. Check for splitting the search
       if (   !SpNode
-          &&  depth >= Threads.min_split_depth()
+          &&  depth >= Threads.minimumSplitDepth
           &&  Threads.available_slave_exists(thisThread))
       {
           assert(bestValue < beta);
@@ -1558,7 +1558,7 @@ void Thread::idle_loop() {
   // object for which the thread is the master.
   const SplitPoint* sp_master = splitPointsCnt ? curSplitPoint : NULL;
 
-  assert(!sp_master || (sp_master->master == this && is_searching));
+  assert(!sp_master || (sp_master->master == this && searching));
 
   // If this thread is the master of a split point and all slaves have
   // finished their work at this split point, return from the idle loop.
@@ -1566,9 +1566,9 @@ void Thread::idle_loop() {
   {
       // If we are not searching, wait for a condition to be signaled
       // instead of wasting CPU time polling for work.
-      while (do_exit || (!is_searching && Threads.sleepWhileIdle))
+      while ((!searching && Threads.sleepWhileIdle) || exit)
       {
-          if (do_exit)
+          if (exit)
           {
               assert(!sp_master);
               return;
@@ -1588,20 +1588,20 @@ void Thread::idle_loop() {
           // particular we need to avoid a deadlock in case a master thread has,
           // in the meanwhile, allocated us and sent the wake_up() call before we
           // had the chance to grab the lock.
-          if (!is_searching && !do_exit)
+          if (!searching && !exit)
               sleepCondition.wait(mutex);
 
           mutex.unlock();
       }
 
       // If this thread has been assigned work, launch a search
-      if (is_searching)
+      if (searching)
       {
-          assert(!do_exit);
+          assert(!exit);
 
           Threads.mutex.lock();
 
-          assert(is_searching);
+          assert(searching);
           SplitPoint* sp = curSplitPoint;
 
           Threads.mutex.unlock();
@@ -1627,9 +1627,9 @@ void Thread::idle_loop() {
           else
               assert(false);
 
-          assert(is_searching);
+          assert(searching);
 
-          is_searching = false;
+          searching = false;
           sp->activePositions[idx] = NULL;
           sp->slavesMask &= ~(1ULL << idx);
           sp->nodes += pos.nodes_searched();
@@ -1640,7 +1640,7 @@ void Thread::idle_loop() {
               &&  this != sp->master
               && !sp->slavesMask)
           {
-              assert(!sp->master->is_searching);
+              assert(!sp->master->searching);
               sp->master->notify_one();
           }
 

src/thread.cpp

@@ -44,7 +44,7 @@ namespace { extern "C" {
 
 Thread::Thread() : splitPoints() {
 
-  is_searching = do_exit = false;
+  searching = exit = false;
   maxPly = splitPointsCnt = 0;
   curSplitPoint = NULL;
   idx = Threads.size();
@@ -61,7 +61,7 @@ Thread::Thread() : splitPoints() {
 
 Thread::~Thread() {
 
-  do_exit = true; // Search must be already finished
+  exit = true; // Search must be already finished
   notify_one();
   thread_join(handle); // Wait for thread termination
 }
@@ -73,11 +73,11 @@ extern void check_time();
 
 void TimerThread::idle_loop() {
 
-  while (!do_exit)
+  while (!exit)
   {
       mutex.lock();
 
-      if (!do_exit)
+      if (!exit)
           sleepCondition.wait_for(mutex, msec ? msec : INT_MAX);
 
       mutex.unlock();
@@ -97,10 +97,9 @@ void MainThread::idle_loop() {
   {
       mutex.lock();
 
-      is_finished = true; // Always return to sleep after a search
+      thinking = false;
-      is_searching = false;
 
-      while (is_finished && !do_exit)
+      while (!thinking && !exit)
       {
           Threads.sleepCondition.notify_one(); // Wake up UI thread if needed
           sleepCondition.wait(mutex);
@@ -108,19 +107,21 @@ void MainThread::idle_loop() {
 
       mutex.unlock();
 
-      if (do_exit)
+      if (exit)
           return;
 
-      is_searching = true;
+      searching = true;
 
       Search::think();
 
-      assert(is_searching);
+      assert(searching);
+
+      searching = false;
   }
 }
 
 
-// Thread::notify_one() wakes up the thread, normally at split time
+// Thread::notify_one() wakes up the thread when there is some search to do
 
 void Thread::notify_one() {
 
@@ -162,7 +163,7 @@ bool Thread::cutoff_occurred() const {
 
 bool Thread::is_available_to(Thread* master) const {
 
-  if (is_searching)
+  if (searching)
       return false;
 
   // Make a local copy to be sure doesn't become zero under our feet while
@@ -283,7 +284,7 @@ Value ThreadPool::split(Position& pos, Stack* ss, Value alpha, Value beta,
   sp.nodes = 0;
   sp.ss = ss;
 
-  assert(master->is_searching);
+  assert(master->searching);
 
   master->curSplitPoint = &sp;
   int slavesCnt = 0;
@@ -299,7 +300,7 @@ Value ThreadPool::split(Position& pos, Stack* ss, Value alpha, Value beta,
       {
           sp.slavesMask |= 1ULL << i;
           threads[i]->curSplitPoint = &sp;
-          threads[i]->is_searching = true; // Slave leaves idle_loop()
+          threads[i]->searching = true; // Slave leaves idle_loop()
           threads[i]->notify_one(); // Could be sleeping
 
           if (++slavesCnt + 1 >= maxThreadsPerSplitPoint) // Master is always included
@@ -321,7 +322,7 @@ Value ThreadPool::split(Position& pos, Stack* ss, Value alpha, Value beta,
 
       // In helpful master concept a master can help only a sub-tree of its split
       // point, and because here is all finished is not possible master is booked.
-      assert(!master->is_searching);
+      assert(!master->searching);
   }
 
   // We have returned from the idle loop, which means that all threads are
@@ -330,7 +331,7 @@ Value ThreadPool::split(Position& pos, Stack* ss, Value alpha, Value beta,
   mutex.lock();
   sp.mutex.lock();
 
-  master->is_searching = true;
+  master->searching = true;
   master->splitPointsCnt--;
   master->curSplitPoint = sp.parent;
   pos.set_nodes_searched(pos.nodes_searched() + sp.nodes);
@@ -347,24 +348,23 @@ template Value ThreadPool::split<false>(Position&, Stack*, Value, Value, Value,
 template Value ThreadPool::split<true>(Position&, Stack*, Value, Value, Value, Move*, Depth, Move, int, MovePicker&, int);
 
 
-// wait_for_search_finished() waits for main thread to go to sleep, this means
+// wait_for_think_finished() waits for main thread to go to sleep then returns
-// search is finished. Then returns.
 
-void ThreadPool::wait_for_search_finished() {
+void ThreadPool::wait_for_think_finished() {
 
   MainThread* t = main_thread();
   t->mutex.lock();
-  while (!t->is_finished) sleepCondition.wait(t->mutex);
+  while (t->thinking) sleepCondition.wait(t->mutex);
   t->mutex.unlock();
 }
 
 
-// start_searching() wakes up the main thread sleeping in  main_loop() so to start
+// start_thinking() wakes up the main thread sleeping in  main_loop() so to start
 // a new search, then returns immediately.
 
-void ThreadPool::start_searching(const Position& pos, const LimitsType& limits,
+void ThreadPool::start_thinking(const Position& pos, const LimitsType& limits,
-                                 const std::vector<Move>& searchMoves, StateStackPtr& states) {
+                                const std::vector<Move>& searchMoves, StateStackPtr& states) {
-  wait_for_search_finished();
+  wait_for_think_finished();
 
   SearchTime = Time::now(); // As early as possible
 
@@ -380,6 +380,6 @@ void ThreadPool::start_searching(const Position& pos, const LimitsType& limits,
       if (searchMoves.empty() || count(searchMoves.begin(), searchMoves.end(), ml.move()))
           RootMoves.push_back(RootMove(ml.move()));
 
-  main_thread()->is_finished = false;
+  main_thread()->thinking = true;
   main_thread()->notify_one(); // Starts main thread
 }

src/thread.h

@@ -56,7 +56,7 @@ private:
   WaitCondition c;
 };
 
-class Thread;
+struct Thread;
 
 struct SplitPoint {
 
@@ -91,9 +91,8 @@ struct SplitPoint {
 /// tables so that once we get a pointer to an entry its life time is unlimited
 /// and we don't have to care about someone changing the entry under our feet.
 
-class Thread {
+struct Thread {
 
-public:
   Thread();
   virtual ~Thread();
 
@@ -114,8 +113,18 @@ public:
   NativeHandle handle;
   SplitPoint* volatile curSplitPoint;
   volatile int splitPointsCnt;
-  volatile bool is_searching;
+  volatile bool searching;
-  volatile bool do_exit;
+  volatile bool exit;
+};
+
+
+/// MainThread and TimerThread are sublassed from Thread to charaterize the two
+/// special threads: the main one and the recurring timer.
+
+struct MainThread : public Thread {
+  MainThread() : thinking(true) {} // Avoid a race with start_thinking()
+  virtual void idle_loop();
+  volatile bool thinking;
 };
 
 struct TimerThread : public Thread {
@@ -124,12 +133,6 @@ struct TimerThread : public Thread {
   int msec;
 };
 
-struct MainThread : public Thread {
-  MainThread() : is_finished(false) {} // Avoid a race with start_searching()
-  virtual void idle_loop();
-  volatile bool is_finished;
-};
-
 
 /// ThreadPool class handles all the threads related stuff like init, starting,
 /// parking and, the most important, launching a slave thread at a split point.
@@ -142,22 +145,25 @@ public:
   void exit(); // be initialized and valid during the whole thread lifetime.
 
   Thread& operator[](size_t id) { return *threads[id]; }
-  int min_split_depth() const { return minimumSplitDepth; }
   size_t size() const { return threads.size(); }
   MainThread* main_thread() { return static_cast<MainThread*>(threads[0]); }
   TimerThread* timer_thread() { return timer; }
 
   void read_uci_options();
   bool available_slave_exists(Thread* master) const;
-  void wait_for_search_finished();
+  void wait_for_think_finished();
-  void start_searching(const Position&, const Search::LimitsType&,
+  void start_thinking(const Position&, const Search::LimitsType&,
                        const std::vector<Move>&, Search::StateStackPtr&);
 
   template <bool Fake>
   Value split(Position& pos, Search::Stack* ss, Value alpha, Value beta, Value bestValue, Move* bestMove,
               Depth depth, Move threatMove, int moveCount, MovePicker& mp, int nodeType);
+
+  bool sleepWhileIdle;
+  Depth minimumSplitDepth;
+
 private:
-  friend class Thread;
+  friend struct Thread;
   friend struct MainThread;
   friend void check_time();
 
@@ -165,10 +171,7 @@ private:
   TimerThread* timer;
   Mutex mutex;
   ConditionVariable sleepCondition;
-  Depth minimumSplitDepth;
   int maxThreadsPerSplitPoint;
-public:
-  bool sleepWhileIdle;
 };
 
 extern ThreadPool Threads;

src/uci.cpp

@@ -113,7 +113,7 @@ void UCI::loop(const string& args) {
 
   } while (token != "quit" && args.empty()); // Args have one-shot behaviour
 
-  Threads.wait_for_search_finished(); // Cannot quit while search is running
+  Threads.wait_for_think_finished(); // Cannot quit while search is running
 }
 
 
@@ -207,6 +207,6 @@ namespace {
         else if (token == "ponder")    limits.ponder = true;
     }
 
-    Threads.start_searching(pos, limits, searchMoves, SetupStates);
+    Threads.start_thinking(pos, limits, searchMoves, SetupStates);
   }
 }