X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.cpp;h=d67b9fcdef16ba6f5cd0f40c3bb7bb33078665d6;hp=457a92780ced8cb17348516c2d8fc69e6b5b6334;hb=c483ffc773c012b49f4ea2f5bd1d788c1f0dc4ac;hpb=b1cf1acb93532248fb10c2ca983d80389d5aeb84

diff --git a/src/thread.cpp b/src/thread.cpp
index 457a9278..d67b9fcd 100644
--- a/src/thread.cpp
+++ b/src/thread.cpp
@@ -32,31 +32,56 @@ ThreadsManager Threads; // Global object
 namespace { extern "C" {
 
  // start_routine() is the C function which is called when a new thread
- // is launched. It simply calls idle_loop() of the supplied thread. The first
- // and last thread are special. First one is the main search thread while the
- // last one mimics a timer, they run in main_loop() and timer_loop().
+ // is launched. It is a wrapper to member function pointed by start_fn
 
-#if defined(_WIN32) || defined(_WIN64)
-  DWORD WINAPI start_routine(LPVOID thread) {
-#else
-  void* start_routine(void* thread) {
-#endif
+ long start_routine(Thread* th) { (th->*(th->start_fn))(); return 0; }
+
+} }
 
-    Thread* th = (Thread*)thread;
 
-    if (th->threadID == 0)
-        th->main_loop();
+// Thread c'tor starts a newly-created thread of execution that will call
+// the idle loop function pointed by start_fn going immediately to sleep.
 
-    else if (th->threadID == MAX_THREADS)
-        th->timer_loop();
+Thread::Thread(Fn fn) {
 
-    else
-        th->idle_loop(NULL);
+  is_searching = do_exit = false;
+  maxPly = splitPointsCnt = 0;
+  curSplitPoint = NULL;
+  start_fn = fn;
+  threadID = Threads.size();
+  do_sleep = (threadID != 0); // Avoid a race with start_thinking()
+
+  lock_init(sleepLock);
+  cond_init(sleepCond);
 
-    return 0;
+  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 " << threadID << std::endl;
+      ::exit(EXIT_FAILURE);
   }
+}
 
-} }
+
+// Thread d'tor will wait for thread termination before to return.
+
+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
@@ -141,7 +166,7 @@ void Thread::wait_for_stop_or_ponderhit() {
 
 bool Thread::cutoff_occurred() const {
 
-  for (SplitPoint* sp = splitPoint; sp; sp = sp->parent)
+  for (SplitPoint* sp = curSplitPoint; sp; sp = sp->parent)
       if (sp->cutoff)
           return true;
 
@@ -163,109 +188,85 @@ bool Thread::is_available_to(int master) const {
 
   // Make a local copy to be sure doesn't become zero under our feet while
   // testing next condition and so leading to an out of bound access.
-  int sp_count = activeSplitPoints;
+  int spCnt = splitPointsCnt;
 
   // No active split points means that the thread is available as a slave for any
   // other thread otherwise apply the "helpful master" concept if possible.
-  return !sp_count || (splitPoints[sp_count - 1].slavesMask & (1ULL << master));
+  return !spCnt || (splitPoints[spCnt - 1].slavesMask & (1ULL << master));
 }
 
 
-// read_uci_options() updates number of active threads and other parameters
-// according to the UCI options values. It is called before to start a new search.
+// read_uci_options() updates internal threads parameters from the corresponding
+// UCI options and creates/destroys threads to match the requested number. Thread
+// objects are dynamically allocated to avoid creating in advance all possible
+// threads, with included pawns and material tables, if only few are used.
 
 void ThreadsManager::read_uci_options() {
 
   maxThreadsPerSplitPoint = Options["Max Threads per Split Point"];
   minimumSplitDepth       = Options["Min Split Depth"] * ONE_PLY;
   useSleepingThreads      = Options["Use Sleeping Threads"];
+  int requested           = Options["Threads"];
 
-  set_size(Options["Threads"]);
-}
-
-
-// set_size() changes the number of active threads and raises do_sleep flag for
-// all the unused threads that will go immediately to sleep.
+  assert(requested > 0);
 
-void ThreadsManager::set_size(int cnt) {
+  while (size() < requested)
+      threads.push_back(new Thread(&Thread::idle_loop));
 
-  assert(cnt > 0 && cnt <= MAX_THREADS);
-
-  activeThreads = cnt;
-
-  for (int i = 1; i < MAX_THREADS; i++) // Ignore main thread
-      if (i < activeThreads)
-      {
-          // 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.
-          threads[i].pawnTable.init();
-          threads[i].materialTable.init();
-
-          threads[i].do_sleep = false;
-      }
-      else
-          threads[i].do_sleep = true;
+  while (size() > requested)
+  {
+      delete threads.back();
+      threads.pop_back();
+  }
 }
 
 
-// init() is called during startup. Initializes locks and condition variables
-// and launches all threads sending them immediately to sleep.
+// wake_up() is called before a new search to start the threads that are waiting
+// on the sleep condition. If useSleepingThreads is set threads will be woken up
+// at split time.
 
-void ThreadsManager::init() {
+void ThreadsManager::wake_up() {
 
-  cond_init(sleepCond);
-  lock_init(splitLock);
-
-  for (int i = 0; i <= MAX_THREADS; i++)
+  for (int i = 0; i < size(); i++)
   {
-      lock_init(threads[i].sleepLock);
-      cond_init(threads[i].sleepCond);
+      threads[i]->do_sleep = false;
 
-      for (int j = 0; j < MAX_ACTIVE_SPLIT_POINTS; j++)
-          lock_init(threads[i].splitPoints[j].lock);
+      if (!useSleepingThreads)
+          threads[i]->wake_up();
   }
+}
 
-  // 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;
+// sleep() is called after the search to ask threads to wait on sleep condition
 
-      if (!thread_create(threads[i].handle, start_routine, threads[i]))
-      {
-          std::cerr << "Failed to create thread number " << i << std::endl;
-          ::exit(EXIT_FAILURE);
-      }
-  }
+void ThreadsManager::sleep() {
+
+  for (int i = 0; i < size(); i++)
+      threads[i]->do_sleep = true;
 }
 
 
-// exit() is called to cleanly terminate the threads when the program finishes
+// init() is called during startup. Initializes locks and condition variables
+// and launches all threads sending them immediately to sleep.
 
-void ThreadsManager::exit() {
+void ThreadsManager::init() {
 
-  for (int i = 0; i <= MAX_THREADS; i++)
-  {
-      assert(threads[i].do_sleep);
+    cond_init(sleepCond);
+    lock_init(splitLock);
+    timer = new Thread(&Thread::timer_loop);
+    threads.push_back(new Thread(&Thread::main_loop));
+    read_uci_options();
+}
 
-      threads[i].do_exit = true; // Search must be already finished
-      threads[i].wake_up();
 
-      thread_join(threads[i].handle); // Wait for thread termination
+// exit() is called to cleanly terminate the threads before the program finishes
 
-      lock_destroy(threads[i].sleepLock);
-      cond_destroy(threads[i].sleepCond);
+void ThreadsManager::exit() {
 
-      for (int j = 0; j < MAX_ACTIVE_SPLIT_POINTS; j++)
-          lock_destroy(threads[i].splitPoints[j].lock);
-  }
+  for (int i = 0; i < size(); i++)
+      delete threads[i];
 
+  delete timer;
   lock_destroy(splitLock);
   cond_destroy(sleepCond);
 }
@@ -276,10 +277,10 @@ void ThreadsManager::exit() {
 
 bool ThreadsManager::available_slave_exists(int master) const {
 
-  assert(master >= 0 && master < activeThreads);
+  assert(master >= 0 && master < size());
 
-  for (int i = 0; i < activeThreads; i++)
-      if (threads[i].is_available_to(master))
+  for (int i = 0; i < size(); i++)
+      if (threads[i]->is_available_to(master))
           return true;
 
   return false;
@@ -297,31 +298,30 @@ bool ThreadsManager::available_slave_exists(int master) const {
 
 template <bool Fake>
 Value ThreadsManager::split(Position& pos, Stack* ss, Value alpha, Value beta,
-                            Value bestValue, Depth depth, Move threatMove,
-                            int moveCount, MovePicker* mp, int nodeType) {
+                            Value bestValue, Move* bestMove, Depth depth,
+                            Move threatMove, int moveCount, MovePicker* mp, int nodeType) {
   assert(pos.pos_is_ok());
   assert(bestValue > -VALUE_INFINITE);
   assert(bestValue <= alpha);
   assert(alpha < beta);
   assert(beta <= VALUE_INFINITE);
   assert(depth > DEPTH_ZERO);
-  assert(pos.thread() >= 0 && pos.thread() < activeThreads);
-  assert(activeThreads > 1);
 
   int master = pos.thread();
-  Thread& masterThread = threads[master];
+  Thread& masterThread = *threads[master];
 
-  if (masterThread.activeSplitPoints >= MAX_ACTIVE_SPLIT_POINTS)
+  if (masterThread.splitPointsCnt >= MAX_SPLITPOINTS_PER_THREAD)
       return bestValue;
 
   // Pick the next available split point from the split point stack
-  SplitPoint* sp = &masterThread.splitPoints[masterThread.activeSplitPoints];
+  SplitPoint* sp = &masterThread.splitPoints[masterThread.splitPointsCnt++];
 
-  sp->parent = masterThread.splitPoint;
+  sp->parent = masterThread.curSplitPoint;
   sp->master = master;
   sp->cutoff = false;
   sp->slavesMask = 1ULL << master;
   sp->depth = depth;
+  sp->bestMove = *bestMove;
   sp->threatMove = threatMove;
   sp->alpha = alpha;
   sp->beta = beta;
@@ -335,6 +335,7 @@ Value ThreadsManager::split(Position& pos, Stack* ss, Value alpha, Value beta,
 
   assert(masterThread.is_searching);
 
+  masterThread.curSplitPoint = sp;
   int slavesCnt = 0;
 
   // Try to allocate available threads and ask them to start searching setting
@@ -343,23 +344,20 @@ Value ThreadsManager::split(Position& pos, Stack* ss, Value alpha, Value beta,
   lock_grab(sp->lock);
   lock_grab(splitLock);
 
-  for (int i = 0; i < activeThreads && !Fake; i++)
-      if (threads[i].is_available_to(master))
+  for (int i = 0; i < size() && !Fake; ++i)
+      if (threads[i]->is_available_to(master))
       {
           sp->slavesMask |= 1ULL << i;
-          threads[i].splitPoint = 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;
       }
 
-  masterThread.splitPoint = sp;
-  masterThread.activeSplitPoints++;
-
   lock_release(splitLock);
   lock_release(sp->lock);
 
@@ -369,18 +367,25 @@ Value ThreadsManager::split(Position& pos, Stack* ss, Value alpha, Value beta,
   // the thread will return from the idle loop when all slaves have finished
   // their work at this split point.
   if (slavesCnt || Fake)
+  {
       masterThread.idle_loop(sp);
 
+      // 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(!masterThread.is_searching);
+  }
+
   // We have returned from the idle loop, which means that all threads are
-  // finished. Note that setting is_searching and decreasing activeSplitPoints is
+  // finished. Note that setting is_searching and decreasing splitPointsCnt is
   // done under lock protection to avoid a race with Thread::is_available_to().
   lock_grab(sp->lock); // To protect sp->nodes
   lock_grab(splitLock);
 
   masterThread.is_searching = true;
-  masterThread.activeSplitPoints--;
-  masterThread.splitPoint = sp->parent;
+  masterThread.splitPointsCnt--;
+  masterThread.curSplitPoint = sp->parent;
   pos.set_nodes_searched(pos.nodes_searched() + sp->nodes);
+  *bestMove = sp->bestMove;
 
   lock_release(splitLock);
   lock_release(sp->lock);
@@ -389,8 +394,8 @@ Value ThreadsManager::split(Position& pos, Stack* ss, Value alpha, Value beta,
 }
 
 // Explicit template instantiations
-template Value ThreadsManager::split<false>(Position&, Stack*, Value, Value, Value, Depth, Move, int, MovePicker*, int);
-template Value ThreadsManager::split<true>(Position&, Stack*, Value, Value, Value, Depth, Move, int, MovePicker*, int);
+template Value ThreadsManager::split<false>(Position&, Stack*, Value, Value, Value, Move*, Depth, Move, int, MovePicker*, int);
+template Value ThreadsManager::split<true>(Position&, Stack*, Value, Value, Value, Move*, Depth, Move, int, MovePicker*, int);
 
 
 // ThreadsManager::set_timer() is used to set the timer to trigger after msec
@@ -398,12 +403,10 @@ 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);
 }
 
 
@@ -414,7 +417,7 @@ 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.front();
 
   lock_grab(main.sleepLock);
 
@@ -454,7 +457,7 @@ void ThreadsManager::start_thinking(const Position& pos, const LimitsType& limit
 
 void ThreadsManager::stop_thinking() {
 
-  Thread& main = threads[0];
+  Thread& main = *threads.front();
 
   Search::Signals.stop = true;