X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fsearch.cpp;h=dcfedcdbe0b05afa14e2c3b6221ee4cfff67ad61;hb=c416133e2fd1b6bb74fda07cd6050227bbe8994a;hp=d8a6e1c8dcd6d5ed10a39de62ab675f66351baf8;hpb=dcf2edfdeaeb262cf89fce9348c8bbddab384373;p=stockfish diff --git a/src/search.cpp b/src/search.cpp index d8a6e1c8..dcfedcdb 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -82,8 +82,7 @@ namespace { bool available_thread_exists(int master) const; bool thread_is_available(int slave, int master) const; bool thread_should_stop(int threadID) const; - void wake_sleeping_threads(); - void put_threads_to_sleep(); + void wake_sleeping_thread(int threadID); void idle_loop(int threadID, SplitPoint* sp); template @@ -94,17 +93,10 @@ namespace { friend void poll(); int ActiveThreads; - volatile bool AllThreadsShouldExit, AllThreadsShouldSleep; + volatile bool AllThreadsShouldExit; Thread threads[MAX_THREADS]; - - Lock MPLock, WaitLock; - -#if !defined(_MSC_VER) - pthread_cond_t WaitCond; -#else - HANDLE SitIdleEvent[MAX_THREADS]; -#endif - + Lock MPLock; + WaitCondition WaitCond[MAX_THREADS]; }; @@ -288,12 +280,14 @@ namespace { Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply); template - inline Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply) { - return search(pos, ss, alpha, beta, depth, ply); - } + Value qsearch(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply); template - Value qsearch(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply); + inline Value search(Position& pos, SearchStack* ss, Value alpha, Value beta, Depth depth, int ply) { + + return depth < ONE_PLY ? qsearch(pos, ss, alpha, beta, DEPTH_ZERO, ply) + : search(pos, ss, alpha, beta, depth, ply); + } template Depth extension(const Position& pos, Move m, bool captureOrPromotion, bool moveIsCheck, bool singleEvasion, bool mateThreat, bool* dangerous); @@ -472,9 +466,6 @@ bool think(const Position& pos, bool infinite, bool ponder, int time[], int incr init_eval(ThreadsMgr.active_threads()); } - // Wake up sleeping threads - ThreadsMgr.wake_sleeping_threads(); - // Set thinking time int myTime = time[pos.side_to_move()]; int myIncrement = increment[pos.side_to_move()]; @@ -507,8 +498,6 @@ bool think(const Position& pos, bool infinite, bool ponder, int time[], int incr if (UseLogFile) LogFile.close(); - ThreadsMgr.put_threads_to_sleep(); - return !Quit; } @@ -1012,10 +1001,8 @@ namespace { } // Step 2. Check for aborted search and immediate draw - if (AbortSearch || ThreadsMgr.thread_should_stop(threadID)) - return VALUE_DRAW; - - if (pos.is_draw() || ply >= PLY_MAX - 1) + if ( AbortSearch || ThreadsMgr.thread_should_stop(threadID) + || pos.is_draw() || ply >= PLY_MAX - 1) return VALUE_DRAW; // Step 3. Mate distance pruning @@ -1032,7 +1019,7 @@ namespace { posKey = excludedMove ? pos.get_exclusion_key() : pos.get_key(); tte = TT.retrieve(posKey); - ttMove = (tte ? tte->move() : MOVE_NONE); + ttMove = tte ? tte->move() : MOVE_NONE; // At PV nodes, we don't use the TT for pruning, but only for move ordering. // This is to avoid problems in the following areas: @@ -1041,12 +1028,9 @@ namespace { // * Fifty move rule detection // * Searching for a mate // * Printing of full PV line - if (!PvNode && tte && ok_to_use_TT(tte, depth, beta, ply)) { - // Refresh tte entry to avoid aging - TT.store(posKey, tte->value(), tte->type(), tte->depth(), ttMove, tte->static_value(), tte->static_value_margin()); - + TT.refresh(tte); ss->bestMove = ttMove; // Can be MOVE_NONE return value_from_tt(tte->value(), ply); } @@ -1122,9 +1106,7 @@ namespace { pos.do_null_move(st); (ss+1)->skipNullMove = true; - - nullValue = depth-R*ONE_PLY < ONE_PLY ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO, ply+1) - : - search(pos, ss+1, -beta, -alpha, depth-R*ONE_PLY, ply+1); + nullValue = -search(pos, ss+1, -beta, -alpha, depth-R*ONE_PLY, ply+1); (ss+1)->skipNullMove = false; pos.undo_null_move(); @@ -1187,7 +1169,7 @@ split_point_start: // At split points actual search starts from here // Initialize a MovePicker object for the current position // FIXME currently MovePicker() c'tor is needless called also in SplitPoint - MovePicker mpBase = MovePicker(pos, ttMove, depth, H, ss, (PvNode ? -VALUE_INFINITE : beta)); + MovePicker mpBase(pos, ttMove, depth, H, ss, (PvNode ? -VALUE_INFINITE : beta)); MovePicker& mp = SpNode ? *sp->mp : mpBase; CheckInfo ci(pos); ss->bestMove = MOVE_NONE; @@ -1256,7 +1238,10 @@ split_point_start: // At split points actual search starts from here newDepth = depth - ONE_PLY + ext; // Update current move (this must be done after singular extension search) - movesSearched[moveCount++] = ss->currentMove = move; + movesSearched[moveCount] = ss->currentMove = move; + + if (!SpNode) + moveCount++; // Step 12. Futility pruning (is omitted in PV nodes) if ( !PvNode @@ -1305,8 +1290,7 @@ split_point_start: // At split points actual search starts from here // Step extra. pv search (only in PV nodes) // The first move in list is the expected PV if (!SpNode && PvNode && moveCount == 1) - value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO, ply+1) - : - search(pos, ss+1, -beta, -alpha, newDepth, ply+1); + value = -search(pos, ss+1, -beta, -alpha, newDepth, ply+1); else { // Step 14. Reduced depth search @@ -1324,8 +1308,7 @@ split_point_start: // At split points actual search starts from here { alpha = SpNode ? sp->alpha : alpha; Depth d = newDepth - ss->reduction; - value = d < ONE_PLY ? -qsearch(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO, ply+1) - : - search(pos, ss+1, -(alpha+1), -alpha, d, ply+1); + value = -search(pos, ss+1, -(alpha+1), -alpha, d, ply+1); doFullDepthSearch = (value > alpha); } @@ -1349,15 +1332,13 @@ split_point_start: // At split points actual search starts from here if (doFullDepthSearch) { alpha = SpNode ? sp->alpha : alpha; - value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO, ply+1) - : - search(pos, ss+1, -(alpha+1), -alpha, newDepth, ply+1); + value = -search(pos, ss+1, -(alpha+1), -alpha, newDepth, ply+1); // Step extra. pv search (only in PV nodes) // Search only for possible new PV nodes, if instead value >= beta then // parent node fails low with value <= alpha and tries another move. if (PvNode && value > alpha && value < beta) - value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO, ply+1) - : - search(pos, ss+1, -beta, -alpha, newDepth, ply+1); + value = -search(pos, ss+1, -beta, -alpha, newDepth, ply+1); } } @@ -1377,24 +1358,29 @@ split_point_start: // At split points actual search starts from here if (value > bestValue && !(SpNode && ThreadsMgr.thread_should_stop(threadID))) { bestValue = value; + + if (SpNode) + sp->bestValue = value; + if (value > alpha) { if (SpNode && (!PvNode || value >= beta)) sp->stopRequest = true; if (PvNode && value < beta) // We want always alpha < beta + { alpha = value; + if (SpNode) + sp->alpha = value; + } if (value == value_mate_in(ply + 1)) ss->mateKiller = move; ss->bestMove = move; - } - if (SpNode) - { - sp->bestValue = bestValue; - sp->alpha = alpha; - sp->parentSstack->bestMove = ss->bestMove; + + if (SpNode) + sp->parentSstack->bestMove = move; } } @@ -2230,30 +2216,37 @@ split_point_start: // At split points actual search starts from here // If we are not thinking, wait for a condition to be signaled // instead of wasting CPU time polling for work. - while (AllThreadsShouldSleep || threadID >= ActiveThreads) + while ( threadID >= ActiveThreads + || threads[threadID].state == THREAD_INITIALIZING + || (!sp && threads[threadID].state == THREAD_AVAILABLE)) { assert(!sp); assert(threadID != 0); - threads[threadID].state = THREAD_SLEEPING; -#if !defined(_MSC_VER) - lock_grab(&WaitLock); - if (AllThreadsShouldSleep || threadID >= ActiveThreads) - pthread_cond_wait(&WaitCond, &WaitLock); - lock_release(&WaitLock); -#else - WaitForSingleObject(SitIdleEvent[threadID], INFINITE); -#endif - } + if (AllThreadsShouldExit) + break; + + lock_grab(&MPLock); - // If thread has just woken up, mark it as available - if (threads[threadID].state == THREAD_SLEEPING) + // Retest condition under lock protection + if (!( threadID >= ActiveThreads + || threads[threadID].state == THREAD_INITIALIZING + || (!sp && threads[threadID].state == THREAD_AVAILABLE))) + { + lock_release(&MPLock); + continue; + } + + // Put thread to sleep threads[threadID].state = THREAD_AVAILABLE; + cond_wait(&WaitCond[threadID], &MPLock); + lock_release(&MPLock); + } // If this thread has been assigned work, launch a search if (threads[threadID].state == THREAD_WORKISWAITING) { - assert(!AllThreadsShouldExit && !AllThreadsShouldSleep); + assert(!AllThreadsShouldExit); threads[threadID].state = THREAD_SEARCHING; @@ -2265,9 +2258,9 @@ split_point_start: // At split points actual search starts from here if (tsp->pvNode) search(pos, ss, tsp->alpha, tsp->beta, tsp->depth, tsp->ply); - else + else { search(pos, ss, tsp->alpha, tsp->beta, tsp->depth, tsp->ply); - + } assert(threads[threadID].state == THREAD_SEARCHING); threads[threadID].state = THREAD_AVAILABLE; @@ -2305,20 +2298,11 @@ split_point_start: // At split points actual search starts from here volatile int i; bool ok; -#if !defined(_MSC_VER) - pthread_t pthread[1]; -#endif - // Initialize global locks lock_init(&MPLock); - lock_init(&WaitLock); -#if !defined(_MSC_VER) - pthread_cond_init(&WaitCond, NULL); -#else for (i = 0; i < MAX_THREADS; i++) - SitIdleEvent[i] = CreateEvent(0, FALSE, FALSE, 0); -#endif + cond_init(&WaitCond[i]); // Initialize splitPoints[] locks for (i = 0; i < MAX_THREADS; i++) @@ -2328,21 +2312,22 @@ split_point_start: // At split points actual search starts from here // Will be set just before program exits to properly end the threads AllThreadsShouldExit = false; - // Threads will be put to sleep as soon as created - AllThreadsShouldSleep = true; - - // All threads except the main thread should be initialized to THREAD_AVAILABLE + // Threads will be put all threads to sleep as soon as created ActiveThreads = 1; + + // All threads except the main thread should be initialized to THREAD_INITIALIZING threads[0].state = THREAD_SEARCHING; for (i = 1; i < MAX_THREADS; i++) - threads[i].state = THREAD_AVAILABLE; + threads[i].state = THREAD_INITIALIZING; // Launch the helper threads for (i = 1; i < MAX_THREADS; i++) { #if !defined(_MSC_VER) + pthread_t pthread[1]; ok = (pthread_create(pthread, NULL, init_thread, (void*)(&i)) == 0); + pthread_detach(pthread[0]); #else ok = (CreateThread(NULL, 0, init_thread, (LPVOID)(&i), 0, NULL) != NULL); #endif @@ -2354,7 +2339,7 @@ split_point_start: // At split points actual search starts from here } // Wait until the thread has finished launching and is gone to sleep - while (threads[i].state != THREAD_SLEEPING) {} + while (threads[i].state == THREAD_INITIALIZING) {} } } @@ -2364,22 +2349,25 @@ split_point_start: // At split points actual search starts from here void ThreadsManager::exit_threads() { - ActiveThreads = MAX_THREADS; // Wake up all the threads - AllThreadsShouldExit = true; // Let the woken up threads to exit idle_loop() - AllThreadsShouldSleep = true; // Avoid an assert in wake_sleeping_threads() - wake_sleeping_threads(); + AllThreadsShouldExit = true; // Let the woken up threads to exit idle_loop() - // Wait for thread termination + // Wake up all the threads and waits for termination for (int i = 1; i < MAX_THREADS; i++) + { + wake_sleeping_thread(i); while (threads[i].state != THREAD_TERMINATED) {} + } // Now we can safely destroy the locks for (int i = 0; i < MAX_THREADS; i++) for (int j = 0; j < MAX_ACTIVE_SPLIT_POINTS; j++) lock_destroy(&(threads[i].splitPoints[j].lock)); - lock_destroy(&WaitLock); lock_destroy(&MPLock); + + // Now we can safely destroy the wait conditions + for (int i = 0; i < MAX_THREADS; i++) + cond_destroy(&WaitCond[i]); } @@ -2455,9 +2443,8 @@ split_point_start: // At split points actual search starts from here // 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 we tell our helper threads that they have - // been assigned work. This will cause them to instantly leave their idle loops - // and call sp_search(). When all threads have returned from sp_search() then - // split() returns. + // 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 void ThreadsManager::split(const Position& p, SearchStack* ss, int ply, Value* alpha, @@ -2540,6 +2527,8 @@ split_point_start: // At split points actual search starts from here assert(i == master || threads[i].state == THREAD_BOOKED); threads[i].state = THREAD_WORKISWAITING; // This makes the slave to exit from idle_loop() + if (i != master) + wake_sleeping_thread(i); } // Everything is set up. The master thread enters the idle loop, from @@ -2562,43 +2551,17 @@ split_point_start: // At split points actual search starts from here } - // wake_sleeping_threads() wakes up all sleeping threads when it is time + // wake_sleeping_thread() wakes up all sleeping threads when it is time // to start a new search from the root. - void ThreadsManager::wake_sleeping_threads() { - - assert(AllThreadsShouldSleep); - assert(ActiveThreads > 0); - - AllThreadsShouldSleep = false; - - if (ActiveThreads == 1) - return; - -#if !defined(_MSC_VER) - pthread_mutex_lock(&WaitLock); - pthread_cond_broadcast(&WaitCond); - pthread_mutex_unlock(&WaitLock); -#else - for (int i = 1; i < MAX_THREADS; i++) - SetEvent(SitIdleEvent[i]); -#endif + void ThreadsManager::wake_sleeping_thread(int threadID) { + lock_grab(&MPLock); + cond_signal(&WaitCond[threadID]); + lock_release(&MPLock); } - // put_threads_to_sleep() makes all the threads go to sleep just before - // to leave think(), at the end of the search. Threads should have already - // finished the job and should be idle. - - void ThreadsManager::put_threads_to_sleep() { - - assert(!AllThreadsShouldSleep); - - // This makes the threads to go to sleep - AllThreadsShouldSleep = true; - } - /// The RootMoveList class // RootMoveList c'tor