Refactor Thread class

Associate platform OS thread to the Thread class instead of
creating it from ThreadsManager.

No functional change.

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

src/material.cpp

@@ -84,12 +84,6 @@ namespace {
 } // namespace
 
 
-/// MaterialInfoTable c'tor and d'tor allocate and free the space for Endgames
-
-void MaterialInfoTable::init() { Base::init(); if (!funcs) funcs = new Endgames(); }
-MaterialInfoTable::~MaterialInfoTable() { delete funcs; }
-
-
 /// MaterialInfoTable::material_info() takes a position object as input,
 /// computes or looks up a MaterialInfo object, and returns a pointer to it.
 /// If the material configuration is not already present in the table, it

src/material.h

@@ -72,8 +72,9 @@ private:
 
 class MaterialInfoTable : public SimpleHash<MaterialInfo, MaterialTableSize> {
 public:
-  ~MaterialInfoTable();
-  void init();
+  MaterialInfoTable() : funcs(new Endgames()) {}
+  ~MaterialInfoTable() { delete funcs; }
+
   MaterialInfo* material_info(const Position& pos) const;
   static Phase game_phase(const Position& pos);
 

src/platform.h

@@ -65,7 +65,7 @@ typedef void*(*start_fn)(void*);
 #  define cond_signal(x) pthread_cond_signal(&(x))
 #  define cond_wait(x,y) pthread_cond_wait(&(x),&(y))
 #  define cond_timedwait(x,y,z) pthread_cond_timedwait(&(x),&(y),z)
-#  define thread_create(x,f,id) !pthread_create(&(x),NULL,(start_fn)f,&(id))
+#  define thread_create(x,f,t) !pthread_create(&(x),NULL,(start_fn)f,t)
 #  define thread_join(x) pthread_join(x, NULL)
 
 #else // Windows and MinGW
@@ -101,7 +101,7 @@ typedef HANDLE ThreadHandle;
 #  define cond_signal(x) SetEvent(x)
 #  define cond_wait(x,y) { lock_release(y); WaitForSingleObject(x, INFINITE); lock_grab(y); }
 #  define cond_timedwait(x,y,z) { lock_release(y); WaitForSingleObject(x,z); lock_grab(y); }
-#  define thread_create(x,f,id) (x = CreateThread(NULL,0,(LPTHREAD_START_ROUTINE)f,&(id),0,NULL), x != NULL)
+#  define thread_create(x,f,t) (x = CreateThread(NULL,0,(LPTHREAD_START_ROUTINE)f,t,0,NULL), x != NULL)
 #  define thread_join(x) { WaitForSingleObject(x, INFINITE); CloseHandle(x); }
 
 #endif

src/thread.cpp

@@ -53,6 +53,45 @@ namespace { extern "C" {
 } }
 
 
+Thread::Thread(int id) {
+
+  threadID = id;
+  do_sleep = (id != 0); // Avoid a race with start_thinking()
+  is_searching = do_exit = false;
+  maxPly = splitPointsCnt = 0;
+  curSplitPoint = NULL;
+
+  lock_init(sleepLock);
+  cond_init(sleepCond);
+
+  for (int j = 0; j < MAX_SPLITPOINTS_PER_THREAD; j++)
+      lock_init(splitPoints[j].lock);
+
+  if (!thread_create(handle, start_routine, this))
+  {
+      std::cerr << "Failed to create thread number " << id << std::endl;
+      ::exit(EXIT_FAILURE);
+  }
+}
+
+
+Thread::~Thread() {
+
+  assert(do_sleep);
+
+  do_exit = true; // Search must be already finished
+  wake_up();
+
+  thread_join(handle); // Wait for thread termination
+
+  lock_destroy(sleepLock);
+  cond_destroy(sleepCond);
+
+  for (int j = 0; j < MAX_SPLITPOINTS_PER_THREAD; j++)
+      lock_destroy(splitPoints[j].lock);
+}
+
+
 // Thread::timer_loop() is where the timer thread waits maxPly milliseconds and
 // then calls do_timer_event(). If maxPly is 0 thread sleeps until is woken up.
 extern void check_time();
@@ -175,15 +214,16 @@ void ThreadsManager::read_uci_options() {
   useSleepingThreads      = Options["Use Sleeping Threads"];
   activeThreads           = Options["Threads"];
 
-  // Dynamically allocate pawn and material hash tables according to the
-  // number of active threads. This avoids preallocating memory for all
-  // possible threads if only few are used.
+  // Dynamically allocate Thread object according to the number of
+  // active threads. This avoids preallocating memory for all possible
+  // threads if only few are used.
   for (int i = 0; i < MAX_THREADS; i++)
-      if (i < activeThreads)
+      if (i < activeThreads && !threads[i])
+          threads[i] = new Thread(i);
+      else if (i >= activeThreads && threads[i])
       {
-          threads[i].pawnTable.init();
-          threads[i].materialTable.init();
-          threads[i].maxPly = 0;
+          delete threads[i];
+          threads[i] = NULL;
       }
 }
 
@@ -192,8 +232,8 @@ void ThreadsManager::wake_up() {
 
   for (int i = 0; i < activeThreads; i++)
   {
-      threads[i].do_sleep = false;
-      threads[i].wake_up();
+      threads[i]->do_sleep = false;
+      threads[i]->wake_up();
   }
 }
 
@@ -201,7 +241,7 @@ void ThreadsManager::wake_up() {
 void ThreadsManager::sleep() {
 
   for (int i = 0; i < activeThreads; i++)
-      threads[i].do_sleep = true;
+      threads[i]->do_sleep = true;
 }
 
 
@@ -210,34 +250,10 @@ void ThreadsManager::sleep() {
 
 void ThreadsManager::init() {
 
-  read_uci_options();
-
-  cond_init(sleepCond);
-  lock_init(splitLock);
-
-  // Allocate main thread tables to call evaluate() also when not searching
-  threads[0].pawnTable.init();
-  threads[0].materialTable.init();
-
-  // Create and launch all the threads, threads will go immediately to sleep
-  for (int i = 0; i <= MAX_THREADS; i++)
-  {
-      threads[i].is_searching = false;
-      threads[i].do_sleep = (i != 0); // Avoid a race with start_thinking()
-      threads[i].threadID = i;
-
-      lock_init(threads[i].sleepLock);
-      cond_init(threads[i].sleepCond);
-
-      for (int j = 0; j < MAX_SPLITPOINTS_PER_THREAD; j++)
-          lock_init(threads[i].splitPoints[j].lock);
-
-      if (!thread_create(threads[i].handle, start_routine, threads[i]))
-      {
-          std::cerr << "Failed to create thread number " << i << std::endl;
-          ::exit(EXIT_FAILURE);
-      }
-  }
+    cond_init(sleepCond);
+    lock_init(splitLock);
+    timer = new Thread(MAX_THREADS);
+    read_uci_options(); // Creates at least main thread
 }
 
 
@@ -245,22 +261,11 @@ void ThreadsManager::init() {
 
 void ThreadsManager::exit() {
 
-  for (int i = 0; i <= MAX_THREADS; i++)
-  {
-      assert(threads[i].do_sleep);
-
-      threads[i].do_exit = true; // Search must be already finished
-      threads[i].wake_up();
-
-      thread_join(threads[i].handle); // Wait for thread termination
-
-      lock_destroy(threads[i].sleepLock);
-      cond_destroy(threads[i].sleepCond);
-
-      for (int j = 0; j < MAX_SPLITPOINTS_PER_THREAD; j++)
-          lock_destroy(threads[i].splitPoints[j].lock);
-  }
+  for (int i = 0; i < MAX_THREADS; i++)
+      if (threads[i])
+          delete threads[i];
 
+  delete timer;
   lock_destroy(splitLock);
   cond_destroy(sleepCond);
 }
@@ -274,7 +279,7 @@ bool ThreadsManager::available_slave_exists(int master) const {
   assert(master >= 0 && master < activeThreads);
 
   for (int i = 0; i < activeThreads; i++)
-      if (threads[i].is_available_to(master))
+      if (threads[i]->is_available_to(master))
           return true;
 
   return false;
@@ -304,7 +309,7 @@ Value ThreadsManager::split(Position& pos, Stack* ss, Value alpha, Value beta,
   assert(activeThreads > 1);
 
   int master = pos.thread();
-  Thread& masterThread = threads[master];
+  Thread& masterThread = *threads[master];
 
   if (masterThread.splitPointsCnt >= MAX_SPLITPOINTS_PER_THREAD)
       return bestValue;
@@ -341,14 +346,14 @@ Value ThreadsManager::split(Position& pos, Stack* ss, Value alpha, Value beta,
   lock_grab(splitLock);
 
   for (int i = 0; i < activeThreads && !Fake; i++)
-      if (threads[i].is_available_to(master))
+      if (threads[i]->is_available_to(master))
       {
           sp->slavesMask |= 1ULL << i;
-          threads[i].curSplitPoint = sp;
-          threads[i].is_searching = true; // Slave leaves idle_loop()
+          threads[i]->curSplitPoint = sp;
+          threads[i]->is_searching = true; // Slave leaves idle_loop()
 
           if (useSleepingThreads)
-              threads[i].wake_up();
+              threads[i]->wake_up();
 
           if (++slavesCnt + 1 >= maxThreadsPerSplitPoint) // Master is always included
               break;
@@ -399,12 +404,10 @@ template Value ThreadsManager::split<true>(Position&, Stack*, Value, Value, Valu
 
 void ThreadsManager::set_timer(int msec) {
 
-  Thread& timer = threads[MAX_THREADS];
-
-  lock_grab(timer.sleepLock);
-  timer.maxPly = msec;
-  cond_signal(timer.sleepCond); // Wake up and restart the timer
-  lock_release(timer.sleepLock);
+  lock_grab(timer->sleepLock);
+  timer->maxPly = msec;
+  cond_signal(timer->sleepCond); // Wake up and restart the timer
+  lock_release(timer->sleepLock);
 }
 
 
@@ -415,7 +418,7 @@ void ThreadsManager::set_timer(int msec) {
 
 void ThreadsManager::start_thinking(const Position& pos, const LimitsType& limits,
                                     const std::set<Move>& searchMoves, bool async) {
-  Thread& main = threads[0];
+  Thread& main = *threads[0];
 
   lock_grab(main.sleepLock);
 
@@ -455,7 +458,7 @@ void ThreadsManager::start_thinking(const Position& pos, const LimitsType& limit
 
 void ThreadsManager::stop_thinking() {
 
-  Thread& main = threads[0];
+  Thread& main = *threads[0];
 
   Search::Signals.stop = true;
 

src/thread.h

@@ -66,6 +66,9 @@ struct SplitPoint {
 
 struct Thread {
 
+  Thread(int id);
+  ~Thread();
+
   void wake_up();
   bool cutoff_occurred() const;
   bool is_available_to(int master) const;
@@ -100,7 +103,7 @@ class ThreadsManager {
      static storage duration are automatically set to zero before enter main()
   */
 public:
-  Thread& operator[](int threadID) { return threads[threadID]; }
+  Thread& operator[](int threadID) { return *threads[threadID]; }
   void init();
   void exit();
 
@@ -123,7 +126,8 @@ public:
 private:
   friend struct Thread;
 
-  Thread threads[MAX_THREADS + 1]; // Last one is used as a timer
+  Thread* timer;
+  Thread* threads[MAX_THREADS];
   Lock splitLock;
   WaitCondition sleepCond;
   Depth minimumSplitDepth;

src/tt.h

@@ -146,10 +146,7 @@ struct SimpleHash {
 
   typedef SimpleHash<Entry, HashSize> Base;
 
-  void init() {
-
-    if (entries)
-        return;
+  SimpleHash() {
 
     entries = new (std::nothrow) Entry[HashSize];
     if (!entries)