- assert(master >= 0 && master < size());
-
- for (int i = 0; i < size(); i++)
- if (threads[i]->is_available_to(master))
- return true;
-
- return false;
-}
-
-
-// split() does the actual work of distributing the work at a node between
-// several available threads. If it does not succeed in splitting the node
-// (because no idle threads are available, or because we have no unused split
-// point objects), the function immediately returns. If splitting is possible, a
-// SplitPoint object is initialized with all the data that must be copied to the
-// helper threads and then helper threads are told that they have been assigned
-// work. This will cause them to instantly leave their idle loops and call
-// search(). When all threads have returned from search() then split() returns.
-
-template <bool Fake>
-Value ThreadsManager::split(Position& pos, Stack* ss, Value alpha, Value beta,
- 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);
-
- int master = pos.thread();
- Thread& masterThread = *threads[master];
-
- 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.splitPointsCnt++];
-
- 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;
- sp->nodeType = nodeType;
- sp->bestValue = bestValue;
- sp->mp = mp;
- sp->moveCount = moveCount;
- sp->pos = &pos;
- sp->nodes = 0;
- sp->ss = ss;
-
- assert(masterThread.is_searching);
-
- masterThread.curSplitPoint = sp;
- int slavesCnt = 0;
-
- // Try to allocate available threads and ask them to start searching setting
- // is_searching flag. This must be done under lock protection to avoid concurrent
- // allocation of the same slave by another master.
- lock_grab(sp->lock);
- lock_grab(splitLock);
-
- for (int i = 0; i < size() && !Fake; ++i)
- if (threads[i]->is_available_to(master))
- {
- sp->slavesMask |= 1ULL << i;
- threads[i]->curSplitPoint = sp;
- threads[i]->is_searching = true; // Slave leaves idle_loop()
-
- if (useSleepingThreads)
- threads[i]->wake_up();
-
- if (++slavesCnt + 1 >= maxThreadsPerSplitPoint) // Master is always included
- break;
- }
-
- lock_release(splitLock);
- lock_release(sp->lock);
-
- // Everything is set up. The master thread enters the idle loop, from which
- // it will instantly launch a search, because its is_searching flag is set.
- // We pass the split point as a parameter to the idle loop, which means that
- // 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 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.splitPointsCnt--;
- masterThread.curSplitPoint = sp->parent;
- pos.set_nodes_searched(pos.nodes_searched() + sp->nodes);
- *bestMove = sp->bestMove;
-
- lock_release(splitLock);
- lock_release(sp->lock);
-
- return sp->bestValue;
-}
-
-// Explicit template instantiations
-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
-// milliseconds. If msec is 0 then timer is stopped.
-
-void ThreadsManager::set_timer(int msec) {
-
- lock_grab(timer->sleepLock);
- timer->maxPly = msec;
- cond_signal(timer->sleepCond); // Wake up and restart the timer
- lock_release(timer->sleepLock);
-}
-
-
-// ThreadsManager::wait_for_search_finished() waits for main thread to go to
-// sleep, this means search is finished. Then returns.
-
-void ThreadsManager::wait_for_search_finished() {
-
- Thread* main = threads[0];
- lock_grab(main->sleepLock);
- while (!main->do_sleep) cond_wait(sleepCond, main->sleepLock);
- lock_release(main->sleepLock);
-}
-
-
-// ThreadsManager::start_searching() wakes up the main thread sleeping in
-// main_loop() so to start a new search, then returns immediately.
-
-void ThreadsManager::start_searching(const Position& pos, const LimitsType& limits,
- const std::set<Move>& searchMoves) {
- wait_for_search_finished();